BUGFIX: don't leak password when running pg_rewind (#1321)

In addition to that:
* enforce security settings from `postgresql.authention`
* update release notes
* bump version
* close https://github.com/zalando/patroni/issues/1320

.gitignore

@@ -51,3 +51,9 @@ scm-source.json
 docs/build/
 docs/source/_static/
 docs/source/_templates/
+
+# Pycharm IDE
+.idea/
+
+#VSCode IDE
+.vscode/

.travis.yml

@@ -1,6 +1,10 @@
 sudo: true
 dist: trusty
 language: python
+addons:
+  apt:
+    packages:
+      - expect-dev # for unbuffer
 env:
   global:
   - ETCDVERSION=3.0.17 ZKVERSION=3.4.11 CONSULVERSION=0.7.4
@@ -115,7 +119,7 @@ install:
             fi
             source ~/virtualenv/python${pv}/bin/activate
             # explicitly install all needed python modules to cache them
-            for p in '-r requirements.txt' 'behave codacy-coverage coverage coveralls flake8 mock pytest-cov pytest setuptools'; do
+            for p in '-r requirements.txt' 'psycopg2-binary behave codacy-coverage coverage coveralls flake8 mock pytest-cov pytest setuptools'; do
                 pip install $p --upgrade
             done
         fi
@@ -131,13 +135,13 @@ script:
 
         if [[ $TEST_SUITE != "behave" ]]; then
             echo Running unit tests using python${pv}
-            $TEST_SUITE test
+            unbuffer $TEST_SUITE test
             $TEST_SUITE flake8
         elif [[ $pv != $EXCLUDE_BEHAVE ]]; then
             echo Running acceptance tests using python${pv}
-            if ! PATH=.:/usr/lib/postgresql/9.6/bin:$PATH $TEST_SUITE; then
+            if ! PATH=.:/usr/lib/postgresql/9.6/bin:$PATH unbuffer $TEST_SUITE; then
                 # output all log files when tests are failing
-                grep . features/output/*/*postgres?.*
+                grep . features/output/*_failed/*postgres?.*
                 exit 1
             fi
         fi

.zappr.yaml

@@ -1,13 +0,0 @@
-# for github.com
-approvals:
-  groups:
-    zalando:
-      minimum: 2
-      from:
-        orgs:
-          - "zalando"
-# team should be valid team id in team service https://teams.auth.zalando.com/api/teams/:id
-X-Zalando-Team: "acid"
-# type should be one of [code, doc, config, tools, secrets]
-# code will be the default value, if X-Zalando-Type is not found in .zappr.yml
-X-Zalando-Type: code

Dockerfile

@@ -1,48 +1,158 @@
 ## This Dockerfile is meant to aid in the building and debugging patroni whilst developing on your local machine
 ## It has all the necessary components to play/debug with a single node appliance, running etcd
-FROM postgres:9.6
-MAINTAINER Alexander Kukushkin <[email protected]>
+ARG PG_MAJOR=10
+ARG COMPRESS=false
+ARG PGHOME=/home/postgres
+ARG PGDATA=$PGHOME/data
+ARG LC_ALL=C.UTF-8
+ARG LANG=C.UTF-8
 
-RUN export DEBIAN_FRONTEND=noninteractive \
+FROM postgres:$PG_MAJOR as builder
+
+ARG PGHOME
+ARG PGDATA
+ARG LC_ALL
+ARG LANG
+
+ENV ETCDVERSION=2.3.8 CONFDVERSION=0.16.0
+
+RUN set -ex \
+    && export DEBIAN_FRONTEND=noninteractive \
     && echo 'APT::Install-Recommends "0";\nAPT::Install-Suggests "0";' > /etc/apt/apt.conf.d/01norecommend \
     && apt-get update -y \
-    && apt-get upgrade -y \
-    && apt-get install -y curl jq haproxy python-psycopg2 python-yaml python-requests python-six python-pysocks \
-        python-dateutil python-pip python-setuptools python-prettytable python-wheel python-psutil python locales \
-
-    ## Make sure we have a en_US.UTF-8 locale available
+    # postgres:10 is based on debian, which has the patroni package. We will install all required dependencies
+    && apt-cache depends patroni | sed -n -e 's/.*Depends: \(python3-.\+\)$/\1/p' \
+            | grep -Ev '^python3-(sphinx|etcd|consul|kazoo|kubernetes)' \
+            | xargs apt-get install -y vim curl less jq locales haproxy sudo \
+                            python3-etcd python3-kazoo python3-pip busybox \
+                            net-tools iputils-ping --fix-missing \
+    && pip3 install dumb-init \
+\
+    # Cleanup all locales but en_US.UTF-8
+    && find /usr/share/i18n/charmaps/ -type f ! -name UTF-8.gz -delete \
+    && find /usr/share/i18n/locales/ -type f ! -name en_US ! -name en_GB ! -name i18n ! -name iso14651_t1 ! -name iso14651_t1_common ! -name 'translit_*' -delete \
+    && echo 'en_US.UTF-8 UTF-8' > /usr/share/i18n/SUPPORTED \
+\
+    # Make sure we have a en_US.UTF-8 locale available
     && localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8 \
-
-    && pip install 'python-etcd>=0.4.3,<0.5' click tzlocal cdiff \
-
-    && mkdir -p /home/postgres \
-    && chown postgres:postgres /home/postgres \
-
-    # Clean up
-    && apt-get remove -y python-pip python-setuptools \
+\
+    # haproxy dummy config
+    && echo 'global\n        stats socket /run/haproxy/admin.sock mode 660 level admin' > /etc/haproxy/haproxy.cfg \
+\
+    # vim config
+    && echo 'syntax on\nfiletype plugin indent on\nset mouse-=a\nautocmd FileType yaml setlocal ts=2 sts=2 sw=2 expandtab' > /etc/vim/vimrc.local \
+\
+    # Prepare postgres/patroni/haproxy environment
+    && mkdir -p $PGHOME/.config/patroni /patroni /run/haproxy \
+    && ln -s ../../postgres0.yml $PGHOME/.config/patroni/patronictl.yaml \
+    && ln -s /patronictl.py /usr/local/bin/patronictl \
+    && sed -i "s|/var/lib/postgresql.*|$PGHOME:/bin/bash|" /etc/passwd \
+    && chown -R postgres:postgres /var/log \
+\
+    # Download etcd
+    && curl -sL https://github.com/coreos/etcd/releases/download/v${ETCDVERSION}/etcd-v${ETCDVERSION}-linux-amd64.tar.gz \
+            | tar xz -C /usr/local/bin --strip=1 --wildcards --no-anchored etcd etcdctl \
+\
+    # Download confd
+    && curl -sL https://github.com/kelseyhightower/confd/releases/download/v${CONFDVERSION}/confd-${CONFDVERSION}-linux-amd64 \
+            > /usr/local/bin/confd && chmod +x /usr/local/bin/confd \
+\
+    # Clean up all useless packages and some files
+    && apt-get purge -y --allow-remove-essential python3-pip gzip bzip2 util-linux e2fsprogs \
+                libmagic1 bsdmainutils login ncurses-bin libmagic-mgc e2fslibs bsdutils \
+                exim4-config gnupg-agent dirmngr libpython2.7-stdlib libpython2.7-minimal \
     && apt-get autoremove -y \
     && apt-get clean -y \
-    && rm -rf /var/lib/apt/lists/* /root/.cache
+    && rm -rf /var/lib/apt/lists/* \
+        /root/.cache \
+        /var/cache/debconf/* \
+        /etc/rc?.d \
+        /etc/systemd \
+        /docker-entrypoint* \
+        /sbin/pam* \
+        /sbin/swap* \
+        /sbin/unix* \
+        /usr/local/bin/gosu \
+        /usr/sbin/[acgipr]* \
+        /usr/sbin/*user* \
+        /usr/share/doc* \
+        /usr/share/man \
+        /usr/share/info \
+        /usr/share/i18n/locales/translit_hangul \
+        /usr/share/locale/?? \
+        /usr/share/locale/??_?? \
+        /usr/share/postgresql/*/man \
+        /usr/share/postgresql-common/pg_wrapper \
+        /usr/share/vim/vim80/doc \
+        /usr/share/vim/vim80/lang \
+        /usr/share/vim/vim80/tutor \
+#        /var/lib/dpkg/info/* \
+    && find /usr/bin -xtype l -delete \
+    && find /var/log -type f -exec truncate --size 0 {} \; \
+    && find /usr/lib/python3/dist-packages -name '*test*' | xargs rm -fr \
+    && find /lib/x86_64-linux-gnu/security -type f ! -name pam_env.so ! -name pam_permit.so ! -name pam_unix.so -delete
 
-ENV ETCDVERSION 3.2.3
-RUN curl -L https://github.com/coreos/etcd/releases/download/v${ETCDVERSION}/etcd-v${ETCDVERSION}-linux-amd64.tar.gz \
-    | tar xz -C /usr/local/bin --strip=1 --wildcards --no-anchored etcd etcdctl
+# perform compression if it is necessary
+ARG COMPRESS
+RUN if [ "$COMPRESS" = "true" ]; then \
+        set -ex \
+        # Allow certain sudo commands from postgres
+        && echo 'postgres ALL=(ALL) NOPASSWD: /bin/tar xpJf /a.tar.xz -C /, /bin/rm /a.tar.xz, /bin/ln -snf dash /bin/sh' >> /etc/sudoers \
+        && ln -snf busybox /bin/sh \
+        && files="/bin/sh /usr/bin/sudo /usr/lib/sudo/sudoers.so /lib/x86_64-linux-gnu/security/pam_*.so" \
+        && libs="$(ldd $files | awk '{print $3;}' | grep '^/' | sort -u) /lib/x86_64-linux-gnu/ld-linux-x86-64.so.* /lib/x86_64-linux-gnu/libnsl.so.* /lib/x86_64-linux-gnu/libnss_compat.so.*" \
+        && (echo /var/run $files $libs | tr ' ' '\n' && realpath $files $libs) | sort -u | sed 's/^\///' > /exclude \
+        && find /etc/alternatives -xtype l -delete \
+        && save_dirs="usr lib var bin sbin etc/ssl etc/init.d etc/alternatives etc/apt" \
+        && XZ_OPT=-e9v tar -X /exclude -cpJf a.tar.xz $save_dirs \
+        # we call "cat /exclude" to avoid including files from the $save_dirs that are also among
+        # the exceptions listed in the /exclude, as "uniq -u" eliminates all non-unique lines.
+        # By calling "cat /exclude" a second time we guarantee that there will be at least two lines
+        # for each exception and therefore they will be excluded from the output passed to 'rm'.
+        && /bin/busybox sh -c "(find $save_dirs -not -type d && cat /exclude /exclude && echo exclude) | sort | uniq -u | xargs /bin/busybox rm" \
+        && /bin/busybox --install -s \
+        && /bin/busybox sh -c "find $save_dirs -type d -depth -exec rmdir -p {} \; 2> /dev/null"; \
+    fi
 
-ENV CONFDVERSION 0.11.0
-RUN curl -L https://github.com/kelseyhightower/confd/releases/download/v${CONFDVERSION}/confd-${CONFDVERSION}-linux-amd64 > /usr/local/bin/confd \
-    && chmod +x /usr/local/bin/confd
+FROM scratch
+COPY --from=builder / /
 
-ADD patronictl.py patroni.py docker/entrypoint.sh /
-ADD patroni /patroni/
-ADD extras/confd /etc/confd
-RUN ln -s /patronictl.py /usr/local/bin/patronictl
+LABEL maintainer="Alexander Kukushkin <[email protected]>"
 
-### Setting up a simple script that will serve as an entrypoint
-RUN mkdir /data/ && touch /pgpass /patroni.yml \
-    && chown postgres:postgres -R /patroni/ /data/ /pgpass /patroni.yml /etc/haproxy /var/run/ /var/lib/ /var/log/
+ARG PG_MAJOR
+ARG COMPRESS
+ARG PGHOME
+ARG PGDATA
+ARG LC_ALL
+ARG LANG
 
-EXPOSE 2379 5432 8008
+ARG PGBIN=/usr/lib/postgresql/$PG_MAJOR/bin
+
+ENV LC_ALL=$LC_ALL LANG=$LANG EDITOR=/usr/bin/editor
+ENV PGDATA=$PGDATA PATH=$PATH:$PGBIN
+
+COPY patroni /patroni/
+COPY extras/confd/conf.d/haproxy.toml /etc/confd/conf.d/
+COPY extras/confd/templates/haproxy.tmpl /etc/confd/templates/
+COPY patroni*.py docker/entrypoint.sh /
+COPY postgres?.yml $PGHOME/
+
+WORKDIR $PGHOME
+
+RUN sed -i 's/env python/&3/' /patroni*.py \
+    # "fix" patroni configs
+    && sed -i 's/^\(  connect_address:\|  - host\)/#&/' postgres?.yml \
+    && sed -i 's/^  listen: 127.0.0.1/  listen: 0.0.0.0/' postgres?.yml \
+    && sed -i "s|^\(  data_dir: \).*|\1$PGDATA|" postgres?.yml \
+    && sed -i "s|^#\(  bin_dir: \).*|\1$PGBIN|" postgres?.yml \
+    && sed -i 's/^  - encoding: UTF8/  - locale: en_US.UTF-8\n&/' postgres?.yml \
+    && sed -i 's/^\(scope\|name\|etcd\|  host\|  authentication\|  pg_hba\|  parameters\):/#&/' postgres?.yml \
+    && sed -i 's/^    \(replication\|superuser\|rewind\|unix_socket_directories\|\(\(  \)\{0,1\}\(username\|password\)\)\):/#&/' postgres?.yml \
+    && sed -i 's/^      parameters:/      pg_hba:\n      - local all all trust\n      - host replication all all md5\n      - host all all all md5\n&\n        max_connections: 100/'  postgres?.yml \
+    && if [ "$COMPRESS" = "true" ]; then chmod u+s /usr/bin/sudo; fi \
+    && chmod +s /bin/ping \
+    && chown -R postgres:postgres $PGHOME /run /etc/haproxy
 
-ENV LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
-ENTRYPOINT ["/bin/bash", "/entrypoint.sh"]
 USER postgres
+
+ENTRYPOINT ["/bin/sh", "/entrypoint.sh"]

README.rst

@@ -12,7 +12,7 @@ Patroni is a template for you to create your own customized, high-availability s
 
 We call Patroni a "template" because it is far from being a one-size-fits-all or plug-and-play replication system. It will have its own caveats. Use wisely.
 
-**Note to Kubernetes users**: Patroni can run natively on top of Kubernetes. Take a look at the `Kubernetes <https://github.com/zalando/patroni/blog/master/docs/kubernetes.rst>`__ chapter of the Patroni documentation.
+**Note to Kubernetes users**: Patroni can run natively on top of Kubernetes. Take a look at the `Kubernetes <https://github.com/zalando/patroni/blob/master/docs/kubernetes.rst>`__ chapter of the Patroni documentation.
 
 .. contents::
     :local:
@@ -29,7 +29,7 @@ For an example of a Docker-based deployment with Patroni, see `Spilo <https://gi
 
 For additional background info, see:
 
-* `Elephants on Automatic: HA Clustered PostgreSQL with Helm <https://www.youtube.com/watch?v=CftcVhFMGSY>`_, talk by Josh Berkus and Oleksii Kliukin at KubeCon Berlin 2017 
+* `Elephants on Automatic: HA Clustered PostgreSQL with Helm <https://www.youtube.com/watch?v=CftcVhFMGSY>`_, talk by Josh Berkus and Oleksii Kliukin at KubeCon Berlin 2017
 * `PostgreSQL HA with Kubernetes and Patroni <https://www.youtube.com/watch?v=iruaCgeG7qs>`__, talk by Josh Berkus at KubeCon 2016 (video)
 * `Feb. 2016 Zalando Tech blog post <https://tech.zalando.de/blog/zalandos-patroni-a-template-for-high-availability-postgresql/>`__
 
@@ -41,6 +41,12 @@ Patroni is in active development and accepts contributions. See our `Contributin
 
 We report new releases information `here <https://github.com/zalando/patroni/releases>`__.
 
+=========
+Community
+=========
+
+There are two places to connect with the Patroni community: `on github <https://github.com/zalando/patroni>`__, via Issues and PRs, and on channel #patroni in the `PostgreSQL Slack <https://postgres-slack.herokuapp.com/>`__.  If you're using Patroni, or just interested, please join us.
+
 ===================================
 Technical Requirements/Installation
 ===================================
@@ -53,6 +59,33 @@ To install requirements on a Mac, run the following:
 
     brew install postgresql etcd haproxy libyaml python
 
+**Psycopg2**
+
+Starting from `psycopg2-2.8 <http://initd.org/psycopg/articles/2019/04/04/psycopg-28-released/>`__ the binary version of psycopg2 will no longer be installed by default. Installing it from the source code requires C compiler and postgres+python dev packages.
+Since in the python world it is not possible to specify dependency as ``psycopg2 OR psycopg2-binary`` you will have to decide how to install it.
+
+There are a few options available:
+
+1. Use the package manager from your distro
+
+::
+
+    sudo apt-get install python-psycopg2   # install python2 psycopg2 module on Debian/Ubuntu
+    sudo apt-get install python3-psycopg2  # install python3 psycopg2 module on Debian/Ubuntu
+    sudo yum install python-psycopg2       # install python2 psycopg2 on RedHat/Fedora/CentOS
+
+2. Install psycopg2 from the binary package
+
+::
+
+    pip install psycopg2-binary
+
+3. Install psycopg2 from source
+
+::
+
+    pip install psycopg2>=2.5.4
+
 **General installation for pip**
 
 Patroni can be installed with pip:

docker-compose.yml

@@ -1,58 +1,69 @@
 # docker compose file for running a 3-node PostgreSQL cluster
-# with etcd as the SIS
+# with 3-node etcd cluster as the DCS and one haproxy node
+version: "2"
 
-patroni_etcd:
-    container_name: patroni_etcd
-    image: patroni
-    command: --etcd
+networks:
+    demo:
 
-dbnode1:
-    image: patroni
-    hostname: dbnode1
-    links:
-        - patroni_etcd:patroni_etcd
-    volumes:
-        - ./patroni:/patroni
-    env_file: docker/patroni-secrets.env
-    environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
-        PATRONI_NAME: dbnode1
-        PATRONI_SCOPE: testcluster
+services:
+    etcd1:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/etcd.env
+        container_name: demo-etcd1
+        hostname: etcd1
+        command: etcd -name etcd1 -initial-advertise-peer-urls http://etcd1:2380
 
-dbnode2:
-    image: patroni
-    hostname: dbnode2
-    links:
-        - patroni_etcd:patroni_etcd
-    volumes:
-        - ./patroni:/patroni
-    env_file: docker/patroni-secrets.env
-    environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
-        PATRONI_NAME: dbnode2
-        PATRONI_SCOPE: testcluster
+    etcd2:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/etcd.env
+        container_name: demo-etcd2
+        hostname: etcd2
+        command: etcd -name etcd2 -initial-advertise-peer-urls http://etcd2:2380
 
-dbnode3:
-    image: patroni
-    hostname: dbnode3
-    links:
-        - patroni_etcd:patroni_etcd
-    volumes:
-        - ./patroni:/patroni
-    env_file: docker/patroni-secrets.env
-    environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
-        PATRONI_NAME: dbnode3
-        PATRONI_SCOPE: testcluster
+    etcd3:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/etcd.env
+        container_name: demo-etcd3
+        hostname: etcd3
+        command: etcd -name etcd3 -initial-advertise-peer-urls http://etcd3:2380
 
-haproxy:
-    image: patroni
-    links:
-        - patroni_etcd:patroni_etcd
-    ports:
-        - "5000:5000"
-        - "5001:5001"
-    environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
-        PATRONI_SCOPE: testcluster
-    command: --confd
+    patroni1:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni1
+        container_name: demo-patroni1
+        environment:
+            PATRONI_NAME: patroni1
+
+    patroni2:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni2
+        container_name: demo-patroni2
+        environment:
+            PATRONI_NAME: patroni2
+
+    patroni3:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni3
+        container_name: demo-patroni3
+        environment:
+            PATRONI_NAME: patroni3
+
+    haproxy:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: haproxy
+        container_name: demo-haproxy
+        ports:
+            - "5000:5000"
+            - "5001:5001"
+        command: haproxy

docker/README.md

@@ -1,47 +1,117 @@
 # Patroni Dockerfile
-You can run Patroni in a docker container using this Dockerfile, or by using one of the Docker image at
-
-    https://registry.opensource.zalan.do/v1/repositories/acid/patroni/tags
+You can run Patroni in a docker container using this Dockerfile
 
 This Dockerfile is meant in aiding development of Patroni and quick testing of features. It is not a production-worthy
 Dockerfile
 
+    docker build -t patroni .
+
 # Examples
 
 ## Standalone Patroni
 
-    docker run -d registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT
+    docker run -d patroni
 
-## Multiple Patroni's communicating with a standalone etcd inside Docker
-
-Basically what you would do would be: 
-
-* Run 1 container which provides etcd
-
-        docker run -d <IMAGE> --etcd-only
-
-* Run n containers running Patroni, passing the `--etcd` option to the `docker run` command
-
-        docker run -d <IMAGE> --etcd=<IP FROM etcd CONTAINER:PORT>
-
-To automate this you can run the following script:
-
-    dev_patroni_cluster.sh [OPTIONS]
-
-    Options:
-
-        --image     IMAGE    The Docker image to use for the cluster
-        --members   INT      The number of members for the cluster
-        --name      NAME     The name of the new cluster
+## Three-node Patroni cluster with three-node etcd cluster and one haproxy container using docker-compose
 
 Example session:
 
-    $ ./dev_patroni_cluster.sh --image registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT --members=2 --name=bravo
-    The etcd container is 6be871a11cb373406ca5ea1c6b39e1.0-SNAPSHOTfdde9fb1d6177212d6ad0c0d1bd9b563, ip=172.17.1.24
-    Started Patroni container 67e611f2eca7c40f9e6e0e24a4a8f2cba7e3e56d22a420e15ab9240a37a9d7a4, ip=172.17.1.25
-    Started Patroni container 47dd12ae635ab83b039f5889e250048b606ed5e48e3650b69e365e7e1d4acbcf, ip=172.17.1.26
+    $ docker-compose up -d
+    Creating demo-haproxy ...
+    Creating demo-patroni2 ...
+    Creating demo-patroni1 ...
+    Creating demo-patroni3 ...
+    Creating demo-etcd2 ...
+    Creating demo-etcd1 ...
+    Creating demo-etcd3 ...
+    Creating demo-haproxy
+    Creating demo-patroni2
+    Creating demo-patroni1
+    Creating demo-patroni3
+    Creating demo-etcd1
+    Creating demo-etcd2
+    Creating demo-etcd2 ... done
+
     $ docker ps
-    CONTAINER ID        IMAGE                                         COMMAND                CREATED             STATUS              PORTS                          NAMES
-    47dd12ae635a        registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   10 seconds ago      Up 8 seconds        4001/tcp, 5432/tcp, 2380/tcp   bravo_OR64g8bx
-    67e611f2eca7        registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   11 seconds ago      Up 10 seconds       2380/tcp, 4001/tcp, 5432/tcp   bravo_si9no8iz
-    6be871a11cb3        registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   12 seconds ago      Up 10 seconds       4001/tcp, 5432/tcp, 2380/tcp   bravo_etcd
+    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                              NAMES
+    5b7a90b4cfbf        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 27 seconds                                          demo-etcd2
+    e30eea5222f2        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 27 seconds                                          demo-etcd1
+    83bcf3cb208f        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 27 seconds                                          demo-etcd3
+    922532c56e7d        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 28 seconds                                          demo-patroni3
+    14f875e445f3        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 28 seconds                                          demo-patroni2
+    110d1073b383        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 28 seconds                                          demo-patroni1
+    5af5e6e36028        patroni             "/bin/sh /entrypoint…"   29 seconds ago      Up 28 seconds       0.0.0.0:5000-5001->5000-5001/tcp   demo-haproxy
+
+    $ docker logs demo-patroni1
+    2019-02-20 08:19:32,714 INFO: Failed to import patroni.dcs.consul
+    2019-02-20 08:19:32,737 INFO: Selected new etcd server http://etcd3:2379
+    2019-02-20 08:19:35,140 INFO: Lock owner: None; I am patroni1
+    2019-02-20 08:19:35,174 INFO: trying to bootstrap a new cluster
+    ...
+    2019-02-20 08:19:39,310 INFO: postmaster pid=37
+    2019-02-20 08:19:39.314 UTC [37] LOG:  listening on IPv4 address "0.0.0.0", port 5432
+    2019-02-20 08:19:39.321 UTC [37] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
+    2019-02-20 08:19:39.353 UTC [39] LOG:  database system was shut down at 2019-02-20 08:19:36 UTC
+    2019-02-20 08:19:39.354 UTC [40] FATAL:  the database system is starting up
+    localhost:5432 - rejecting connections
+    2019-02-20 08:19:39.369 UTC [37] LOG:  database system is ready to accept connections
+    localhost:5432 - accepting connections
+    2019-02-20 08:19:39,383 INFO: establishing a new patroni connection to the postgres cluster
+    2019-02-20 08:19:39,408 INFO: running post_bootstrap
+    2019-02-20 08:19:39,432 WARNING: Could not activate Linux watchdog device: "Can't open watchdog device: [Errno 2] No such file or directory: '/dev/watchdog'"
+    2019-02-20 08:19:39,515 INFO: initialized a new cluster
+    2019-02-20 08:19:49,424 INFO: Lock owner: patroni1; I am patroni1
+    2019-02-20 08:19:49,447 INFO: Lock owner: patroni1; I am patroni1
+    2019-02-20 08:19:49,480 INFO: no action.  i am the leader with the lock
+    2019-02-20 08:19:59,422 INFO: Lock owner: patroni1; I am patroni1
+
+    $ docker exec -ti demo-patroni1 bash
+    postgres@patroni1:~$ patronictl list
+    +---------+----------+------------+--------+---------+----+-----------+
+    | Cluster |  Member  |    Host    |  Role  |  State  | TL | Lag in MB |
+    +---------+----------+------------+--------+---------+----+-----------+
+    |   demo  | patroni1 | 172.22.0.3 | Leader | running |  1 |         0 |
+    |   demo  | patroni2 | 172.22.0.7 |        | running |  1 |         0 |
+    |   demo  | patroni3 | 172.22.0.4 |        | running |  1 |         0 |
+    +---------+----------+------------+--------+---------+----+-----------+
+
+    postgres@patroni1:~$ etcdctl ls --recursive --sort -p /service/demo
+    /service/demo/config
+    /service/demo/initialize
+    /service/demo/leader
+    /service/demo/members/
+    /service/demo/members/patroni1
+    /service/demo/members/patroni2
+    /service/demo/members/patroni3
+    /service/demo/optime/
+    /service/demo/optime/leader
+
+    postgres@patroni1:~$ etcdctl member list
+    1bab629f01fa9065: name=etcd3 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=false
+    8ecb6af518d241cc: name=etcd2 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=true
+    b2e169fcb8a34028: name=etcd1 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
+    postgres@patroni1:~$ exit
+
+    $ psql -h localhost -p 5000 -U postgres -W
+    Password: postgres
+    psql (11.2 (Ubuntu 11.2-1.pgdg18.04+1), server 10.7 (Debian 10.7-1.pgdg90+1))
+    Type "help" for help.
+
+    localhost/postgres=# select pg_is_in_recovery();
+     pg_is_in_recovery
+    ───────────────────
+     f
+    (1 row)
+
+    localhost/postgres=# \q
+
+    $ psql -h localhost -p 5001 -U postgres -W
+    Password: postgres
+    psql (11.2 (Ubuntu 11.2-1.pgdg18.04+1), server 10.7 (Debian 10.7-1.pgdg90+1))
+    Type "help" for help.
+
+    localhost/postgres=# select pg_is_in_recovery();
+     pg_is_in_recovery
+    ───────────────────
+     t
+    (1 row)

docker/dev_patroni_cluster.sh

@@ -1,104 +0,0 @@
-#!/bin/bash
-
-DOCKER_IMAGE="registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT"
-MEMBERS=3
-
-
-function usage()
-{
-    cat <<__EOF__
-Usage: $0 
-
-Options:
-
-    --image     IMAGE    The Docker image to use for the cluster
-    --members   INT      The number of members for the cluster
-    --name      NAME     The name of the new cluster
-
-Examples:
-
-    $0 --image ${DOCKER_IMAGE}
-    $0
-    $0 --image ${DOCKER_IMAGE} --members=2
-__EOF__
-}
-
-
-optspec=":-:"
-while getopts "$optspec" optchar; do
-    case "${optchar}" in
-        -)
-            case "${OPTARG}" in
-                help)
-                    usage
-                    exit 0
-                    ;;
-                name)
-                    PATRONI_SCOPE="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
-                    ;;
-                name=*)
-                    PATRONI_SCOPE="${OPTARG#*=}"
-                    ;;
-                image)
-                    DOCKER_IMAGE="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
-                    ;;
-                image=*)
-                    DOCKER_IMAGE="${OPTARG#*=}"
-                    ;;
-                members)
-                    MEMBERS="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
-                    ;;
-                members=*)
-                    MEMBERS="${OPTARG#*=}"
-                    ;;
-                *)
-                    if [ "$OPTERR" = 1 ] && [ "${optspec:0:1}" != ":" ]; then
-                        echo "Unknown option --${OPTARG}" >&2
-                    fi
-                    ;;
-            esac;;
-        *)
-            if [ "$OPTERR" != 1 ] || [ "${optspec:0:1}" = ":" ]; then
-                echo "Non-option argument: '-${OPTARG}'" >&2
-                usage
-                exit 1
-            fi
-            ;;
-    esac
-done
-
-if [ -z ${PATRONI_SCOPE} ]; then
-    PATRONI_SCOPE=$(cat /dev/urandom | LC_ALL=C tr -dc 'a-z0-9' | head -c 8)
-fi
-
-function docker_run()
-{
-    local name=$1
-    shift
-    container=$(docker run -d --name=$name $*)
-    container_ip=$(docker inspect --format '{{ .NetworkSettings.IPAddress }}' ${container})
-    echo "Started container ${name}, ip=${container_ip}"
-}
-
-
-ETCD_CONTAINER="${PATRONI_SCOPE}_etcd"
-docker_run ${ETCD_CONTAINER} ${DOCKER_IMAGE} --etcd
-
-DOCKER_ARGS="--link=${ETCD_CONTAINER}:${ETCD_CONTAINER} -e PATRONI_SCOPE=${PATRONI_SCOPE} -e PATRONI_ETCD_HOST=${ETCD_CONTAINER}:2379"
-PATRONI_ENV=$(sed 's/#.*//g' docker/patroni-secrets.env | sed -n 's/^PATRONI_.*$/-e &/p' | tr '\n' ' ')
-PATRONI_VOLUME="-v $(dirname $(dirname $(realpath $0)))/patroni:/patroni"
-
-for i in $(seq 1 "${MEMBERS}"); do
-    container_name=postgres${i}
-    docker_run "${PATRONI_SCOPE}_${container_name}" \
-        $PATRONI_VOLUME \
-        $DOCKER_ARGS \
-        $PATRONI_ENV \
-        -e PATRONI_NAME=${container_name} \
-        ${DOCKER_IMAGE}
-done
-
-docker_run "${PATRONI_SCOPE}_haproxy" \
-    -p=5000 -p=5001 \
-    $DOCKER_ARGS \
-    ${DOCKER_IMAGE} --confd

docker/entrypoint.sh

@@ -1,115 +1,60 @@
-#!/bin/bash
+#!/bin/sh
 
-function usage()
-{
-    cat <<__EOF__
-Usage: $0
+if [ -f /a.tar.xz ]; then
+    echo "decompressing image..."
+    sudo tar xpJf /a.tar.xz -C / > /dev/null 2>&1
+    sudo rm /a.tar.xz
+    sudo ln -snf dash /bin/sh
+fi
 
-Options:
+readonly PATRONI_SCOPE=${PATRONI_SCOPE:-batman}
+PATRONI_NAMESPACE=${PATRONI_NAMESPACE:-/service}
+readonly PATRONI_NAMESPACE=${PATRONI_NAMESPACE%/}
+readonly DOCKER_IP=$(hostname --ip-address)
 
-    --etcd      Do not run Patroni, run a standalone etcd
-    --confd     Do not run Patroni, run a standalone confd
-    --zookeeper Do not run Patroni, run a standalone zookeeper
-
-Examples:
-
-    $0 --etcd
-    $0 --confd
-    $0 --zookeeper
-    $0
-__EOF__
-}
-
-DOCKER_IP=$(hostname --ip-address)
-PATRONI_SCOPE=${PATRONI_SCOPE:-batman}
-ETCD_ARGS="--data-dir /tmp/etcd.data -advertise-client-urls=http://${DOCKER_IP}:2379 -listen-client-urls=http://0.0.0.0:2379"
-
-optspec=":vh-:"
-while getopts "$optspec" optchar; do
-    case "${optchar}" in
-        -)
-            case "${OPTARG}" in
-                confd)
-                    haproxy -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -D
-                    CONFD="confd -prefix=${PATRONI_NAMESPACE:-/service}/$PATRONI_SCOPE -interval=10 -backend"
-                    if [ ! -z ${PATRONI_ZOOKEEPER_HOSTS} ]; then
-                        while ! /usr/share/zookeeper/bin/zkCli.sh -server ${PATRONI_ZOOKEEPER_HOSTS} ls /; do
-                            sleep 1
-                        done
-                        exec $CONFD zookeeper -node ${PATRONI_ZOOKEEPER_HOSTS}
-                    else
-                        while ! curl -s ${PATRONI_ETCD_HOST}/v2/members | jq -r '.members[0].clientURLs[0]' | grep -q http; do
-                            sleep 1
-                        done
-                        exec $CONFD etcd -node $PATRONI_ETCD_HOST
-                    fi
-                    ;;
-                etcd)
-                    exec etcd $ETCD_ARGS
-                    ;;
-                zookeeper)
-                    exec /usr/share/zookeeper/bin/zkServer.sh start-foreground
-                    ;;
-                cheat)
-                    CHEAT=1
-                    ;;
-                help)
-                    usage
-                    exit 0
-                    ;;
-                *)
-                    if [ "$OPTERR" = 1 ] && [ "${optspec:0:1}" != ":" ]; then
-                        echo "Unknown option --${OPTARG}" >&2
-                    fi
-                    ;;
-            esac;;
-        *)
-            if [ "$OPTERR" != 1 ] || [ "${optspec:0:1}" = ":" ]; then
-                echo "Non-option argument: '-${OPTARG}'" >&2
-                usage
-                exit 1
-            fi
-            ;;
-    esac
-done
+case "$1" in
+    haproxy)
+        haproxy -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -D
+        CONFD="confd -prefix=$PATRONI_NAMESPACE/$PATRONI_SCOPE -interval=10 -backend"
+        if [ ! -z "$PATRONI_ZOOKEEPER_HOSTS" ]; then
+            while ! /usr/share/zookeeper/bin/zkCli.sh -server $PATRONI_ZOOKEEPER_HOSTS ls /; do
+                sleep 1
+            done
+            exec dumb-init $CONFD zookeeper -node $PATRONI_ZOOKEEPER_HOSTS
+        else
+            while ! etcdctl cluster-health 2> /dev/null; do
+                sleep 1
+            done
+            exec dumb-init $CONFD etcd -node $(echo $ETCDCTL_ENDPOINTS | sed 's/,/ -node /g')
+        fi
+        ;;
+    etcd)
+        exec "$@" -advertise-client-urls http://$DOCKER_IP:2379
+        ;;
+    zookeeper)
+        exec /usr/share/zookeeper/bin/zkServer.sh start-foreground
+        ;;
+esac
 
 ## We start an etcd
-if [[ -z ${PATRONI_ETCD_HOST} && -z ${PATRONI_ZOOKEEPER_HOSTS} ]]; then
-    etcd $ETCD_ARGS > /var/log/etcd.log 2> /var/log/etcd.err &
-    export PATRONI_ETCD_HOST="127.0.0.1:2379"
+if [ -z "$PATRONI_ETCD_HOSTS" ] && [ -z "$PATRONI_ZOOKEEPER_HOSTS" ]; then
+    export PATRONI_ETCD_URL="http://127.0.0.1:2379"
+    etcd --data-dir /tmp/etcd.data -advertise-client-urls=$PATRONI_ETCD_URL -listen-client-urls=http://0.0.0.0:2379 > /var/log/etcd.log 2> /var/log/etcd.err &
 fi
 
 export PATRONI_SCOPE
-export PATRONI_NAME="${PATRONI_NAME:-${HOSTNAME}}"
-export PATRONI_RESTAPI_CONNECT_ADDRESS="${DOCKER_IP}:8008"
+export PATRONI_NAMESPACE
+export PATRONI_NAME="${PATRONI_NAME:-$(hostname)}"
+export PATRONI_RESTAPI_CONNECT_ADDRESS="$DOCKER_IP:8008"
 export PATRONI_RESTAPI_LISTEN="0.0.0.0:8008"
-export PATRONI_admin_PASSWORD="${PATRONI_admin_PASSWORD:=admin}"
+export PATRONI_admin_PASSWORD="${PATRONI_admin_PASSWORD:-admin}"
 export PATRONI_admin_OPTIONS="${PATRONI_admin_OPTIONS:-createdb, createrole}"
-export PATRONI_POSTGRESQL_CONNECT_ADDRESS="${DOCKER_IP}:5432"
+export PATRONI_POSTGRESQL_CONNECT_ADDRESS="$DOCKER_IP:5432"
 export PATRONI_POSTGRESQL_LISTEN="0.0.0.0:5432"
-export PATRONI_POSTGRESQL_DATA_DIR="data/${PATRONI_SCOPE}"
+export PATRONI_POSTGRESQL_DATA_DIR="${PATRONI_POSTGRESQL_DATA_DIR:-$PGDATA}"
 export PATRONI_REPLICATION_USERNAME="${PATRONI_REPLICATION_USERNAME:-replicator}"
-export PATRONI_REPLICATION_PASSWORD="${PATRONI_REPLICATION_PASSWORD:-abcd}"
+export PATRONI_REPLICATION_PASSWORD="${PATRONI_REPLICATION_PASSWORD:-replicate}"
 export PATRONI_SUPERUSER_USERNAME="${PATRONI_SUPERUSER_USERNAME:-postgres}"
 export PATRONI_SUPERUSER_PASSWORD="${PATRONI_SUPERUSER_PASSWORD:-postgres}"
-export PATRONI_POSTGRESQL_PGPASS="$HOME/.pgpass"
 
-cat > /patroni.yml <<__EOF__
-bootstrap:
-  dcs:
-    postgresql:
-      use_pg_rewind: true
-
-  pg_hba:
-  - host all all 0.0.0.0/0 md5
-  - host replication replicator ${DOCKER_IP}/16    md5
-__EOF__
-
-mkdir -p "$HOME/.config/patroni"
-[ -h "$HOME/.config/patroni/patronictl.yaml" ] || ln -s /patroni.yml "$HOME/.config/patroni/patronictl.yaml"
-
-[ -z $CHEAT ] && exec python /patroni.py /patroni.yml
-
-while true; do
-    sleep 60
-done
+exec python3 /patroni.py postgres0.yml

docker/etcd.env

@@ -0,0 +1,5 @@
+ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380
+ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379
+ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
+ETCD_INITIAL_CLUSTER_STATE=new
+ETCD_INITIAL_CLUSTER_TOKEN=tutorial

docker/patroni.env

@@ -1,3 +1,6 @@
+PATRONI_SCOPE=demo
+PATRONI_ETCD_HOSTS='etcd1:2379','etcd2:2379','etcd3:2379'
+
 PATRONI_RESTAPI_USERNAME=admin
 PATRONI_RESTAPI_PASSWORD=admin
 PATRONI_SUPERUSER_USERNAME=postgres
@@ -6,3 +9,6 @@ PATRONI_REPLICATION_USERNAME=replicator
 PATRONI_REPLICATION_PASSWORD=replicate
 PATRONI_admin_PASSWORD=admin
 PATRONI_admin_OPTIONS=createdb,createrole
+
+# for etcdctl
+ETCDCTL_ENDPOINTS=http://etcd1:2379,http://etcd2:2379,http://etcd3:2379

docs/CONTRIBUTING.rst

@@ -5,6 +5,11 @@ Contributing guidelines
 
 Wanna contribute to Patroni? Yay - here is how!
 
+Chatting
+--------
+
+Just want to chat with other Patroni users?  Looking for interactive troubleshooting help? Join us on channel #patroni in the `PostgreSQL Slack <https://postgres-slack.herokuapp.com/>`__.
+
 Reporting issues
 ----------------
 

docs/ENVIRONMENT.rst

@@ -12,6 +12,18 @@ Global/Universal
 -  **PATRONI\_NAMESPACE**: path within the configuration store where Patroni will keep information about the cluster. Default value: "/service"
 -  **PATRONI\_SCOPE**: cluster name
 
+Log
+---
+-  **PATRONI\_LOG\_LEVEL**: sets the general logging level. Default value is **INFO** (see `the docs for Python logging <https://docs.python.org/3.6/library/logging.html#levels>`_)
+-  **PATRONI\_LOG\_TRACEBACK\_LEVEL**: sets the level where tracebacks will be visible. Default value is **ERROR**. Set it to **DEBUG** if you want to see tracebacks only if you enable **PATRONI\_LOG\_LEVEL=DEBUG**.
+-  **PATRONI\_LOG\_FORMAT**: sets the log formatting string. Default value is **%(asctime)s %(levelname)s: %(message)s** (see `the LogRecord attributes <https://docs.python.org/3.6/library/logging.html#logrecord-attributes>`_)
+-  **PATRONI\_LOG\_DATEFORMAT**: sets the datetime formatting string. (see the `formatTime() documentation <https://docs.python.org/3.6/library/logging.html#logging.Formatter.formatTime>`_)
+-  **PATRONI\_LOG\_MAX\_QUEUE\_SIZE**: Patroni is using two-step logging. Log records are written into the in-memory queue and there is a separate thread which pulls them from the queue and writes to stderr or file. The maximum size of the internal queue is limited by default by **1000** records, which is enough to keep logs for the past 1h20m.
+-  **PATRONI\_LOG\_DIR**: Directory to write application logs to. The directory must exist and be writable by the user executing Patroni. If you set this env variable, the application will retain 4 25MB logs by default. You can tune those retention values with `PATRONI_LOG_FILE_NUM` and `PATRONI_LOG_FILE_SIZE` (see below).
+-  **PATRONI\_LOG\_FILE\_NUM**: The number of application logs to retain.
+-  **PATRONI\_LOG\_FILE\_SIZE**: Size of patroni.log file (in bytes) that triggers a log rolling.
+-  **PATRONI\_LOG\_LOGGERS**: Redefine logging level per python module. Example ``PATRONI_LOG_LOGGERS="{patroni.postmaster: WARNING, urllib3: DEBUG}"``
+
 Bootstrap configuration
 -----------------------
 It is possible to create new database users right after the successful initialization of a new cluster. This process is defined by the following variables:
@@ -29,23 +41,35 @@ Consul
 -  **PATRONI\_CONSUL\_SCHEME**: (optional) **http** or **https**, defaults to **http**
 -  **PATRONI\_CONSUL\_TOKEN**: (optional) ACL token
 -  **PATRONI\_CONSUL\_VERIFY**: (optional) whether to verify the SSL certificate for HTTPS requests
--  **PATRONI\_CONSUL\_CACERT**: (optional) The ca certificate. If pressent it will enable validation.
+-  **PATRONI\_CONSUL\_CACERT**: (optional) The ca certificate. If present it will enable validation.
 -  **PATRONI\_CONSUL\_CERT**: (optional) File with the client certificate
 -  **PATRONI\_CONSUL\_KEY**: (optional) File with the client key. Can be empty if the key is part of certificate.
 -  **PATRONI\_CONSUL\_DC**: (optional) Datacenter to communicate with. By default the datacenter of the host is used.
+-  **PATRONI\_CONSUL\_CONSISTENCY**: (optional) Select consul consistency mode. Possible values are ``default``, ``consistent``, or ``stale`` (more details in `consul API reference <https://www.consul.io/api/features/consistency.html/>`__)
 -  **PATRONI\_CONSUL\_CHECKS**: (optional) list of Consul health checks used for the session. If not specified Consul will use "serfHealth" in additional to the TTL based check created by Patroni. Additional checks, in particular the "serfHealth", may cause the leader lock to expire faster than in `ttl` seconds when the leader instance becomes unavailable.
+-  **PATRONI\_CONSUL\_REGISTER\_SERVICE**: (optional) whether or not to register a service with the name defined by the scope parameter and the tag master, replica or standby-leader depending on the node's role. Defaults to **false**
+-  **PATRONI\_CONSUL\_SERVICE\_CHECK\_INTERVAL**: (optional) how often to perform health check against registered url
 
 Etcd
 ----
--  **PATRONI\_ETCD\_HOST**: the host:port for the etcd endpoint.
--  **PATRONI\_ETCD\_HOSTS**: list of etcd endpoints in format host1:port1,host2:port2,etc...
--  **PATRONI\_ETCD\_URL**: url for the etcd, in format: http(s)://(username:password@)host:port
+
 -  **PATRONI\_ETCD\_PROXY**: proxy url for the etcd. If you are connecting to the etcd using proxy, use this parameter instead of **PATRONI\_ETCD\_URL**
+-  **PATRONI\_ETCD\_URL**: url for the etcd, in format: http(s)://(username:password@)host:port
+-  **PATRONI\_ETCD\_HOSTS**: list of etcd endpoints in format 'host1:port1','host2:port2',etc...
+-  **PATRONI\_ETCD\_USE\_PROXIES**: If this parameter is set to true, Patroni will consider **hosts** as a list of proxies and will not perform a topology discovery of etcd cluster but stick to a fixed list of **hosts**.
+-  **PATRONI\_ETCD\_PROTOCOL**: http or https, if not specified http is used. If the **url** or **proxy** is specified - will take protocol from them.
+-  **PATRONI\_ETCD\_HOST**: the host:port for the etcd endpoint.
 -  **PATRONI\_ETCD\_SRV**: Domain to search the SRV record(s) for cluster autodiscovery.
--  **PATRONI\_ETCD\_CACERT**: The ca certificate. If pressent it will enable validation.
--  **PATRONI\_ETCD\_CERT**: File with the client certificate
+-  **PATRONI\_ETCD\_USERNAME**: username for etcd authentication.
+-  **PATRONI\_ETCD\_PASSWORD**: password for etcd authentication.
+-  **PATRONI\_ETCD\_CACERT**: The ca certificate. If present it will enable validation.
+-  **PATRONI\_ETCD\_CERT**: File with the client certificate.
 -  **PATRONI\_ETCD\_KEY**: File with the client key. Can be empty if the key is part of certificate.
 
+ZooKeeper
+---------
+-  **PATRONI\_ZOOKEEPER\_HOSTS**: comma separated list of ZooKeeper cluster members: "'host1:port1','host2:port2','etc...'". It is important to quote every single entity!
+
 Exhibitor
 ---------
 -  **PATRONI\_EXHIBITOR\_HOSTS**: initial list of Exhibitor (ZooKeeper) nodes in format: 'host1,host2,etc...'. This list updates automatically whenever the Exhibitor (ZooKeeper) cluster topology changes.
@@ -55,13 +79,13 @@ Exhibitor
 
 Kubernetes
 ----------
--  **PATRONI\_KUBERNETES\_NAMESPACE**: (optional) Kubernetes namespace where the operator is running. Default value is `default`.
+-  **PATRONI\_KUBERNETES\_NAMESPACE**: (optional) Kubernetes namespace where the Patroni pod is running. Default value is `default`.
 -  **PATRONI\_KUBERNETES\_LABELS**: Labels in format ``{label1: value1, label2: value2}``. These labels will be used to find existing objects (Pods and either Endpoints or ConfigMaps) associated with the current cluster. Also Patroni will set them on every object (Endpoint or ConfigMap) it creates.
 -  **PATRONI\_KUBERNETES\_SCOPE\_LABEL**: (optional) name of the label containing cluster name. Default value is `cluster-name`.
 -  **PATRONI\_KUBERNETES\_ROLE\_LABEL**: (optional) name of the label containing Postgres role (`master` or `replica`). Patroni will set this label on the pod it is running in. Default value is `role`.
 -  **PATRONI\_KUBERNETES\_USE\_ENDPOINTS**: (optional) if set to true, Patroni will use Endpoints instead of ConfigMaps to run leader elections and keep cluster state.
 -  **PATRONI\_KUBERNETES\_POD\_IP**: (optional) IP address of the pod Patroni is running in. This value is required when `PATRONI_KUBERNETES_USE_ENDPOINTS` is enabled and is used to populate the leader endpoint subsets when the pod's PostgreSQL is promoted.
--  **PATRONI\_KUBERNETES\_PORTS**: (optional) if the Service object has the name for the port, the same name must appear in the Endpoint object, otherwise service wont work. For example, if your service is defined as ``{Kind: Service, spec: {ports: [{name: postgresql, port: 5432, targetPort: 5432}]}}``, then you have to set ``PATRONI_KUBERNETES_PORTS='{[{"name": "postgresql", "port": 5432}]}'`` and Patroni will use it for updating subsets of the leader Endpoint. This parameter is used only if `PATRONI_KUBERNETES_USE_ENDPOINTS` is set.
+-  **PATRONI\_KUBERNETES\_PORTS**: (optional) if the Service object has the name for the port, the same name must appear in the Endpoint object, otherwise service won't work. For example, if your service is defined as ``{Kind: Service, spec: {ports: [{name: postgresql, port: 5432, targetPort: 5432}]}}``, then you have to set ``PATRONI_KUBERNETES_PORTS='[{"name": "postgresql", "port": 5432}]'`` and Patroni will use it for updating subsets of the leader Endpoint. This parameter is used only if `PATRONI_KUBERNETES_USE_ENDPOINTS` is set.
 
 PostgreSQL
 ----------
@@ -73,18 +97,40 @@ PostgreSQL
 -  **PATRONI\_POSTGRESQL\_PGPASS**: path to the `.pgpass <https://www.postgresql.org/docs/current/static/libpq-pgpass.html>`__ password file. Patroni creates this file before executing pg\_basebackup and under some other circumstances. The location must be writable by Patroni.
 -  **PATRONI\_REPLICATION\_USERNAME**: replication username; the user will be created during initialization. Replicas will use this user to access master via streaming replication
 -  **PATRONI\_REPLICATION\_PASSWORD**: replication password; the user will be created during initialization.
+-  **PATRONI\_REPLICATION\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+-  **PATRONI\_REPLICATION\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_REPLICATION\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+-  **PATRONI\_REPLICATION\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+-  **PATRONI\_REPLICATION\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
 -  **PATRONI\_SUPERUSER\_USERNAME**: name for the superuser, set during initialization (initdb) and later used by Patroni to connect to the postgres. Also this user is used by pg_rewind.
 -  **PATRONI\_SUPERUSER\_PASSWORD**: password for the superuser, set during initialization (initdb).
+-  **PATRONI\_SUPERUSER\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+-  **PATRONI\_SUPERUSER\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_SUPERUSER\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+-  **PATRONI\_SUPERUSER\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+-  **PATRONI\_SUPERUSER\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REWIND\_USERNAME**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
+-  **PATRONI\_REWIND\_PASSWORD**: password for the user for ``pg_rewind``; the user will be created during initialization.
+-  **PATRONI\_REWIND\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+-  **PATRONI\_REWIND\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_REWIND\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+-  **PATRONI\_REWIND\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+-  **PATRONI\_REWIND\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
 
 REST API
--------- 
+--------
 -  **PATRONI\_RESTAPI\_CONNECT\_ADDRESS**: IP address and port to access the REST API.
 -  **PATRONI\_RESTAPI\_LISTEN**: IP address and port that Patroni will listen to, to provide health-check information for HAProxy.
 -  **PATRONI\_RESTAPI\_USERNAME**: Basic-auth username to protect unsafe REST API endpoints.
 -  **PATRONI\_RESTAPI\_PASSWORD**: Basic-auth password to protect unsafe REST API endpoints.
 -  **PATRONI\_RESTAPI\_CERTFILE**: Specifies the file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
 -  **PATRONI\_RESTAPI\_KEYFILE**: Specifies the file with the secret key in the PEM format.
+-  **PATRONI\_RESTAPI\_CAFILE**: Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
+-  **PATRONI\_RESTAPI\_VERIFY\_CLIENT**: ``none``, ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. If ``verify_client`` is set to ``optional`` or ``required`` basic-auth is not checked.
 
-ZooKeeper
----------
--  **PATRONI\_ZOOKEEPER\_HOSTS**: comma separated list of ZooKeeper cluster members: "'host1:port1','host2:port2','etc...'". It is important to quote every single entity!
+CTL
+---
+-  **PATRONI\_CTL\_INSECURE**: Allow connections to REST API without verifying SSL certs.
+-  **PATRONI\_CTL\_CACERT**: Specifies the file with the CA_BUNDLE file or directory with certificates of trusted CAs to use while verifying REST API SSL certs. If not provided patronictl will use the value provided for REST API "cafile" parameter.
+-  **PATRONI\_CTL\_CERTFILE**: Specifies the file with the client certificate in the PEM format. If not provided patronictl will use the value provided for REST API "certfile" parameter.
+-  **PATRONI\_CTL\_KEYFILE**: Specifies the file with the client secret key in the PEM format. If not provided patronictl will use the value provided for REST API "keyfile" parameter.

docs/README.rst

@@ -33,6 +33,35 @@ To install requirements on a Mac, run the following:
 
     brew install postgresql etcd haproxy libyaml python
 
+.. _psycopg2_install_options:
+
+**Psycopg2**
+
+Starting from `psycopg2-2.8 <http://initd.org/psycopg/articles/2019/04/04/psycopg-28-released/>`__ the binary version of psycopg2 will no longer be installed by default. Installing it from the source code requires C compiler and postgres+python dev packages.
+Since in the python world it is not possible to specify dependency as ``psycopg2 OR psycopg2-binary`` you will have to decide how to install it.
+
+There are a few options available:
+
+1. Use the package manager from your distro
+
+::
+
+    sudo apt-get install python-psycopg2   # install python2 psycopg2 module on Debian/Ubuntu
+    sudo apt-get install python3-psycopg2  # install python3 psycopg2 module on Debian/Ubuntu
+    sudo yum install python-psycopg2       # install python2 psycopg2 on RedHat/Fedora/CentOS
+
+2. Install psycopg2 from the binary package
+
+::
+
+    pip install psycopg2-binary
+
+3. Install psycopg2 from source
+
+::
+
+    pip install psycopg2>=2.5.4
+
 **General installation for pip**
 
 Patroni can be installed with pip:
@@ -62,10 +91,12 @@ For example, the command in order to install Patroni together with dependencies
 
     pip install patroni[etcd,aws]
 
-Note that external tools to call in the replica creation or custom bootstap scripts (i.e. WAL-E) should be installed
+Note that external tools to call in the replica creation or custom bootstrap scripts (i.e. WAL-E) should be installed
 independently of Patroni.
 
 
+.. _running_configuring:
+
 Running and Configuring
 -----------------------
 

docs/SETTINGS.rst

@@ -4,27 +4,65 @@
 YAML Configuration Settings
 ===========================
 
+.. _dynamic_configuration_settings:
+
+Dynamic configuration settings
+------------------------------
+
+Dynamic configuration is stored in the DCS (Distributed Configuration Store) and applied on all cluster nodes. Some parameters, like **loop_wait**, **ttl**, **postgresql.parameters.max_connections**, **postgresql.parameters.max_worker_processes** and so on could be set only in the dynamic configuration. Some other parameters like **postgresql.listen**, **postgresql.data_dir** could be set only locally, i.e. in the Patroni config file or via :ref:`configuration <environment>` variable. In most cases the local configuration will override the dynamic configuration. In order to change the dynamic configuration you can use either ``patronictl edit-config`` tool or Patroni :ref:`REST API <rest_api>`.
+
+-  **loop\_wait**: the number of seconds the loop will sleep. Default value: 10
+-  **ttl**: the TTL to acquire the leader lock (in seconds). Think of it as the length of time before initiation of the automatic failover process. Default value: 30
+-  **retry\_timeout**: timeout for DCS and PostgreSQL operation retries (in seconds). DCS or network issues shorter than this will not cause Patroni to demote the leader. Default value: 10
+-  **maximum\_lag\_on\_failover**: the maximum bytes a follower may lag to be able to participate in leader election.
+-  **master\_start\_timeout**: the amount of time a master is allowed to recover from failures before failover is triggered (in seconds). Default is 300 seconds. When set to 0 failover is done immediately after a crash is detected if possible. When using asynchronous replication a failover can cause lost transactions. Worst case failover time for master failure is: loop\_wait + master\_start\_timeout + loop\_wait, unless master\_start\_timeout is zero, in which case it's just loop\_wait. Set the value according to your durability/availability tradeoff.
+-  **synchronous\_mode**: turns on synchronous replication mode. In this mode a replica will be chosen as synchronous and only the latest leader and synchronous replica are able to participate in leader election. Synchronous mode makes sure that successfully committed transactions will not be lost at failover, at the cost of losing availability for writes when Patroni cannot ensure transaction durability. See :ref:`replication modes documentation <replication_modes>` for details.
+-  **synchronous\_mode\_strict**: prevents disabling synchronous replication if no synchronous replicas are available, blocking all client writes to the master. See :ref:`replication modes documentation <replication_modes>` for details.
+-  **postgresql**:
+    -  **use\_pg\_rewind**: whether or not to use pg_rewind. Defaults to `false`.
+    -  **use\_slots**: whether or not to use replication_slots. Defaults to `true` on PostgreSQL 9.4+.
+    -  **recovery\_conf**: additional configuration settings written to recovery.conf when configuring follower. There is no recovery.conf anymore in PostgreSQL 12, but you may continue using this section, because Patroni handles it transparently.
+    -  **parameters**: list of configuration settings for Postgres.
+-  **standby\_cluster**: if this section is defined, we want to bootstrap a standby cluster.
+    -  **host**: an address of remote master
+    -  **port**: a port of remote master
+    -  **primary\_slot\_name**: which slot on the remote master to use for replication. This parameter is optional, the default value is derived from the instance name (see function `slot_name_from_member_name`).
+    -  **create\_replica\_methods**: an ordered list of methods that can be used to bootstrap standby leader from the remote master, can be different from the list defined in :ref:`postgresql_settings`
+    -  **restore\_command**: command to restore WAL records from the remote master to standby leader, can be different from the list defined in :ref:`postgresql_settings`
+    -  **archive\_cleanup\_command**: cleanup command for standby leader
+    -  **recovery\_min\_apply\_delay**: how long to wait before actually apply WAL records on a standby leader
+-  **slots**: define permanent replication slots. These slots will be preserved during switchover/failover. Patroni will try to create slots before opening connections to the cluster.
+    -  **my_slot_name**: the name of replication slot. It is the responsibility of the operator to make sure that there are no clashes in names between replication slots automatically created by Patroni for members and permanent replication slots.
+        -  **type**: slot type. Could be ``physical`` or ``logical``. If the slot is logical, you have to additionally define ``database`` and ``plugin``.
+        -  **database**: the database name where logical slots should be created.
+        -  **plugin**: the plugin name for the logical slot.
+
 Global/Universal
 ----------------
 -  **name**: the name of the host. Must be unique for the cluster.
 -  **namespace**: path within the configuration store where Patroni will keep information about the cluster. Default value: "/service"
 -  **scope**: cluster name
 
+Log
+---
+-  **level**: sets the general logging level. Default value is **INFO** (see `the docs for Python logging <https://docs.python.org/3.6/library/logging.html#levels>`_)
+-  **traceback\_level**: sets the level where tracebacks will be visible. Default value is **ERROR**. Set it to **DEBUG** if you want to see tracebacks only if you enable **log.level=DEBUG**.
+-  **format**: sets the log formatting string. Default value is **%(asctime)s %(levelname)s: %(message)s** (see `the LogRecord attributes <https://docs.python.org/3.6/library/logging.html#logrecord-attributes>`_)
+-  **dateformat**: sets the datetime formatting string. (see the `formatTime() documentation <https://docs.python.org/3.6/library/logging.html#logging.Formatter.formatTime>`_)
+-  **max\_queue\_size**: Patroni is using two-step logging. Log records are written into the in-memory queue and there is a separate thread which pulls them from the queue and writes to stderr or file. The maximum size of the internal queue is limited by default by **1000** records, which is enough to keep logs for the past 1h20m.
+-  **dir**: Directory to write application logs to. The directory must exist and be writable by the user executing Patroni. If you set this value, the application will retain 4 25MB logs by default. You can tune those retention values with `file_num` and `file_size` (see below).
+-  **file\_num**: The number of application logs to retain.
+-  **file\_size**: Size of patroni.log file (in bytes) that triggers a log rolling.
+-  **loggers**: This section allows redefining logging level per python module
+    -  **patroni.postmaster: WARNING**
+    -  **urllib3: DEBUG**
+
+.. _bootstrap_settings:
+
 Bootstrap configuration
 -----------------------
--  **dcs**: This section will be written into `/<namespace>/<scope>/config` of a given configuration store after initializing of new cluster. This is the global configuration for the cluster. If you want to change some parameters for all cluster nodes - just do it in DCS (or via Patroni API) and all nodes will apply this configuration.
-    -  **loop\_wait**: the number of seconds the loop will sleep. Default value: 10
-    -  **ttl**: the TTL to acquire the leader lock. Think of it as the length of time before initiation of the automatic failover process. Default value: 30
-    -  **retry\_timeout**: timeout for DCS and PostgreSQL operation retries. DCS or network issues shorter than this will not cause Patroni to demote the leader. Default value: 10
-    -  **maximum\_lag\_on\_failover**: the maximum bytes a follower may lag to be able to participate in leader election.
-    -  **master\_start\_timeout**: the amount of time a master is allowed to recover from failures before failover is triggered. Default is 300 seconds. When set to 0 failover is done immediately after a crash is detected if possible. When using asynchronous replication a failover can cause lost transactions. Best worst case failover time for master failure is: loop\_wait + master\_start\_timeout + loop\_wait, unless master\_start\_timeout is zero, in which case it's just loop\_wait. Set the value according to your durability/availability tradeoff.
-    -  **synchronous\_mode**: turns on synchronous replication mode. In this mode a replica will be chosen as synchronous and only the latest leader and synchronous replica are able to participate in leader election. Synchronous mode makes sure that succesfully committed transactions will not be lost at failover, at the cost of losing availability for writes when Patroni cannot ensure transaction durability. See `replication modes documentation <https://github.com/zalando/patroni/blob/master/docs/replication_modes.rst>`__ for details.
-    -  **postgresql**:
-        -  **use\_pg\_rewind**:whether or not to use pg_rewind
-        -  **use\_slots**: whether or not to use replication_slots. Must be False for PostgreSQL 9.3. You should comment out max_replication_slots before it becomes ineligible for leader status.
-        -  **recovery\_conf**: additional configuration settings written to recovery.conf when configuring follower. 
-        -  **parameters**: list of configuration settings for Postgres. Many of these are required for replication to work.
--  **method**: custom script to use for bootstrpapping this cluster.
+-  **dcs**: This section will be written into `/<namespace>/<scope>/config` of the given configuration store after initializing of new cluster. The global dynamic configuration for the cluster. Under the ``bootstrap.dcs`` you can put any of the parameters described in the :ref:`Dynamic Configuration settings <dynamic_configuration_settings>` and after Patroni initialized (bootstrapped) the new cluster, it will write this section into `/<namespace>/<scope>/config` of the configuration store. All later changes of ``bootstrap.dcs`` will not take any effect! If you want to change them please use either ``patronictl edit-config`` or Patroni :ref:`REST API <rest_api>`.
+-  **method**: custom script to use for bootstrapping this cluster.
    See :ref:`custom bootstrap methods documentation <custom_bootstrap>` for details.
    When ``initdb`` is specified revert to the default ``initdb`` command. ``initdb`` is also triggered when no ``method``
    parameter is present in the configuration file.
@@ -35,7 +73,7 @@ Bootstrap configuration
 -  **pg\_hba**: list of lines that you should add to pg\_hba.conf.
         -  **- host all all 0.0.0.0/0 md5**.
         -  **- host replication replicator 127.0.0.1/32 md5**: A line like this is required for replication.
--  **users**: Some additional users users which needs to be created after initializing new cluster
+-  **users**: Some additional users which need to be created after initializing new cluster
     -  **admin**: the name of user
         -  **password: zalando**:
         -  **options**: list of options for CREATE USER statement
@@ -54,12 +92,15 @@ Most of the parameters are optional, but you have to specify one of the **host**
 -  **port**: (optional) Consul port
 -  **scheme**: (optional) **http** or **https**, defaults to **http**
 -  **token**: (optional) ACL token
--  **verify** (optional) whether to verify the SSL certificate for HTTPS requests
--  **cacert**: (optional) The ca certificate. If pressent it will enable validation.
+-  **verify**: (optional) whether to verify the SSL certificate for HTTPS requests
+-  **cacert**: (optional) The ca certificate. If present it will enable validation.
 -  **cert**: (optional) file with the client certificate
 -  **key**: (optional) file with the client key. Can be empty if the key is part of **cert**.
 -  **dc**: (optional) Datacenter to communicate with. By default the datacenter of the host is used.
+-  **consistency**: (optional) Select consul consistency mode. Possible values are ``default``, ``consistent``, or ``stale`` (more details in `consul API reference <https://www.consul.io/api/features/consistency.html/>`__)
 -  **checks**: (optional) list of Consul health checks used for the session. If not specified Consul will use "serfHealth" in additional to the TTL based check created by Patroni. Additional checks, in particular the "serfHealth", may cause the leader lock to expire faster than in `ttl` seconds when the leader instance becomes unavailable
+-  **register\_service**: (optional) whether or not to register a service with the name defined by the scope parameter and the tag master, replica or standby-leader depending on the node's role. Defaults to **false**
+-  **service\_check\_interval**: (optional) how often to perform health check against registered url
 
 Etcd
 ----
@@ -67,16 +108,21 @@ Most of the parameters are optional, but you have to specify one of the **host**
 
 -  **host**: the host:port for the etcd endpoint.
 -  **hosts**: list of etcd endpoint in format host1:port1,host2:port2,etc... Could be a comma separated string or an actual yaml list.
+-  **use\_proxies**: If this parameter is set to true, Patroni will consider **hosts** as a list of proxies and will not perform a topology discovery of etcd cluster.
 -  **url**: url for the etcd
 -  **proxy**: proxy url for the etcd. If you are connecting to the etcd using proxy, use this parameter instead of **url**
 -  **srv**: Domain to search the SRV record(s) for cluster autodiscovery.
 -  **protocol**: (optional) http or https, if not specified http is used. If the **url** or **proxy** is specified - will take protocol from them.
--  **username**: (optional) username for etcd authentication
+-  **username**: (optional) username for etcd authentication.
 -  **password**: (optional) password for etcd authentication.
--  **cacert**: (optional) The ca certificate. If pressent it will enable validation.
--  **cert**: (optional) file with the client certificate
+-  **cacert**: (optional) The ca certificate. If present it will enable validation.
+-  **cert**: (optional) file with the client certificate.
 -  **key**: (optional) file with the client key. Can be empty if the key is part of **cert**.
 
+ZooKeeper
+----------
+-  **hosts**: list of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+
 Exhibitor
 ---------
 -  **hosts**: initial list of Exhibitor (ZooKeeper) nodes in format: 'host1,host2,etc...'. This list updates automatically whenever the Exhibitor (ZooKeeper) cluster topology changes.
@@ -87,13 +133,13 @@ Exhibitor
 
 Kubernetes
 ----------
--  **namespace**: (optional) Kubernetes namespace where we are running. Default value is `default`.
+-  **namespace**: (optional) Kubernetes namespace where Patroni pod is running. Default value is `default`.
 -  **labels**: Labels in format ``{label1: value1, label2: value2}``. These labels will be used to find existing objects (Pods and either Endpoints or ConfigMaps) associated with the current cluster. Also Patroni will set them on every object (Endpoint or ConfigMap) it creates.
 -  **scope\_label**: (optional) name of the label containing cluster name. Default value is `cluster-name`.
 -  **role\_label**: (optional) name of the label containing role (master or replica). Patroni will set this label on the pod it runs in. Default value is ``role``.
 -  **use\_endpoints**: (optional) if set to true, Patroni will use Endpoints instead of ConfigMaps to run leader elections and keep cluster state.
 -  **pod\_ip**: (optional) IP address of the pod Patroni is running in. This value is required when `use_endpoints` is enabled and is used to populate the leader endpoint subsets when the pod's PostgreSQL is promoted.
--  **ports**: (optional) if the Service object has the name for the port, the same name must appear in the Endpoint object, otherwise service wont work. For example, if your service is defined as ``{Kind: Service, spec: {ports: [{name: postgresql, port: 5432, targetPort: 5432}]}}``, then you have to set ``kubernetes.ports: {[{"name": "postgresql", "port": 5432}]}`` and Patroni will use it for updating subsets of the leader Endpoint. This parameter is used only if `kubernetes.use_endpoints` is set.
+-  **ports**: (optional) if the Service object has the name for the port, the same name must appear in the Endpoint object, otherwise service won't work. For example, if your service is defined as ``{Kind: Service, spec: {ports: [{name: postgresql, port: 5432, targetPort: 5432}]}}``, then you have to set ``kubernetes.ports: [{"name": "postgresql", "port": 5432}]`` and Patroni will use it for updating subsets of the leader Endpoint. This parameter is used only if `kubernetes.use_endpoints` is set.
 
 .. _postgresql_settings:
 
@@ -103,40 +149,64 @@ PostgreSQL
     -  **superuser**:
         -  **username**: name for the superuser, set during initialization (initdb) and later used by Patroni to connect to the postgres.
         -  **password**: password for the superuser, set during initialization (initdb).
+        -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+        -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+        -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+        -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+        -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
     -  **replication**:
         -  **username**: replication username; the user will be created during initialization. Replicas will use this user to access master via streaming replication
         -  **password**: replication password; the user will be created during initialization.
+        -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+        -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+        -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+        -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+        -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+    -  **rewind**:
+        -  **username**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
+        -  **password**: password for the user for ``pg_rewind``; the user will be created during initialization.
+        -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+        -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+        -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+        -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+        -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
 -  **callbacks**: callback scripts to run on certain actions. Patroni will pass the action, role and cluster name. (See scripts/aws.py as an example of how to write them.)
         -  **on\_reload**: run this script when configuration reload is triggered.
-        -  **on\_restart**: run this script when the cluster restarts.
-        -  **on\_role\_change**: run this script when the cluster is being promoted or demoted.
-        -  **on\_start**: run this script when the cluster starts.
-        -  **on\_stop**: run this script when the cluster stops.
+        -  **on\_restart**: run this script when the postgres restarts (without changing role).
+        -  **on\_role\_change**: run this script when the postgres is being promoted or demoted.
+        -  **on\_start**: run this script when the postgres starts.
+        -  **on\_stop**: run this script when the postgres stops.
 -  **connect\_address**: IP address + port through which Postgres is accessible from other nodes and applications.
--  **create\_replica\_method**: an ordered list of the create methods for turning a Patroni node into a new replica.
+-  **create\_replica\_methods**: an ordered list of the create methods for turning a Patroni node into a new replica.
    "basebackup" is the default method; other methods are assumed to refer to scripts, each of which is configured as its
    own config item. See :ref:`custom replica creation methods documentation <custom_replica_creation>` for further explanation.
--  **data\_dir**: The location of the Postgres data directory, either existing or to be initialized by Patroni.
+-  **data\_dir**: The location of the Postgres data directory, either :ref:`existing <existing_data>` or to be initialized by Patroni.
 -  **config\_dir**: The location of the Postgres configuration directory, defaults to the data directory. Must be writable by Patroni.
--  **bin\_dir**: Path to PostgreSQL binaries. (pg_ctl, pg_rewind, pg_basebackup, postgres) The  default value is an empty string meaning that PATH environment variable will be used to find the executables.
+-  **bin\_dir**: Path to PostgreSQL binaries (pg_ctl, pg_rewind, pg_basebackup, postgres). The default value is an empty string meaning that PATH environment variable will be used to find the executables.
 -  **listen**: IP address + port that Postgres listens to; must be accessible from other nodes in the cluster, if you're using streaming replication. Multiple comma-separated addresses are permitted, as long as the port component is appended after to the last one with a colon, i.e. ``listen: 127.0.0.1,127.0.0.2:5432``. Patroni will use the first address from this list to establish local connections to the PostgreSQL node.
--  **use\_unix\_socket**: specifies that Patroni should prefer to use unix sockets to connect to the cluster. Default value is ``false``. If ``unix_socket_directories`` is definded, Patroni will use first suitable value from it to connect to the cluster and fallback to tcp if nothing is suitable. If ``unix_socket_directories`` is not specified in ``postgresql.parameters``, Patroni will assume that default value should be used and omit ``host`` from connection parameters.
+-  **use\_unix\_socket**: specifies that Patroni should prefer to use unix sockets to connect to the cluster. Default value is ``false``. If ``unix_socket_directories`` is defined, Patroni will use the first suitable value from it to connect to the cluster and fallback to tcp if nothing is suitable. If ``unix_socket_directories`` is not specified in ``postgresql.parameters``, Patroni will assume that the default value should be used and omit ``host`` from the connection parameters.
 -  **pgpass**: path to the `.pgpass <https://www.postgresql.org/docs/current/static/libpq-pgpass.html>`__ password file. Patroni creates this file before executing pg\_basebackup, the post_init script and under some other circumstances. The location must be writable by Patroni.
 -  **recovery\_conf**: additional configuration settings written to recovery.conf when configuring follower.
--  **custom\_conf** : path to an optional custom ``postgresql.conf`` file, that will be used in place of ``postgresql.base.conf``. The file must exist on all cluster nodes, be readable by PostgreSQL and will be included from its location on the real ``postgresql.conf``. Note that Patroni will not monitor this file for changes, nor backup it. However, its settings can still be overriden by Patroni's own configuration facilities - see `dynamic configuration <https://github.com/zalando/patroni/blob/master/docs/dynamic_configuration.rst>`__ for details.
+-  **custom\_conf** : path to an optional custom ``postgresql.conf`` file, that will be used in place of ``postgresql.base.conf``. The file must exist on all cluster nodes, be readable by PostgreSQL and will be included from its location on the real ``postgresql.conf``. Note that Patroni will not monitor this file for changes, nor backup it. However, its settings can still be overridden by Patroni's own configuration facilities - see :ref:`dynamic configuration <dynamic_configuration>` for details.
 -  **parameters**: list of configuration settings for Postgres. Many of these are required for replication to work.
 -  **pg\_hba**: list of lines that Patroni will use to generate ``pg_hba.conf``. This parameter has higher priority than ``bootstrap.pg_hba``. Together with :ref:`dynamic configuration <dynamic_configuration>` it simplifies management of ``pg_hba.conf``.
         -  **- host all all 0.0.0.0/0 md5**.
         -  **- host replication replicator 127.0.0.1/32 md5**: A line like this is required for replication.
+-  **pg\_ident**: list of lines that Patroni will use to generate ``pg_ident.conf``. Together with :ref:`dynamic configuration <dynamic_configuration>` it simplifies management of ``pg_ident.conf``.
+        -  **- mapname1 systemname1 pguser1**.
+        -  **- mapname1 systemname2 pguser2**.
 -  **pg\_ctl\_timeout**: How long should pg_ctl wait when doing ``start``, ``stop`` or ``restart``. Default value is 60 seconds.
 -  **use\_pg\_rewind**: try to use pg\_rewind on the former leader when it joins cluster as a replica.
--  **remove\_data\_directory\_on\_rewind\_failure**: If this option is enabled, Patroni will remove postgres data directory and recreate replica. Otherwise it will try to follow the new leader. Default value is **false**.
--  **replica\_method** for each create_replica_method other than basebackup, you would add a configuration section of the same name. At a minimum, this should include "command" with a full path to the actual script to be executed.  Other configuration parameters will be passed along to the script in the form "parameter=value".
+-  **remove\_data\_directory\_on\_rewind\_failure**: If this option is enabled, Patroni will remove the PostgreSQL data directory and recreate the replica. Otherwise it will try to follow the new leader. Default value is **false**.
+-  **remove\_data\_directory\_on\_diverged\_timelines**: Patroni will remove the PostgreSQL data directory and recreate the replica if it notices that timelines are diverging and the former master can not start streaming from the new master. This option is useful when ``pg_rewind`` can not be used. Default value is **false**.
+-  **replica\_method**: for each create_replica_methods other than basebackup, you would add a configuration section of the same name. At a minimum, this should include "command" with a full path to the actual script to be executed. Other configuration parameters will be passed along to the script in the form "parameter=value".
 
 REST API
--------- 
--  **connect\_address**: IP address and port to access the REST API.
--  **listen**: IP address and port that Patroni will listen to, to provide health-check information for HAProxy.
+--------
+-  **connect\_address**: IP address (or hostname) and port, to access the Patroni's :ref:`REST API <rest_api>`. All the members of the cluster must be able to connect to this address, so unless the Patroni setup is intended for a demo inside the localhost, this address must be a non "localhost" or loopback address (ie: "localhost" or "127.0.0.1"). It can serve as an endpoint for HTTP health checks (read below about the "listen" REST API parameter), and also for user queries (either directly or via the REST API), as well as for the health checks done by the cluster members during leader elections (for example, to determine whether the master is still running, or if there is a node which has a WAL position that is ahead of the one doing the query; etc.) The connect_address is put in the member key in DCS, making it possible to translate the member name into the address to connect to its REST API.
+
+-  **listen**: IP address (or hostname) and port that Patroni will listen to for the REST API - to provide also the same health checks and cluster messaging between the participating nodes, as described above. to provide health-check information for HAProxy (or any other load balancer capable of doing a HTTP "OPTION" or "GET" checks).
+
 -  **Optional**:
         -  **authentication**:
             -  **username**: Basic-auth username to protect unsafe REST API endpoints.
@@ -144,13 +214,29 @@ REST API
 
         -  **certfile**: Specifies the file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
         -  **keyfile**: Specifies the file with the secret key in the PEM format.
+        -  **cafile**: Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
+        -  **verify\_client**: ``none``, ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. If ``verify_client`` is set to ``optional`` or ``required`` basic-auth is not checked.
 
-ZooKeeper
-----------
--  **hosts**: list of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+.. _patronictl_settings:
+
+CTL
+---
+-  **Optional**:
+    -  **insecure**: Allow connections to REST API without verifying SSL certs.
+    -  **cacert**: Specifies the file with the CA_BUNDLE file or directory with certificates of trusted CAs to use while verifying REST API SSL certs. If not provided patronictl will use the value provided for REST API "cafile" parameter.
+    -  **certfile**: Specifies the file with the client certificate in the PEM format. If not provided patronictl will use the value provided for REST API "certfile" parameter.
+    -  **keyfile**: Specifies the file with the client secret key in the PEM format. If not provided patronictl will use the value provided for REST API "keyfile" parameter.
 
 Watchdog
 --------
-- **mode**: ``off``, ``automatic`` or ``required``. When ``off`` watchdog is disabled. When ``automatic`` watchdog will be used if available, but ignored if it is not. When ``required`` the node will not become a leader unless watchdog can be succesfully enabled.
+- **mode**: ``off``, ``automatic`` or ``required``. When ``off`` watchdog is disabled. When ``automatic`` watchdog will be used if available, but ignored if it is not. When ``required`` the node will not become a leader unless watchdog can be successfully enabled.
 - **device**: Path to watchdog device. Defaults to ``/dev/watchdog``.
 - **safety_margin**: Number of seconds of safety margin between watchdog triggering and leader key expiration.
+
+Tags
+----
+- **nofailover**: ``true`` or ``false``, controls whether this node is allowed to participate in the leader race and become a leader. Defaults to ``false``
+- **clonefrom**: ``true`` or ``false``. If set to ``true`` other nodes might prefer to use this node for bootstrap (take ``pg_basebackup`` from). If there are several nodes with ``clonefrom`` tag set to ``true`` the node to bootstrap from will be chosen randomly. The default value is ``false``.
+- **noloadbalance**: ``true`` or ``false``. If set to ``true`` the node will return HTTP Status Code 503 for the ``GET /replica`` REST API health-check and therefore will be excluded from the load-balancing. Defaults to ``false``.
+- **replicatefrom**: The IP address/hostname of another replica. Used to support cascading replication.
+- **nosync**: ``true`` or ``false``. If set to ``true`` the node will never be selected as a synchronous replica.

docs/dynamic_configuration.rst

@@ -14,11 +14,11 @@ Patroni configuration is stored in the DCS (Distributed Configuration Store). Th
 
 - Local :ref:`configuration <settings>` (patroni.yml).
 	These options are defined in the configuration file and take precedence over dynamic configuration.
-	patroni.yml could be changed and reload in runtime (without restart of Patroni) by sending SIGHUP to the Patroni process or by performing ``POST /reload`` REST-API request.
+	patroni.yml could be changed and reloaded in runtime (without restart of Patroni) by sending SIGHUP to the Patroni process, performing ``POST /reload`` REST-API request or executing ``patronictl reload``.
 
-- Environment :ref:`configuration <environment>` .
+- Environment :ref:`configuration <environment>`.
 	It is possible to set/override some of the "Local" configuration parameters with environment variables.
-	Environment configuration is very useful when you are running in a dynamic environment and you don't know some of the parameters in advance (for example it's not possible to know you external IP address when you are running inside ``docker``).
+	Environment configuration is very useful when you are running in a dynamic environment and you don't know some of the parameters in advance (for example it's not possible to know your external IP address when you are running inside ``docker``).
 
 Some of the PostgreSQL parameters must hold the same values on the master and the replicas. For those, values set either in the local patroni configuration files or via the environment variables take no effect. To alter or set their values one must change the shared configuration in the DCS. Below is the actual list of such parameters together with the default values:
 
@@ -42,7 +42,7 @@ There are some other Postgres parameters controlled by Patroni:
 
 - listen_addresses - is set either from ``postgresql.listen`` or from ``PATRONI_POSTGRESQL_LISTEN`` environment variable
 - port - is set either from ``postgresql.listen`` or from ``PATRONI_POSTGRESQL_LISTEN`` environment variable
-- cluster_name - is set either from ``scope`` or from ``PATRRONI_SCOPE`` environment variable
+- cluster_name - is set either from ``scope`` or from ``PATRONI_SCOPE`` environment variable
 - hot_standby: on
 
 To be on the safe side parameters from the above lists are not written into ``postgresql.conf``, but passed as a list of arguments to the ``pg_ctl start`` which gives them the highest precedence, even above `ALTER SYSTEM <https://www.postgresql.org/docs/current/static/sql-altersystem.html>`__
@@ -76,153 +76,10 @@ Also, the following Patroni configuration options can be changed only dynamicall
 - loop_wait: 10
 - retry_timeouts: 10
 - maximum_lag_on_failover: 1048576
+- check_timeline: false
 - postgresql.use_slots: true
 
 Upon changing these options, Patroni will read the relevant section of the configuration stored in DCS and change its
 run-time values.
 
 Patroni nodes are dumping the state of the DCS options to disk upon for every change of the configuration into the file ``patroni.dynamic.json`` located in the Postgres data directory. Only the master is allowed to restore these options from the on-disk dump if these are completely absent from the DCS or if they are invalid.
-
-REST API
-========
-
-We provide a REST API endpoint for working with dynamic configuration.
-
-GET /config
------------
-Get current version of dynamic configuration.
-
-.. code-block:: bash
-
-	$ curl -s localhost:8008/config | jq .
-	{
-	  "ttl": 30,
-	  "loop_wait": 10,
-	  "retry_timeout": 10,
-	  "maximum_lag_on_failover": 1048576,
-	  "postgresql": {
-	    "use_slots": true,
-	    "use_pg_rewind": true,
-	    "parameters": {
-	      "hot_standby": "on",
-	      "wal_log_hints": "on",
-	      "wal_keep_segments": 8,
-	      "wal_level": "hot_standby",
-	      "max_wal_senders": 5,
-	      "max_replication_slots": 5,
-	      "max_connections": "100"
-	    }
-	  }
-	}
-
-PATCH /config
--------------
-Change existing configuration.
-
-.. code-block:: bash
-
-	$ curl -s -XPATCH -d \
-		'{"loop_wait":5,"ttl":20,"postgresql":{"parameters":{"max_connections":"101"}}}' \
-		http://localhost:8008/config | jq .
-	{
-	  "ttl": 20,
-	  "loop_wait": 5,
-	  "maximum_lag_on_failover": 1048576,
-	  "retry_timeout": 10,
-	  "postgresql": {
-	    "use_slots": true,
-	    "use_pg_rewind": true,
-	    "parameters": {
-	      "hot_standby": "on",
-	      "wal_log_hints": "on",
-	      "wal_keep_segments": 8,
-	      "wal_level": "hot_standby",
-	      "max_wal_senders": 5,
-	      "max_replication_slots": 5,
-	      "max_connections": "101"
-	    }
-	  }
-	}
-
-The above REST API call patches the existing configuration and returns the new configuration.
-
-Let's check that the node processed this configuration. First of all it should start printing log lines every 5 seconds (loop_wait=5). The change of "max_connections" requires a restart, so the "restart_pending" flag should be exposed:
-
-.. code-block:: bash
-
-	$ curl -s http://localhost:8008/patroni | jq .
-	{
-	  "pending_restart": true,
-	  "database_system_identifier": "6287881213849985952",
-	  "postmaster_start_time": "2016-06-13 13:13:05.211 CEST",
-	  "xlog": {
-	    "location": 2197818976
-	  },
-	  "patroni": {
-	    "scope": "batman",
-	    "version": "1.0"
-	  },
-	  "state": "running",
-	  "role": "master",
-	  "server_version": 90503
-	}
-
-Removing parameters:
-
-If you want to remove (reset) some setting just patch it with ``null``:
-
-.. code-block:: bash
-
-	$ curl -s -XPATCH -d \
-		'{"postgresql":{"parameters":{"max_connections":null}}}' \
-		http://localhost:8008/config | jq .
-	{
-	  "ttl": 20,
-	  "loop_wait": 5,
-	  "retry_timeout": 10,
-	  "maximum_lag_on_failover": 1048576,
-	  "postgresql": {
-	    "use_slots": true,
-	    "use_pg_rewind": true,
-	    "parameters": {
-	      "hot_standby": "on",
-	      "unix_socket_directories": ".",
-	      "wal_keep_segments": 8,
-	      "wal_level": "hot_standby",
-	      "wal_log_hints": "on",
-	      "max_wal_senders": 5,
-	      "max_replication_slots": 5
-	    }
-	  }
-	}
-
-Above call removes ``postgresql.parameters.max_connections`` from the dynamic configuration.
-
-PUT /config
------------
-
-It's also possible to perform the full rewrite of an existing dynamic configuration unconditionally:
-
-.. code-block:: bash
-
-	$ curl -s -XPUT -d \
-		'{"maximum_lag_on_failover":1048576,"retry_timeout":10,"postgresql":{"use_slots":true,"use_pg_rewind":true,"parameters":{"hot_standby":"on","wal_log_hints":"on","wal_keep_segments":8,"wal_level":"hot_standby","unix_socket_directories":".","max_wal_senders":5}},"loop_wait":3,"ttl":20}' \
-		http://localhost:8008/config | jq .
-	{
-	  "ttl": 20,
-	  "maximum_lag_on_failover": 1048576,
-	  "retry_timeout": 10,
-	  "postgresql": {
-	    "use_slots": true,
-	    "parameters": {
-	      "hot_standby": "on",
-	      "unix_socket_directories": ".",
-	      "wal_keep_segments": 8,
-	      "wal_level": "hot_standby",
-	      "wal_log_hints": "on",
-	      "max_wal_senders": 5
-	    },
-	    "use_pg_rewind": true
-	  },
-	  "loop_wait": 3
-	}

docs/existing_data.rst

@@ -0,0 +1,36 @@
+.. _existing_data:
+
+Convert a Standalone to a Patroni Cluster
+=========================================
+
+This section describes the process for converting a standalone PostgreSQL instance into a Patroni cluster.
+
+To deploy a Patroni cluster without using a pre-existing PostgreSQL instance, see :ref:`Running and Configuring <running_configuring>` instead.
+
+Procedure
+---------
+
+A Patroni cluster can be started with a data directory from a single-node PostgreSQL database. This is achieved by following closely these steps:
+
+1. Manually start PostgreSQL daemon
+2. Create Patroni superuser and replication users as defined in the :ref:`authentication <postgresql_settings>` section of the Patroni configuration. If this user is created in SQL, the following queries achieve this:
+
+.. code-block:: sql
+
+   CREATE USER $PATRONI_SUPERUSER_USERNAME WITH SUPERUSER ENCRYPTED PASSWORD '$PATRONI_SUPERUSER_PASSWORD';
+   CREATE USER $PATRONI_REPLICATION_USERNAME WITH REPLICATION ENCRYPTED PASSWORD '$PATRONI_REPLICATION_PASSWORD';
+
+3. Start Patroni (e.g. ``patroni /etc/patroni/patroni.yml``). It automatically detects that PostgreSQL daemon is already running but its configuration might be out-of-date.
+4. Ask Patroni to restart the node with ``patronictl restart cluster-name node-name``. This step is only required if PostgreSQL configuration is out-of-date.
+
+
+FAQ
+---
+
+- During Patroni startup, Patroni complains that it cannot bind to the PostgreSQL port.
+
+  You need to verify ``listen_addresses`` and ``port`` in ``postgresql.conf`` and ``postgresql.listen`` in ``patroni.yml``. Don't forget that ``pg_hba.conf`` should allow such access.
+
+- After asking Patroni to restart the node, PostgreSQL displays the error message ``could not open configuration file "/etc/postgresql/10/main/pg_hba.conf": No such file or directory``
+
+  It can mean various things depending on how you manage PostgreSQL configuration. If you specified `postgresql.config_dir`, Patroni generates the ``pg_hba.conf`` based on the settings in the :ref:`bootstrap <bootstrap_settings>` section only when it bootstraps a new cluster. In this scenario the ``PGDATA`` was not empty, therefore no bootstrap happened. This file must exist beforehand.

docs/index.rst

@@ -19,6 +19,7 @@ We call Patroni a "template" because it is far from being a one-size-fits-all or
 
    README
    dynamic_configuration
+   rest_api
    ENVIRONMENT
    SETTINGS
    replica_bootstrap

docs/kubernetes.rst

@@ -45,7 +45,7 @@ Examples
 - You can find the full-featured Docker image that can use Persistent Volumes in the
   `Spilo Project <https://github.com/zalando/spilo>`_.
 
-- There is also a `Helm chart <https://github.com/unguiculus/charts/tree/feature/patroni/incubator/patroni>`_
+- There is also a `Helm chart <https://github.com/kubernetes/charts/tree/master/incubator/patroni>`_
   to deploy the Spilo image configured with Patroni running using Kubernetes.
 
 - In order to run your database clusters at scale using Patroni and Spilo, take a look at the

docs/pause.rst

@@ -25,7 +25,7 @@ When Patroni runs in a paused mode, it does not change the state of PostgreSQL,
 
 - If there is no leader lock in the cluster, the running master acquires the lock. If there is more than one master node, then the first master to acquire the lock wins. If there are no masters altogether, Patroni does not try to promote any replicas. There is an exception in this rule: if there is no leader lock because the old master has demoted itself due to the manual promotion, then only the candidate node mentioned in the promotion request may take the leader lock. When the new leader lock is granted (i.e. after promoting a replica manually), Patroni makes sure the replicas that were streaming from the previous leader will switch to the new one.
 
-- When Postgres is stopped, Patroni does not try to start it. When Patroni is stopped, it does not to stop Postgres instance it is managing.
+- When Postgres is stopped, Patroni does not try to start it. When Patroni is stopped, it does not try to stop the Postgres instance it is managing.
 
 User guide
 ----------

docs/releases.rst

@@ -3,6 +3,785 @@
 Release notes
 =============
 
+Version 1.6.3
+-------------
+
+**Bugfixes**
+
+- Don't expose password when running ``pg_rewind`` (Alexander Kukushkin)
+
+  Bug was introduced in the `#1301 <https://github.com/zalando/patroni/pull/1301>`__
+
+- Apply connection parameters specified in the ``postgresql.authentication`` to ``pg_basebackup`` and custom replica creation methods (Alexander)
+
+  They were relying on url-like connection string and therefore parameters never applied.
+
+
+Version 1.6.2
+-------------
+
+**New features**
+
+- Implemented ``patroni --version`` (Igor Yanchenko)
+
+  It prints the current version of Patroni and exits.
+
+- Set the ``user-agent`` http header for all http requests (Alexander Kukushkin)
+
+  Patroni is communicating with Consul, Etcd, and Kubernetes API via the http protocol. Having a specifically crafted ``user-agent`` (example: ``Patroni/1.6.2 Python/3.6.8 Linux``) might be useful for debugging and monitoring.
+
+- Make it possible to configure log level for exception tracebacks (Igor)
+
+  If you set ``log.traceback_level=DEBUG`` the tracebacks will be visible only when ``log.level=DEBUG``. The default behavior remains the same.
+
+
+**Stability improvements**
+
+- Avoid importing all DCS modules when searching for the module required by the config file (Alexander)
+
+  There is no need to import modules for Etcd, Consul, and Kubernetes if we need only e.g. Zookeeper. It helps to reduce memory usage and solves the problem of having INFO messages ``Failed to import smth``.
+
+- Removed python ``requests`` module from explicit requirements (Alexander)
+
+  It wasn't used for anything critical, but causing a lot of problems when the new version of ``urllib3`` is released.
+
+- Improve handling of ``etcd.hosts`` written as a comma-separated string instead of YAML array (Igor)
+
+  Previously it was failing when written in format ``host1:port1, host2:port2`` (the space character after the comma).
+
+
+**Usability improvements**
+
+- Don't force users to choose members from an empty list in ``patronictl`` (Igor)
+
+  If the user provides a wrong cluster name, we will raise an exception rather than ask to choose a member from an empty list.
+
+- Make the error message more helpful if the REST API cannot bind (Igor)
+
+  For an inexperienced user it might be hard to figure out what is wrong from the Python stacktrace.
+
+
+**Bugfixes**
+
+- Fix calculation of ``wal_buffers`` (Alexander)
+
+  The base unit has been changed from 8 kB blocks to bytes in PostgreSQL 11.
+
+- Use ``passfile`` in ``primary_conninfo`` only on PostgreSQL 10+ (Alexander)
+
+  On older versions there is no guarantee that ``passfile`` will work, unless the latest version of ``libpq`` is installed.
+
+
+Version 1.6.1
+-------------
+
+**New features**
+
+- Added ``PATRONICTL_CONFIG_FILE`` environment variable (msvechla)
+
+  It allows configuring the ``--config-file`` argument for ``patronictl`` from the environment.
+
+- Implement ``patronictl history`` (Alexander Kukushkin)
+
+  It shows the history of failovers/switchovers.
+
+- Pass ``-c statement_timeout=0`` in ``PGOPTIONS`` when doing ``pg_rewind`` (Alexander Kukushkin)
+
+  It protects from the case when ``statement_timeout`` on the server is set to some small value and one of the statements executed by pg_rewind is canceled.
+
+- Allow lower values for PostgreSQL configuration (Soulou)
+
+  Patroni didn't allow some of the PostgreSQL configuration parameters be set smaller than some hardcoded values. Now the minimal allowed values are smaller, default values have not been changed.
+
+- Allow for certificate-based authentication (Jonathan S. Katz)
+
+  This feature enables certificate-based authentication for superuser, replication, rewind accounts and allows the user to specify the ``sslmode`` they wish to connect with.
+
+- Use the ``passfile`` in the ``primary_conninfo`` instead of password (Alexander Kukushkin)
+
+  It allows to avoid setting ``600`` permissions on postgresql.conf
+
+- Perform ``pg_ctl reload`` regardless of config changes (Alexander Kukushkin)
+
+  It is possible that some config files are not controlled by Patroni. When somebody is doing a reload via the REST API or by sending SIGHUP to the Patroni process, the usual expectation is that Postgres will also be reloaded. Previously it didn't happen when there were no changes in the ``postgresql`` section of Patroni config.
+
+- Compare all recovery parameters, not only ``primary_conninfo`` (Alexander Kukushkin)
+
+  Previously the ``check_recovery_conf()`` method was only checking whether ``primary_conninfo`` has changed, never taking into account all other recovery parameters.
+
+- Make it possible to apply some recovery parameters without restart (Alexander Kukushkin)
+
+  Starting from PostgreSQL 12 the following recovery parameters could be changed without restart: ``archive_cleanup_command``, ``promote_trigger_file``, ``recovery_end_command``, and ``recovery_min_apply_delay``. In future Postgres releases this list will be extended and Patroni will support it automatically.
+
+- Make it possible to change ``use_slots`` online (Alexander Kukushkin)
+
+  Previously it required restarting Patroni and removing slots manually.
+
+- Remove only ``PATRONI_`` prefixed environment variables when starting up Postgres (Cody Coons)
+
+  It will solve a lot of problems with running different Foreign Data Wrappers.
+
+
+**Stability improvements**
+
+- Use LIST + WATCH when working with K8s API (Alexander Kukushkin)
+
+  It allows to efficiently receive object changes (pods, endpoints/configmaps) and makes less stress on K8s master nodes.
+
+- Improve the workflow when PGDATA is not empty during bootstrap (Alexander Kukushkin)
+
+  According to the ``initdb`` source code it might consider a PGDATA empty when there are only ``lost+found`` and ``.dotfiles`` in it. Now Patroni does the same. If ``PGDATA`` happens to be non-empty, and at the same time not valid from the ``pg_controldata`` point of view, Patroni will complain and exit.
+
+- Avoid calling expensive ``os.listdir()`` on every HA loop (Alexander Kukushkin)
+
+  When the system is under IO stress, ``os.listdir()`` could take a few seconds (or even minutes) to execute, badly affecting the HA loop of Patroni. This could even cause the leader key to disappear from DCS due to the lack of updates. There is a better and less expensive way to check that the PGDATA is not empty. Now we check the presence of the ``global/pg_control`` file in the PGDATA.
+
+- Some improvements in logging infrastructure (Alexander Kukushkin)
+
+  Previously threre was a possibility to loose the last few log lines on shutdown because the logging thread was a ``daemon`` thread.
+
+- Use ``spawn`` multiprocessing start method on python 3.4+ (Maciej Kowalczyk)
+
+  It is a known `issue <https://bugs.python.org/issue6721>`__ in Python that threading and multiprocessing do not mix well. Switching from the default method ``fork`` to the ``spawn`` is a recommended workaround. Not doing so might result in the Postmaster starting process hanging and Patroni indefinitely reporting ``INFO: restarting after failure in progress``, while  Postgres is actually up and running.
+
+**Improvements in REST API**
+
+- Make it possible to check client certificates in the REST API (Alexander Kukushkin)
+
+  If the ``verify_client`` is set to ``required``, Patroni will check client certificates for all REST API calls. When it is set to ``optional``, client certificates are checked for all unsafe REST API endpoints.
+
+- Return the response code 503 for the ``GET /replica`` health check request if Postgres is not running (Alexander Anikin)
+
+  Postgres might spend significant time in recovery before it starts accepting client connections.
+
+- Implement ``/history`` and ``/cluster`` endpoints (Alexander Kukushkin)
+
+  The ``/history`` endpoint shows the content of the ``history`` key in DCS. The ``/cluster`` endpoint shows all cluster members and some service info like pending and scheduled restarts or switchovers.
+
+
+**Improvements in Etcd support**
+
+- Retry on Etcd RAFT internal error (Alexander Kukushkin)
+
+  When the Etcd node is being shut down, it sends ``response code=300, data='etcdserver: server stopped'``, which was causing Patroni to demote the primary.
+
+- Don't give up on Etcd request retry too early (Alexander Kukushkin)
+
+  When there were some network problems, Patroni was quickly exhausting the list of Etcd nodes and giving up without using the whole ``retry_timeout``, potentially resulting in demoting the primary.
+
+
+**Bugfixes**
+
+- Disable ``synchronous_commit`` when granting execute permissions to the ``pg_rewind`` user (kremius)
+
+  If the bootstrap is done with ``synchronous_mode_strict: true`` the `GRANT EXECUTE` statement was waiting indefinitely due to the non-synchronous nodes being available.
+
+- Fix memory leak on python 3.7 (Alexander Kukushkin)
+
+  Patroni is using ``ThreadingMixIn`` to process REST API requests and python 3.7 made threads spawn for every request non-daemon by default.
+
+- Fix race conditions in asynchronous actions (Alexander Kukushkin)
+
+  There was a chance that ``patronictl reinit --force`` could be overwritten by the attempt to recover stopped Postgres. This ended up in a situation when Patroni was trying to start Postgres while basebackup was running.
+
+- Fix race condition in ``postmaster_start_time()`` method (Alexander Kukushkin)
+
+  If the method is executed from the REST API thread, it requires a separate cursor object to be created.
+
+- Fix the problem of not promoting the sync standby that had a name contaning upper case letters (Alexander Kukushkin)
+
+  We converted the name to the lower case because Postgres was doing the same while comparing the ``application_name`` with the value in ``synchronous_standby_names``.
+
+- Kill all children along with the callback process before starting the new one (Alexander Kukushkin)
+
+  Not doing so makes it hard to implement callbacks in bash and eventually can lead to the situation when two callbacks are running at the same time. 
+
+- Fix 'start failed' issue (Alexander Kukushkin)
+
+  Under certain conditions the Postgres state might be set to 'start failed' despite Postgres being up and running.
+
+
+Version 1.6.0
+-------------
+
+This version adds compatibility with PostgreSQL 12, makes is possible to run pg_rewind without superuser on PostgreSQL 11 and newer, and enables IPv6 support.
+
+
+**New features**
+
+- Psycopg2 was removed from requirements and must be installed independently (Alexander Kukushkin)
+
+  Starting from 2.8.0 ``psycopg2`` was split into two different packages, ``psycopg2``, and ``psycopg2-binary``, which could be installed at the same time into the same place on the filesystem. In order to decrease dependency hell problem, we let a user choose how to install it. There are a few options available, please consult the :ref:`documentation <psycopg2_install_options>`.
+
+- Compatibility with PostgreSQL 12 (Alexander Kukushkin)
+
+  Starting from PostgreSQL 12 there is no ``recovery.conf`` anymore and all former recovery parameters are converted into `GUC <https://www.enterprisedb.com/blog/what-is-a-guc-variable>`_. In order to protect from ``ALTER SYSTEM SET primary_conninfo`` or similar, Patroni will parse ``postgresql.auto.conf`` and remove all standby and recovery parameters from there. Patroni config remains backward compatible. For example despite ``restore_command`` being a GUC, one can still specify it in the ``postgresql.recovery_conf.restore_command`` section and Patroni will write it into ``postgresql.conf`` for PostgreSQL 12.
+
+- Make it possible to use ``pg_rewind`` without superuser on PostgreSQL 11 and newer (Alexander Kukushkin)
+
+  If you want to use this feature please define ``username`` and ``password`` in the ``postgresql.authentication.rewind`` section of Patroni configuration file. For an already existing cluster you will have to create the user manually and ``GRANT EXECUTE`` permission on a few functions. You can find more details in the PostgreSQL `documentation <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__.
+
+- Do a smart comparison of actual and desired ``primary_conninfo`` values on replicas (Alexander Kukushkin)
+
+  It might help to avoid replica restart when you are converting an already existing primary-standby cluster to one managed by Patroni
+
+- IPv6 support (Alexander Kukushkin)
+
+  There were two major issues. Patroni REST API service was listening only on ``0.0.0.0`` and IPv6 IP addresses used in the ``api_url`` and ``conn_url`` were not properly quoted.
+
+- Kerberos support (Ajith Vilas, Alexander Kukushkin)
+
+  It makes possible using Kerberos authentication between Postgres nodes instead of defining passwords in Patroni configuration file
+
+- Manage ``pg_ident.conf`` (Alexander Kukushkin)
+
+  This functionality works similarly to ``pg_hba.conf``: if the ``postgresql.pg_ident`` is defined in the config file or DCS, Patroni will write its value to ``pg_ident.conf``, however, if ``postgresql.parameters.ident_file`` is defined, Patroni will assume that ``pg_ident`` is managed from outside and not update the file.
+
+
+**Improvements in REST API**
+
+- Added ``/health`` endpoint (Wilfried Roset)
+
+  It will return an HTTP status code only if PostgreSQL is running
+
+- Added ``/read-only`` and ``/read-write`` endpoints (Julien Riou)
+
+  The ``/read-only`` endpoint enables reads balanced across replicas and the primary. The ``/read-write`` endpoint is an alias for ``/primary``, ``/leader`` and ``/master``.
+
+- Use ``SSLContext`` to wrap the REST API socket (Julien Riou)
+
+  Usage of ``ssl.wrap_socket()`` is deprecated and was still allowing soon-to-be-deprecated protocols like TLS 1.1.
+
+
+**Logging improvements**
+
+- Two-step logging (Alexander Kukushkin)
+
+  All log messages are first written into the in-memory queue and later they are asynchronously flushed into the stderr or file from a separate thread. The maximum queue size is limited (configurable). If the limit is reached, Patroni will start losing logs, which is still better than blocking the HA loop.
+
+- Enable debug logging for GET/OPTIONS API calls together with latency (Jan Tomsa)
+
+  It will help with debugging of health-checks performed by HAProxy, Consul or other tooling that decides which node is the primary/replica.
+
+- Log exceptions caught in Retry (Daniel Kucera)
+
+  Log the final exception when either the number of attempts or the timeout were reached. It will hopefully help to debug some issues when communication to DCS fails.
+
+
+**Improvements in patronictl**
+
+- Enhance dialogues for scheduled switchover and restart (Rafia Sabih)
+
+  Previously dialogues did not take into account scheduled actions and therefore were misleading.
+
+- Check if config file exists (Wilfried Roset)
+
+  Be verbose about configuration file when the given filename does not exists, instead of ignoring silently (which can lead to misunderstanding).
+
+- Add fallback value for ``EDITOR`` (Wilfried Roset)
+
+  When the ``EDITOR`` environment variable was not defined, ``patronictl edit-config`` was failing with `PatroniCtlException`. The new strategy is to try ``editor`` and than ``vi``, which should be available on most systems.
+
+
+**Improvements in Consul support**
+
+- Allow to specify Consul consistency mode (Jan Tomsa)
+
+  You can read more about consistency mode `here <https://www.consul.io/api/features/consistency.html>`__.
+
+- Reload Consul config on SIGHUP (Cameron Daniel, Alexander Kukushkin)
+
+  It is especially useful when somebody is changing the value of ``token``.
+
+
+**Bugfixes**
+
+- Fix corner case in switchover/failover (Sharoon Thomas)
+
+  The variable ``scheduled_at`` may be undefined if REST API is not accessible and we are using DCS as a fallback.
+
+- Open trust to localhost in ``pg_hba.conf`` during custom bootstrap (Alexander Kukushkin)
+
+  Previously it was open only to unix_socket, which was causing a lot of errors: ``FATAL:  no pg_hba.conf entry for replication connection from host "127.0.0.1", user "replicator"``
+
+- Consider synchronous node as healthy even when the former leader is ahead (Alexander Kukushkin)
+
+  If the primary loses access to the DCS, it restarts Postgres in read-only, but it might happen that other nodes can still access the old primary via the REST API. Such a situation was causing the synchronous standby not to promote because the old primary was reporting WAL position ahead of the synchronous standby.
+
+- Standby cluster bugfixes (Alexander Kukushkin)
+
+  Make it possible to bootstrap a replica in a standby cluster when the standby_leader is not accessible and a few other minor fixes.
+
+
+Version 1.5.6
+-------------
+
+**New features**
+
+- Support work with etcd cluster via set of proxies (Alexander Kukushkin)
+
+  It might happen that etcd cluster is not accessible directly but via set of proxies. In this case Patroni will not perform etcd topology discovery but just round-robin via proxy hosts. Behavior is controlled by `etcd.use_proxies`.
+
+- Changed callbacks behavior when role on the node is changed (Alexander)
+
+  If the role was changed from `master` or `standby_leader` to `replica` or from `replica` to `standby_leader`, `on_restart` callback will not be called anymore in favor of `on_role_change` callback.
+
+- Change the way how we start postgres (Alexander)
+
+  Use `multiprocessing.Process` instead of executing itself and `multiprocessing.Pipe` to transmit the postmaster pid to the Patroni process. Before that we were using pipes, what was leaving postmaster process with stdin closed.
+
+**Bug fixes**
+
+- Fix role returned by REST API for the standby leader (Alexander)
+
+  It was incorrectly returning `replica` instead of `standby_leader`
+
+- Wait for callback end if it could not be killed (Julien Tachoires)
+
+  Patroni doesn't have enough privileges to terminate the callback script running under `sudo` what was cancelling the new callback. If the running script could not be killed, Patroni will wait until it finishes and then run the next callback.
+
+- Reduce lock time taken by dcs.get_cluster method (Alexander)
+
+  Due to the lock being held DCS slowness was affecting the REST API health checks causing false positives.
+
+- Improve cleaning of PGDATA when `pg_wal`/`pg_xlog` is a symlink (Julien)
+
+  In this case Patroni will explicitly remove files from the target directory.
+
+- Remove unnecessary usage of os.path.relpath (Ants Aasma)
+
+  It depends on being able to resolve the working directory, what will fail if Patroni is started in a directory that is later unlinked from the filesystem.
+
+- Do not enforce ssl version when communicating with Etcd (Alexander)
+
+  For some unknown reason python3-etcd on debian and ubuntu are not based on the latest version of the package and therefore it enforces TLSv1 which is not supported by Etcd v3. We solved this problem on Patroni side.
+
+Version 1.5.5
+-------------
+
+This version introduces the possibility of automatic reinit of the former master, improves patronictl list output and fixes a number of bugs.
+
+**New features**
+
+- Add support of `PATRONI_ETCD_PROTOCOL`, `PATRONI_ETCD_USERNAME` and `PATRONI_ETCD_PASSWORD` environment variables (Étienne M)
+
+  Before it was possible to configure them only in the config file or as a part of `PATRONI_ETCD_URL`, which is not always convenient.
+
+- Make it possible to automatically reinit the former master (Alexander Kukushkin)
+
+  If the pg_rewind is disabled or can't be used, the former master could fail to start as a new replica due to diverged timelines. In this case, the only way to fix it is wiping the data directory and reinitializing. This behavior could be changed by setting `postgresql.remove_data_directory_on_diverged_timelines`. When it is set, Patroni will wipe the data directory and reinitialize the former master automatically.
+
+- Show information about timelines in patronictl list (Alexander)
+
+  It helps to detect stale replicas. In addition to that, `Host` will include ':{port}' if the port value isn't default or there is more than one member running on the same host.
+
+- Create a headless service associated with the $SCOPE-config endpoint (Alexander)
+
+  The "config" endpoint keeps information about the cluster-wide Patroni and Postgres configuration, history file, and last but the most important, it holds the `initialize` key. When the Kubernetes master node is restarted or upgraded, it removes endpoints without services. The headless service will prevent it from being removed.
+
+**Bug fixes**
+
+- Adjust the read timeout for the leader watch blocking query (Alexander)
+
+  According to the Consul documentation, the actual response timeout is increased by a small random amount of additional wait time added to the supplied maximum wait time to spread out the wake up time of any concurrent requests. It adds up to `wait / 16` additional time to the maximum duration. In our case we are adding `wait / 15` or 1 second depending on what is bigger.
+
+- Always use replication=1 when connecting via replication protocol to the postgres (Alexander)
+
+  Starting from Postgres 10 the line in the pg_hba.conf with database=replication doesn't accept connections with the parameter replication=database.
+
+- Don't write primary_conninfo into recovery.conf for wal-only standby cluster (Alexander)
+
+  Despite not having neither `host` nor `port` defined in the `standby_cluster` config, Patroni was putting the `primary_conninfo` into the `recovery.conf`, which is useless and generating a lot of errors.
+
+
+Version 1.5.4
+-------------
+
+This version implements flexible logging and fixes a number of bugs.
+
+**New features**
+
+- Improvements in logging infrastructure (Alexander Kukushkin, Lucas Capistrant, Alexander Anikin)
+
+  Logging configuration could be configured not only from environment variables but also from Patroni config file. It makes it possible to change logging configuration in runtime by updating config and doing reload or sending SIGHUP to the Patroni process. By default Patroni writes logs to stderr, but now it becomes possible to write logs directly into the file and rotate when it reaches a certain size. In addition to that added support of custom dateformat and the possibility to fine-tune log level for each python module.
+
+- Make it possible to take into account the current timeline during leader elections (Alexander Kukushkin)
+
+  It could happen that the node is considering itself as a healthiest one although it is currently not on the latest known timeline. In some cases we want to avoid promoting of such node, which could be achieved by setting `check_timeline` parameter to `true` (default behavior remains unchanged).
+
+- Relaxed requirements on superuser credentials
+
+  Libpq allows opening connections without explicitly specifying neither username nor password. Depending on situation it relies either on pgpass file or trust authentication method in pg_hba.conf. Since pg_rewind is also using libpq, it will work the same way.
+
+- Implemented possibility to configure Consul Service registration and check interval via environment variables (Alexander Kukushkin)
+
+  Registration of service in Consul was added in the 1.5.0, but so far it was only possible to turn it on via patroni.yaml.
+
+**Stability Improvements**
+
+- Set archive_mode to off during the custom bootstrap (Alexander Kukushkin)
+
+  We want to avoid archiving wals and history files until the cluster is fully functional.  It really helps if the custom bootstrap involves pg_upgrade.
+
+- Apply five seconds backoff when loading global config on start (Alexander Kukushkin)
+
+  It helps to avoid hammering DCS when Patroni just starting up.
+
+- Reduce amount of error messages generated on shutdown (Alexander Kukushkin)
+
+  They were harmless but rather annoying and sometimes scary.
+
+- Explicitly secure rw perms for recovery.conf at creation time (Lucas)
+
+  We don't want anybody except patroni/postgres user reading this file, because it contains replication user and password.
+
+- Redirect HTTPServer exceptions to logger (Julien Riou)
+
+  By default, such exceptions were logged on standard output messing with regular logs.
+
+**Bug fixes**
+
+- Removed stderr pipe to stdout on pg_ctl process (Cody Coons)
+
+  Inheriting stderr from the main Patroni process allows all Postgres logs to be seen along with all patroni logs. This is very useful in a container environment as Patroni and Postgres logs may be consumed using standard tools (docker logs, kubectl, etc). In addition to that, this change fixes a bug with Patroni not being able to catch postmaster pid when postgres writing some warnings into stderr.
+
+- Set Consul service check deregister timeout in Go time format (Pavel Kirillov)
+
+  Without explicitly mentioned time unit registration was failing.
+
+- Relax checks of standby_cluster cluster configuration (Dmitry Dolgov, Alexander Kukushkin)
+
+  It was accepting only strings as valid values and therefore it was not possible to specify the port as integer and create_replica_methods as a list.
+
+Version 1.5.3
+-------------
+
+Compatibility and bugfix release.
+
+- Improve stability when running with python3 against zookeeper (Alexander Kukushkin)
+
+  Change of `loop_wait` was causing Patroni to disconnect from zookeeper and never reconnect back.
+
+- Fix broken compatibility with postgres 9.3 (Alexander)
+
+  When opening a replication connection we should specify replication=1, beacuse 9.3 does not understand replication='database'
+
+- Make sure we refresh Consul session at least once per HA loop and improve handling of consul sessions exceptions (Alexander)
+
+  Restart of local consul agent invalidates all sessions related to the node. Not calling session refresh on time and not doing proper handling of session errors was causing demote of the primary.
+
+Version 1.5.2
+-------------
+
+Compatibility and bugfix release.
+
+- Compatibility with kazoo-2.6.0 (Alexander Kukushkin)
+
+  In order to make sure that requests are performed with an appropriate timeout, Patroni redefines create_connection method from python-kazoo module. The last release of kazoo slightly changed the way how create_connection method is called.
+
+- Fix Patroni crash when Consul cluster loses the leader (Alexander)
+
+  The crash was happening due to incorrect implementation of touch_member method, it should return boolean and not raise any exceptions.
+
+Version 1.5.1
+-------------
+
+This version implements support of permanent replication slots, adds support of pgBackRest and fixes number of bugs.
+
+**New features**
+
+- Permanent replication slots (Alexander Kukushkin)
+
+  Permanent replication slots are preserved on failover/switchover, that is, Patroni on the new primary will create configured replication slots right after doing promote. Slots could be configured with the help of `patronictl edit-config`. The initial configuration could be also done in the :ref:`bootstrap.dcs <settings>`.
+
+- Add pgbackrest support (Yogesh Sharma)
+
+  pgBackrest can restore in existing $PGDATA folder, this allows speedy restore as files which have not changed since last backup are skipped, to support this feature new parameter `keep_data` has been introduced. See :ref:`replica creation method <custom_replica_creation>` section for additional examples.
+
+**Bug fixes**
+
+- A few bugfixes in the "standby cluster" workflow (Alexander)
+
+  Please see https://github.com/zalando/patroni/pull/823 for more details.
+
+- Fix REST API health check when cluster management is paused and DCS is not accessible (Alexander)
+
+  Regression was introduced in https://github.com/zalando/patroni/commit/90cf930036a9d5249265af15d2b787ec7517cf57
+
+Version 1.5.0
+-------------
+
+This version enables Patroni HA cluster to operate in a standby mode, introduces experimental support for running on Windows, and provides a new configuration parameter to register PostgreSQL service in Consul.
+
+**New features**
+
+- Standby cluster (Dmitry Dolgov)
+
+  One or more Patroni nodes can form a standby cluster that runs alongside the primary one (i.e. in another datacenter) and consists of standby nodes that replicate from the master in the primary cluster. All PostgreSQL nodes in the standby cluster are replicas; one of those replicas elects itself to replicate directly from the remote master, while the others replicate from it in a cascading manner. More detailed description of this feature and some configuration examples can be found at :ref:`here <standby_cluster>`.
+
+- Register Services in Consul (Pavel Kirillov, Alexander Kukushkin)
+
+  If `register_service` parameter in the consul :ref:`configuration <consul_settings>` is enabled, the node will register a service with the name `scope` and the tag `master`, `replica` or `standby-leader`.
+
+- Experimental Windows support (Pavel Golub)
+
+  From now on it is possible to run Patroni on Windows, although Windows support is brand-new and hasn't received as much real-world testing as its Linux counterpart. We welcome your feedback!
+
+**Improvements in patronictl**
+
+- Add patronictl -k/--insecure flag and support for restapi cert (Wilfried Roset)
+
+  In the past if the REST API was protected by the self-signed certificates `patronictl` would fail to verify them. There was no way to  disable that verification. It is now possible to configure `patronictl` to skip the certificate verification altogether or provide CA and client certificates in the :ref:`ctl: <patronictl_settings>` section of configuration.
+
+- Exclude members with nofailover tag from patronictl switchover/failover output (Alexander Anikin)
+
+  Previously, those members were incorrectly proposed as candidates when performing interactive switchover or failover via patronictl.
+
+**Stability improvements**
+
+- Avoid parsing non-key-value output lines of pg_controldata (Alexander Anikin)
+
+  Under certain circuimstances pg_controldata outputs lines without a colon character. That would trigger an error in Patroni code that parsed pg_controldata output, hiding the actual problem; often such lines are emitted in a warning shown by pg_controldata before the regular output, i.e. when the binary major version does not match the one of the PostgreSQL data directory.
+
+- Add member name to the error message during the leader election (Jan Mussler)
+
+  During the leader election, Patroni connects to all known members of the cluster and requests their status. Such status is written to the Patroni log and includes the name of the member. Previously, if the member was not accessible, the error message did not indicate its name, containing only the URL.
+
+- Immediately reserve the WAL position upon creation of the replication slot (Alexander Kukushkin)
+
+  Starting from 9.6, `pg_create_physical_replication_slot` function provides an additional boolean parameter `immediately_reserve`. When it is set to `false`, which is also the default, the slot doesn't reserve the WAL position until it receives the first client connection, potentially losing some segments required by the client in a time window between the slot creation and the intiial client connection.
+
+- Fix bug in strict synchronous replication (Alexander Kukushkin)
+
+  When running with `synchronous_mode_strict: true`, in some cases Patroni puts `*` into the `synchronous_standby_names`, changing the sync state for most of the replication connections to `potential`. Previously, Patroni couldn't pick a synchronous candidate under such curcuimstances, as it only considered those with the state `async`.
+
+
+Version 1.4.6
+-------------
+
+**Bug fixes and stability improvements**
+
+This release fixes a critical issue with Patroni API /master endpoint returning 200 for the non-master node. This is a
+reporting issue, no actual split-brain, but under certain circumstances clients might be directed to the read-only node.
+
+- Reset is_leader status on demote (Alexander Kukushkin, Oleksii Kliukin)
+
+  Make sure demoted cluster member stops responding with code 200 on the /master API call.
+
+- Add new "cluster_unlocked" field to the API output (Dmitry Dolgov)
+
+  This field indicates whether the cluster has the master running. It can be used when it is not possible to query any
+  other node but one of the replicas.
+
+Version 1.4.5
+-------------
+
+**New features**
+
+- Improve logging when applying new postgres configuration (Don Seiler)
+
+  Patroni logs changed parameter names and values.
+
+- Python 3.7 compatibility (Christoph Berg)
+
+  async is a reserved keyword in python3.7
+
+- Set state to "stopped" in the DCS when a member is shut down (Tony Sorrentino)
+
+  This shows the member state as "stopped" in "patronictl list" command.
+
+- Improve the message logged when stale postmaster.pid matches a running process (Ants Aasma)
+
+  The previous one was beyond confusing.
+
+- Implement patronictl reload functionality (Don Seiler)
+
+  Before that it was only possible to reload configuration by either calling REST API or by sending SIGHUP signal to the Patroni process.
+
+- Take and apply some parameters from controldata when starting as a replica (Alexander Kukushkin)
+
+  The value of `max_connections` and some other parameters set in the global configuration may be lower than the one actually used by the primary; when this happens, the replica cannot start and should be fixed manually. Patroni takes care of that now by reading and applying the value from  `pg_controldata`, starting postgres and setting `pending_restart` flag.
+
+- If set, use LD_LIBRARY_PATH when starting postgres (Chris Fraser)
+
+  When starting up Postgres, Patroni was passing along PATH, LC_ALL and LANG env vars if they are set. Now it is doing the same with LD_LIBRARY_PATH. It should help if somebody installed PostgreSQL to non-standard place.
+
+- Rename create_replica_method to create_replica_methods (Dmitry Dolgov)
+
+  To make it clear that it's actually an array. The old name is still supported for backward compatibility.
+
+**Bug fixes and stability improvements**
+
+- Fix condition for the replica start due to pg_rewind in paused state (Oleksii  Kliukin)
+
+  Avoid starting the replica that had already executed pg_rewind before.
+
+- Respond 200 to the master health-check only if update_lock has been successful (Alexander)
+
+  Prevent Patroni from reporting itself a master on the former (demoted) master if DCS is partitioned.
+
+- Fix compatibility with the new consul module (Alexander)
+
+  Starting from v1.1.0 python-consul changed internal API and started using `list` instead of `dict` to pass query parameters.
+
+- Catch exceptions from Patroni REST API thread during shutdown (Alexander)
+
+  Those uncaught exceptions kept PostgreSQL running at shutdown.
+
+- Do crash recovery only when Postgres runs as the master (Alexander)
+
+  Require `pg_controldata` to report  'in production' or 'shutting down' or 'in crash recovery'. In all other cases no crash recovery is necessary.
+
+- Improve handling of configuration errors (Henning Jacobs, Alexander)
+
+  It is possible to change a lot of parameters in runtime (including `restapi.listen`) by updating Patroni config file and sending SIGHUP to Patroni process. This fix eliminates obscure exceptions from the 'restapi' thread when some of the parameters receive invalid values.
+
+
+Version 1.4.4
+-------------
+
+**Stability improvements**
+
+- Fix race condition in poll_failover_result (Alexander Kukushkin)
+
+  It didn't affect directly neither failover nor switchover, but in some rare cases it was reporting success too early, when the former leader released the lock, producing a 'Failed over to "None"' instead of 'Failed over to "desired-node"' message.
+
+- Treat Postgres parameter names as case insensitive (Alexander)
+
+  Most of the Postgres parameters have snake_case names, but there are three exceptions from this rule: DateStyle, IntervalStyle and TimeZone. Postgres accepts those parameters when written in a different case (e.g. timezone = 'some/tzn'); however, Patroni was unable to find case-insensitive matches of those parameter names in pg_settings and ignored such parameters as a result.
+
+- Abort start if attaching to running postgres and cluster not initialized (Alexander)
+
+  Patroni can attach itself to an already running Postgres instance. It is imperative to start running Patroni on the master node before getting to the replicas.
+
+- Fix behavior of patronictl scaffold (Alexander)
+
+  Pass dict object to touch_member instead of json encoded string, DCS implementation will take care of encoding it.
+
+- Don't demote master if failed to update leader key in pause (Alexander)
+
+  During maintenance a DCS may start failing write requests while continuing to responds to read ones. In that case, Patroni used to put the Postgres master node to a read-only mode after failing to update the leader lock in DCS.
+
+- Sync replication slots when Patroni notices a new postmaster process (Alexander)
+
+  If Postgres has been restarted, Patroni has to make sure that list of replication slots matches its expectations.
+
+- Verify sysid and sync replication slots after coming out of pause (Alexander)
+
+  During the `maintenance` mode it may happen that data directory was completely rewritten and therefore we have to make sure that `Database system identifier` still belongs to our cluster and replication slots are in sync with Patroni expectations.
+
+- Fix a possible failure to start not running Postgres on a data directory with postmaster lock file present (Alexander)
+
+  Detect reuse of PID from the postmaster lock file. More likely to hit such problem if you run Patroni and Postgres in the docker container.
+
+- Improve protection of DCS being accidentally wiped (Alexander)
+
+  Patroni has a lot of logic in place to prevent failover in such case; it can also restore all keys back; however, until this change an accidental removal of /config key was switching off pause mode for 1 cycle of HA loop.
+
+- Do not exit when encountering invalid system ID (Oleksii Kliukin)
+
+  Do not exit when the cluster system ID is empty or the one that doesn't pass the validation check. In that case, the cluster most likely needs a reinit; mention it in the result message. Avoid terminating Patroni, as otherwise reinit cannot happen.
+
+**Compatibility with Kubernetes 1.10+**
+
+- Added check for empty subsets (Cody Coons)
+
+  Kubernetes 1.10.0+ started returning `Endpoints.subsets` set to `None` instead of `[]`.
+
+**Bootstrap improvements**
+
+- Make deleting recovery.conf optional (Brad Nicholson)
+
+  If `bootstrap.<custom_bootstrap_method_name>.keep_existing_recovery_conf` is defined and set to ``True``, Patroni will not remove the existing ``recovery.conf`` file. This is useful when bootstrapping from a backup with tools like pgBackRest that generate the appropriate `recovery.conf` for you.
+
+- Allow options to the basebackup built-in method (Oleksii)
+
+  It is now possible to supply options to the built-in basebackup method by defining the `basebackup` section in the configuration, similar to how those are defined for custom replica creation methods. The difference is in the format accepted by the `basebackup` section: since pg_basebackup accepts both `--key=value` and `--key` options, the contents of the section could be either a dictionary of key-value pairs, or a list of either one-element dictionaries or just keys (for the options that don't accept values). See :ref:`replica creation method <custom_replica_creation>` section for additional examples.
+
+
+Version 1.4.3
+-------------
+
+**Improvements in logging**
+
+- Make log level configurable from environment variables (Andy Newton, Keyvan Hedayati)
+
+  `PATRONI_LOGLEVEL` - sets the general logging level
+  `PATRONI_REQUESTS_LOGLEVEL` - sets the logging level for all HTTP requests e.g. Kubernetes API calls
+  See `the docs for Python logging <https://docs.python.org/3.6/library/logging.html#levels>` to get the names of possible log levels
+
+**Stability improvements and bug fixes**
+
+- Don't rediscover etcd cluster topology when watch timed out (Alexander Kukushkin)
+
+  If we have only one host in etcd configuration and exactly this host is not accessible, Patroni was starting discovery of cluster topology and never succeeding. Instead it should just switch to the next available node.
+
+- Write content of bootstrap.pg_hba into a pg_hba.conf after custom bootstrap (Alexander)
+
+  Now it behaves similarly to the usual bootstrap with `initdb`
+
+- Single user mode was waiting for user input and never finish (Alexander)
+
+  Regression was introduced in https://github.com/zalando/patroni/pull/576
+
+
+Version 1.4.2
+-------------
+
+**Improvements in patronictl**
+
+- Rename scheduled failover to scheduled switchover (Alexander Kukushkin)
+
+  Failover and switchover functions were separated in version 1.4, but `patronictl list` was still reporting `Scheduled failover` instead of `Scheduled switchover`.
+
+- Show information about pending restarts (Alexander)
+
+  In order to apply some configuration changes sometimes it is necessary to restart postgres. Patroni was already giving a hint about that in the REST API and when writing node status into DCS, but there were no easy way to display it.
+
+- Make show-config to work with cluster_name from config file (Alexander)
+
+  It works similar to the `patronictl edit-config`
+
+**Stability improvements**
+
+- Avoid calling pg_controldata during bootstrap (Alexander)
+
+  During initdb or custom bootstrap there is a time window when pgdata is not empty but pg_controldata has not been written yet. In such case pg_controldata call was failing with error messages.
+
+- Handle exceptions raised from psutil (Alexander)
+
+  cmdline is read and parsed every time when `cmdline()` method is called. It could happen that the process being examined
+  has already disappeared, in that case `NoSuchProcess` is raised.
+
+**Kubernetes support improvements**
+
+- Don't swallow errors from k8s API (Alexander)
+
+  A call to Kubernetes API could fail for a different number of reasons. In some cases such call should be retried, in some other cases we should log the error message and the exception stack trace. The change here will help debug Kubernetes permission issues.
+
+- Update Kubernetes example Dockerfile to install Patroni from the master branch (Maciej Szulik)
+
+  Before that it was using `feature/k8s`, which became outdated.
+
+- Add proper RBAC to run patroni on k8s (Maciej)
+
+  Add the Service account that is assigned to the pods of the cluster, the role that holds only the necessary permissions, and the rolebinding that connects the Service account and the Role.
+
+
+Version 1.4.1
+-------------
+
+**Fixes in patronictl**
+
+- Don't show current leader in suggested list of members to failover to. (Alexander Kukushkin)
+
+  patronictl failover could still work when there is leader in the cluster and it should be excluded from the list of member where it is possible to failover to.
+
+- Make patronictl switchover compatible with the old Patroni api (Alexander)
+
+  In case if POST /switchover REST API call has failed with status code 501 it will do it once again, but to /failover endpoint.
+
+
 Version 1.4
 -----------
 
@@ -25,8 +804,8 @@ In addition to using Endpoints, Patroni supports ConfigMaps. You can find more i
 
 - Minimize the amount of SELECT's issued by Patroni on every loop of HA cylce (Alexander Kukushkin)
 
-  On every iteration of HA loop Patroni needs to know recovery status and absolute wal position. From now on Patroni will run only single SELECT to get this information instead of two on the replica and three on the master. 
-  
+  On every iteration of HA loop Patroni needs to know recovery status and absolute wal position. From now on Patroni will run only single SELECT to get this information instead of two on the replica and three on the master.
+
 - Remove leader key on shutdown only when we have the lock (Ants)
 
   Unconditional removal was generating unnecessary and missleading exceptions.
@@ -36,7 +815,7 @@ In addition to using Endpoints, Patroni supports ConfigMaps. You can find more i
 - Add version command to patronictl (Ants)
 
   It will show the version of installed Patroni and versions of running Patroni instances (if the cluster name is specified).
-  
+
 - Make optional specifying cluster_name argument for some of patronictl commands (Alexander, Ants)
 
   It will work if patronictl is using usual Patroni configuration file with the ``scope`` defined.
@@ -44,11 +823,11 @@ In addition to using Endpoints, Patroni supports ConfigMaps. You can find more i
 - Show information about scheduled switchover and maintenance mode (Alexander)
 
   Before that it was possible to get this information only from Patroni logs or directly from DCS.
-  
+
 - Improve ``patronictl reinit`` (Alexander)
 
   Sometimes ``patronictl reinit`` refused to proceed when Patroni was busy with other actions, namely trying to start postgres. `patronictl` didn't provide any commands to cancel such long running actions and the only (dangerous) workarond was removing a data directory manually. The new implementation of `reinit` forcefully cancells other long-running actions before proceeding with reinit.
-  
+
 - Implement ``--wait`` flag in ``patronictl pause`` and ``patronictl resume`` (Alexander)
 
   It will make ``patronictl`` wait until the requested action is acknowledged by all nodes in the cluster.
@@ -95,7 +874,7 @@ Version 1.3.6
   After a crash that doesn't clean up postmaster.pid there could be a new process with the same pid, resulting in a false positive for is_running(), which will lead to all kinds of bad behavior.
 
 - Shutdown postgresql before bootstrap when we lost data directory (ainlolcat)
-  
+
   When data directory on the master is forcefully removed, postgres process can still stay alive for some time and prevent the replica created in place of that former master from starting or replicating.
   The fix makes Patroni cache the postmaster pid and its start time and let it terminate the old postmaster in case it is still running after the corresponding data directory has been removed.
 
@@ -165,7 +944,7 @@ Version 1.3.4
 - Pass the consul token as a header (Andrew Colin Kissa)
 
   Headers are now the prefered way to pass the token to the consul `API <https://www.consul.io/api/index.html#authentication>`__.
-  
+
 
 - Advanced configuration for Consul (Alexander Kukushkin)
 

docs/replica_bootstrap.rst

@@ -3,7 +3,7 @@ Replica imaging and bootstrap
 
 Patroni allows customizing creation of a new replica. It also supports defining what happens when the new empty cluster
 is being bootstrapped. The distinction between two is well defined: Patroni creates replicas only if the ``initialize``
-key is present in Etcd for the cluster. If there is no ``initialize`` key - Patroni calls bootstrap exclusively on the
+key is present in DCS for the cluster. If there is no ``initialize`` key - Patroni calls bootstrap exclusively on the
 first node that takes the initialize key lock.
 
 .. _custom_bootstrap:
@@ -23,6 +23,7 @@ arguments to them, i.e. the name of the cluster and the path to the data directo
         method: <custom_bootstrap_method_name>
         <custom_bootstrap_method_name>:
             command: <path_to_custom_bootstrap_script> [param1 [, ...]]
+            keep_existing_recovery_conf: False
             recovery_conf:
                 recovery_target_action: promote
                 recovery_target_timeline: latest
@@ -47,6 +48,9 @@ If a ``recovery_conf`` block is defined in the same section as the custom bootst
 ``recovery.conf`` before starting the newly bootstrapped instance. Typically, such recovery.conf should contain at least
 one of the ``recovery_target_*`` parameters, together with the ``recovery_target_timeline`` set to ``promote``.
 
+If ``keep_existing_recovery_conf`` is defined and set to ``True``, Patroni will not remove the existing ``recovery.conf`` file if it exists.
+This is useful when bootstrapping from a backup with tools like pgBackRest that generate the appropriate ``recovery.conf`` for you.
+
  .. note:: Bootstrap methods are neither chained, nor fallen-back to the default one in case the primary one fails
 
 
@@ -64,7 +68,20 @@ scripts to clone a new replica. Those are configured in the ``postgresql`` confi
 .. code:: YAML
 
     postgresql:
-        create_replica_method:
+        create_replica_methods:
+            - <method name>
+        <method name>:
+            command: <command name>
+            keep_data: True
+            no_params: True
+            no_master: 1
+
+example: wal_e
+
+.. code:: YAML
+
+    postgresql:
+        create_replica_methods:
             - wal_e
             - basebackup
         wal_e:
@@ -72,13 +89,29 @@ scripts to clone a new replica. Those are configured in the ``postgresql`` confi
             no_master: 1
             envdir: {{WALE_ENV_DIR}}
             use_iam: 1
+        basebackup:
+            max-rate: '100M'
+
+example: pgbackrest
+
+.. code:: YAML
+
+    postgresql:
+        create_replica_methods:
+            - pgbackrest
+            - basebackup
+        pgbackrest:
+            command: /usr/bin/pgbackrest --stanza=<scope> --delta restore
+            keep_data: True
+            no_params: True
+        basebackup:
+            max-rate: '100M'
 
 
-The ``create_replica_method`` defines available replica creation methods and the order of executing them. Patroni will
-stop on the first one that returns 0. The basebackup is the built-in method and doesn't require any configuration. The
-rest of the methods should define a separate section in the configuration file, listing the command to execute and any
-custom parameters that should be passed to that command. All parameters will be passed in a ``--name=value`` format.
-Besides user-defined parameters, Patroni supplies a couple of cluster-specific ones:
+The ``create_replica_methods`` defines available replica creation methods and the order of executing them. Patroni will
+stop on the first one that returns 0. Each method should define a separate section in the configuration file, listing the command
+to execute and any custom parameters that should be passed to that command. All parameters will be passed in a
+``--name=value`` format. Besides user-defined parameters, Patroni supplies a couple of cluster-specific ones:
 
 --scope
     Which cluster this replica belongs to
@@ -94,4 +127,81 @@ A special ``no_master`` parameter, if defined, allows Patroni to call the replic
 running master or replicas. In that case, an empty string will be passed in a connection string. This is useful for
 restoring the formerly running cluster from the binary backup.
 
+A special ``keep_data`` parameter, if defined, will instruct Patroni to  not clean PGDATA folder before calling restore.
+
+A special ``no_params`` parameter, if defined, restricts passing parameters to custom command.
+
+A ``basebackup`` method is a special case: it will be used if
+``create_replica_methods`` is empty, although it is possible
+to list it explicitly among the ``create_replica_methods`` methods. This method initializes a new replica with the
+``pg_basebackup``, the base backup is taken from the master unless there are replicas with ``clonefrom`` tag, in which case one
+of such replicas will be used as the origin for pg_basebackup. It works without any configuration; however, it is
+possible to specify a ``basebackup`` configuration section. Same rules as with the other method configuration apply,
+namely, only long (with --) options should be specified there. Not all parameters make sense, if you override a connection
+string or provide an option to created tar-ed or compressed base backups, patroni won't be able to make a replica out
+of it. There is no validation performed on the names or values of the parameters passed to the ``basebackup`` section.
+You can specify basebackup parameters as either a map (key-value pairs) or a list of elements, where each element
+could be either a key-value pair or a single key (for options that does not receive any values, for instance, ``--verbose``).
+Consider those 2 examples:
+
+.. code:: YAML
+
+    postgresql:
+        basebackup:
+            max-rate: '100M'
+            checkpoint: 'fast'
+
+and
+
+.. code:: YAML
+
+    postgresql:
+        basebackup:
+            - verbose
+            - max-rate: '100M'
+
 If all replica creation methods fail, Patroni will try again all methods in order during the next event loop cycle.
+
+.. _standby_cluster:
+
+Standby cluster
+---------------
+
+Another available option is to run a "standby cluster", that contains only of
+standby nodes replicating from some remote master. This type of clusters has:
+
+* "standby leader", that behaves pretty much like a regular cluster leader,
+  except it replicates from a remote master.
+
+* cascade replicas, that are replicating from standby leader.
+
+Standby leader holds and updates a leader lock in DCS. If the leader lock
+expires, cascade replicas will perform an election to choose another leader
+from the standbys.
+
+For the sake of flexibility, you can specify methods of creating a replica and
+recovery WAL records when a cluster is in the "standby mode" by providing
+`create_replica_methods` key in `standby_cluster` section. It is distinct from
+creating replicas, when cluster is detached and functions as a normal cluster,
+which is controlled by `create_replica_methods` in `postgresql` section. Both
+"standby" and "normal" `create_replica_methods` reference  keys in `postgresql`
+section.
+
+To configure such cluster you need to specify the section ``standby_cluster``
+in a patroni configuration:
+
+.. code:: YAML
+
+    bootstrap:
+        dcs:
+            standby_cluster:
+                host: 1.2.3.4
+                port: 5432
+                primary_slot_name: patroni
+                create_replica_methods:
+                - basebackup
+
+Note, that these options will be applied only once during cluster bootstrap,
+and the only way to change them afterwards is through DCS.
+
+If you use replication slots on the standby cluster, you must also create the corresponding replication slot on the primary cluster.  It will not be done automatically by the standby cluster implementation.  You can use Patroni's permanent replication slots feature on the primary cluster to maintain a replication slot with the same name as ``primary_slot_name``, or its default value if ``primary_slot_name`` is not provided.

docs/replication_modes.rst

@@ -9,9 +9,11 @@ Patroni uses PostgreSQL streaming replication. For more information about stream
 Asynchronous mode durability
 ----------------------------
 
-In asynchronous mode the cluster is allowed to lose some committed transactions to ensure availability. When master server fails or becomes unavailable for any other reason Patroni will automatically promote a sufficiently healthy standby to master. Any transactions that have not been replicated to that standby remain in a "forked timeline" on the master, and are effectively unrecoverable [1]_.
+In asynchronous mode the cluster is allowed to lose some committed transactions to ensure availability. When the primary server fails or becomes unavailable for any other reason Patroni will automatically promote a sufficiently healthy standby to primary. Any transactions that have not been replicated to that standby remain in a "forked timeline" on the primary, and are effectively unrecoverable [1]_.
 
-The amount of transactions that can be lost is controlled via ``maximum_lag_on_failover`` parameter. Because master transaction log position is not sampled in real time, in reality the amount of lost data on failover is worst case bounded by  ``maximum_lag_on_failover`` bytes of transaction log plus the amount that is written in the last ``ttl`` seconds (``loop_wait``/2 seconds in the average case). However typical steady state replication delay is well under a second.
+The amount of transactions that can be lost is controlled via ``maximum_lag_on_failover`` parameter. Because the primary transaction log position is not sampled in real time, in reality the amount of lost data on failover is worst case bounded by  ``maximum_lag_on_failover`` bytes of transaction log plus the amount that is written in the last ``ttl`` seconds (``loop_wait``/2 seconds in the average case). However typical steady state replication delay is well under a second.
+
+By default, when running leader elections, Patroni does not take into account the current timeline of replicas, what in some cases could be undesirable behavior. You can prevent the node not having the same timeline as a former master become the new leader by changing the value of ``check_timeline`` parameter to ``true``.
 
 PostgreSQL synchronous replication
 ----------------------------------
@@ -20,7 +22,7 @@ You can use Postgres's `synchronous replication <http://www.postgresql.org/docs/
 
 In hosted datacenter environments (like AWS, Rackspace, or any network you do not control), synchronous replication significantly increases the variability of write performance. If followers become inaccessible from the leader, the leader effectively becomes read-only.
 
-To enable a simple synchronous replication test, add the follow lines to the ``parameters`` section of your YAML configuration files:
+To enable a simple synchronous replication test, add the following lines to the ``parameters`` section of your YAML configuration files:
 
 .. code:: YAML
 
@@ -29,18 +31,27 @@ To enable a simple synchronous replication test, add the follow lines to the ``p
 
 When using PostgreSQL synchronous replication, use at least three Postgres data nodes to ensure write availability if one host fails.
 
-Using PostgreSQL synchronous replication does not guarantee zero lost transactions under all circumstances. When master and standby that is currently acting as synchronous fail simultaneously a third node that might not contain all transactions will be promoted.
+Using PostgreSQL synchronous replication does not guarantee zero lost transactions under all circumstances. When the primary and the secondary that is currently acting as a synchronous replica fail simultaneously a third node that might not contain all transactions will be promoted.
 
 .. _synchronous_mode:
 
 Synchronous mode
 ----------------
 
-For use cases where losing committed transactions is not permissible you can turn on Patronis ``synchronous_mode``. When ``synchronous_mode`` is turned on Patroni will not promote a standby unless it is certain that the standby contains all transactions that may have returned a successful commit status to client [2]_. This means that the system may be unavailable for writes even though some servers are available. System administrators can still use manual failover commmands to promote a standby even if it results in transaction loss.
+For use cases where losing committed transactions is not permissible you can turn on Patroni's ``synchronous_mode``. When ``synchronous_mode`` is turned on Patroni will not promote a standby unless it is certain that the standby contains all transactions that may have returned a successful commit status to client [2]_. This means that the system may be unavailable for writes even though some servers are available. System administrators can still use manual failover commands to promote a standby even if it results in transaction loss.
 
-Turning on ``synchronous_mode`` does not guarantee multi node durability of commits under all circumstances. When no suitable standby is available, master server will still accept writes, but does not guarantee their replication. When the master fails in this mode no standby will be promote.  When the host that used to be master comes back it will get promoted automatically, unless system administrator performed a manual failover. This behavior makes synchronous mode usable with 2 node clusters.
+Turning on ``synchronous_mode`` does not guarantee multi node durability of commits under all circumstances. When no suitable standby is available, primary server will still accept writes, but does not guarantee their replication. When the primary fails in this mode no standby will be promoted. When the host that used to be the primary comes back it will get promoted automatically, unless system administrator performed a manual failover. This behavior makes synchronous mode usable with 2 node clusters.
 
-When ``synchronous_mode`` is on and a standby crashes, commits will block until next iteration of Patroni runs and switches master to standalone mode (worst case delay for writes ``ttl`` seconds, average case ``loop_wait``/2 seconds). Manually shutting down or restarting a standby will not cause a commit service interruption. Standby will signal the master to release itself from synchronous standby duties before PostgreSQL shutdown is initiated.
+When ``synchronous_mode`` is on and a standby crashes, commits will block until next iteration of Patroni runs and switches the primary to standalone mode (worst case delay for writes ``ttl`` seconds, average case ``loop_wait``/2 seconds). Manually shutting down or restarting a standby will not cause a commit service interruption. Standby will signal the primary to release itself from synchronous standby duties before PostgreSQL shutdown is initiated.
+
+When it is absolutely necessary to guarantee that each write is stored durably
+on at least two nodes, enable ``synchronous_mode_strict`` in addition to the
+``synchronous_mode``. This parameter prevents Patroni from switching off the
+synchronous replication on the primary when no synchronous standby candidates
+are available. As a downside, the primary is not be available for writes
+(unless the Postgres transaction explicitly turns of ``synchronous_mode``),
+blocking all client write requests until at least one synchronous replica comes
+up.
 
 You can ensure that a standby never becomes the synchronous standby by setting ``nosync`` tag to true. This is recommended to set for standbys that are behind slow network connections and would cause performance degradation when becoming a synchronous standby.
 
@@ -50,7 +61,7 @@ Synchronous mode can be switched on and off via Patroni REST interface. See :ref
 Synchronous mode implementation
 -------------------------------
 
-When in synchronous mode Patroni maintains synchronization state in the DCS, containing the latest master and current synchronous standby. This state is updated with strict ordering constraints to ensure the following invariants:
+When in synchronous mode Patroni maintains synchronization state in the DCS, containing the latest primary and current synchronous standby. This state is updated with strict ordering constraints to ensure the following invariants:
 
 - A node must be marked as the latest leader whenever it can accept write transactions. Patroni crashing or PostgreSQL not shutting down can cause violations of this invariant.
 
@@ -60,9 +71,9 @@ When in synchronous mode Patroni maintains synchronization state in the DCS, con
 
 Patroni will only ever assign one standby to ``synchronous_standby_names`` because with multiple candidates it is not possible to know which node was acting as synchronous during the failure.
 
-On each HA loop iteration Patroni re-evaluates synchronous standby choice. If the current synchronous standby is connected and has not requested its synchronous status to be removed it remains picked. Otherwise the cluster member avaiable for sync that is furthest ahead in replication is picked.
+On each HA loop iteration Patroni re-evaluates synchronous standby choice. If the current synchronous standby is connected and has not requested its synchronous status to be removed it remains picked. Otherwise the cluster member available for sync that is furthest ahead in replication is picked.
 
 
-.. [1] The data is still there, but recovering it requires a manual recovery effort by data recovery specialists. When Patroni is allowed to rewind with ``use_pg_rewind`` the forked timeline will be automatically erased to rejoin the failed master with the cluster.
+.. [1] The data is still there, but recovering it requires a manual recovery effort by data recovery specialists. When Patroni is allowed to rewind with ``use_pg_rewind`` the forked timeline will be automatically erased to rejoin the failed primary with the cluster.
 
 .. [2] Clients can change the behavior per transaction using PostgreSQL's ``synchronous_commit`` setting. Transactions with ``synchronous_commit`` values of ``off`` and ``local`` may be lost on fail over, but will not be blocked by replication delays.

docs/rest_api.rst

@@ -0,0 +1,336 @@
+.. _rest_api:
+
+Patroni REST API
+================
+
+Patroni has a rich REST API, which is used by Patroni itself during the leader race, by the ``patronictl`` tool in order to perform failovers/switchovers/reinitialize/restarts/reloads, by HAProxy or any other kind of load balancer to perform HTTP health checks, and of course could also be used for monitoring. Below you will find the list of Patroni REST API endpoints.
+
+Health check endpoints
+----------------------
+For all health check ``GET`` requests Patroni returns a JSON document with the status of the node, along with the HTTP status code. If you don't want or don't need the JSON document, you might consider using the ``OPTIONS`` method instead of ``GET``.
+
+- The following requests to Patroni REST API will return HTTP status code **200** only when the Patroni node is running as the leader:
+
+  - ``GET /``
+  - ``GET /master``
+  - ``GET /leader``
+  - ``GET /primary``
+  - ``GET /read-write``
+
+- ``GET /replica``: replica health check endpoint. It returns HTTP status code **200** only when the Patroni node is in the state ``running``, the role is ``replica`` and ``noloadbalance`` tag is not set.
+
+- ``GET /read-only``: like the above endpoint, but also includes the primary.
+
+- ``GET /standby-leader``: returns HTTP status code **200** only when the Patroni node is running as the leader in a :ref:`standby cluster <standby_cluster>`.
+
+- ``GET /synchronous`` or ``GET /sync``: returns HTTP status code **200** only when the Patroni node is running as a synchronous standby.
+
+- ``GET /asynchronous`` or ``GET /async``: returns HTTP status code **200** only when the Patroni node is running as an asynchronous standby.
+
+- ``GET /health``: returns HTTP status code **200** only when PostgreSQL is up and running.
+
+Monitoring endpoint
+-------------------
+
+The ``GET /patroni`` is used by Patroni during the leader race. It also could be used by your monitoring system. The JSON document produced by this endpoint has the same structure as the JSON produced by the health check endpoints.
+
+.. code-block:: bash
+
+    $ curl -s http://localhost:8008/patroni | jq .
+    {
+      "state": "running",
+      "postmaster_start_time": "2019-09-24 09:22:32.555 CEST",
+      "role": "master",
+      "server_version": 110005,
+      "cluster_unlocked": false,
+      "xlog": {
+        "location": 25624640
+      },
+      "timeline": 3,
+      "database_system_identifier": "6739877027151648096",
+      "patroni": {
+        "version": "1.6.0",
+        "scope": "batman"
+      }
+    }
+
+Cluster status endpoints
+------------------------
+
+- The ``GET /cluster`` endpoint generates a JSON document describing the current cluster topology and state:
+
+.. code-block:: bash
+
+    $ curl -s http://localhost:8008/cluster | jq .
+    {
+      "members": [
+        {
+          "name": "postgresql0",
+          "host": "127.0.0.1",
+          "port": 5432,
+          "role": "leader",
+          "state": "running",
+          "api_url": "http://127.0.0.1:8008/patroni",
+          "timeline": 5,
+          "tags": {
+            "clonefrom": true
+          }
+        },
+        {
+          "name": "postgresql1",
+          "host": "127.0.0.1",
+          "port": 5433,
+          "role": "replica",
+          "state": "running",
+          "api_url": "http://127.0.0.1:8009/patroni",
+          "timeline": 5,
+          "tags": {
+            "clonefrom": true
+          },
+          "lag": 0
+        }
+      ],
+      "scheduled_switchover": {
+        "at": "2019-09-24T10:36:00+02:00",
+        "from": "postgresql0"
+      }
+    }
+
+
+- The ``GET /history`` endpoint provides a view on the history of cluster switchovers/failovers. The format is very similar to the content of history files in the ``pg_wal`` directory. The only difference is the timestamp field showing when the new timeline was created.
+
+.. code-block:: bash
+
+    $ curl -s http://localhost:8008/history | jq .
+    [
+      [
+        1,
+        25623960,
+        "no recovery target specified",
+        "2019-09-23T16:57:57+02:00"
+      ],
+      [
+        2,
+        25624344,
+        "no recovery target specified",
+        "2019-09-24T09:22:33+02:00"
+      ],
+      [
+        3,
+        25624752,
+        "no recovery target specified",
+        "2019-09-24T09:26:15+02:00"
+      ],
+      [
+        4,
+        50331856,
+        "no recovery target specified",
+        "2019-09-24T09:35:52+02:00"
+      ]
+    ]
+
+
+Config endpoint
+---------------
+
+``GET /config``: Get the current version of the dynamic configuration:
+
+.. code-block:: bash
+
+	$ curl -s localhost:8008/config | jq .
+	{
+	  "ttl": 30,
+	  "loop_wait": 10,
+	  "retry_timeout": 10,
+	  "maximum_lag_on_failover": 1048576,
+	  "postgresql": {
+	    "use_slots": true,
+	    "use_pg_rewind": true,
+	    "parameters": {
+	      "hot_standby": "on",
+	      "wal_log_hints": "on",
+	      "wal_keep_segments": 8,
+	      "wal_level": "hot_standby",
+	      "max_wal_senders": 5,
+	      "max_replication_slots": 5,
+	      "max_connections": "100"
+	    }
+	  }
+	}
+
+
+``PATCH /config``: Change the existing configuration.
+
+.. code-block:: bash
+
+	$ curl -s -XPATCH -d \
+		'{"loop_wait":5,"ttl":20,"postgresql":{"parameters":{"max_connections":"101"}}}' \
+		http://localhost:8008/config | jq .
+	{
+	  "ttl": 20,
+	  "loop_wait": 5,
+	  "maximum_lag_on_failover": 1048576,
+	  "retry_timeout": 10,
+	  "postgresql": {
+	    "use_slots": true,
+	    "use_pg_rewind": true,
+	    "parameters": {
+	      "hot_standby": "on",
+	      "wal_log_hints": "on",
+	      "wal_keep_segments": 8,
+	      "wal_level": "hot_standby",
+	      "max_wal_senders": 5,
+	      "max_replication_slots": 5,
+	      "max_connections": "101"
+	    }
+	  }
+	}
+
+The above REST API call patches the existing configuration and returns the new configuration.
+
+Let's check that the node processed this configuration. First of all it should start printing log lines every 5 seconds (loop_wait=5). The change of "max_connections" requires a restart, so the "pending_restart" flag should be exposed:
+
+.. code-block:: bash
+
+	$ curl -s http://localhost:8008/patroni | jq .
+	{
+	  "pending_restart": true,
+	  "database_system_identifier": "6287881213849985952",
+	  "postmaster_start_time": "2016-06-13 13:13:05.211 CEST",
+	  "xlog": {
+	    "location": 2197818976
+	  },
+	  "patroni": {
+	    "scope": "batman",
+	    "version": "1.0"
+	  },
+	  "state": "running",
+	  "role": "master",
+	  "server_version": 90503
+	}
+
+Removing parameters:
+
+If you want to remove (reset) some setting just patch it with ``null``:
+
+.. code-block:: bash
+
+	$ curl -s -XPATCH -d \
+		'{"postgresql":{"parameters":{"max_connections":null}}}' \
+		http://localhost:8008/config | jq .
+	{
+	  "ttl": 20,
+	  "loop_wait": 5,
+	  "retry_timeout": 10,
+	  "maximum_lag_on_failover": 1048576,
+	  "postgresql": {
+	    "use_slots": true,
+	    "use_pg_rewind": true,
+	    "parameters": {
+	      "hot_standby": "on",
+	      "unix_socket_directories": ".",
+	      "wal_keep_segments": 8,
+	      "wal_level": "hot_standby",
+	      "wal_log_hints": "on",
+	      "max_wal_senders": 5,
+	      "max_replication_slots": 5
+	    }
+	  }
+	}
+
+The above call removes ``postgresql.parameters.max_connections`` from the dynamic configuration.
+
+``PUT /config``: It's also possible to perform the full rewrite of an existing dynamic configuration unconditionally:
+
+.. code-block:: bash
+
+	$ curl -s -XPUT -d \
+		'{"maximum_lag_on_failover":1048576,"retry_timeout":10,"postgresql":{"use_slots":true,"use_pg_rewind":true,"parameters":{"hot_standby":"on","wal_log_hints":"on","wal_keep_segments":8,"wal_level":"hot_standby","unix_socket_directories":".","max_wal_senders":5}},"loop_wait":3,"ttl":20}' \
+		http://localhost:8008/config | jq .
+	{
+	  "ttl": 20,
+	  "maximum_lag_on_failover": 1048576,
+	  "retry_timeout": 10,
+	  "postgresql": {
+	    "use_slots": true,
+	    "parameters": {
+	      "hot_standby": "on",
+	      "unix_socket_directories": ".",
+	      "wal_keep_segments": 8,
+	      "wal_level": "hot_standby",
+	      "wal_log_hints": "on",
+	      "max_wal_senders": 5
+	    },
+	    "use_pg_rewind": true
+	  },
+	  "loop_wait": 3
+	}
+
+
+Switchover and failover endpoints
+---------------------------------
+
+``POST /switchover`` or ``POST /failover``. These endpoints are very similar to each other. There are a couple of minor differences though:
+
+1. The failover endpoint allows to perform a manual failover when there are no healthy nodes, but at the same time it will not allow you to schedule a switchover.
+
+2. The switchover endpoint is the opposite. It works only when the cluster is healthy (there is a leader) and allows to schedule a switchover at a given time.
+
+
+In the JSON body of the ``POST`` request you must specify at least the ``leader`` or ``candidate`` fields and optionally the ``scheduled_at`` field if you want to schedule a switchover at a specific time.
+
+
+Example: perform a failover to the specific node:
+
+.. code-block:: bash
+
+    $ curl -s http://localhost:8009/failover -XPOST -d '{"candidate":"postgresql1"}'
+    Successfully failed over to "postgresql1"
+
+
+Example: schedule a switchover from the leader to any other healthy replica in the cluster at a specific time:
+
+.. code-block:: bash
+
+    $ curl -s http://localhost:8008/switchover -XPOST -d \
+	    '{"leader":"postgresql0","scheduled_at":"2019-09-24T12:00+00"}'
+    Switchover scheduled
+
+
+Depending on the situation the request might finish with a different HTTP status code and body. The status code **200** is returned when the switchover or failover successfully completed. If the switchover was successfully scheduled, Patroni will return HTTP status code **202**. In case something went wrong, the error status code (one of **400**, **412** or **503**) will be returned with some details in the response body. For more information please check the source code of ``patroni/api.py:do_POST_failover()`` method.
+
+The switchover and failover endpoints are used by ``patronictl switchover`` and ``patronictl failover``, respectively.
+
+
+Restart endpoint
+----------------
+
+- ``POST /restart``: You can restart Postgres on the specific node by performing the ``POST /restart`` call. In the JSON body of ``POST`` request it is possible to optionally specify some restart conditions:
+
+  - **restart_pending**: boolean, if set to ``true`` Patroni will restart PostgreSQL only when restart is pending in order to apply some changes in the PostgreSQL config.
+  - **role**: perform restart only if the current role of the node matches with the role from the POST request.
+  - **postgres_version**: perform restart only if the current version of postgres is smaller than specified in the POST request.
+  - **timeout**: how long we should wait before PostgreSQL starts accepting connections. Overrides ``master_start_timeout``.
+  - **schedule**: timestamp with time zone, schedule the restart somewhere in the future.
+
+- ``DELETE /restart``: delete the scheduled restart
+
+``POST /restart`` and ``DELETE /restart`` endpoints are used by ``patronictl restart`` and ``patronictl flush`` respectively.
+
+
+Reload endpoint
+---------------
+
+The ``POST /reload`` call will order Patroni to re-read and apply the configuration file. This is the equivalent of sending the ``SIGHUP`` signal to the Patroni process. In case you changed some of the Postgres parameters which require a restart (like **shared_buffers**), you still have to explicitly do the restart of Postgres by either calling the ``POST /restart`` endpoint or with the help of ``patronictl restart``.
+
+The reload endpoint is used by ``patronictl reload``.
+
+
+Reinitialize endpoint
+---------------------
+
+``POST /reinitialize``: reinitialize the PostgreSQL data directory on the specified node. It is allowed to be executed only on replicas. Once called, it will remove the data directory and start ``pg_basebackup`` or some alternative :ref:`replica creation method <custom_replica_creation>`.
+
+The call might fail if Patroni is in a loop trying to recover (restart) a failed Postgres. In order to overcome this problem one can specify ``{"force":true}`` in the request body.
+
+The reinitialize endpoint is used by ``patronictl reinit``.

docs/watchdog.rst

@@ -9,7 +9,7 @@ Having multiple PostgreSQL servers running as master can result in transactions
 
 - Shutting down PostgreSQL is too slow.
 
-- Patroni does not get to run due to high load on the system, th VM being paused by the hypervisor, or other infrastructure issues.
+- Patroni does not get to run due to high load on the system, the VM being paused by the hypervisor, or other infrastructure issues.
 
 To guarantee correct behavior under these conditions Patroni supports watchdog devices. Watchdog devices are software or hardware mechanisms that will reset the whole system when they do not get a keepalive heartbeat within a specified timeframe. This adds an additional layer of fail safe in case usual Patroni split-brain protection mechanisms fail.
 

extras/README.md

@@ -1,11 +1,11 @@
 ### confd
 
-`confd` directory contains haproxy template files for the [confd](https://github.com/kelseyhightower/confd) -- lightweight configuration management tool
+`confd` directory contains haproxy and pgbouncer template files for the [confd](https://github.com/kelseyhightower/confd) -- lightweight configuration management tool
 You need to copy content of `confd` directory into /etcd/confd and run confd service:
 ```bash
-$ confd -prefix=/service/$PATRONI_SCOPE -backend etcd -node $PATRONI_ETCD_HOST -interval=10
+$ confd -prefix=/service/$PATRONI_SCOPE -backend etcd -node $PATRONI_ETCD_URL -interval=10
 ```
-It will periodically update haproxy.cfg with the actual list of Patroni nodes from `etcd` and "reload" haproxy when it is necessary.
+It will periodically update haproxy.cfg and pgbouncer.ini with the actual list of Patroni nodes from `etcd` and "reload" haproxy and pgbouncer.ini when it is necessary.
 
 
 ### startup-scripts

extras/confd/conf.d/pgbouncer.toml

@@ -0,0 +1,12 @@
+[template]
+prefix = "/service/batman"
+owner = "postgres"
+mode = "0644"
+src = "pgbouncer.tmpl"
+dest = "/etc/pgbouncer/pgbouncer.ini"
+
+reload_cmd = "systemctl reload pgbouncer"
+
+keys = [
+    "/members/","/leader"
+]

extras/confd/templates/haproxy.tmpl

@@ -10,19 +10,23 @@ defaults
 	timeout server 30m
 	timeout check 5s
 
-frontend master_postgresql
+listen stats
+	mode http
+	bind *:7000
+	stats enable
+	stats uri /
+
+listen master
 	bind *:5000
-	default_backend backend_master
-
-frontend replicas_postgresql
-	bind *:5001
-	default_backend backend_replicas
-
-backend backend_master
 	option httpchk OPTIONS /master
+	http-check expect status 200
+	default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
 {{range gets "/members/*"}}	server {{base .Key}} {{$data := json .Value}}{{base (replace (index (split $data.conn_url "/") 2) "@" "/" -1)}} maxconn 100 check port {{index (split (index (split $data.api_url "/") 2) ":") 1}}
 {{end}}
-backend backend_replicas
+listen replicas
+	bind *:5001
 	option httpchk OPTIONS /replica
+	http-check expect status 200
+	default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
 {{range gets "/members/*"}}	server {{base .Key}} {{$data := json .Value}}{{base (replace (index (split $data.conn_url "/") 2) "@" "/" -1)}} maxconn 100 check port {{index (split (index (split $data.api_url "/") 2) ":") 1}}
 {{end}}

extras/confd/templates/pgbouncer.tmpl

@@ -0,0 +1,17 @@
+[databases]
+{{with get "/leader"}}{{$leader := .Value}}{{$leadkey := printf "/members/%s" $leader}}{{with get $leadkey}}{{$data := json .Value}}{{$hostport := base (replace (index (split $data.conn_url "/") 2) "@" "/" -1)}}{{ $host := base (index (split $hostport ":") 0)}}{{ $port := base (index (split $hostport ":") 1)}}* = host={{ $host }} port={{ $port }} pool_size=10{{end}}{{end}}
+
+[pgbouncer]
+logfile = /var/log/postgresql/pgbouncer.log
+pidfile = /var/run/postgresql/pgbouncer.pid
+listen_addr = *
+listen_port = 6432
+unix_socket_dir = /var/run/postgresql
+auth_type = trust
+auth_file = /etc/pgbouncer/userlist.txt
+auth_hba_file = /etc/pgbouncer/pg_hba.txt
+admin_users = pgbouncer
+stats_users = pgbouncer
+pool_mode = session
+max_client_conn = 100
+default_pool_size = 20

extras/startup-scripts/patroni.service

@@ -11,12 +11,26 @@ Type=simple
 User=postgres
 Group=postgres
 
+# Read in configuration file if it exists, otherwise proceed
+EnvironmentFile=-/etc/patroni_env.conf
+
+WorkingDirectory=~
+
 # Where to send early-startup messages from the server
 # This is normally controlled by the global default set by systemd
-# StandardOutput=syslog
+#StandardOutput=syslog
 
+# Pre-commands to start watchdog device
+# Uncomment if watchdog is part of your patroni setup
+#ExecStartPre=-/usr/bin/sudo /sbin/modprobe softdog
+#ExecStartPre=-/usr/bin/sudo /bin/chown postgres /dev/watchdog
+
+# Start the patroni process
 ExecStart=/bin/patroni /etc/patroni.yml
 
+# Send HUP to reload from patroni.yml
+ExecReload=/bin/kill -s HUP $MAINPID
+
 # only kill the patroni process, not it's children, so it will gracefully stop postgres
 KillMode=process
 

features/basic_replication.feature

@@ -4,6 +4,7 @@ Feature: basic replication
   Scenario: check replication of a single table
     Given I start postgres0
     Then postgres0 is a leader after 10 seconds
+    And there is a non empty initialize key in DCS after 15 seconds
     When I issue a PATCH request to http://127.0.0.1:8008/config with {"ttl": 20, "loop_wait": 2, "synchronous_mode": true}
     Then I receive a response code 200
     When I start postgres1
@@ -14,11 +15,13 @@ Feature: basic replication
     Then table foo is present on postgres2 after 20 seconds
 
   Scenario: check restart of sync replica
-    Given I run patronictl.py restart batman postgres2 --force
-    And "sync" key in DCS has sync_standby=postgres1 after 2 seconds
-    And I run patronictl.py restart batman postgres1 --force
-    Then I receive a response returncode 0
-    And "sync" key in DCS has sync_standby=postgres2 after 10 seconds
+    Given I shut down postgres2
+    Then "sync" key in DCS has sync_standby=postgres1 after 5 seconds
+    When I start postgres2
+    And I shut down postgres1
+    Then "sync" key in DCS has sync_standby=postgres2 after 10 seconds
+    When I start postgres1
+    And "members/postgres1" key in DCS has state=running after 10 seconds
     And I sleep for 2 seconds
     When I issue a GET request to http://127.0.0.1:8010/sync
     Then I receive a response code 200
@@ -30,13 +33,15 @@ Feature: basic replication
     Then I receive a response returncode 0
     When I sleep for 2 seconds
     And I shut down postgres0
-    And I run patronictl.py resume batman 
+    And I run patronictl.py resume batman
     Then I receive a response returncode 0
     And postgres2 role is the primary after 24 seconds
+    And Response on GET http://127.0.0.1:8010/history contains recovery after 10 seconds
     When I issue a PATCH request to http://127.0.0.1:8010/config with {"synchronous_mode": null, "master_start_timeout": 0}
     Then I receive a response code 200
     When I add the table bar to postgres2
     Then table bar is present on postgres1 after 20 seconds
+    And Response on GET http://127.0.0.1:8010/config contains master_start_timeout after 10 seconds
 
   Scenario: check immediate failover when master_start_timeout=0
     Given I kill postmaster on postgres2

features/callback.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+[[ "$3" == "master" ]] || exit
+
+PGPASSWORD=zalando psql -h localhost -U postgres -p $1 -w -tAc "SELECT slot_name FROM pg_replication_slots WHERE slot_type = 'logical'" >> data/postgres0/label

features/custom_bootstrap.feature

@@ -13,5 +13,5 @@ Scenario: make a backup and do a restore into a new cluster
     Given I add the table bar to postgres1
     And I do a backup of postgres1
     When I start postgres2 in a cluster batman2 from backup
-    Then postgres2 is a leader of batman2 after 10 seconds
+    Then postgres2 is a leader of batman2 after 30 seconds
     And table bar is present on postgres2 after 10 seconds

features/environment.py

@@ -1,17 +1,13 @@
 import abc
-import consul
 import datetime
-import etcd
-import kazoo.client
-import kazoo.exceptions
 import os
-import psutil
 import psycopg2
 import json
 import shutil
 import signal
 import six
 import subprocess
+import sys
 import tempfile
 import threading
 import time
@@ -84,7 +80,7 @@ class AbstractController(object):
 
 
 class PatroniController(AbstractController):
-    __PORT = 5440
+    __PORT = 5360
     PATRONI_CONFIG = '{}.yml'
     """ starts and stops individual patronis"""
 
@@ -110,19 +106,31 @@ class PatroniController(AbstractController):
         with open(os.path.join(self._data_dir, 'label'), 'w') as f:
             f.write(content)
 
-    def read_label(self):
+    def read_label(self, label):
         try:
-            with open(os.path.join(self._data_dir, 'label'), 'r') as f:
+            with open(os.path.join(self._data_dir, label), 'r') as f:
                 return f.read().strip()
         except IOError:
             return None
 
-    def add_tag_to_config(self, tag, value):
+    @staticmethod
+    def recursive_update(dst, src):
+        for k, v in src.items():
+            if k in dst and isinstance(dst[k], dict):
+                PatroniController.recursive_update(dst[k], v)
+            else:
+                dst[k] = v
+
+    def update_config(self, custom_config):
         with open(self._config) as r:
             config = yaml.safe_load(r)
-            config['tags']['tag'] = value
+            self.recursive_update(config, custom_config)
             with open(self._config, 'w') as w:
                 yaml.safe_dump(config, w, default_flow_style=False)
+        self._scope = config.get('scope', 'batman')
+
+    def add_tag_to_config(self, tag, value):
+        self.update_config({'tags': {tag: value}})
 
     def _start(self):
         if self.watchdog:
@@ -130,7 +138,8 @@ class PatroniController(AbstractController):
         if isinstance(self._context.dcs_ctl, KubernetesController):
             self._context.dcs_ctl.create_pod(self._name[8:], self._scope)
             os.environ['PATRONI_KUBERNETES_POD_IP'] = '10.0.0.' + self._name[-1]
-        return subprocess.Popen(['coverage', 'run', '--source=patroni', '-p', 'patroni.py', self._config],
+        return subprocess.Popen([sys.executable, '-m', 'coverage', 'run',
+                                '--source=patroni', '-p', 'patroni.py', self._config],
                                 stdout=self._log, stderr=subprocess.STDOUT, cwd=self._work_directory)
 
     def stop(self, kill=False, timeout=15, postgres=False):
@@ -174,13 +183,10 @@ class PatroniController(AbstractController):
                 config['bootstrap']['initdb'].extend([{'auth': 'md5'}, {'auth-host': 'md5'}])
 
         if custom_config is not None:
-            def recursive_update(dst, src):
-                for k, v in src.items():
-                    if k in dst and isinstance(dst[k], dict):
-                        recursive_update(dst[k], v)
-                    else:
-                        dst[k] = v
-            recursive_update(config, custom_config)
+            self.recursive_update(config, custom_config)
+
+        if config['postgresql'].get('callbacks', {}).get('on_role_change'):
+            config['postgresql']['callbacks']['on_role_change'] += ' ' + str(self.__PORT)
 
         with open(patroni_config_path, 'w') as f:
             yaml.safe_dump(config, f, default_flow_style=False)
@@ -238,58 +244,23 @@ class PatroniController(AbstractController):
         except Exception:
             return None
 
-    def database_is_running(self):
-        pid = self._get_pid()
-        if not pid:
-            return False
-        try:
-            os.kill(pid, 0)
-        except OSError:
-            return False
-        return True
-
     def patroni_hang(self, timeout):
         hang = ProcessHang(self._handle.pid, timeout)
         self._closables.append(hang)
         hang.start()
 
-    def checkpoint_hang(self, timeout):
-        pid = self._get_pid()
-        if not pid:
-            return False
-        proc = psutil.Process(pid)
-        for child in proc.children():
-            if 'checkpoint' in child.cmdline()[0]:
-                checkpointer = child
-                break
-        else:
-            return False
-        hang = ProcessHang(checkpointer.pid, timeout)
-        self._closables.append(hang)
-        hang.start()
-        return True
-
     def cancel_background(self):
         for obj in self._closables:
             obj.close()
         self._closables = []
 
-    def terminate_backends(self):
-        pid = self._get_pid()
-        if not pid:
-            return False
-        proc = psutil.Process(pid)
-        for p in proc.children():
-            if 'process' not in p.cmdline()[0]:
-                p.terminate()
-
     @property
     def backup_source(self):
         return 'postgres://{username}:{password}@{host}:{port}/{database}'.format(**self._replication)
 
-    def backup(self, dest='basebackup'):
+    def backup(self, dest='data/basebackup'):
         subprocess.call([PatroniPoolController.BACKUP_SCRIPT, '--walmethod=none',
-                         '--datadir=' + os.path.join(self._output_dir, dest),
+                         '--datadir=' + os.path.join(self._work_directory, dest),
                          '--dbname=' + self.backup_source])
 
 
@@ -363,9 +334,12 @@ class ConsulController(AbstractDcsController):
     def __init__(self, context):
         super(ConsulController, self).__init__(context)
         os.environ['PATRONI_CONSUL_HOST'] = 'localhost:8500'
-        self._client = consul.Consul()
+        os.environ['PATRONI_CONSUL_REGISTER_SERVICE'] = 'on'
         self._config_file = None
 
+        import consul
+        self._client = consul.Consul()
+
     def _start(self):
         self._config_file = self._work_directory + '.json'
         with open(self._config_file, 'wb') as f:
@@ -405,6 +379,8 @@ class EtcdController(AbstractDcsController):
     def __init__(self, context):
         super(EtcdController, self).__init__(context)
         os.environ['PATRONI_ETCD_HOST'] = 'localhost:2379'
+
+        import etcd
         self._client = etcd.Client(port=2379)
 
     def _start(self):
@@ -412,12 +388,14 @@ class EtcdController(AbstractDcsController):
                                 stdout=self._log, stderr=subprocess.STDOUT)
 
     def query(self, key, scope='batman'):
+        import etcd
         try:
             return self._client.get(self.path(key, scope)).value
         except etcd.EtcdKeyNotFound:
             return None
 
     def cleanup_service_tree(self):
+        import etcd
         try:
             self._client.delete(self.path(scope=''), recursive=True)
         except (etcd.EtcdKeyNotFound, etcd.EtcdConnectionFailed):
@@ -461,13 +439,13 @@ class KubernetesController(AbstractDcsController):
 
     def delete_pod(self, name):
         try:
-            self._api.delete_namespaced_pod(name, self._namespace, self._client.V1DeleteOptions())
-        except:
+            self._api.delete_namespaced_pod(name, self._namespace, body=self._client.V1DeleteOptions())
+        except Exception:
             pass
         while True:
             try:
                 self._api.read_namespaced_pod(name, self._namespace)
-            except:
+            except Exception:
                 break
 
     def query(self, key, scope='batman'):
@@ -476,22 +454,23 @@ class KubernetesController(AbstractDcsController):
             return (pod.metadata.annotations or {}).get('status', '')
         else:
             try:
-                e = self._api.read_namespaced_endpoints(scope + ('' if key == 'leader' else '-' + key), self._namespace)
-                if key == 'leader':
+                ep = scope + {'leader': '', 'history': '-config', 'initialize': '-config'}.get(key, '-' + key)
+                e = self._api.read_namespaced_endpoints(ep, self._namespace)
+                if key != 'sync':
                     return e.metadata.annotations[key]
                 else:
                     return json.dumps(e.metadata.annotations)
-            except:
+            except Exception:
                 return None
 
     def cleanup_service_tree(self):
         try:
             self._api.delete_collection_namespaced_pod(self._namespace, label_selector=self._label_selector)
-        except:
+        except Exception:
             pass
         try:
             self._api.delete_collection_namespaced_endpoints(self._namespace, label_selector=self._label_selector)
-        except:
+        except Exception:
             pass
 
         while True:
@@ -511,18 +490,22 @@ class ZooKeeperController(AbstractDcsController):
         super(ZooKeeperController, self).__init__(context, False)
         if export_env:
             os.environ['PATRONI_ZOOKEEPER_HOSTS'] = "'localhost:2181'"
+
+        import kazoo.client
         self._client = kazoo.client.KazooClient()
 
     def _start(self):
         pass  # TODO: implement later
 
     def query(self, key, scope='batman'):
+        import kazoo.exceptions
         try:
             return self._client.get(self.path(key, scope))[0].decode('utf-8')
         except kazoo.exceptions.NoNodeError:
             return None
 
     def cleanup_service_tree(self):
+        import kazoo.exceptions
         try:
             self._client.delete(self.path(scope=''), recursive=True)
         except (kazoo.exceptions.NoNodeError):
@@ -582,9 +565,8 @@ class PatroniPoolController(object):
         self._processes[name].start(max_wait_limit)
 
     def __getattr__(self, func):
-        if func not in ['stop', 'query', 'write_label', 'read_label', 'check_role_has_changed_to', 'add_tag_to_config',
-                        'get_watchdog', 'database_is_running', 'checkpoint_hang', 'patroni_hang',
-                        'terminate_backends', 'backup']:
+        if func not in ['stop', 'query', 'write_label', 'read_label', 'check_role_has_changed_to',
+                        'add_tag_to_config', 'get_watchdog', 'patroni_hang', 'backup']:
             raise AttributeError("PatroniPoolController instance has no attribute '{0}'".format(func))
 
         def wrapper(name, *args, **kwargs):
@@ -598,7 +580,7 @@ class PatroniPoolController(object):
         self._processes.clear()
 
     def create_and_set_output_directory(self, feature_name):
-        feature_dir = os.path.join(self.patroni_path, 'features/output', feature_name.replace(' ', '_'))
+        feature_dir = os.path.join(self.patroni_path, 'features', 'output', feature_name.replace(' ', '_'))
         if os.path.exists(feature_dir):
             shutil.rmtree(feature_dir)
         os.makedirs(feature_dir)
@@ -612,13 +594,20 @@ class PatroniPoolController(object):
                 'method': 'pg_basebackup',
                 'pg_basebackup': {
                     'command': self.BACKUP_SCRIPT + ' --walmethod=stream --dbname=' + f.backup_source
+                },
+                'dcs': {
+                    'postgresql': {
+                        'parameters': {
+                            'max_connections': 101
+                        }
+                    }
                 }
             },
             'postgresql': {
                 'parameters': {
                     'archive_mode': 'on',
                     'archive_command': 'mkdir -p {0} && test ! -f {0}/%f && cp %p {0}/%f'.format(
-                            os.path.join(self._output_dir, 'wal_archive'))
+                            os.path.join(self.patroni_path, 'data', 'wal_archive'))
                 },
                 'authentication': {
                     'superuser': {'password': 'zalando1'},
@@ -634,11 +623,12 @@ class PatroniPoolController(object):
             'bootstrap': {
                 'method': 'backup_restore',
                 'backup_restore': {
-                    'command': 'features/backup_restore.sh --sourcedir=' + os.path.join(self._output_dir, 'basebackup'),
+                    'command': 'features/backup_restore.sh --sourcedir=' + os.path.join(self.patroni_path,
+                                                                                        'data', 'basebackup'),
                     'recovery_conf': {
                         'recovery_target_action': 'promote',
                         'recovery_target_timeline': 'latest',
-                        'restore_command': 'cp {0}/wal_archive/%f %p'.format(self._output_dir)
+                        'restore_command': 'cp {0}/data/wal_archive/%f %p'.format(self.patroni_path)
                     }
                 }
             },
@@ -792,8 +782,8 @@ def before_all(context):
 
 def after_all(context):
     context.dcs_ctl.stop()
-    subprocess.call(['coverage', 'combine'])
-    subprocess.call(['coverage', 'report'])
+    subprocess.call([sys.executable, '-m', 'coverage', 'combine'])
+    subprocess.call([sys.executable, '-m', 'coverage', 'report'])
 
 
 def before_feature(context, feature):
@@ -806,3 +796,5 @@ def after_feature(context, feature):
     context.pctl.stop_all()
     shutil.rmtree(os.path.join(context.pctl.patroni_path, 'data'))
     context.dcs_ctl.cleanup_service_tree()
+    if feature.status == 'failed':
+        shutil.copytree(context.pctl.output_dir, context.pctl.output_dir + '_failed')

features/patroni_api.feature

@@ -8,6 +8,8 @@ Scenario: check API requests on a stand-alone server
 	Then I receive a response code 200
 	And I receive a response state running
 	And I receive a response role master
+	When I issue a GET request to http://127.0.0.1:8008/health
+	Then I receive a response code 200
 	When I issue a GET request to http://127.0.0.1:8008/replica
 	Then I receive a response code 503
 	When I run patronictl.py reinit batman postgres0 --force
@@ -26,10 +28,7 @@ Scenario: check API requests on a stand-alone server
 	And I receive a response text "Failover could be performed only to a specific candidate"
 
 Scenario: check local configuration reload
-	Given I issue an empty POST request to http://127.0.0.1:8008/reload
-	Then I receive a response code 200
-	And I receive a response text nothing changed
-	When I add tag new_tag new_value to postgres0 config
+	Given I add tag new_tag new_value to postgres0 config
 	And I issue an empty POST request to http://127.0.0.1:8008/reload
 	Then I receive a response code 202
 
@@ -43,7 +42,21 @@ Scenario: check dynamic configuration change via DCS
 	And I receive a response loop_wait 2
 	When I issue a GET request to http://127.0.0.1:8008/patroni
 	Then I receive a response code 200
-	And I receive a response tags {'tag': 'new_value'}
+	And I receive a response tags {'new_tag': 'new_value'}
+	And I sleep for 4 seconds
+
+Scenario: check the scheduled restart
+	Given I issue a PATCH request to http://127.0.0.1:8008/config with {"postgresql": {"parameters": {"superuser_reserved_connections": "6"}}}
+	Then I receive a response code 200
+		And Response on GET http://127.0.0.1:8008/patroni contains pending_restart after 5 seconds
+	Given I issue a scheduled restart at http://127.0.0.1:8008 in 3 seconds with {"role": "replica"}
+	Then I receive a response code 202
+		And I sleep for 4 seconds
+		And Response on GET http://127.0.0.1:8008/patroni contains pending_restart after 10 seconds
+	Given I issue a scheduled restart at http://127.0.0.1:8008 in 3 seconds with {"restart_pending": "True"}
+	Then I receive a response code 202
+		And Response on GET http://127.0.0.1:8008/patroni does not contain pending_restart after 10 seconds
+		And postgres0 role is the primary after 10 seconds
 
 Scenario: check API requests for the primary-replica pair in the pause mode
 	Given I run patronictl.py pause batman
@@ -71,6 +84,15 @@ Scenario: check the switchover via the API in the pause mode
 	And postgres1 role is the primary after 10 seconds
 	And postgres0 role is the secondary after 10 seconds
 	And replication works from postgres1 to postgres0 after 20 seconds
+	And "members/postgres0" key in DCS has state=running after 10 seconds
+	When I issue a GET request to http://127.0.0.1:8008/master
+	Then I receive a response code 503
+	When I issue a GET request to http://127.0.0.1:8008/replica
+	Then I receive a response code 200
+	When I issue a GET request to http://127.0.0.1:8009/master
+	Then I receive a response code 200
+	When I issue a GET request to http://127.0.0.1:8009/replica
+	Then I receive a response code 503
 
 Scenario: check the scheduled switchover
 	Given I issue a scheduled switchover from postgres1 to postgres0 in 3 seconds
@@ -84,16 +106,12 @@ Scenario: check the scheduled switchover
 	And postgres0 role is the primary after 10 seconds
 	And postgres1 role is the secondary after 10 seconds
 	And replication works from postgres0 to postgres1 after 25 seconds
-
-Scenario: check the scheduled restart
-	Given I issue a PATCH request to http://127.0.0.1:8008/config with {"postgresql": {"parameters": {"superuser_reserved_connections": "6"}}}
+	And "members/postgres1" key in DCS has state=running after 10 seconds
+	When I issue a GET request to http://127.0.0.1:8008/master
+	Then I receive a response code 200
+	When I issue a GET request to http://127.0.0.1:8008/replica
+	Then I receive a response code 503
+	When I issue a GET request to http://127.0.0.1:8009/master
+	Then I receive a response code 503
+	When I issue a GET request to http://127.0.0.1:8009/replica
 	Then I receive a response code 200
-		And Response on GET http://127.0.0.1:8008/patroni contains pending_restart after 5 seconds
-	Given I issue a scheduled restart at http://127.0.0.1:8008 in 3 seconds with {"role": "replica"}
-	Then I receive a response code 202
-		And I sleep for 4 seconds
-		And Response on GET http://127.0.0.1:8008/patroni contains pending_restart after 10 seconds
-	Given I issue a scheduled restart at http://127.0.0.1:8008 in 3 seconds with {"restart_pending": "True"}
-	Then I receive a response code 202
-		And Response on GET http://127.0.0.1:8008/patroni does not contain pending_restart after 10 seconds
-

features/standby_cluster.feature

@@ -0,0 +1,48 @@
+Feature: standby cluster
+  Scenario: check permanent logical slots are preserved on failover/switchover
+    Given I start postgres1
+    Then postgres1 is a leader after 10 seconds
+    And there is a non empty initialize key in DCS after 15 seconds
+    When I issue a PATCH request to http://127.0.0.1:8009/config with {"loop_wait": 2, "slots": {"pm_1": {"type": "physical"}}, "postgresql": {"parameters": {"wal_level": "logical"}}}
+    Then I receive a response code 200
+    And Response on GET http://127.0.0.1:8009/config contains slots after 10 seconds
+    And I sleep for 3 seconds
+    When I issue a PATCH request to http://127.0.0.1:8009/config with {"slots": {"test_logical": {"type": "logical", "database": "postgres", "plugin": "test_decoding"}}}
+    Then I receive a response code 200
+    And I do a backup of postgres1
+    When I start postgres0 with callback configured
+    Then "members/postgres0" key in DCS has state=running after 10 seconds
+    And replication works from postgres1 to postgres0 after 15 seconds
+    When I shut down postgres1
+    Then postgres0 is a leader after 10 seconds
+    And "members/postgres0" key in DCS has role=master after 3 seconds
+    When I issue a GET request to http://127.0.0.1:8008/
+    Then I receive a response code 200
+    And there is a label with "test_logical" in postgres0 data directory
+
+  Scenario: check replication of a single table in a standby cluster
+    Given I start postgres1 in a standby cluster batman1 as a clone of postgres0
+    Then postgres1 is a leader of batman1 after 10 seconds
+    When I add the table foo to postgres0
+    Then table foo is present on postgres1 after 20 seconds
+    When I issue a GET request to http://127.0.0.1:8009/master
+    Then I receive a response code 200
+    When I issue a GET request to http://127.0.0.1:8009/standby_leader
+    Then I receive a response code 200
+    And I receive a response role standby_leader
+    And there is a postgres1_cb.log with "on_start replica batman1\non_role_change standby_leader batman1" in postgres1 data directory
+    When I start postgres2 in a cluster batman1
+    Then postgres2 role is the replica after 24 seconds
+    And table foo is present on postgres2 after 20 seconds
+
+  Scenario: check failover
+    When I kill postgres1
+    And I kill postmaster on postgres1
+    Then postgres2 is replicating from postgres0 after 32 seconds
+    When I issue a GET request to http://127.0.0.1:8010/master
+    Then I receive a response code 200
+    When I issue a GET request to http://127.0.0.1:8010/standby_leader
+    Then I receive a response code 200
+    And I receive a response role standby_leader
+    And replication works from postgres0 to postgres2 after 15 seconds
+    And there is a postgres2_cb.log with "on_start replica batman1\non_role_change standby_leader batman1" in postgres2 data directory

features/steps/cascading_replication.py

@@ -9,9 +9,10 @@ def start_patroni_with_a_name_value_tag(context, name, tag_name, tag_value):
     return context.pctl.start(name, custom_config={'tags': {tag_name: tag_value}})
 
 
-@then('There is a label with "{content:w}" in {name:w} data directory')
-def check_label(context, content, name):
-    label = context.pctl.read_label(name)
+@then('There is a {label} with "{content}" in {name:w} data directory')
+def check_label(context, label, content, name):
+    label = context.pctl.read_label(name, label)
+    label = label.replace('\n', '\\n')
     assert label == content, "{0} is not equal to {1}".format(label, content)
 
 
@@ -33,3 +34,17 @@ def check_member(context, name, key, value, time_limit):
             pass
         time.sleep(1)
     assert False, "{0} does not have {1}={2} in dcs after {3} seconds".format(name, key, value, time_limit)
+
+
+@step('there is a non empty {key:w} key in DCS after {time_limit:d} seconds')
+def check_initialize(context, key, time_limit):
+    time_limit *= context.timeout_multiplier
+    max_time = time.time() + int(time_limit)
+    while time.time() < max_time:
+        try:
+            if context.dcs_ctl.query(key):
+                return
+        except Exception:
+            pass
+        time.sleep(1)
+    assert False, "There is no {0} in dcs after {1} seconds".format(key, time_limit)

features/steps/patroni_api.py

@@ -1,18 +1,19 @@
-import base64
 import json
 import os
 import parse
-import requests
 import shlex
 import subprocess
+import sys
 import time
 import yaml
 
 from behave import register_type, step, then
 from dateutil import tz
 from datetime import datetime, timedelta
+from patroni.request import PatroniRequest
 
 tzutc = tz.tzutc()
+request_executor = PatroniRequest({'ctl': {'auth': 'username:password'}})
 
 
 @parse.with_pattern(r'https?://(?:\w|\.|:|/)+')
@@ -44,9 +45,9 @@ def sleep_for_n_seconds(context, value):
 
 
 def _set_response(context, response):
-    context.status_code = response.status_code
-    data = response.content.decode('utf-8')
-    ct = response.headers.get('content-type', '')
+    context.status_code = response.status
+    data = response.data.decode('utf-8')
+    ct = response.getheader('content-type', '')
     if ct.startswith('application/json') or\
             ct.startswith('text/yaml') or\
             ct.startswith('text/x-yaml') or\
@@ -62,13 +63,7 @@ def _set_response(context, response):
 
 @step('I issue a GET request to {url:url}')
 def do_get(context, url):
-    try:
-        r = requests.get(url)
-    except requests.exceptions.RequestException:
-        context.status_code = None
-        context.response = None
-    else:
-        _set_response(context, r)
+    do_request(context, 'GET', url, None)
 
 
 @step('I issue an empty POST request to {url:url}')
@@ -78,24 +73,18 @@ def do_post_empty(context, url):
 
 @step('I issue a {request_method:w} request to {url:url} with {data}')
 def do_request(context, request_method, url, data):
-    data = data and json.loads(data) or {}
-    headers = {'Authorization': 'Basic ' + base64.b64encode('username:password'.encode('utf-8')).decode('utf-8'),
-               'Content-Type': 'application/json'}
+    data = data and json.loads(data)
     try:
-        if request_method == 'PATCH':
-            r = requests.patch(url, headers=headers, json=data)
-        else:
-            r = requests.post(url, headers=headers, json=data)
-    except requests.exceptions.RequestException:
-        context.status_code = None
-        context.response = None
+        r = request_executor.request(request_method, url, data)
+    except Exception:
+        context.status_code = context.response = None
     else:
         _set_response(context, r)
 
 
 @step('I run {cmd}')
 def do_run(context, cmd):
-    cmd = ['coverage', 'run', '--source=patroni', '-p'] + shlex.split(cmd)
+    cmd = [sys.executable, '-m', 'coverage', 'run', '--source=patroni', '-p'] + shlex.split(cmd)
     try:
         # XXX: Dirty hack! We need to take name/passwd from the config!
         env = os.environ.copy()
@@ -148,8 +137,8 @@ def add_tag_to_config(context, tag, value, pg_name):
 def check_http_response(context, url, value, timeout, negate=False):
     timeout *= context.timeout_multiplier
     for _ in range(int(timeout)):
-        r = requests.get(url)
-        if (value in r.content.decode('utf-8')) != negate:
+        r = request_executor.request('GET', url)
+        if (value in r.data.decode('utf-8')) != negate:
             break
         time.sleep(1)
     else:

features/steps/standby_cluster.py

@@ -0,0 +1,82 @@
+import os
+import time
+
+from behave import step
+
+
+select_replication_query = """
+SELECT * FROM pg_catalog.pg_stat_replication
+WHERE application_name = '{0}'
+"""
+
+callback = "bash -c 'echo \"${*: -3:1} ${*: -2:1} ${*: -1:1}\" >> data/$1/$1_cb.log' -- "
+
+
+@step('I start {name:w} with callback configured')
+def start_patroni_with_callbacks(context, name):
+    return context.pctl.start(name, custom_config={
+        "postgresql": {
+            "callbacks": {
+                "on_role_change": "features/callback.sh"
+            }
+        }
+    })
+
+
+@step('I start {name:w} in a cluster {cluster_name:w}')
+def start_patroni(context, name, cluster_name):
+    return context.pctl.start(name, custom_config={
+        "scope": cluster_name,
+        "postgresql": {
+            "callbacks": {c: callback + name for c in ('on_start', 'on_stop', 'on_restart', 'on_role_change')},
+            "backup_restore": {
+                "command": "features/backup_restore.sh --sourcedir=" + os.path.join(context.pctl.patroni_path,
+                                                                                    'data', 'basebackup')}
+        }
+    })
+
+
+@step('I start {name:w} in a standby cluster {cluster_name:w} as a clone of {name2:w}')
+def start_patroni_standby_cluster(context, name, cluster_name, name2):
+    # we need to remove patroni.dynamic.json in order to "bootstrap" standby cluster with existing PGDATA
+    os.unlink(os.path.join(context.pctl._processes[name]._data_dir, 'patroni.dynamic.json'))
+    port = context.pctl._processes[name2]._connkwargs.get('port')
+    context.pctl._processes[name].update_config({
+        "scope": cluster_name,
+        "bootstrap": {
+            "dcs": {
+                "ttl": 20,
+                "loop_wait": 2,
+                "retry_timeout": 5,
+                "standby_cluster": {
+                    "host": "localhost",
+                    "port": port,
+                    "primary_slot_name": "pm_1",
+                    "create_replica_methods": ["backup_restore", "basebackup"]
+                }
+            }
+        },
+        "postgresql": {
+            "callbacks": {c: callback + name for c in ('on_start', 'on_stop', 'on_restart', 'on_role_change')}
+        }
+    })
+    return context.pctl.start(name)
+
+
+@step('{pg_name1:w} is replicating from {pg_name2:w} after {timeout:d} seconds')
+def check_replication_status(context, pg_name1, pg_name2, timeout):
+    bound_time = time.time() + timeout
+
+    while time.time() < bound_time:
+        cur = context.pctl.query(
+            pg_name2,
+            select_replication_query.format(pg_name1),
+            fail_ok=True
+        )
+
+        if cur and len(cur.fetchall()) != 0:
+            break
+
+        time.sleep(1)
+    else:
+        assert False, "{0} is not replicating from {1} after {2} seconds".format(pg_name1, pg_name2, timeout)

features/steps/watchdog.py

@@ -44,31 +44,6 @@ def watchdog_was_triggered(context, name, timeout):
     assert False
 
 
-@then('{name:w} watchdog was not triggered')
-def watchdog_was_not_triggered(context, name):
-    assert not context.pctl.get_watchdog(name).was_triggered
-
-
-@step('{name:w} checkpoint takes {timeout:d} seconds')
-def checkpoint_hang(context, name, timeout):
-    assert context.pctl.checkpoint_hang(name, timeout)
-
-
 @step('{name:w} hangs for {timeout:d} seconds')
 def patroni_hang(context, name, timeout):
     return context.pctl.patroni_hang(name, timeout)
-
-
-@step('I terminate {name:w} user processes')
-def terminate_backends(context, name):
-    return context.pctl.terminate_backends(name)
-
-
-@step('Sleep for {timeout:d} seconds')
-def dcs_connection_lost(context, timeout):
-    time.sleep(timeout)
-
-
-@then('{name:w} database is running')
-def database_is_running(context, name):
-    assert context.pctl.database_is_running(name)

kubernetes/Dockerfile

@@ -1,32 +1,34 @@
-FROM postgres:9.6
+FROM postgres:11
 MAINTAINER Alexander Kukushkin <[email protected]>
 
 RUN export DEBIAN_FRONTEND=noninteractive \
     && echo 'APT::Install-Recommends "0";\nAPT::Install-Suggests "0";' > /etc/apt/apt.conf.d/01norecommend \
     && apt-get update -y \
     && apt-get upgrade -y \
-    && apt-get install -y git curl jq python-psycopg2 python-yaml python-requests python-six python-pysocks \
-        python-dateutil python-pip python-prettytable python-wheel python-psutil python locales \
-
+    && apt-cache depends patroni | sed -n -e 's/.* Depends: \(python3-.\+\)$/\1/p' \
+            | grep -Ev '^python3-(sphinx|etcd|consul|kazoo|kubernetes)' \
+            | xargs apt-get install -y vim-tiny curl jq locales git python3-pip python3-wheel \
     ## Make sure we have a en_US.UTF-8 locale available
     && localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8 \
-
-    && pip install setuptools pip --upgrade \
-    && pip install 'git+https://github.com/zalando/patroni.git@feature/k8s#egg=patroni[kubernetes]' \
-
-    && mkdir -p /home/postgres \
-    && chown postgres:postgres /home/postgres \
-
+    && pip3 install setuptools \
+    && pip3 install 'git+https://github.com/zalando/patroni.git#egg=patroni[kubernetes]' \
+    && PGHOME=/home/postgres \
+    && mkdir -p $PGHOME \
+    && chown postgres $PGHOME \
+    && sed -i "s|/var/lib/postgresql.*|$PGHOME:/bin/bash|" /etc/passwd \
+    # Set permissions for OpenShift
+    && chmod 775 $PGHOME \
+    && chmod 664 /etc/passwd \
     # Clean up
-    && apt-get remove -y git python-pip python-setuptools \
+    && apt-get remove -y git python3-pip python3-wheel \
     && apt-get autoremove -y \
     && apt-get clean -y \
     && rm -rf /var/lib/apt/lists/* /root/.cache
 
-ADD entrypoint.sh callback.py /
+ADD entrypoint.sh /
 
 EXPOSE 5432 8008
-ENV LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
+ENV LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8 EDITOR=/usr/bin/editor
 USER postgres
 WORKDIR /home/postgres
 CMD ["/bin/bash", "/entrypoint.sh"]

kubernetes/callback.py

@@ -1,62 +0,0 @@
-#!/usr/bin/env python
-
-import logging
-import os
-import socket
-import sys
-import time
-
-from kubernetes import client as k8s_client, config as k8s_config
-from urllib3.exceptions import HTTPError
-from six.moves.http_client import HTTPException
-
-logger = logging.getLogger(__name__)
-
-
-class CoreV1Api(k8s_client.CoreV1Api):
-
-    def retry(func):
-        def wrapped(*args, **kwargs):
-            count = 0
-            while True:
-                try:
-                    return func(*args, **kwargs)
-                except (HTTPException, HTTPError, socket.error, socket.timeout):
-                    if count >= 10:
-                        raise
-                    logger.info('Throttling API requests...')
-                    time.sleep(2 ** count * 0.5)
-                    count += 1
-        return wrapped
-
-    @retry
-    def patch_namespaced_endpoints(self, *args, **kwargs):
-        return super(CoreV1Api, self).patch_namespaced_endpoints(*args, **kwargs)
-
-
-def patch_master_endpoint(api, namespace, cluster):
-    addresses = [k8s_client.V1EndpointAddress(ip=os.environ['POD_IP'])]
-    ports = [k8s_client.V1EndpointPort(port=5432)]
-    subsets = [k8s_client.V1EndpointSubset(addresses=addresses, ports=ports)]
-    body = k8s_client.V1Endpoints(subsets=subsets)
-    return api.patch_namespaced_endpoints(cluster, namespace, body)
-
-
-def main():
-    logging.basicConfig(format='%(asctime)s %(levelname)s: %(message)s', level=logging.INFO)
-    if len(sys.argv) != 4 or sys.argv[1] not in ('on_start', 'on_stop', 'on_role_change'):
-        sys.exit('Usage: %s <action> <role> <cluster_name>', sys.argv[0])
-
-    action, role, cluster = sys.argv[1:4]
-
-    k8s_config.load_incluster_config()
-    k8s_api = CoreV1Api()
-
-    namespace = os.environ['KUBERNETES_NAMESPACE']
-
-    if role == 'master' and action in ('on_start', 'on_role_change'):
-        patch_master_endpoint(k8s_api, namespace, cluster)
-
-
-if __name__ == '__main__':
-    main()

kubernetes/entrypoint.sh

@@ -1,5 +1,12 @@
 #!/bin/bash
 
+if [[ $UID -ge 10000 ]]; then
+    GID=$(id -g)
+    sed -e "s/^postgres:x:[^:]*:[^:]*:/postgres:x:$UID:$GID:/" /etc/passwd > /tmp/passwd
+    cat /tmp/passwd > /etc/passwd
+    rm /tmp/passwd
+fi
+
 cat > /home/postgres/patroni.yml <<__EOF__
 bootstrap:
   dcs:
@@ -13,24 +20,20 @@ bootstrap:
   - data-checksums
   pg_hba:
   - host all all 0.0.0.0/0 md5
-  - host replication ${PATRONI_REPLICATION_USERNAME} ${POD_IP}/16    md5
+  - host replication ${PATRONI_REPLICATION_USERNAME} ${PATRONI_KUBERNETES_POD_IP}/16 md5
 restapi:
-  connect_address: '${POD_IP}:8008'
+  connect_address: '${PATRONI_KUBERNETES_POD_IP}:8008'
 postgresql:
-  connect_address: '${POD_IP}:5432'
+  connect_address: '${PATRONI_KUBERNETES_POD_IP}:5432'
   authentication:
     superuser:
       password: '${PATRONI_SUPERUSER_PASSWORD}'
     replication:
       password: '${PATRONI_REPLICATION_PASSWORD}'
-  callbacks:
-    on_start: /callback.py
-    on_stop: /callback.py
-    on_role_change: /callback.py
 __EOF__
 
 unset PATRONI_SUPERUSER_PASSWORD PATRONI_REPLICATION_PASSWORD
 export KUBERNETES_NAMESPACE=$PATRONI_KUBERNETES_NAMESPACE
 export POD_NAME=$PATRONI_NAME
 
-exec /usr/bin/python /usr/local/bin/patroni /home/postgres/patroni.yml
+exec /usr/bin/python3 /usr/local/bin/patroni /home/postgres/patroni.yml

kubernetes/openshift-example/README.md

@@ -0,0 +1,49 @@
+# Patroni OpenShift Configuration
+Patroni can be run in OpenShift. Based on the kubernetes configuration, the Dockerfile and Entrypoint has been modified to support the dynamic UID/GID configuration that is applied in OpenShift. This can be run under the standard `restricted` SCC. 
+
+# Examples
+
+## Create test project
+
+```
+oc new-project patroni-test
+```
+
+## Build the image
+
+Note: Update the references when merged upstream. 
+Note: If deploying as a template for multiple users, the following commands should be performed in a shared namespace like `openshift`. 
+
+```
+oc import-image postgres:10 --confirm -n openshift
+oc new-build https://github.com/zalando/patroni --context-dir=kubernetes -n openshift
+```
+
+## Deploy the Image 
+Two configuration templates exist in [templates](templates) directory: 
+- Patroni Ephemeral
+- Patroni Persistent
+
+The only difference is whether or not the statefulset requests persistent storage. 
+
+## Create the Template
+Install the template into the `openshift` namespace if this should be shared across projects: 
+
+```
+oc create -f templates/template_patroni_ephemeral.yml -n openshift
+```
+
+Then, from your own project: 
+
+```
+oc new-app patroni-pgsql-ephemeral
+```
+
+Once the pods are running, two configmaps should be available: 
+
+```
+$ oc get configmap
+NAME                DATA      AGE
+patroniocp-config   0         1m
+patroniocp-leader   0         1m
+```

kubernetes/openshift-example/templates/template_patroni_ephemeral.yml

@@ -0,0 +1,287 @@
+apiVersion: v1
+kind: Template
+metadata:
+  name: patroni-pgsql-ephemeral
+  annotations:
+    description: |-
+      Patroni Postgresql database cluster, without persistent storage.
+
+      WARNING: Any data stored will be lost upon pod destruction. Only use this template for testing.
+    iconClass: icon-postgresql
+    openshift.io/display-name: Patroni Postgresql (Ephemeral)
+    openshift.io/long-description: This template deploys a a patroni postgresql HA cluster without persistent storage.
+    tags: postgresql
+objects:
+- apiVersion: v1
+  kind: Service
+  metadata:
+    creationTimestamp: null
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${PATRONI_CLUSTER_NAME}
+  spec:
+    ports:
+    - port: 5432
+      protocol: TCP
+      targetPort: 5432
+    sessionAffinity: None
+    type: ClusterIP
+  status:
+    loadBalancer: {}
+- apiVersion: v1
+  kind: Service
+  metadata:
+    creationTimestamp: null
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${PATRONI_MASTER_SERVICE_NAME}
+  spec:
+    ports:
+    - port: 5432
+      protocol: TCP
+      targetPort: 5432
+    selector:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+      role: master
+    sessionAffinity: None
+    type: ClusterIP
+  status:
+    loadBalancer: {}
+- apiVersion: v1
+  kind: Secret
+  metadata:
+    name: ${PATRONI_CLUSTER_NAME}
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+  stringData:
+    superuser-password: ${PATRONI_SUPERUSER_PASSWORD}
+    replication-password: ${PATRONI_REPLICATION_PASSWORD}
+- apiVersion: v1
+  kind: Service
+  metadata:
+    creationTimestamp: null
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${PATRONI_REPLICA_SERVICE_NAME}
+  spec:
+    ports:
+    - port: 5432
+      protocol: TCP
+      targetPort: 5432
+    selector:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+      role: replica
+    sessionAffinity: None
+    type: ClusterIP
+  status:
+    loadBalancer: {}
+- apiVersion: apps/v1
+  kind: StatefulSet
+  metadata:
+    creationTimestamp: null
+    generation: 3
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${APPLICATION_NAME}
+  spec:
+    podManagementPolicy: OrderedReady
+    replicas: 3
+    revisionHistoryLimit: 10
+    selector:
+      matchLabels:
+        application: ${APPLICATION_NAME}
+        cluster-name: ${PATRONI_CLUSTER_NAME}
+    serviceName: ${APPLICATION_NAME}
+    template:
+      metadata:
+        creationTimestamp: null
+        labels:
+          application: ${APPLICATION_NAME}
+          cluster-name: ${PATRONI_CLUSTER_NAME}
+      spec:
+        containers:
+        - env:
+          - name: PATRONI_KUBERNETES_POD_IP
+            valueFrom:
+              fieldRef:
+                apiVersion: v1
+                fieldPath: status.podIP
+          - name: PATRONI_KUBERNETES_NAMESPACE
+            valueFrom:
+              fieldRef:
+                apiVersion: v1
+                fieldPath: metadata.namespace
+          - name: PATRONI_KUBERNETES_LABELS
+            value: '{application: ${APPLICATION_NAME}, cluster-name: ${PATRONI_CLUSTER_NAME}}'
+          - name: PATRONI_SUPERUSER_USERNAME
+            value: ${PATRONI_SUPERUSER_USERNAME}
+          - name: PATRONI_SUPERUSER_PASSWORD
+            valueFrom:
+              secretKeyRef:
+                key: superuser-password
+                name: ${PATRONI_CLUSTER_NAME}
+          - name: PATRONI_REPLICATION_USERNAME
+            value: ${PATRONI_REPLICATION_USERNAME}
+          - name: PATRONI_REPLICATION_PASSWORD
+            valueFrom:
+              secretKeyRef:
+                key: replication-password
+                name: ${PATRONI_CLUSTER_NAME}
+          - name: PATRONI_SCOPE
+            value: ${PATRONI_CLUSTER_NAME}
+          - name: PATRONI_NAME
+            valueFrom:
+              fieldRef:
+                apiVersion: v1
+                fieldPath: metadata.name
+          - name: PATRONI_POSTGRESQL_DATA_DIR
+            value: /home/postgres/pgdata/pgroot/data
+          - name: PATRONI_POSTGRESQL_PGPASS
+            value: /tmp/pgpass
+          - name: PATRONI_POSTGRESQL_LISTEN
+            value: 0.0.0.0:5432
+          - name: PATRONI_RESTAPI_LISTEN
+            value: 0.0.0.0:8008
+          image: docker-registry.default.svc:5000/${NAMESPACE}/patroni:latest
+          imagePullPolicy: IfNotPresent
+          name: ${APPLICATION_NAME}
+          ports:
+          - containerPort: 8008
+            protocol: TCP
+          - containerPort: 5432
+            protocol: TCP
+          resources: {}
+          terminationMessagePath: /dev/termination-log
+          terminationMessagePolicy: File
+          volumeMounts:
+          - mountPath: /home/postgres/pgdata
+            name: pgdata
+        dnsPolicy: ClusterFirst
+        restartPolicy: Always
+        schedulerName: default-scheduler
+        securityContext: {}
+        serviceAccount: ${SERVICE_ACCOUNT}
+        serviceAccountName: ${SERVICE_ACCOUNT}
+        terminationGracePeriodSeconds: 0
+        volumes:
+        - name: pgdata
+          emptyDir: {}
+    updateStrategy:
+      type: OnDelete
+- apiVersion: v1
+  kind: Endpoints
+  metadata:
+    name: ${APPLICATION_NAME}
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+  subsets: []
+- apiVersion: v1
+  kind: ServiceAccount
+  metadata:
+    name: ${SERVICE_ACCOUNT}
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: Role
+  metadata:
+    name: ${SERVICE_ACCOUNT}
+  rules:
+  - apiGroups:
+    - ""
+    resources:
+    - configmaps
+    verbs:
+    - create
+    - get
+    - list
+    - patch
+    - update
+    - watch
+    # delete is required only for 'patronictl remove'
+    - delete
+  - apiGroups:
+    - ""
+    resources:
+    - endpoints
+    verbs:
+    - get
+    - patch
+    - update
+    # the following three privileges are necessary only when using endpoints
+    - create
+    - list
+    - watch
+    # delete is required only for for 'patronictl remove'
+    - delete
+  - apiGroups:
+    - ""
+    resources:
+    - pods
+    verbs:
+    - get
+    - list
+    - patch
+    - update
+    - watch
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: RoleBinding
+  metadata:
+    name: ${SERVICE_ACCOUNT}
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: Role
+    name: ${SERVICE_ACCOUNT}
+  subjects:
+  - kind: ServiceAccount
+    name: ${SERVICE_ACCOUNT}
+parameters:
+- description: The name of the application for labelling all artifacts.
+  displayName: Application Name
+  name: APPLICATION_NAME
+  value: patroni-ephemeral
+- description: The name of the patroni-pgsql cluster.
+  displayName: Cluster Name
+  name: PATRONI_CLUSTER_NAME
+  value: patroni-ephemeral
+- description: The name of the OpenShift Service exposed for the patroni-ephemeral-master container.
+  displayName: Master service name.  
+  name: PATRONI_MASTER_SERVICE_NAME
+  value: patroni-ephemeral-master
+- description: The name of the OpenShift Service exposed for the patroni-ephemeral-replica containers.
+  displayName: Replica service name. 
+  name: PATRONI_REPLICA_SERVICE_NAME
+  value: patroni-ephemeral-replica
+- description: Maximum amount of memory the container can use.
+  displayName: Memory Limit
+  name: MEMORY_LIMIT
+  value: 512Mi
+- description: The OpenShift Namespace where the patroni and postgresql ImageStream resides.
+  displayName: ImageStream Namespace
+  name: NAMESPACE
+  value: openshift
+- description: Username of the superuser account for initialization.
+  displayName: Superuser Username
+  name: PATRONI_SUPERUSER_USERNAME
+  value: postgres
+- description: Password of the superuser account for initialization.
+  displayName: Superuser Passsword
+  name: PATRONI_SUPERUSER_PASSWORD
+  value: postgres
+- description: Username of the replication account for initialization.
+  displayName: Replication Username
+  name: PATRONI_REPLICATION_USERNAME
+  value: postgres
+- description: Password of the replication account for initialization.
+  displayName: Repication Passsword
+  name: PATRONI_REPLICATION_PASSWORD
+  value: postgres
+- description: Service account name used for pods and rolebindings to form a cluster in the project. 
+  displayName: Service Account
+  name: SERVICE_ACCOUNT
+  value: patroniocp

kubernetes/openshift-example/templates/template_patroni_persistent.yaml

@@ -0,0 +1,303 @@
+apiVersion: v1
+kind: Template
+metadata:
+  name: patroni-pgsql-persistent
+  annotations:
+    description: |-
+      Patroni Postgresql database cluster, with persistent storage.
+
+      WARNING: Any data stored will be lost upon pod destruction. Only use this template for testing.
+    iconClass: icon-postgresql
+    openshift.io/display-name: Patroni Postgresql (Persistent)
+    openshift.io/long-description: This template deploys a a patroni postgresql HA cluster without persistent storage.
+    tags: postgresql
+objects:
+- apiVersion: v1
+  kind: Service
+  metadata:
+    creationTimestamp: null
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${PATRONI_CLUSTER_NAME}
+  spec:
+    ports:
+    - port: 5432
+      protocol: TCP
+      targetPort: 5432
+    sessionAffinity: None
+    type: ClusterIP
+  status:
+    loadBalancer: {}
+- apiVersion: v1
+  kind: Service
+  metadata:
+    creationTimestamp: null
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${PATRONI_MASTER_SERVICE_NAME}
+  spec:
+    ports:
+    - port: 5432
+      protocol: TCP
+      targetPort: 5432
+    selector:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+      role: master
+    sessionAffinity: None
+    type: ClusterIP
+  status:
+    loadBalancer: {}
+- apiVersion: v1
+  kind: Secret
+  metadata:
+    name: ${PATRONI_CLUSTER_NAME}
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+  stringData:
+    superuser-password: ${PATRONI_SUPERUSER_PASSWORD}
+    replication-password: ${PATRONI_REPLICATION_PASSWORD}
+- apiVersion: v1
+  kind: Service
+  metadata:
+    creationTimestamp: null
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${PATRONI_REPLICA_SERVICE_NAME}
+  spec:
+    ports:
+    - port: 5432
+      protocol: TCP
+      targetPort: 5432
+    selector:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+      role: replica
+    sessionAffinity: None
+    type: ClusterIP
+  status:
+    loadBalancer: {}
+- apiVersion: apps/v1
+  kind: StatefulSet
+  metadata:
+    creationTimestamp: null
+    generation: 3
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+    name: ${APPLICATION_NAME}
+  spec:
+    podManagementPolicy: OrderedReady
+    replicas: 3
+    revisionHistoryLimit: 10
+    selector:
+      matchLabels:
+        application: ${APPLICATION_NAME}
+        cluster-name: ${PATRONI_CLUSTER_NAME}
+    serviceName: ${APPLICATION_NAME}
+    template:
+      metadata:
+        creationTimestamp: null
+        labels:
+          application: ${APPLICATION_NAME}
+          cluster-name: ${PATRONI_CLUSTER_NAME}
+      spec:
+        containers:
+        - env:
+          - name: PATRONI_KUBERNETES_POD_IP
+            valueFrom:
+              fieldRef:
+                apiVersion: v1
+                fieldPath: status.podIP
+          - name: PATRONI_KUBERNETES_NAMESPACE
+            valueFrom:
+              fieldRef:
+                apiVersion: v1
+                fieldPath: metadata.namespace
+          - name: PATRONI_KUBERNETES_LABELS
+            value: '{application: ${APPLICATION_NAME}, cluster-name: ${PATRONI_CLUSTER_NAME}}'
+          - name: PATRONI_SUPERUSER_USERNAME
+            value: ${PATRONI_SUPERUSER_USERNAME}
+          - name: PATRONI_SUPERUSER_PASSWORD
+            valueFrom:
+              secretKeyRef:
+                key: superuser-password
+                name: ${PATRONI_CLUSTER_NAME}
+          - name: PATRONI_REPLICATION_USERNAME
+            value: ${PATRONI_REPLICATION_USERNAME}
+          - name: PATRONI_REPLICATION_PASSWORD
+            valueFrom:
+              secretKeyRef:
+                key: replication-password
+                name: ${PATRONI_CLUSTER_NAME}
+          - name: PATRONI_SCOPE
+            value: ${PATRONI_CLUSTER_NAME}
+          - name: PATRONI_NAME
+            valueFrom:
+              fieldRef:
+                apiVersion: v1
+                fieldPath: metadata.name
+          - name: PATRONI_POSTGRESQL_DATA_DIR
+            value: /home/postgres/pgdata/pgroot/data
+          - name: PATRONI_POSTGRESQL_PGPASS
+            value: /tmp/pgpass
+          - name: PATRONI_POSTGRESQL_LISTEN
+            value: 0.0.0.0:5432
+          - name: PATRONI_RESTAPI_LISTEN
+            value: 0.0.0.0:8008
+          image: docker-registry.default.svc:5000/${NAMESPACE}/patroni:latest
+          imagePullPolicy: IfNotPresent
+          name: ${APPLICATION_NAME}
+          ports:
+          - containerPort: 8008
+            protocol: TCP
+          - containerPort: 5432
+            protocol: TCP
+          resources: {}
+          terminationMessagePath: /dev/termination-log
+          terminationMessagePolicy: File
+          volumeMounts:
+          - mountPath: /home/postgres/pgdata
+            name: ${APPLICATION_NAME}
+        dnsPolicy: ClusterFirst
+        restartPolicy: Always
+        schedulerName: default-scheduler
+        securityContext: {}
+        serviceAccount: ${SERVICE_ACCOUNT}
+        serviceAccountName: ${SERVICE_ACCOUNT}
+        terminationGracePeriodSeconds: 0
+        volumes:
+        - name: ${APPLICATION_NAME}
+          persistentVolumeClaim: 
+            claimName: ${APPLICATION_NAME}
+    volumeClaimTemplates:
+    - metadata:
+        labels:
+          application: ${APPLICATION_NAME}
+        name: ${APPLICATION_NAME}
+      spec:
+        accessModes:
+        - ReadWriteOnce
+        resources:
+          requests:
+            storage: ${PVC_SIZE}
+    updateStrategy:
+      type: OnDelete
+- apiVersion: v1
+  kind: Endpoints
+  metadata:
+    name: ${APPLICATION_NAME}
+    labels:
+      application: ${APPLICATION_NAME}
+      cluster-name: ${PATRONI_CLUSTER_NAME}
+  subsets: []
+- apiVersion: v1
+  kind: ServiceAccount
+  metadata:
+    name: ${SERVICE_ACCOUNT}
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: Role
+  metadata:
+    name: ${SERVICE_ACCOUNT}
+  rules:
+  - apiGroups:
+    - ""
+    resources:
+    - configmaps
+    verbs:
+    - create
+    - get
+    - list
+    - patch
+    - update
+    - watch
+    # delete is required only for 'patronictl remove'
+    - delete
+  - apiGroups:
+    - ""
+    resources:
+    - endpoints
+    verbs:
+    - get
+    - patch
+    - update
+    # the following three privileges are necessary only when using endpoints
+    - create
+    - list
+    - watch
+    # delete is required only for for 'patronictl remove'
+    - delete
+  - apiGroups:
+    - ""
+    resources:
+    - pods
+    verbs:
+    - get
+    - list
+    - patch
+    - update
+    - watch
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: RoleBinding
+  metadata:
+    name: ${SERVICE_ACCOUNT}
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: Role
+    name: ${SERVICE_ACCOUNT}
+  subjects:
+  - kind: ServiceAccount
+    name: ${SERVICE_ACCOUNT}
+parameters:
+- description: The name of the application for labelling all artifacts.
+  displayName: Application Name
+  name: APPLICATION_NAME
+  value: patroni-persistent
+- description: The name of the patroni-pgsql cluster.
+  displayName: Cluster Name
+  name: PATRONI_CLUSTER_NAME
+  value: patroni-persistent
+- description: The name of the OpenShift Service exposed for the patroni-persistent-master container.
+  displayName: Master service name.  
+  name: PATRONI_MASTER_SERVICE_NAME
+  value: patroni-persistent-master
+- description: The name of the OpenShift Service exposed for the patroni-persistent-replica containers.
+  displayName: Replica service name. 
+  name: PATRONI_REPLICA_SERVICE_NAME
+  value: patroni-persistent-replica
+- description: Maximum amount of memory the container can use.
+  displayName: Memory Limit
+  name: MEMORY_LIMIT
+  value: 512Mi
+- description: The OpenShift Namespace where the patroni and postgresql ImageStream resides.
+  displayName: ImageStream Namespace
+  name: NAMESPACE
+  value: openshift
+- description: Username of the superuser account for initialization.
+  displayName: Superuser Username
+  name: PATRONI_SUPERUSER_USERNAME
+  value: postgres
+- description: Password of the superuser account for initialization.
+  displayName: Superuser Passsword
+  name: PATRONI_SUPERUSER_PASSWORD
+  value: postgres
+- description: Username of the replication account for initialization.
+  displayName: Replication Username
+  name: PATRONI_REPLICATION_USERNAME
+  value: postgres
+- description: Password of the replication account for initialization.
+  displayName: Repication Passsword
+  name: PATRONI_REPLICATION_PASSWORD
+  value: postgres
+- description: Service account name used for pods and rolebindings to form a cluster in the project. 
+  displayName: Service Account
+  name: SERVICE_ACCOUNT
+  value: patroni-persistent
+- description: The size of the persistent volume to create. 
+  displayName: Persistent Volume Size
+  name: PVC_SIZE
+  value: 5Gi

kubernetes/openshift-example/test/Jenkinsfile

@@ -0,0 +1,43 @@
+pipeline {
+  agent any
+  stages {
+    stage ('Deploy test pod'){
+      when {
+          expression {
+            openshift.withCluster() {
+              openshift.withProject() {
+                return !openshift.selector( "dc", "pgbench" ).exists()
+              }
+            }
+          }
+        }
+      steps {
+        script {
+            openshift.withCluster() {
+                openshift.withProject() {
+                  def pgbench = openshift.newApp( "https://github.com/stewartshea/docker-pgbench/", "--name=pgbench", "-e PGPASSWORD=postgres", "-e PGUSER=postgres", "-e PGHOST=patroni-persistent-master", "-e PGDATABASE=postgres", "-e TEST_CLIENT_COUNT=20", "-e TEST_DURATION=120" )
+                  def pgbenchdc = openshift.selector( "dc", "pgbench" )
+                  timeout(5) { 
+                    pgbenchdc.rollout().status()
+                    }
+                  }
+                }
+            }
+        }
+    }
+    stage ('Run benchmark Test'){
+      steps {
+          sh '''
+          oc exec $(oc get pods -l app=pgbench | grep Running | awk '{print $1}')  ./test.sh
+          '''
+      }
+    }
+    stage ('Clean up pgtest pod'){
+      steps {
+          sh '''
+          oc delete all -l app=pgbench
+          '''
+      }
+    }
+  }
+}

kubernetes/openshift-example/test/README.md

@@ -0,0 +1,2 @@
+# Jenkins Test
+This pipeline test will create a separate deployment config for a pgbench pod and execute a test against the patroni cluster. This is a sample and should be customized. 

kubernetes/patroni_k8s.yaml

@@ -1,3 +1,15 @@
+# headless service to avoid deletion of patronidemo-config endpoint
+apiVersion: v1
+kind: Service
+metadata:
+  name: patronidemo-config
+  labels:
+    application: patroni
+    cluster-name: patronidemo
+spec:
+  clusterIP: None
+
+---
 apiVersion: apps/v1beta1
 kind: StatefulSet
 metadata:
@@ -14,6 +26,7 @@ spec:
         application: patroni
         cluster-name: *cluster_name
     spec:
+      serviceAccountName: patronidemo
       containers:
       - name: *cluster_name
         image: patroni  # docker build -t patroni .
@@ -27,7 +40,7 @@ spec:
         - mountPath: /home/postgres/pgdata
           name: pgdata
         env:
-        - name: POD_IP
+        - name: PATRONI_KUBERNETES_POD_IP
           valueFrom:
             fieldRef:
               fieldPath: status.podIP
@@ -35,6 +48,8 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
+        - name: PATRONI_KUBERNETES_USE_ENDPOINTS
+          value: 'true'
         - name: PATRONI_KUBERNETES_LABELS
           value: '{application: patroni, cluster-name: patronidemo}'
         - name: PATRONI_SUPERUSER_USERNAME
@@ -120,3 +135,78 @@ type: Opaque
 data:
   superuser-password: emFsYW5kbw==
   replication-password: cmVwLXBhc3M=
+
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: patronidemo
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: patronidemo
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - configmaps
+  verbs:
+  - create
+  - get
+  - list
+  - patch
+  - update
+  - watch
+  # delete and deletecollection are required only for 'patronictl remove'
+  - delete
+  - deletecollection
+- apiGroups:
+  - ""
+  resources:
+  - endpoints
+  verbs:
+  - get
+  - patch
+  - update
+  # the following three privileges are necessary only when using endpoints
+  - create
+  - list
+  - watch
+  # delete and deletecollection are required only for for 'patronictl remove'
+  - delete
+  - deletecollection
+- apiGroups:
+  - ""
+  resources:
+  - pods
+  verbs:
+  - get
+  - list
+  - patch
+  - update
+  - watch
+# The following privilege is only necessary for creation of headless service
+# for patronidemo-config endpoint, in order to prevent cleaning it up by the
+# k8s master. You can avoid giving this privilege by explicitly creating the
+# service like it is done in this manifest (lines 2..10)
+- apiGroups:
+  - ""
+  resources:
+  - services
+  verbs:
+  - create
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: patronidemo
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: patronidemo
+subjects:
+- kind: ServiceAccount
+  name: patronidemo

patroni/__init__.py

@@ -4,30 +4,37 @@ import signal
 import sys
 import time
 
+from patroni.version import __version__
+
 logger = logging.getLogger(__name__)
 
+PATRONI_ENV_PREFIX = 'PATRONI_'
+
 
 class Patroni(object):
 
-    def __init__(self):
+    def __init__(self, conf):
         from patroni.api import RestApiServer
-        from patroni.config import Config
         from patroni.dcs import get_dcs
         from patroni.ha import Ha
+        from patroni.log import PatroniLogger
         from patroni.postgresql import Postgresql
-        from patroni.version import __version__
+        from patroni.request import PatroniRequest
         from patroni.watchdog import Watchdog
 
         self.setup_signal_handlers()
 
         self.version = __version__
-        self.config = Config()
+        self.logger = PatroniLogger()
+        self.config = conf
+        self.logger.reload_config(self.config.get('log', {}))
         self.dcs = get_dcs(self.config)
         self.watchdog = Watchdog(self.config)
         self.load_dynamic_configuration()
 
         self.postgresql = Postgresql(self.config['postgresql'])
         self.api = RestApiServer(self, self.config['restapi'])
+        self.request = PatroniRequest(self.config, True)
         self.ha = Ha(self)
 
         self.tags = self.get_tags()
@@ -49,6 +56,7 @@ class Patroni(object):
                 break
             except DCSError:
                 logger.warning('Can not get cluster from dcs')
+                time.sleep(5)
 
     def get_tags(self):
         return {tag: value for tag, value in self.config.get('tags', {}).items()
@@ -62,13 +70,16 @@ class Patroni(object):
     def nosync(self):
         return bool(self.tags.get('nosync', False))
 
-    def reload_config(self):
+    def reload_config(self, sighup=False):
         try:
             self.tags = self.get_tags()
-            self.dcs.reload_config(self.config)
+            self.logger.reload_config(self.config.get('log', {}))
             self.watchdog.reload_config(self.config)
+            if sighup:
+                self.request.reload_config(self.config)
             self.api.reload_config(self.config['restapi'])
-            self.postgresql.reload_config(self.config['postgresql'])
+            self.postgresql.reload_config(self.config['postgresql'], sighup)
+            self.dcs.reload_config(self.config)
         except Exception:
             logger.exception('Failed to reload config_file=%s', self.config.config_file)
 
@@ -80,9 +91,10 @@ class Patroni(object):
         self._received_sighup = True
 
     def sigterm_handler(self, *args):
-        if not self._received_sigterm:
-            self._received_sigterm = True
-            sys.exit()
+        with self._sigterm_lock:
+            if not self._received_sigterm:
+                self._received_sigterm = True
+                sys.exit()
 
     @property
     def noloadbalance(self):
@@ -101,15 +113,23 @@ class Patroni(object):
         elif self.ha.watch(nap_time):
             self.next_run = time.time()
 
+    @property
+    def received_sigterm(self):
+        with self._sigterm_lock:
+            return self._received_sigterm
+
     def run(self):
         self.api.start()
+        self.logger.start()
         self.next_run = time.time()
 
-        while not self._received_sigterm:
+        while not self.received_sigterm:
             if self._received_sighup:
                 self._received_sighup = False
                 if self.config.reload_local_configuration():
-                    self.reload_config()
+                    self.reload_config(True)
+                else:
+                    self.postgresql.config.reload_config(self.config['postgresql'], True)
 
             logger.info(self.ha.run_cycle())
 
@@ -123,22 +143,44 @@ class Patroni(object):
             self.schedule_next_run()
 
     def setup_signal_handlers(self):
+        from threading import Lock
+
         self._received_sighup = False
+        self._sigterm_lock = Lock()
         self._received_sigterm = False
-        signal.signal(signal.SIGHUP, self.sighup_handler)
+        if os.name != 'nt':
+            signal.signal(signal.SIGHUP, self.sighup_handler)
         signal.signal(signal.SIGTERM, self.sigterm_handler)
 
     def shutdown(self):
-        self.api.shutdown()
+        with self._sigterm_lock:
+            self._received_sigterm = True
+        try:
+            self.api.shutdown()
+        except Exception:
+            logger.exception('Exception during RestApi.shutdown')
         self.ha.shutdown()
+        self.logger.shutdown()
 
 
 def patroni_main():
-    logformat = os.environ.get('PATRONI_LOGFORMAT', '%(asctime)s %(levelname)s: %(message)s')
-    logging.basicConfig(format=logformat, level=logging.INFO)
-    logging.getLogger('requests').setLevel(logging.WARNING)
+    import argparse
+    from patroni.config import Config, ConfigParseError
 
-    patroni = Patroni()
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--version', action='version', version='%(prog)s {0}'.format(__version__))
+    parser.add_argument('configfile', nargs='?', default='',
+                        help='Patroni may also read the configuration from the {0} environment variable'
+                        .format(Config.PATRONI_CONFIG_VARIABLE))
+    args = parser.parse_args()
+    try:
+        conf = Config(args.configfile)
+    except ConfigParseError as e:
+        if e.value:
+            print(e.value)
+        parser.print_help()
+        sys.exit(1)
+    patroni = Patroni(conf)
     try:
         patroni.run()
     except KeyboardInterrupt:
@@ -147,32 +189,38 @@ def patroni_main():
         patroni.shutdown()
 
 
-def pg_ctl_start(args):
-    import subprocess
-    postmaster = subprocess.Popen(args)
-    print(postmaster.pid)
+def fatal(string, *args):
+    sys.stderr.write('FATAL: ' + string.format(*args) + '\n')
+    sys.exit(1)
 
 
-def call_self(args, **kwargs):
-    """This function executes Patroni once again with provided arguments.
+def check_psycopg2():
+    min_psycopg2 = (2, 5, 4)
+    min_psycopg2_str = '.'.join(map(str, min_psycopg2))
 
-    :args: list of arguments to call Patroni with.
-    :returns: `Popen` object"""
+    def parse_version(version):
+        for e in version.split('.'):
+            try:
+                yield int(e)
+            except ValueError:
+                break
 
-    exe = [sys.executable]
-    if not getattr(sys, 'frozen', False):  # Binary distribution?
-        exe.append(sys.argv[0])
-
-    import subprocess
-    return subprocess.Popen(exe + args, **kwargs)
+    try:
+        import psycopg2
+        version_str = psycopg2.__version__.split(' ')[0]
+        version = tuple(parse_version(version_str))
+        if version < min_psycopg2:
+            fatal('Patroni requires psycopg2>={0}, but only {1} is available', min_psycopg2_str, version_str)
+    except ImportError:
+        fatal('Patroni requires psycopg2>={0} or psycopg2-binary', min_psycopg2_str)
 
 
 def main():
     if os.getpid() != 1:
-        if len(sys.argv) > 5 and sys.argv[1] == 'pg_ctl_start':
-            return pg_ctl_start(sys.argv[2:])
+        check_psycopg2()
         return patroni_main()
 
+    # Patroni started with PID=1, it looks like we are in the container
     pid = 0
 
     # Looks like we are in a docker, so we will act like init
@@ -183,7 +231,7 @@ def main():
                 if ret == (0, 0):
                     break
                 elif ret[0] != pid:
-                    logging.info('Reaped pid=%s, exit status=%s', *ret)
+                    logger.info('Reaped pid=%s, exit status=%s', *ret)
         except OSError:
             pass
 
@@ -191,14 +239,18 @@ def main():
         if pid:
             os.kill(pid, signo)
 
-    signal.signal(signal.SIGCHLD, sigchld_handler)
-    signal.signal(signal.SIGHUP, passtochild)
+    if os.name != 'nt':
+        signal.signal(signal.SIGCHLD, sigchld_handler)
+        signal.signal(signal.SIGHUP, passtochild)
+        signal.signal(signal.SIGQUIT, passtochild)
+        signal.signal(signal.SIGUSR1, passtochild)
+        signal.signal(signal.SIGUSR2, passtochild)
     signal.signal(signal.SIGINT, passtochild)
-    signal.signal(signal.SIGUSR1, passtochild)
-    signal.signal(signal.SIGUSR2, passtochild)
-    signal.signal(signal.SIGQUIT, passtochild)
+    signal.signal(signal.SIGABRT, passtochild)
     signal.signal(signal.SIGTERM, passtochild)
 
-    patroni = call_self(sys.argv[1:])
+    import multiprocessing
+    patroni = multiprocessing.Process(target=patroni_main)
+    patroni.start()
     pid = patroni.pid
-    patroni.wait()
+    patroni.join()

patroni/api.py

@@ -1,14 +1,19 @@
 import base64
-import fcntl
 import json
 import logging
 import psycopg2
 import time
+import traceback
 import dateutil.parser
 import datetime
+import os
+import six
+import socket
 
-from patroni.postgresql import PostgresConnectionException, PostgresException, Postgresql
-from patroni.utils import deep_compare, parse_bool, patch_config, Retry, RetryFailedError, parse_int, tzutc
+from patroni.exceptions import PostgresConnectionException, PostgresException
+from patroni.postgresql.misc import postgres_version_to_int
+from patroni.utils import deep_compare, parse_bool, patch_config, Retry, \
+    RetryFailedError, parse_int, split_host_port, tzutc, uri, cluster_as_json
 from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from six.moves.socketserver import ThreadingMixIn
 from threading import Thread
@@ -16,20 +21,6 @@ from threading import Thread
 logger = logging.getLogger(__name__)
 
 
-def check_auth(func):
-    """Decorator function to check authorization header.
-
-    Usage example:
-    @check_auth
-    def do_PUT_foo():
-        pass
-    """
-    def wrapper(handler, *args, **kwargs):
-        if handler.check_auth_header():
-            return func(handler, *args, **kwargs)
-    return wrapper
-
-
 class RestApiHandler(BaseHTTPRequestHandler):
 
     def _write_response(self, status_code, body, content_type='text/html', headers=None):
@@ -45,14 +36,20 @@ class RestApiHandler(BaseHTTPRequestHandler):
     def _write_json_response(self, status_code, response):
         self._write_response(status_code, json.dumps(response), content_type='application/json')
 
-    def send_auth_request(self, body):
-        headers = {'WWW-Authenticate': 'Basic realm="' + self.server.patroni.__class__.__name__ + '"'}
-        self._write_response(401, body, headers=headers)
+    def check_auth(func):
+        """Decorator function to check authorization header or client certificates
 
-    def check_auth_header(self):
-        auth_header = self.headers.get('Authorization')
-        status = self.server.check_auth_header(auth_header)
-        return not status or self.send_auth_request(status)
+        Usage example:
+        @check_auth
+        def do_PUT_foo():
+            pass
+        """
+
+        def wrapper(self, *args, **kwargs):
+            if self.server.check_auth(self):
+                return func(self, *args, **kwargs)
+
+        return wrapper
 
     def _write_status_response(self, status_code, response):
         patroni = self.server.patroni
@@ -72,46 +69,52 @@ class RestApiHandler(BaseHTTPRequestHandler):
             response['watchdog_failed'] = True
         if patroni.ha.is_paused():
             response['pause'] = True
+        qsize = patroni.logger.queue_size
+        if qsize > patroni.logger.NORMAL_LOG_QUEUE_SIZE:
+            response['logger_queue_size'] = qsize
+            lost = patroni.logger.records_lost
+            if lost:
+                response['logger_records_lost'] = lost
         self._write_json_response(status_code, response)
 
     def do_GET(self, write_status_code_only=False):
         """Default method for processing all GET requests which can not be routed to other methods"""
 
+        time_start = time.time()
+        request_type = 'OPTIONS' if write_status_code_only else 'GET'
+
         path = '/master' if self.path == '/' else self.path
         response = self.get_postgresql_status()
 
         patroni = self.server.patroni
         cluster = patroni.dcs.cluster
 
-        def is_synchronous():
-            return (cluster.is_synchronous_mode() and cluster.sync
-                    and cluster.sync.sync_standby == patroni.postgresql.name)
-
-        def is_balanceable_replica():
-            return response.get('role') == 'replica' and not patroni.noloadbalance
-
-        if cluster:  # dcs available
-            if cluster.leader and cluster.leader.name == patroni.postgresql.name:  # is_leader
-                status_code = 200 if 'master' in path else 503
-            elif 'role' not in response:
-                status_code = 503
-            elif response['role'] == 'master':  # running as master but without leader lock!!!!
-                status_code = 503
-            elif path in ('/sync', '/synchronous'):
-                status_code = 200 if is_balanceable_replica() and is_synchronous() else 503
-            elif path in ('/async', '/asynchronous'):
-                status_code = 200 if is_balanceable_replica() and not is_synchronous() else 503
-            elif response['role'] in path:  # response['role'] != 'master'
-                status_code = 503 if patroni.noloadbalance else 200
-            else:
-                status_code = 503
-        elif 'role' in response and response['role'] in path:
-            status_code = 503 if response['role'] != 'master' and patroni.noloadbalance else 200
-        elif patroni.ha.restart_scheduled() and patroni.postgresql.role == 'master' and 'master' in path:
-            # exceptional case for master node when the postgres is being restarted via API
-            status_code = 200
+        if not cluster and patroni.ha.is_paused():
+            primary_status_code = 200 if response['role'] == 'master' else 503
         else:
-            status_code = 503
+            primary_status_code = 200 if patroni.ha.is_leader() else 503
+
+        replica_status_code = 200 if not patroni.noloadbalance and \
+            response.get('role') == 'replica' and response.get('state') == 'running' else 503
+        status_code = 503
+
+        if patroni.ha.is_standby_cluster() and ('standby_leader' in path or 'standby-leader' in path):
+            status_code = 200 if patroni.ha.is_leader() else 503
+        elif 'master' in path or 'leader' in path or 'primary' in path or 'read-write' in path:
+            status_code = primary_status_code
+        elif 'replica' in path:
+            status_code = replica_status_code
+        elif 'read-only' in path:
+            status_code = 200 if primary_status_code == 200 else replica_status_code
+        elif 'health' in path:
+            status_code = 200 if response.get('state') == 'running' else 503
+        elif cluster:  # dcs is available
+            is_synchronous = cluster.is_synchronous_mode() and cluster.sync \
+                    and cluster.sync.sync_standby == patroni.postgresql.name
+            if path in ('/sync', '/synchronous') and is_synchronous:
+                status_code = replica_status_code
+            elif path in ('/async', '/asynchronous') and not is_synchronous:
+                status_code = replica_status_code
 
         if write_status_code_only:  # when haproxy sends OPTIONS request it reads only status code and nothing more
             message = self.responses[status_code][0]
@@ -119,6 +122,10 @@ class RestApiHandler(BaseHTTPRequestHandler):
         else:
             self._write_status_response(status_code, response)
 
+        time_end = time.time()
+        self.log_message('%s %s %s latency: %s ms', request_type, path,
+                         status_code, (time_end - time_start) * 1000)
+
     def do_OPTIONS(self):
         self.do_GET(write_status_code_only=True)
 
@@ -126,6 +133,14 @@ class RestApiHandler(BaseHTTPRequestHandler):
         response = self.get_postgresql_status(True)
         self._write_status_response(200, response)
 
+    def do_GET_cluster(self):
+        cluster = self.server.patroni.dcs.cluster or self.server.patroni.dcs.get_cluster()
+        self._write_json_response(200, cluster_as_json(cluster))
+
+    def do_GET_history(self):
+        cluster = self.server.patroni.dcs.cluster or self.server.patroni.dcs.get_cluster()
+        self._write_json_response(200, cluster.history and cluster.history.lines or [])
+
     def do_GET_config(self):
         cluster = self.server.patroni.dcs.cluster or self.server.patroni.dcs.get_cluster()
         if cluster.config:
@@ -173,18 +188,8 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     @check_auth
     def do_POST_reload(self):
-        try:
-            if self.server.patroni.config.reload_local_configuration(True):
-                status_code = 202
-                response = 'reload scheduled'
-                self.server.patroni.sighup_handler()
-            else:
-                status_code = 200
-                response = 'nothing changed'
-        except Exception as e:
-            status_code = 500
-            response = str(e)
-        self._write_response(status_code, response)
+        self.server.patroni.sighup_handler()
+        self._write_response(202, 'reload scheduled')
 
     @staticmethod
     def parse_schedule(schedule, action):
@@ -236,7 +241,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     break
             elif k == 'postgres_version':
                 try:
-                    Postgresql.postgres_version_to_int(request[k])
+                    postgres_version_to_int(request[k])
                 except PostgresException as e:
                     status_code = 400
                     data = e.value
@@ -295,22 +300,23 @@ class RestApiHandler(BaseHTTPRequestHandler):
             status_code = 503
         self._write_response(status_code, data)
 
-    def poll_failover_result(self, leader, candidate):
+    def poll_failover_result(self, leader, candidate, action):
         timeout = max(10, self.server.patroni.dcs.loop_wait)
         for _ in range(0, timeout*2):
             time.sleep(1)
             try:
                 cluster = self.server.patroni.dcs.get_cluster()
-                if cluster.leader and cluster.leader.name != leader:
+                if not cluster.is_unlocked() and cluster.leader.name != leader:
                     if not candidate or candidate == cluster.leader.name:
-                        return 200, 'Successfully failed over to "{0}"'.format(cluster.leader.name)
+                        return 200, 'Successfully {0}ed over to "{1}"'.format(action[:-4], cluster.leader.name)
                     else:
-                        return 200, 'Failed over to "{0}" instead of "{1}"'.format(cluster.leader.name, candidate)
+                        return 200, '{0}ed over to "{1}" instead of "{2}"'.format(action[:-4].title(),
+                                                                                  cluster.leader.name, candidate)
                 if not cluster.failover:
-                    return 503, 'Failover failed'
+                    return 503, action.title() + ' failed'
             except Exception as e:
-                logger.debug('Exception occured during polling failover result: %s', e)
-        return 503, 'Failover status unknown'
+                logger.debug('Exception occured during polling %s result: %s', action, e)
+        return 503, action.title() + ' status unknown'
 
     def is_failover_possible(self, cluster, leader, candidate, action):
         if leader and (not cluster.leader or cluster.leader.name != leader):
@@ -377,7 +383,8 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     data = action.title() + ' scheduled'
                     status_code = 202
                 else:
-                    status_code, data = self.poll_failover_result(cluster.leader and cluster.leader.name, candidate)
+                    status_code, data = self.poll_failover_result(cluster.leader and cluster.leader.name,
+                                                                  candidate, action)
             else:
                 data = 'failed to write {0} key into DCS'.format(action)
                 status_code = 503
@@ -412,21 +419,25 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     def get_postgresql_status(self, retry=False):
         try:
+            cluster = self.server.patroni.dcs.cluster
+
             if self.server.patroni.postgresql.state not in ('running', 'restarting', 'starting'):
                 raise RetryFailedError('')
-            stmt = ("WITH replication_info AS ("
-                    "SELECT usename, application_name, client_addr, state, sync_state, sync_priority"
-                    " FROM pg_stat_replication) SELECT"
-                    " to_char(pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),"
-                    " CASE WHEN pg_is_in_recovery() THEN 0"
-                    " ELSE ('x' || SUBSTR(pg_{0}file_name(pg_current_{0}_{1}()), 1, 8))::bit(32)::int END,"
-                    " CASE WHEN pg_is_in_recovery() THEN 0"
-                    " ELSE pg_{0}_{1}_diff(pg_current_{0}_{1}(), '0/0')::bigint END,"
-                    " pg_{0}_{1}_diff(COALESCE(pg_last_{0}_receive_{1}(), pg_last_{0}_replay_{1}()), '0/0')::bigint,"
-                    " pg_{0}_{1}_diff(pg_last_{0}_replay_{1}(), '0/0')::bigint,"
-                    " to_char(pg_last_xact_replay_timestamp(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),"
-                    " pg_is_in_recovery() AND pg_is_{0}_replay_paused(),"
-                    " (SELECT array_to_json(array_agg(row_to_json(ri))) FROM replication_info ri)")
+            stmt = ("SELECT pg_catalog.to_char(pg_catalog.pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),"
+                    " CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0"
+                    " ELSE ('x' || pg_catalog.substr(pg_catalog.pg_{0}file_name("
+                    "pg_catalog.pg_current_{0}_{1}()), 1, 8))::bit(32)::int END,"
+                    " CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0"
+                    " ELSE pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_current_{0}_{1}(), '0/0')::bigint END,"
+                    " pg_catalog.pg_{0}_{1}_diff(COALESCE(pg_catalog.pg_last_{0}_receive_{1}(),"
+                    " pg_catalog.pg_last_{0}_replay_{1}()), '0/0')::bigint,"
+                    " pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_last_{0}_replay_{1}(), '0/0')::bigint,"
+                    " pg_catalog.to_char(pg_catalog.pg_last_xact_replay_timestamp(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),"
+                    " pg_catalog.pg_is_in_recovery() AND pg_catalog.pg_is_{0}_replay_paused(), "
+                    " pg_catalog.array_to_json(pg_catalog.array_agg(pg_catalog.row_to_json(ri))) "
+                    "FROM (SELECT (SELECT rolname FROM pg_authid WHERE oid = usesysid) AS usename,"
+                    " application_name, client_addr, w.state, sync_state, sync_priority"
+                    " FROM pg_catalog.pg_stat_get_wal_senders() w, pg_catalog.pg_stat_get_activity(pid)) AS ri")
 
             row = self.query(stmt.format(self.server.patroni.postgresql.wal_name,
                                          self.server.patroni.postgresql.lsn_name), retry=retry)[0]
@@ -436,6 +447,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 'postmaster_start_time': row[0],
                 'role': 'replica' if row[1] == 0 else 'master',
                 'server_version': self.server.patroni.postgresql.server_version,
+                'cluster_unlocked': bool(not cluster or cluster.is_unlocked()),
                 'xlog': ({
                     'received_location': row[3],
                     'replayed_location': row[4],
@@ -445,10 +457,12 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 })
             }
 
+            if result['role'] == 'replica' and self.server.patroni.ha.is_standby_cluster():
+                result['role'] = self.server.patroni.postgresql.role
+
             if row[1] > 0:
                 result['timeline'] = row[1]
             else:
-                cluster = self.server.patroni.dcs.cluster
                 leader_timeline = None if not cluster or cluster.is_unlocked() else cluster.leader.timeline
                 result['timeline'] = self.server.patroni.postgresql.replica_cached_timeline(leader_timeline)
 
@@ -468,11 +482,14 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
 
 class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
+    # On 3.7+ the `ThreadingMixIn` gathers all non-daemon worker threads in order to join on them at server close.
+    daemon_threads = True  # Make worker threads "fire and forget" to prevent a memory leak.
 
     def __init__(self, patroni, config):
         self.patroni = patroni
-        self.__initialize(config)
-        self.__set_config_parameters(config)
+        self.__listen = None
+        self.__ssl_options = None
+        self.reload_config(config)
         self.daemon = True
 
     def query(self, sql, *params):
@@ -488,8 +505,10 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
 
     @staticmethod
     def _set_fd_cloexec(fd):
-        flags = fcntl.fcntl(fd, fcntl.F_GETFD)
-        fcntl.fcntl(fd, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)
+        if os.name != 'nt':
+            import fcntl
+            flags = fcntl.fcntl(fd, fcntl.F_GETFD)
+            fcntl.fcntl(fd, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)
 
     def check_basic_auth_key(self, key):
         return self.__auth_key == key
@@ -501,38 +520,102 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
             if not auth_header.startswith('Basic ') or not self.check_basic_auth_key(auth_header[6:]):
                 return 'not authenticated'
 
+    def check_auth(self, rh):
+        if not hasattr(rh.request, 'getpeercert') or not rh.request.getpeercert():  # valid client cert isn't present
+            if self.__protocol == 'https' and self.__ssl_options.get('verify_client') in ('required', 'optional'):
+                return rh._write_response(403, 'client certificate required')
+
+            reason = self.check_auth_header(rh.headers.get('Authorization'))
+            if reason:
+                headers = {'WWW-Authenticate': 'Basic realm="' + self.patroni.__class__.__name__ + '"'}
+                return rh._write_response(401, reason, headers=headers)
+        return True
+
     @staticmethod
-    def __get_ssl_options(config):
-        return {option: config[option] for option in ['certfile', 'keyfile'] if option in config}
+    def __has_dual_stack():
+        if hasattr(socket, 'AF_INET6') and hasattr(socket, 'IPPROTO_IPV6') and hasattr(socket, 'IPV6_V6ONLY'):
+            sock = None
+            try:
+                sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
+                sock.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, False)
+                return True
+            except socket.error as e:
+                logger.debug('Error when working with ipv6 socket: %s', e)
+            finally:
+                if sock:
+                    sock.close()
+        return False
 
-    def __set_connection_string(self, connect_address):
-        self.connection_string = '{0}://{1}/patroni'.format(self.__protocol, connect_address or self.__listen)
+    def __httpserver_init(self, host, port):
+        dual_stack = self.__has_dual_stack()
+        if host in ('', '*'):
+            host = None
 
-    def __set_config_parameters(self, config):
-        self.__auth_key = base64.b64encode(config['auth'].encode('utf-8')).decode('utf-8') if 'auth' in config else None
-        self.__set_connection_string(config.get('connect_address'))
+        info = socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE)
+        # in case dual stack is not supported we want IPv4 to be preferred over IPv6
+        info.sort(key=lambda x: x[0] == socket.AF_INET, reverse=not dual_stack)
 
-    def __initialize(self, config):
-        self.__ssl_options = self.__get_ssl_options(config)
-        self.__listen = config['listen']
-        host, port = config['listen'].rsplit(':', 1)
-        HTTPServer.__init__(self, (host, int(port)), RestApiHandler)
+        self.address_family = info[0][0]
+        try:
+            HTTPServer.__init__(self, info[0][-1][:2], RestApiHandler)
+        except socket.error:
+            logger.error(
+                    "Couldn't start a service on '%s:%s', please check your `restapi.listen` configuration", host, port)
+            raise
+
+    def __initialize(self, listen, ssl_options):
+        try:
+            host, port = split_host_port(listen, None)
+        except Exception:
+            raise ValueError('Invalid "restapi" config: expected <HOST>:<PORT> for "listen", but got "{0}"'
+                             .format(listen))
+
+        reloading_config = self.__listen is not None  # changing config in runtime
+        if reloading_config:
+            self.shutdown()
+
+        self.__listen = listen
+        self.__ssl_options = ssl_options
+
+        self.__httpserver_init(host, port)
         Thread.__init__(self, target=self.serve_forever)
         self._set_fd_cloexec(self.socket)
 
-        self.__protocol = 'http'
-
         # wrap socket with ssl if 'certfile' is defined in a config.yaml
         # Sometime it's also needed to pass reference to a 'keyfile'.
-        if self.__ssl_options.get('certfile'):
+        self.__protocol = 'https' if ssl_options.get('certfile') else 'http'
+        if self.__protocol == 'https':
             import ssl
-            self.socket = ssl.wrap_socket(self.socket, server_side=True, **self.__ssl_options)
-            self.__protocol = 'https'
-        self.__set_connection_string(config.get('connect_address'))
+            ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH, cafile=ssl_options.get('cafile'))
+            ctx.load_cert_chain(certfile=ssl_options['certfile'], keyfile=ssl_options.get('keyfile'))
+            verify_client = ssl_options.get('verify_client')
+            if verify_client:
+                modes = {'none': ssl.CERT_NONE, 'optional': ssl.CERT_OPTIONAL, 'required': ssl.CERT_REQUIRED}
+                if verify_client in modes:
+                    ctx.verify_mode = modes[verify_client]
+                else:
+                    logger.error('Bad value in the "restapi.verify_client": %s', verify_client)
+            self.socket = ctx.wrap_socket(self.socket, server_side=True)
+        if reloading_config:
+            self.start()
 
     def reload_config(self, config):
-        self.__set_config_parameters(config)
-        if self.__listen != config['listen'] or self.__ssl_options != self.__get_ssl_options(config):
-            self.shutdown()
-            self.__initialize(config)
-            self.start()
+        if 'listen' not in config:  # changing config in runtime
+            raise ValueError('Can not find "restapi.listen" config')
+
+        ssl_options = {n: config[n] for n in ('certfile', 'keyfile', 'cafile') if n in config}
+
+        if isinstance(config.get('verify_client'), six.string_types):
+            ssl_options['verify_client'] = config['verify_client'].lower()
+
+        if self.__listen != config['listen'] or self.__ssl_options != ssl_options:
+            self.__initialize(config['listen'], ssl_options)
+
+        self.__auth_key = base64.b64encode(config['auth'].encode('utf-8')).decode('utf-8') if 'auth' in config else None
+        self.connection_string = uri(self.__protocol, config.get('connect_address') or self.__listen, 'patroni')
+
+    @staticmethod
+    def handle_error(request, client_address):
+        address, port = client_address
+        logger.warning('Exception happened during processing of request from {}:{}'.format(address, port))
+        logger.warning(traceback.format_exc())

patroni/async_executor.py

@@ -52,8 +52,8 @@ class CriticalTask(object):
 
 class AsyncExecutor(object):
 
-    def __init__(self, state_handler, ha_wakeup):
-        self.state_handler = state_handler
+    def __init__(self, cancellable, ha_wakeup):
+        self._cancellable = cancellable
         self._ha_wakeup = ha_wakeup
         self._thread_lock = RLock()
         self._scheduled_action = None
@@ -92,7 +92,7 @@ class AsyncExecutor(object):
                     return
                 self._finish_event.clear()
 
-            self.state_handler.reset_is_cancelled()
+            self._cancellable.reset_is_cancelled()
             # if the func returned something (not None) - wake up main HA loop
             wakeup = func(*args) if args else func()
             return wakeup
@@ -110,6 +110,12 @@ class AsyncExecutor(object):
     def run_async(self, func, args=()):
         Thread(target=self.run, args=(func, args)).start()
 
+    def try_run_async(self, action, func, args=()):
+        prev = self.schedule(action)
+        if prev is None:
+            return self.run_async(func, args)
+        return 'Failed to run {0}, {1} is already in progress'.format(action, prev)
+
     def cancel(self):
         with self:
             with self._scheduled_action_lock:
@@ -118,7 +124,7 @@ class AsyncExecutor(object):
                 logger.warning('Cancelling long running task %s', self._scheduled_action)
             self._is_cancelled = True
 
-        self.state_handler.cancel()
+        self._cancellable.cancel()
         self._finish_event.wait()
 
         with self:

patroni/callback_executor.py

@@ -1,37 +0,0 @@
-import logging
-import subprocess
-from threading import Event, Lock, Thread
-
-logger = logging.getLogger(__name__)
-
-
-class CallbackExecutor(Thread):
-
-    def __init__(self):
-        super(CallbackExecutor, self).__init__()
-        self.daemon = True
-        self._lock = Lock()
-        self._cmd = None
-        self._process = None
-        self._callback_event = Event()
-        self.start()
-
-    def call(self, cmd):
-        with self._lock:
-            if self._process and self._process.poll() is None:
-                self._process.kill()
-                logger.warning('Killed the old callback process because it was still running: %s', self._cmd)
-        self._cmd = cmd
-        self._callback_event.set()
-
-    def run(self):
-        while True:
-            self._callback_event.wait()
-            self._callback_event.clear()
-            with self._lock:
-                try:
-                    self._process = subprocess.Popen(self._cmd, close_fds=True)
-                except Exception:
-                    logger.exception('Failed to execute %s',  self._cmd)
-                    continue
-            self._process.wait()

patroni/config.py

@@ -1,18 +1,35 @@
 import json
 import logging
 import os
-import sys
+import shutil
 import tempfile
 import yaml
 
 from collections import defaultdict
 from copy import deepcopy
+from patroni import PATRONI_ENV_PREFIX
+from patroni.exceptions import ConfigParseError
 from patroni.dcs import ClusterConfig
-from patroni.postgresql import Postgresql
-from patroni.utils import deep_compare, parse_int, patch_config
+from patroni.postgresql.config import CaseInsensitiveDict, ConfigHandler
+from patroni.utils import deep_compare, parse_bool, parse_int, patch_config
 
 logger = logging.getLogger(__name__)
 
+_AUTH_ALLOWED_PARAMETERS = (
+    'username',
+    'password',
+    'sslmode',
+    'sslcert',
+    'sslkey',
+    'sslrootcert',
+    'sslcrl'
+)
+
+
+def default_validator(conf):
+    if not conf:
+        return "Config is empty."
+
 
 class Config(object):
     """
@@ -34,47 +51,55 @@ class Config(object):
          to work with it as with the old `config` object.
     """
 
-    PATRONI_ENV_PREFIX = 'PATRONI_'
     PATRONI_CONFIG_VARIABLE = PATRONI_ENV_PREFIX + 'CONFIGURATION'
 
     __CACHE_FILENAME = 'patroni.dynamic.json'
     __DEFAULT_CONFIG = {
         'ttl': 30, 'loop_wait': 10, 'retry_timeout': 10,
         'maximum_lag_on_failover': 1048576,
+        'check_timeline': False,
         'master_start_timeout': 300,
         'synchronous_mode': False,
         'synchronous_mode_strict': False,
+        'standby_cluster': {
+            'create_replica_methods': '',
+            'host': '',
+            'port': '',
+            'primary_slot_name': '',
+            'restore_command': '',
+            'archive_cleanup_command': '',
+            'recovery_min_apply_delay': ''
+        },
         'postgresql': {
             'bin_dir': '',
             'use_slots': True,
-            'parameters': {p: v[0] for p, v in Postgresql.CMDLINE_OPTIONS.items()}
+            'parameters': CaseInsensitiveDict({p: v[0] for p, v in ConfigHandler.CMDLINE_OPTIONS.items()})
         },
         'watchdog': {
             'mode': 'automatic',
         }
     }
 
-    def __init__(self):
+    def __init__(self, configfile, validator=default_validator):
         self._modify_index = -1
         self._dynamic_configuration = {}
 
         self.__environment_configuration = self._build_environment_configuration()
 
         # Patroni reads the configuration from the command-line argument if it exists, otherwise from the environment
-        self._config_file = len(sys.argv) >= 2 and os.path.isfile(sys.argv[1]) and sys.argv[1]
+        self._config_file = configfile and os.path.isfile(configfile) and configfile
         if self._config_file:
             self._local_configuration = self._load_config_file()
         else:
             config_env = os.environ.pop(self.PATRONI_CONFIG_VARIABLE, None)
             self._local_configuration = config_env and yaml.safe_load(config_env) or self.__environment_configuration
-            if not self._local_configuration:
-                print('Usage: {0} config.yml'.format(sys.argv[0]))
-                print('\tPatroni may also read the configuration from the {0} environment variable'.
-                      format(self.PATRONI_CONFIG_VARIABLE))
-                sys.exit(1)
+        if validator:
+            error = validator(self._local_configuration)
+            if error:
+                raise ConfigParseError(error)
 
         self.__effective_configuration = self._build_effective_configuration({}, self._local_configuration)
-        self._data_dir = self.__effective_configuration['postgresql']['data_dir']
+        self._data_dir = self.__effective_configuration.get('postgresql', {}).get('data_dir', "")
         self._cache_file = os.path.join(self._data_dir, self.__CACHE_FILENAME)
         self._load_cache()
         self._cache_needs_saving = False
@@ -87,6 +112,9 @@ class Config(object):
     def dynamic_configuration(self):
         return deepcopy(self._dynamic_configuration)
 
+    def check_mode(self, mode):
+        return bool(parse_bool(self._dynamic_configuration.get(mode)))
+
     def _load_config_file(self):
         """Loads config.yaml from filesystem and applies some values which were set via ENV"""
         with open(self._config_file) as f:
@@ -110,7 +138,7 @@ class Config(object):
                 with os.fdopen(fd, 'w') as f:
                     fd = None
                     json.dump(self.dynamic_configuration, f)
-                tmpfile = os.rename(tmpfile, self._cache_file)
+                tmpfile = shutil.move(tmpfile, self._cache_file)
                 self._cache_needs_saving = False
             except Exception:
                 logger.exception('Exception when saving file: %s', self._cache_file)
@@ -143,29 +171,25 @@ class Config(object):
             except Exception:
                 logger.exception('Exception when setting dynamic_configuration')
 
-    def reload_local_configuration(self, dry_run=False):
+    def reload_local_configuration(self):
         if self.config_file:
             try:
                 configuration = self._load_config_file()
                 if not deep_compare(self._local_configuration, configuration):
                     new_configuration = self._build_effective_configuration(self._dynamic_configuration, configuration)
-                    if dry_run:
-                        return not deep_compare(new_configuration, self.__effective_configuration)
                     self._local_configuration = configuration
                     self.__effective_configuration = new_configuration
                     return True
+                else:
+                    logger.info('No local configuration items changed.')
             except Exception:
                 logger.exception('Exception when reloading local configuration from %s', self.config_file)
-                if dry_run:
-                    raise
 
     @staticmethod
     def _process_postgresql_parameters(parameters, is_local=False):
-        ret = {}
-        for name, value in (parameters or {}).items():
-            if name not in Postgresql.CMDLINE_OPTIONS or not is_local and Postgresql.CMDLINE_OPTIONS[name][1](value):
-                ret[name] = value
-        return ret
+        return {name: value for name, value in (parameters or {}).items()
+                if name not in ConfigHandler.CMDLINE_OPTIONS or
+                not is_local and ConfigHandler.CMDLINE_OPTIONS[name][1](value)}
 
     def _safe_copy_dynamic_configuration(self, dynamic_configuration):
         config = deepcopy(self.__DEFAULT_CONFIG)
@@ -177,6 +201,10 @@ class Config(object):
                         config['postgresql'][name].update(self._process_postgresql_parameters(value))
                     elif name not in ('connect_address', 'listen', 'data_dir', 'pgpass', 'authentication'):
                         config['postgresql'][name] = deepcopy(value)
+            elif name == 'standby_cluster':
+                for name, value in (value or {}).items():
+                    if name in self.__DEFAULT_CONFIG['standby_cluster']:
+                        config['standby_cluster'][name] = deepcopy(value)
             elif name in config:  # only variables present in __DEFAULT_CONFIG allowed to be overriden from DCS
                 if name in ('synchronous_mode', 'synchronous_mode_strict'):
                     config[name] = value
@@ -189,25 +217,52 @@ class Config(object):
         ret = defaultdict(dict)
 
         def _popenv(name):
-            return os.environ.pop(Config.PATRONI_ENV_PREFIX + name.upper(), None)
+            return os.environ.pop(PATRONI_ENV_PREFIX + name.upper(), None)
 
         for param in ('name', 'namespace', 'scope'):
             value = _popenv(param)
             if value:
                 ret[param] = value
 
+        def _fix_log_env(name, oldname):
+            value = _popenv(oldname)
+            name = PATRONI_ENV_PREFIX + 'LOG_' + name.upper()
+            if value and name not in os.environ:
+                os.environ[name] = value
+
+        for name, oldname in (('level', 'loglevel'), ('format', 'logformat'), ('dateformat', 'log_datefmt')):
+            _fix_log_env(name, oldname)
+
         def _set_section_values(section, params):
             for param in params:
                 value = _popenv(section + '_' + param)
                 if value:
                     ret[section][param] = value
 
-        _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile'])
-        _set_section_values('postgresql', ['listen', 'connect_address', 'data_dir', 'pgpass', 'bin_dir'])
+        _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile', 'cafile', 'verify_client'])
+        _set_section_values('ctl', ['insecure', 'cacert', 'certfile', 'keyfile'])
+        _set_section_values('postgresql', ['listen', 'connect_address', 'config_dir', 'data_dir', 'pgpass', 'bin_dir'])
+        _set_section_values('log', ['level', 'traceback_level', 'format', 'dateformat', 'max_queue_size',
+                                    'dir', 'file_size', 'file_num', 'loggers'])
 
-        def _get_auth(name):
+        def _parse_dict(value):
+            if not value.strip().startswith('{'):
+                value = '{{{0}}}'.format(value)
+            try:
+                return yaml.safe_load(value)
+            except Exception:
+                logger.exception('Exception when parsing dict %s', value)
+                return None
+
+        value = ret.get('log', {}).pop('loggers', None)
+        if value:
+            value = _parse_dict(value)
+            if value:
+                ret['log']['loggers'] = value
+
+        def _get_auth(name, params=None):
             ret = {}
-            for param in ('username', 'password'):
+            for param in params or _AUTH_ALLOWED_PARAMETERS[:2]:
                 value = _popenv(name + '_' + param)
                 if value:
                     ret[param] = value
@@ -218,16 +273,14 @@ class Config(object):
             ret['restapi']['authentication'] = restapi_auth
 
         authentication = {}
-        for user_type in ('replication', 'superuser'):
-            entry = _get_auth(user_type)
+        for user_type in ('replication', 'superuser', 'rewind'):
+            entry = _get_auth(user_type, _AUTH_ALLOWED_PARAMETERS)
             if entry:
                 authentication[user_type] = entry
 
         if authentication:
             ret['postgresql']['authentication'] = authentication
 
-        users = {}
-
         def _parse_list(value):
             if not (value.strip().startswith('-') or '[' in value):
                 value = '[{0}]'.format(value)
@@ -238,38 +291,41 @@ class Config(object):
                 return None
 
         for param in list(os.environ.keys()):
-            if param.startswith(Config.PATRONI_ENV_PREFIX):
+            if param.startswith(PATRONI_ENV_PREFIX):
+                # PATRONI_(ETCD|CONSUL|ZOOKEEPER|EXHIBITOR|...)_(HOSTS?|PORT|..)
                 name, suffix = (param[8:].split('_', 1) + [''])[:2]
-                if name and suffix:
-                    # PATRONI_(ETCD|CONSUL|ZOOKEEPER|EXHIBITOR|...)_(HOSTS?|PORT|..)
-                    if suffix in ('HOST', 'HOSTS', 'PORT', 'SRV', 'URL', 'PROXY', 'CACERT', 'CERT',
-                                  'KEY', 'VERIFY', 'TOKEN', 'CHECKS', 'DC', 'NAMESPACE', 'CONTEXT',
-                                  'USE_ENDPOINTS', 'SCOPE_LABEL', 'ROLE_LABEL', 'POD_IP', 'PORTS', 'LABELS'):
-                        value = os.environ.pop(param)
-                        if suffix == 'PORT':
-                            value = value and parse_int(value)
-                        elif suffix in ('HOSTS', 'PORTS', 'CHECKS'):
-                            value = value and _parse_list(value)
-                        elif suffix == 'LABELS':
-                            if not value.strip().startswith('{'):
-                                value = '{{{0}}}'.format(value)
-                            try:
-                                value = yaml.safe_load(value)
-                            except Exception:
-                                logger.exception('Exception when parsing dict %s', value)
-                                value = None
-                        if value:
-                            ret[name.lower()][suffix.lower()] = value
-                    # PATRONI_<username>_PASSWORD=<password>, PATRONI_<username>_OPTIONS=<option1,option2,...>
-                    # CREATE USER "<username>" WITH <OPTIONS> PASSWORD '<password>'
-                    elif suffix == 'PASSWORD':
-                        password = os.environ.pop(param)
-                        if password:
-                            users[name] = {'password': password}
-                            options = os.environ.pop(param[:-9] + '_OPTIONS', None)
-                            options = options and _parse_list(options)
-                            if options:
-                                users[name]['options'] = options
+                if suffix in ('HOST', 'HOSTS', 'PORT', 'USE_PROXIES', 'PROTOCOL', 'SRV', 'URL', 'PROXY',
+                              'CACERT', 'CERT', 'KEY', 'VERIFY', 'TOKEN', 'CHECKS', 'DC', 'CONSISTENCY',
+                              'REGISTER_SERVICE', 'SERVICE_CHECK_INTERVAL', 'NAMESPACE', 'CONTEXT',
+                              'USE_ENDPOINTS', 'SCOPE_LABEL', 'ROLE_LABEL', 'POD_IP', 'PORTS', 'LABELS') and name:
+                    value = os.environ.pop(param)
+                    if suffix == 'PORT':
+                        value = value and parse_int(value)
+                    elif suffix in ('HOSTS', 'PORTS', 'CHECKS'):
+                        value = value and _parse_list(value)
+                    elif suffix == 'LABELS':
+                        value = _parse_dict(value)
+                    elif suffix in ('USE_PROXIES', 'REGISTER_SERVICE'):
+                        value = parse_bool(value)
+                    if value:
+                        ret[name.lower()][suffix.lower()] = value
+        if 'etcd' in ret:
+            ret['etcd'].update(_get_auth('etcd'))
+
+        users = {}
+        for param in list(os.environ.keys()):
+            if param.startswith(PATRONI_ENV_PREFIX):
+                name, suffix = (param[8:].rsplit('_', 1) + [''])[:2]
+                # PATRONI_<username>_PASSWORD=<password>, PATRONI_<username>_OPTIONS=<option1,option2,...>
+                # CREATE USER "<username>" WITH <OPTIONS> PASSWORD '<password>'
+                if name and suffix == 'PASSWORD':
+                    password = os.environ.pop(param)
+                    if password:
+                        users[name] = {'password': password}
+                        options = os.environ.pop(param[:-9] + '_OPTIONS', None)
+                        options = options and _parse_list(options)
+                        if options:
+                            users[name]['options'] = options
         if users:
             ret['bootstrap']['users'] = users
 
@@ -288,7 +344,7 @@ class Config(object):
                 config[name] = deepcopy(value) if value else {}
 
         # restapi server expects to get restapi.auth = 'username:password'
-        if 'authentication' in config['restapi']:
+        if 'restapi' in config and 'authentication' in config['restapi']:
             config['restapi']['auth'] = '{username}:{password}'.format(**config['restapi']['authentication'])
 
         # special treatment for old config
@@ -307,12 +363,24 @@ class Config(object):
         if 'superuser' not in pg_config['authentication'] and 'pg_rewind' in pg_config:
             pg_config['authentication']['superuser'] = pg_config['pg_rewind']
 
+        # handle setting additional connection parameters that may be available
+        # in the configuration file, such as SSL connection parameters
+        for name, value in pg_config['authentication'].items():
+            pg_config['authentication'][name] = {n: v for n, v in value.items() if n in _AUTH_ALLOWED_PARAMETERS}
+
         # no 'name' in config
         if 'name' not in config and 'name' in pg_config:
             config['name'] = pg_config['name']
 
-        pg_config.update({p: config[p] for p in ('name', 'scope', 'retry_timeout',
-                          'synchronous_mode', 'maximum_lag_on_failover') if p in config})
+        updated_fields = (
+            'name',
+            'scope',
+            'retry_timeout',
+            'synchronous_mode',
+            'synchronous_mode_strict',
+        )
+
+        pg_config.update({p: config[p] for p in updated_fields if p in config})
 
         return config
 

patroni/ctl.py

@@ -2,7 +2,6 @@
 Patroni Control
 '''
 
-import base64
 import click
 import codecs
 import datetime
@@ -14,9 +13,8 @@ import io
 import json
 import logging
 import os
-import psycopg2
 import random
-import requests
+import six
 import subprocess
 import sys
 import tempfile
@@ -26,15 +24,15 @@ import yaml
 
 from click import ClickException
 from contextlib import contextmanager
-from patroni.config import Config
 from patroni.dcs import get_dcs as _get_dcs
 from patroni.exceptions import PatroniException
 from patroni.postgresql import Postgresql
-from patroni.utils import patch_config, polling_loop
+from patroni.postgresql.misc import postgres_version_to_int
+from patroni.utils import cluster_as_json, patch_config, polling_loop
+from patroni.request import PatroniRequest
 from patroni.version import __version__
 from prettytable import PrettyTable
 from six.moves.urllib_parse import urlparse
-from six import text_type
 
 CONFIG_DIR_PATH = click.get_app_dir('patroni')
 CONFIG_FILE_PATH = os.path.join(CONFIG_DIR_PATH, 'patronictl.yaml')
@@ -63,23 +61,18 @@ def parse_dcs(dcs):
     elif scheme not in DCS_DEFAULTS:
         raise PatroniCtlException('Unknown dcs scheme: {}'.format(scheme))
 
-    dcs_info = DCS_DEFAULTS[scheme]
-    return yaml.load(dcs_info['template'].format(host=parsed.hostname or 'localhost', port=port or dcs_info['port']))
+    default = DCS_DEFAULTS[scheme]
+    return yaml.safe_load(default['template'].format(host=parsed.hostname or 'localhost', port=port or default['port']))
 
 
 def load_config(path, dcs):
-    logging.debug('Loading configuration from file %s', path)
-    config = {}
-    old_argv = list(sys.argv)
-    try:
-        sys.argv[1] = path
-        if Config.PATRONI_CONFIG_VARIABLE not in os.environ:
-            for p in ('PATRONI_RESTAPI_LISTEN', 'PATRONI_POSTGRESQL_DATA_DIR'):
-                if p not in os.environ:
-                    os.environ[p] = '.'
-        config = Config().copy()
-    finally:
-        sys.argv = old_argv
+    from patroni.config import Config
+
+    if not (os.path.exists(path) and os.access(path, os.R_OK)):
+        logging.debug('Ignoring configuration file "%s". It does not exists or is not readable.', path)
+    else:
+        logging.debug('Loading configuration from file %s', path)
+    config = Config(path, validator=None).copy()
 
     dcs = parse_dcs(dcs) or parse_dcs(config.get('dcs_api')) or {}
     if dcs:
@@ -103,15 +96,24 @@ option_watch = click.option('-W', is_flag=True, help='Auto update the screen eve
 option_force = click.option('--force', is_flag=True, help='Do not ask for confirmation at any point')
 arg_cluster_name = click.argument('cluster_name', required=False,
                                   default=lambda: click.get_current_context().obj.get('scope'))
+option_insecure = click.option('-k', '--insecure', is_flag=True, help='Allow connections to SSL sites without certs')
 
 
 @click.group()
-@click.option('--config-file', '-c', help='Configuration file', default=CONFIG_FILE_PATH)
+@click.option('--config-file', '-c', help='Configuration file',
+              envvar='PATRONICTL_CONFIG_FILE', default=CONFIG_FILE_PATH)
 @click.option('--dcs', '-d', help='Use this DCS', envvar='DCS')
+@option_insecure
 @click.pass_context
-def ctl(ctx, config_file, dcs):
-    logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s', level=os.environ.get('LOGLEVEL', 'WARNING'))
+def ctl(ctx, config_file, dcs, insecure):
+    level = 'WARNING'
+    for name in ('LOGLEVEL', 'PATRONI_LOGLEVEL', 'PATRONI_LOG_LEVEL'):
+        level = os.environ.get(name, level)
+    logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s', level=level)
+    logging.captureWarnings(True)  # Capture eventual SSL warning
     ctx.obj = load_config(config_file, dcs)
+    # backward compatibility for configuration file where ctl section is not define
+    ctx.obj.setdefault('ctl', {})['insecure'] = ctx.obj.get('ctl', {}).get('insecure') or insecure
 
 
 def get_dcs(config, scope):
@@ -123,22 +125,12 @@ def get_dcs(config, scope):
         raise PatroniCtlException(str(e))
 
 
-def auth_header(config):
-    if config.get('restapi', {}).get('auth', ''):
-        return {'Authorization': 'Basic ' + base64.b64encode(config['restapi']['auth'].encode('utf-8')).decode('utf-8')}
-
-
-def request_patroni(member, request_type, endpoint, content=None, headers=None):
-    headers = headers or {}
-    url_parts = urlparse(member.api_url)
-    logging.debug(url_parts)
-    if 'Content-Type' not in headers:
-        headers['Content-Type'] = 'application/json'
-
-    url = '{0}://{1}/{2}'.format(url_parts.scheme, url_parts.netloc, endpoint)
-
-    return getattr(requests, request_type)(url, headers=headers,
-                                           data=json.dumps(content) if content else None, timeout=60)
+def request_patroni(member, method='GET', endpoint=None, data=None):
+    ctx = click.get_current_context()  # the current click context
+    request_executor = ctx.obj.get('__request_patroni')
+    if not request_executor:
+        request_executor = ctx.obj['__request_patroni'] = PatroniRequest(ctx.obj)
+    return request_executor(member, method, endpoint, data)
 
 
 def print_output(columns, rows=None, alignment=None, fmt='pretty', header=True, delimiter='\t'):
@@ -161,7 +153,7 @@ def print_output(columns, rows=None, alignment=None, fmt='pretty', header=True,
 
     if fmt == 'tsv':
         if columns is not None and header:
-            click.echo(delimiter.join(columns) + '\n')
+            click.echo(delimiter.join(columns))
 
         for r in rows:
             c = [str(c) for c in r]
@@ -227,13 +219,14 @@ def get_cursor(cluster, connect_parameters, role='master', member=None):
     else:
         params.pop('database')
 
+    import psycopg2
     conn = psycopg2.connect(**params)
     conn.autocommit = True
     cursor = conn.cursor()
     if role == 'any':
         return cursor
 
-    cursor.execute('SELECT pg_is_in_recovery()')
+    cursor.execute('SELECT pg_catalog.pg_is_in_recovery()')
     in_recovery = cursor.fetchone()[0]
 
     if in_recovery and role == 'replica' or not in_recovery and role == 'master':
@@ -244,10 +237,12 @@ def get_cursor(cluster, connect_parameters, role='master', member=None):
     return None
 
 
-def get_members(cluster, cluster_name, member_names, role, force, action):
+def get_members(cluster, cluster_name, member_names, role, force, action, ask_confirmation=True):
     candidates = {m.name: m for m in cluster.members}
 
     if not force or role:
+        if not member_names and not candidates:
+            raise PatroniCtlException('{0} cluster doesn\'t have any members'.format(cluster_name))
         output_members(cluster, cluster_name)
 
     if role:
@@ -267,12 +262,25 @@ def get_members(cluster, cluster_name, member_names, role, force, action):
         if member_name not in candidates:
             raise PatroniCtlException('{0} is not a member of cluster'.format(member_name))
 
-    if not force:
-        confirm = click.confirm('Are you sure you want to {0} members {1}?'.format(action, ', '.join(member_names)))
-        if not confirm:
-            raise PatroniCtlException('Aborted {0}'.format(action))
+    members = [candidates[n] for n in member_names]
+    if ask_confirmation:
+        confirm_members_action(members, force, action)
+    return members
 
-    return [candidates[n] for n in member_names]
+
+def confirm_members_action(members, force, action, scheduled_at=None):
+    if scheduled_at:
+        if not force:
+            confirm = click.confirm('Are you sure you want to schedule {0} of members {1} at {2}?'
+                                    .format(action, ', '.join([m.name for m in members]), scheduled_at))
+            if not confirm:
+                raise PatroniCtlException('Aborted scheduled {0}'.format(action))
+    else:
+        if not force:
+            confirm = click.confirm('Are you sure you want to {0} members {1}?'
+                                    .format(action, ', '.join([m.name for m in members])))
+            if not confirm:
+                raise PatroniCtlException('Aborted {0}'.format(action))
 
 
 @ctl.command('dsn', help='Generate a dsn for the provided member, defaults to a dsn of the master')
@@ -361,6 +369,7 @@ def query(
 
 
 def query_member(cluster, cursor, member, role, command, connect_parameters):
+    import psycopg2
     try:
         if cursor is None:
             cursor = get_cursor(cluster, connect_parameters, role=role, member=member)
@@ -373,7 +382,7 @@ def query_member(cluster, cursor, member, role, command, connect_parameters):
             logging.debug(message)
             return [[timestamp(0), message]], None
 
-        cursor.execute('SELECT pg_is_in_recovery()')
+        cursor.execute('SELECT pg_catalog.pg_is_in_recovery()')
         in_recovery = cursor.fetchone()[0]
 
         if in_recovery and role == 'master' or not in_recovery and role == 'replica':
@@ -421,9 +430,9 @@ def remove(obj, cluster_name, fmt):
 
 
 def check_response(response, member_name, action_name, silent_success=False):
-    if response.status_code >= 400:
+    if response.status >= 400:
         click.echo('Failed: {0} for member {1}, status code={2}, ({3})'.format(
-            action_name, member_name, response.status_code, response.text
+            action_name, member_name, response.status, response.data.decode('utf-8')
         ))
         return False
     elif not silent_success:
@@ -445,6 +454,32 @@ def parse_scheduled(scheduled):
     return None
 
 
+@ctl.command('reload', help='Reload cluster member configuration')
+@click.argument('cluster_name')
+@click.argument('member_names', nargs=-1)
+@click.option('--role', '-r', help='Reload only members with this role', default='any',
+              type=click.Choice(['master', 'replica', 'any']))
+@option_force
+@click.pass_obj
+def reload(obj, cluster_name, member_names, force, role):
+    cluster = get_dcs(obj, cluster_name).get_cluster()
+
+    members = get_members(cluster, cluster_name, member_names, role, force, 'reload')
+
+    for member in members:
+        r = request_patroni(member, 'post', 'reload')
+        if r.status == 200:
+            click.echo('No changes to apply on member {0}'.format(member.name))
+        elif r.status == 202:
+            click.echo('Reload request received for member {0} and will be processed within {1} seconds'.format(
+                member.name, cluster.config.data.get('loop_wait'))
+            )
+        else:
+            click.echo('Failed: reload for member {0}, status code={1}, ({2})'.format(
+                member.name, r.status, r.data.decode('utf-8'))
+            )
+
+
 @ctl.command('restart', help='Restart cluster member')
 @click.argument('cluster_name')
 @click.argument('member_names', nargs=-1)
@@ -463,7 +498,15 @@ def parse_scheduled(scheduled):
 def restart(obj, cluster_name, member_names, force, role, p_any, scheduled, version, pending, timeout):
     cluster = get_dcs(obj, cluster_name).get_cluster()
 
-    members = get_members(cluster, cluster_name, member_names, role, force, 'restart')
+    members = get_members(cluster, cluster_name, member_names, role, force, 'restart', False)
+    if scheduled is None and not force:
+        next_hour = (datetime.datetime.now() + datetime.timedelta(hours=1)).strftime('%Y-%m-%dT%H:%M')
+        scheduled = click.prompt('When should the restart take place (e.g. ' + next_hour + ') ',
+                                 type=str, default='now')
+
+    scheduled_at = parse_scheduled(scheduled)
+    confirm_members_action(members, force, 'restart', scheduled_at)
+
     if p_any:
         random.shuffle(members)
         members = members[:1]
@@ -478,16 +521,12 @@ def restart(obj, cluster_name, member_names, force, role, p_any, scheduled, vers
 
     if version:
         try:
-            Postgresql.postgres_version_to_int(version)
+            postgres_version_to_int(version)
         except PatroniException as e:
             raise PatroniCtlException(e.value)
 
         content['postgres_version'] = version
 
-    if scheduled is None and not force:
-        scheduled = click.prompt('When should the restart take place (e.g. 2015-10-01T14:30) ', type=str, default='now')
-
-    scheduled_at = parse_scheduled(scheduled)
     if scheduled_at:
         if cluster.is_paused():
             raise PatroniCtlException("Can't schedule restart in the paused state")
@@ -499,19 +538,19 @@ def restart(obj, cluster_name, member_names, force, role, p_any, scheduled, vers
     for member in members:
         if 'schedule' in content:
             if force and member.data.get('scheduled_restart'):
-                r = request_patroni(member, 'delete', 'restart', headers=auth_header(obj))
+                r = request_patroni(member, 'delete', 'restart')
                 check_response(r, member.name, 'flush scheduled restart', True)
 
-        r = request_patroni(member, 'post', 'restart', content, auth_header(obj))
-        if r.status_code == 200:
+        r = request_patroni(member, 'post', 'restart', content)
+        if r.status == 200:
             click.echo('Success: restart on member {0}'.format(member.name))
-        elif r.status_code == 202:
+        elif r.status == 202:
             click.echo('Success: restart scheduled on member {0}'.format(member.name))
-        elif r.status_code == 409:
+        elif r.status == 409:
             click.echo('Failed: another restart is already scheduled on member {0}'.format(member.name))
         else:
             click.echo('Failed: restart for member {0}, status code={1}, ({2})'.format(
-                member.name, r.status_code, r.text)
+                member.name, r.status, r.data.decode('utf-8'))
             )
 
 
@@ -527,8 +566,8 @@ def reinit(obj, cluster_name, member_names, force):
     for member in members:
         body = {'force': force}
         while True:
-            r = request_patroni(member, 'post', 'reinitialize', body, auth_header(obj))
-            if not check_response(r, member.name, 'reinitialize') and r.text.endswith(' already in progress') \
+            r = request_patroni(member, 'post', 'reinitialize', body)
+            if not check_response(r, member.name, 'reinitialize') and r.data.endswith(b' already in progress') \
                     and not force and click.confirm('Do you want to cancel it and reinitialize anyway?'):
                 body['force'] = True
                 continue
@@ -546,20 +585,20 @@ def _do_failover_or_switchover(obj, action, cluster_name, master, candidate, for
     dcs = get_dcs(obj, cluster_name)
     cluster = dcs.get_cluster()
 
-    if action == 'switchover':
-        if cluster.leader is None:
-            raise PatroniCtlException('This cluster has no master')
+    if action == 'switchover' and cluster.leader is None:
+        raise PatroniCtlException('This cluster has no master')
 
-        if master is None:
-            if force:
-                master = cluster.leader.member.name
-            else:
-                master = click.prompt('Master', type=str, default=cluster.leader.member.name)
+    if master is None:
+        if force or action == 'failover':
+            master = cluster.leader and cluster.leader.name
+        else:
+            master = click.prompt('Master', type=str, default=cluster.leader.member.name)
 
     if master is not None and cluster.leader and cluster.leader.member.name != master:
         raise PatroniCtlException('Member {0} is not the leader of cluster {1}'.format(master, cluster_name))
 
-    candidate_names = [str(m.name) for m in cluster.members if m.name != master]
+    # excluding members with nofailover tag
+    candidate_names = [str(m.name) for m in cluster.members if m.name != master and not m.nofailover]
     # We sort the names for consistent output to the client
     candidate_names.sort()
 
@@ -579,10 +618,12 @@ def _do_failover_or_switchover(obj, action, cluster_name, master, candidate, for
         raise PatroniCtlException('Member {0} does not exist in cluster {1}'.format(candidate, cluster_name))
 
     scheduled_at_str = None
+    scheduled_at = None
 
     if action == 'switchover':
         if scheduled is None and not force:
-            scheduled = click.prompt('When should the switchover take place (e.g. 2015-10-01T14:30) ',
+            next_hour = (datetime.datetime.now() + datetime.timedelta(hours=1)).strftime('%Y-%m-%dT%H:%M')
+            scheduled = click.prompt('When should the switchover take place (e.g. ' + next_hour + ' ) ',
                                      type=str, default='now')
 
         scheduled_at = parse_scheduled(scheduled)
@@ -601,22 +642,32 @@ def _do_failover_or_switchover(obj, action, cluster_name, master, candidate, for
 
     if not force:
         demote_msg = ', demoting current master ' + master if master else ''
-
-        if not click.confirm('Are you sure you want to {0} cluster {1}{2}?'.format(action, cluster_name, demote_msg)):
-            raise PatroniCtlException('Aborting ' + action)
+        if scheduled_at_str:
+            if not click.confirm('Are you sure you want to schedule {0} of cluster {1} at {2}{3}?'
+                                 .format(action, cluster_name, scheduled_at_str, demote_msg)):
+                raise PatroniCtlException('Aborting scheduled ' + action)
+        else:
+            if not click.confirm('Are you sure you want to {0} cluster {1}{2}?'
+                                 .format(action, cluster_name, demote_msg)):
+                raise PatroniCtlException('Aborting ' + action)
 
     r = None
     try:
         member = cluster.leader.member if cluster.leader else cluster.get_member(candidate, False)
 
-        r = request_patroni(member, 'post', action, failover_value, auth_header(obj))
-        if r.status_code in (200, 202):
+        r = request_patroni(member, 'post', action, failover_value)
+
+        # probably old patroni, which doesn't support switchover yet
+        if r.status == 501 and action == 'switchover' and b'Server does not support this operation' in r.data:
+            r = request_patroni(member, 'post', 'failover', failover_value)
+
+        if r.status in (200, 202):
             logging.debug(r)
             cluster = dcs.get_cluster()
             logging.debug(cluster)
-            click.echo('{0} {1}'.format(timestamp(), r.text))
+            click.echo('{0} {1}'.format(timestamp(), r.data.decode('utf-8')))
         else:
-            click.echo('{0} failed, details: {1}, {2}'.format(action.title(), r.status_code, r.text))
+            click.echo('{0} failed, details: {1}, {2}'.format(action.title(), r.status, r.data.decode('utf-8')))
             return
     except Exception:
         logging.exception(r)
@@ -653,66 +704,51 @@ def switchover(obj, cluster_name, master, candidate, force, scheduled):
 def output_members(cluster, name, extended=False, fmt='pretty'):
     rows = []
     logging.debug(cluster)
-    leader_name = None
-    if cluster.leader:
-        leader_name = cluster.leader.name
+    cluster = cluster_as_json(cluster)
 
-    xlog_location_cluster = cluster.last_leader_operation or 0
+    columns = ['Cluster', 'Member', 'Host', 'Role', 'State', 'TL', 'Lag in MB']
+    for c in ('Pending restart', 'Scheduled restart'):
+        if extended or any(m.get(c.lower().replace(' ', '_')) for m in cluster['members']):
+            columns.append(c)
 
-    # Mainly for consistent pretty printing and watching we sort the output
-    cluster.members.sort(key=lambda x: x.name)
+    # Show Host as 'host:port' if somebody is running on non-standard port or two nodes are running on the same host
+    append_port = any(m['port'] != 5432 for m in cluster['members']) or\
+        len(set(m['host'] for m in cluster['members'])) < len(cluster['members'])
 
-    extended = extended or any(m.data.get('scheduled_restart') for m in cluster.members)
-
-    for m in cluster.members:
+    for m in cluster['members']:
         logging.debug(m)
 
-        role = ''
-        if m.name == leader_name:
-            role = 'Leader'
-        elif m.name == cluster.sync.sync_standby:
-            role = 'Sync standby'
+        lag = m.get('lag', '')
+        m.update(cluster=name, member=m['name'], tl=m.get('timeline', ''),
+                 role='' if m['role'] == 'replica' else m['role'].replace('_', ' ').title(),
+                 lag_in_mb=round(lag/1024/1024) if isinstance(lag, six.integer_types) else lag,
+                 pending_restart='*' if m.get('pending_restart') else '')
 
-        xlog_location = m.data.get('xlog_location')
-        lag = ''
-        if xlog_location is None:
-            lag = 'unknown'
-        elif xlog_location_cluster >= xlog_location:
-            lag = round((xlog_location_cluster - xlog_location)/1024/1024)
+        if append_port:
+            m['host'] = ':'.join([m['host'], str(m['port'])])
 
-        row = [name, m.name, m.conn_kwargs()['host'], role, m.data.get('state', ''), lag]
+        if 'scheduled_restart' in m:
+            value = m['scheduled_restart']['schedule']
+            if 'postgres_version' in m['scheduled_restart']:
+                value += ' if version < {0}'.format(m['scheduled_restart']['postgres_version'])
+            m['scheduled_restart'] = value
 
-        if extended:
-            value = ''
-            scheduled_restart = m.data.get('scheduled_restart')
-            if scheduled_restart:
-                value = scheduled_restart['schedule']
-                if 'postgres_version' in scheduled_restart:
-                    value += ' if version < {0}'.format(scheduled_restart['postgres_version'])
+        rows.append([m.get(n.lower().replace(' ', '_'), '') for n in columns])
 
-            row.append(value)
+    print_output(columns, rows, {'Lag in MB': 'r', 'TL': 'r'}, fmt)
 
-        rows.append(row)
-
-    columns = ['Cluster', 'Member', 'Host', 'Role', 'State', 'Lag in MB']
-    alignment = {'Cluster': 'l', 'Member': 'l', 'Host': 'l', 'Lag in MB': 'r'}
-
-    if extended:
-        columns.append('Scheduled restart')
-        alignment['Scheduled restart'] = 'l'
-
-    print_output(columns, rows, alignment, fmt)
+    if fmt != 'pretty':  # Omit service info when using machine-readable formats
+        return
 
     service_info = []
-    if cluster.is_paused():
+    if cluster.get('pause'):
         service_info.append('Maintenance mode: on')
 
-    if cluster.failover and cluster.failover.scheduled_at:
-        info = 'Failover scheduled at: ' + cluster.failover.scheduled_at.isoformat()
-        if cluster.failover.leader:
-            info += '\n                  from: ' + cluster.failover.leader
-        if cluster.failover.candidate:
-            info += '\n                    to: ' + cluster.failover.candidate
+    if 'scheduled_switchover' in cluster:
+        info = 'Switchover scheduled at: ' + cluster['scheduled_switchover']['at']
+        for name in ('from', 'to'):
+            if name in cluster['scheduled_switchover']:
+                info += '\n{0:>24}: {1}'.format(name, cluster['scheduled_switchover'][name])
         service_info.append(info)
 
     if service_info:
@@ -776,7 +812,7 @@ def touch_member(config, dcs):
         'role': p.role
     }
 
-    return dcs.touch_member(json.dumps(data, separators=(',', ':')), permanent=True)
+    return dcs.touch_member(data, permanent=True)
 
 
 def set_defaults(config, cluster_name):
@@ -827,7 +863,7 @@ def flush(obj, cluster_name, member_names, force, role, target):
     for member in members:
         if target == 'restart':
             if member.data.get('scheduled_restart'):
-                r = request_patroni(member, 'delete', 'restart', None, auth_header(obj))
+                r = request_patroni(member, 'delete', 'restart')
                 check_response(r, member.name, 'flush scheduled restart')
             else:
                 click.echo('No scheduled restart for member {0}'.format(member.name))
@@ -864,19 +900,20 @@ def toggle_pause(config, cluster_name, paused, wait):
 
     for member in members:
         try:
-            r = request_patroni(member, 'patch', 'config', {'pause': paused or None}, auth_header(config))
-        except Exception:
+            r = request_patroni(member, 'patch', 'config', {'pause': paused or None})
+        except Exception as err:
+            logging.warning(str(err))
             logging.warning('Member %s is not accessible', member.name)
             continue
 
-        if r.status_code == 200:
+        if r.status == 200:
             if wait:
                 wait_until_pause_is_applied(dcs, paused, cluster)
             else:
                 click.echo('Success: cluster management is {0}'.format(paused and 'paused' or 'resumed'))
         else:
             click.echo('Failed: {0} cluster management status code={1}, ({2})'.format(
-                       paused and 'pause' or 'resume', r.status_code, r.text))
+                       paused and 'pause' or 'resume', r.status, r.data.decode('utf-8')))
         break
     else:
         raise PatroniCtlException('Can not find accessible cluster member')
@@ -931,7 +968,7 @@ def show_diff(before_editing, after_editing):
         buf = io.StringIO()
         for line in unified_diff:
             # Force cast to unicode as difflib on Python 2.7 returns a mix of unicode and str.
-            buf.write(text_type(line))
+            buf.write(six.text_type(line))
         buf.seek(0)
 
         class opts:
@@ -1013,15 +1050,40 @@ def apply_yaml_file(data, filename):
     return format_config_for_editing(changed_data), changed_data
 
 
+def find_executable(executable, path=None):
+    _, ext = os.path.splitext(executable)
+
+    if (sys.platform == 'win32') and (ext != '.exe'):
+        executable = executable + '.exe'
+
+    if os.path.isfile(executable):
+        return executable
+
+    if path is None:
+        path = os.environ.get('PATH', os.defpath)
+
+    for p in path.split(os.pathsep):
+        f = os.path.join(p, executable)
+        if os.path.isfile(f):
+            return f
+
+
 def invoke_editor(before_editing, cluster_name):
     """Starts editor command to edit configuration in human readable format
 
     :param before_editing: human representation before editing
     :returns tuple of human readable and parsed datastructure after changes
     """
+
     editor_cmd = os.environ.get('EDITOR')
     if not editor_cmd:
-        raise PatroniCtlException('EDITOR environment variable is not set')
+        for editor in ('editor', 'vi'):
+            editor_cmd = find_executable(editor)
+            if editor_cmd:
+                logging.debug('Setting fallback editor_cmd=%s', editor)
+                break
+    if not editor_cmd:
+        raise PatroniCtlException('EDITOR environment variable is not set. editor or vi are not available')
 
     with temporary_file(contents=before_editing.encode('utf-8'),
                         suffix='.yaml',
@@ -1091,7 +1153,7 @@ def edit_config(obj, cluster_name, force, quiet, kvpairs, pgkvpairs, apply_filen
 
 
 @ctl.command('show-config', help="Show cluster configuration")
-@click.argument('cluster_name')
+@arg_cluster_name
 @click.pass_obj
 def show_config(obj, cluster_name):
     cluster = get_dcs(obj, cluster_name).get_cluster()
@@ -1115,8 +1177,8 @@ def version(obj, cluster_name, member_names):
         if m.api_url:
             if not member_names or m.name in member_names:
                 try:
-                    response = request_patroni(m, 'get', 'patroni')
-                    data = response.json()
+                    response = request_patroni(m)
+                    data = json.loads(response.data.decode('utf-8'))
                     version = data.get('patroni', {}).get('version')
                     pg_version = data.get('server_version')
                     pg_version_str = " PostgreSQL {0}".format(format_pg_version(pg_version)) if pg_version else ""
@@ -1125,6 +1187,19 @@ def version(obj, cluster_name, member_names):
                     click.echo("{0}: failed to get version: {1}".format(m.name, e))
 
 
+@ctl.command('history', help="Show the history of failovers/switchovers")
+@arg_cluster_name
+@option_format
+@click.pass_obj
+def history(obj, cluster_name, fmt):
+    cluster = get_dcs(obj, cluster_name).get_cluster()
+    history = cluster.history and cluster.history.lines or []
+    for line in history:
+        if len(line) < 4:
+            line.append('')
+    print_output(['TL', 'LSN', 'Reason', 'Timestamp'], history, {'TL': 'r', 'LSN': 'r'}, fmt)
+
+
 def format_pg_version(version):
     if version < 100000:
         return "{0}.{1}.{2}".format(version // 10000, version // 100 % 100, version % 100)

patroni/dcs/__init__.py

@@ -6,18 +6,39 @@ import json
 import logging
 import os
 import pkgutil
+import re
 import six
 import sys
+import time
 
-from collections import namedtuple
+from collections import defaultdict, namedtuple
+from copy import deepcopy
 from patroni.exceptions import PatroniException
+from patroni.utils import parse_bool, uri
 from random import randint
 from six.moves.urllib_parse import urlparse, urlunparse, parse_qsl
 from threading import Event, Lock
 
+slot_name_re = re.compile('^[a-z0-9_]{1,63}$')
 logger = logging.getLogger(__name__)
 
 
+def slot_name_from_member_name(member_name):
+    """Translate member name to valid PostgreSQL slot name.
+
+    PostgreSQL replication slot names must be valid PostgreSQL names. This function maps the wider space of
+    member names to valid PostgreSQL names. Names are lowercased, dashes and periods common in hostnames
+    are replaced with underscores, other characters are encoded as their unicode codepoint. Name is truncated
+    to 64 characters. Multiple different member names may map to a single slot name."""
+
+    def replace_char(match):
+        c = match.group(0)
+        return '_' if c in '-.' else "u{:04d}".format(ord(c))
+
+    slot_name = re.sub('[^a-z0-9_]', replace_char, member_name.lower())
+    return slot_name[0:63]
+
+
 def parse_connection_string(value):
     """Original Governor stores connection strings for each cluster members if a following format:
         postgres://{username}:{password}@{connect_address}/postgres
@@ -52,26 +73,34 @@ def dcs_modules():
 
 
 def get_dcs(config):
-    available_implementations = set()
-    for module_name in dcs_modules():
-        try:
-            module = importlib.import_module(module_name)
-            for name in filter(lambda name: not name.startswith('__'), dir(module)):  # iterate through module content
-                item = getattr(module, name)
-                name = name.lower()
-                # try to find implementation of AbstractDCS interface, class name must match with module_name
-                if inspect.isclass(item) and issubclass(item, AbstractDCS) and __package__ + '.' + name == module_name:
-                    available_implementations.add(name)
-                    if name in config:  # which has configuration section in the config file
+    modules = dcs_modules()
+
+    for module_name in modules:
+        name = module_name.split('.')[-1]
+        if name in config:  # we will try to import only modules which have configuration section in the config file
+            try:
+                module = importlib.import_module(module_name)
+                for key, item in module.__dict__.items():  # iterate through the module content
+                    # try to find implementation of AbstractDCS interface, class name must match with module_name
+                    if key.lower() == name and inspect.isclass(item) and issubclass(item, AbstractDCS):
                         # propagate some parameters
                         config[name].update({p: config[p] for p in ('namespace', 'name', 'scope', 'loop_wait',
                                              'patronictl', 'ttl', 'retry_timeout') if p in config})
                         return item(config[name])
+            except ImportError:
+                logger.debug('Failed to import %s', module_name)
+
+    available_implementations = []
+    for module_name in modules:
+        name = module_name.split('.')[-1]
+        try:
+            module = importlib.import_module(module_name)
+            available_implementations.extend(name for key, item in module.__dict__.items() if key.lower() == name
+                                             and inspect.isclass(item) and issubclass(item, AbstractDCS))
         except ImportError:
-            if not config.get('patronictl'):
-                logger.info('Failed to import %s', module_name)
+            logger.info('Failed to import %s', module_name)
     raise PatroniException("""Can not find suitable configuration of distributed configuration store
-Available implementations: """ + ', '.join(available_implementations))
+Available implementations: """ + ', '.join(sorted(set(available_implementations))))
 
 
 class Member(namedtuple('Member', 'index,name,session,data')):
@@ -107,12 +136,26 @@ class Member(namedtuple('Member', 'index,name,session,data')):
 
     @property
     def conn_url(self):
-        return self.data.get('conn_url')
+        conn_url = self.data.get('conn_url')
+        conn_kwargs = self.data.get('conn_kwargs')
+        if conn_url:
+            return conn_url
+
+        if conn_kwargs:
+            conn_url = uri('postgresql', (conn_kwargs.get('host'), conn_kwargs.get('port', 5432)))
+            self.data['conn_url'] = conn_url
+            return conn_url
 
     def conn_kwargs(self, auth=None):
+        defaults = {
+            "host": "",
+            "port": "",
+            "database": ""
+        }
         ret = self.data.get('conn_kwargs')
         if ret:
-            ret = ret.copy()
+            defaults.update(ret)
+            ret = defaults
         else:
             r = urlparse(self.conn_url)
             ret = {
@@ -122,11 +165,11 @@ class Member(namedtuple('Member', 'index,name,session,data')):
             }
             self.data['conn_kwargs'] = ret.copy()
 
+        # apply any remaining authentication parameters
         if auth and isinstance(auth, dict):
+            ret.update(auth)
             if 'username' in auth:
-                ret['user'] = auth['username']
-            if 'password' in auth:
-                ret['password'] = auth['password']
+                ret['user'] = ret.pop('username')
         return ret
 
     @property
@@ -158,6 +201,26 @@ class Member(namedtuple('Member', 'index,name,session,data')):
         return self.state == 'running'
 
 
+class RemoteMember(Member):
+    """ Represents a remote master for a standby cluster
+    """
+    def __new__(cls, name, data):
+        return super(RemoteMember, cls).__new__(cls, None, name, None, data)
+
+    @staticmethod
+    def allowed_keys():
+        return ('primary_slot_name',
+                'create_replica_methods',
+                'restore_command',
+                'archive_cleanup_command',
+                'recovery_min_apply_delay',
+                'no_replication_slot')
+
+    def __getattr__(self, name):
+        if name in RemoteMember.allowed_keys():
+            return self.data.get(name)
+
+
 class Leader(namedtuple('Leader', 'index,session,member')):
 
     """Immutable object (namedtuple) which represents leader key.
@@ -181,6 +244,20 @@ class Leader(namedtuple('Leader', 'index,session,member')):
     def timeline(self):
         return self.member.data.get('timeline')
 
+    @property
+    def checkpoint_after_promote(self):
+        """
+        >>> Leader(1, '', Member.from_node(1, '', '', '{"version":"z"}')).checkpoint_after_promote
+        """
+        version = self.member.data.get('version')
+        if version:
+            try:
+                # 1.5.6 is the last version which doesn't expose checkpoint_after_promote: false
+                if tuple(map(int, version.split('.'))) > (1, 5, 6):
+                    return self.member.data['role'] == 'master' and 'checkpoint_after_promote' not in self.member.data
+            except Exception:
+                logger.debug('Failed to parse Patroni version %s', version)
+
 
 class Failover(namedtuple('Failover', 'index,leader,candidate,scheduled_at')):
 
@@ -235,14 +312,24 @@ class ClusterConfig(namedtuple('ClusterConfig', 'index,data,modify_index')):
     def from_node(index, data, modify_index=None):
         """
         >>> ClusterConfig.from_node(1, '{') is None
-        True
+        False
         """
 
         try:
             data = json.loads(data)
         except (TypeError, ValueError):
-            return None
-        return ClusterConfig(index, data, modify_index or index)
+            data = None
+            modify_index = 0
+        if not isinstance(data, dict):
+            data = {}
+        return ClusterConfig(index, data, index if modify_index is None else modify_index)
+
+    @property
+    def permanent_slots(self):
+        return isinstance(self.data, dict) and (
+                self.data.get('permanent_replication_slots') or
+                self.data.get('permanent_slots') or self.data.get('slots')
+        ) or {}
 
 
 class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
@@ -301,7 +388,7 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
         return name is not None and name in (self.leader, self.sync_standby)
 
 
-class TimelineHistory(namedtuple('TimelineHistory', 'index,lines')):
+class TimelineHistory(namedtuple('TimelineHistory', 'index,value,lines')):
     """Object representing timeline history file"""
 
     @staticmethod
@@ -317,7 +404,7 @@ class TimelineHistory(namedtuple('TimelineHistory', 'index,lines')):
             lines = None
         if not isinstance(lines, list):
             lines = []
-        return TimelineHistory(index, lines)
+        return TimelineHistory(index, value, lines)
 
 
 class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operation,members,failover,sync,history')):
@@ -349,14 +436,95 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
         candidates = [m for m in self.members if m.clonefrom and m.is_running and m.name not in exclude]
         return candidates[randint(0, len(candidates) - 1)] if candidates else self.leader
 
+    def check_mode(self, mode):
+        return bool(self.config and parse_bool(self.config.data.get(mode)))
+
     def is_paused(self):
-        return self.config and self.config.data.get('pause', False) or False
+        return self.check_mode('pause')
 
     def is_synchronous_mode(self):
-        return bool(self.config and self.config.data.get('synchronous_mode'))
+        return self.check_mode('synchronous_mode')
 
-    def is_synchronous_mode_strict(self):
-        return bool(self.config and self.config.data.get('synchronous_mode_strict'))
+    def get_replication_slots(self, name, role):
+        # if the replicatefrom tag is set on the member - we should not create the replication slot for it on
+        # the current master, because that member would replicate from elsewhere. We still create the slot if
+        # the replicatefrom destination member is currently not a member of the cluster (fallback to the
+        # master), or if replicatefrom destination member happens to be the current master
+        use_slots = self.config and self.config.data.get('postgresql', {}).get('use_slots', True)
+        if role in ('master', 'standby_leader'):
+            slot_members = [m.name for m in self.members if use_slots and m.name != name and
+                            (m.replicatefrom is None or m.replicatefrom == name or
+                             not self.has_member(m.replicatefrom))]
+            permanent_slots = (self.config and self.config.permanent_slots or {}).copy()
+        else:
+            # only manage slots for replicas that replicate from this one, except for the leader among them
+            slot_members = [m.name for m in self.members if use_slots and
+                            m.replicatefrom == name and m.name != self.leader.name]
+            permanent_slots = {}
+
+        slots = {slot_name_from_member_name(name): {'type': 'physical'} for name in slot_members}
+
+        if len(slots) < len(slot_members):
+            # Find which names are conflicting for a nicer error message
+            slot_conflicts = defaultdict(list)
+            for name in slot_members:
+                slot_conflicts[slot_name_from_member_name(name)].append(name)
+            logger.error("Following cluster members share a replication slot name: %s",
+                         "; ".join("{} map to {}".format(", ".join(v), k)
+                                   for k, v in slot_conflicts.items() if len(v) > 1))
+
+        # "merge" replication slots for members with permanent_replication_slots
+        for name, value in permanent_slots.items():
+            if not slot_name_re.match(name):
+                logger.error("Invalid permanent replication slot name '%s'", name)
+                logger.error("Slot name may only contain lower case letters, numbers, and the underscore chars")
+                continue
+
+            if name in slots:
+                logger.error("Permanent replication slot {'%s': %s} is conflicting with" +
+                             " physical replication slot for cluster member", name, value)
+                continue
+
+            value = deepcopy(value)
+            if not value:
+                value = {'type': 'physical'}
+
+            if isinstance(value, dict):
+                if 'type' not in value:
+                    value['type'] = 'logical' if value.get('database') and value.get('plugin') else 'physical'
+
+                if value['type'] == 'physical' or value['type'] == 'logical' \
+                        and value.get('database') and value.get('plugin'):
+                    slots[name] = value
+                    continue
+
+            logger.error("Bad value for slot '%s' in permanent_slots: %s", name, permanent_slots[name])
+
+        return slots
+
+    def has_permanent_logical_slots(self, name):
+        slots = self.get_replication_slots(name, 'master').values()
+        return any(v for v in slots if v.get("type") == "logical")
+
+    @property
+    def timeline(self):
+        """
+        >>> Cluster(0, 0, 0, 0, 0, 0, 0, 0).timeline
+        0
+        >>> Cluster(0, 0, 0, 0, 0, 0, 0, TimelineHistory.from_node(1, '[]')).timeline
+        1
+        >>> Cluster(0, 0, 0, 0, 0, 0, 0, TimelineHistory.from_node(1, '[["a"]]')).timeline
+        0
+        """
+        if self.history:
+            if self.history.lines:
+                try:
+                    return int(self.history.lines[-1][0]) + 1
+                except Exception:
+                    logger.error('Failed to parse cluster history from DCS: %s', self.history.lines)
+            elif self.history.value == '[]':
+                return 1
+        return 0
 
 
 @six.add_metaclass(abc.ABCMeta)
@@ -378,11 +546,12 @@ class AbstractDCS(object):
             i.e.: `zookeeper` for zookeeper, `etcd` for etcd, etc...
         """
         self._name = config['name']
-        self._base_path = os.path.join('/', config.get('namespace', '/service/').strip('/'), config['scope'])
+        self._base_path = re.sub('/+', '/', '/'.join(['', config.get('namespace', 'service'), config['scope']]))
         self._set_loop_wait(config.get('loop_wait', 10))
 
         self._ctl = bool(config.get('patronictl', False))
         self._cluster = None
+        self._cluster_valid_till = 0
         self._cluster_thread_lock = Lock()
         self._last_leader_operation = ''
         self.event = Event()
@@ -430,6 +599,10 @@ class AbstractDCS(object):
     def set_ttl(self, ttl):
         """Set the new ttl value for leader key"""
 
+    @abc.abstractmethod
+    def ttl(self):
+        """Get new ttl value"""
+
     @abc.abstractmethod
     def set_retry_timeout(self, retry_timeout):
         """Set the new value for retry_timeout"""
@@ -457,22 +630,26 @@ class AbstractDCS(object):
            instance would be demoted."""
 
     def get_cluster(self):
+        try:
+            cluster = self._load_cluster()
+        except Exception:
+            self.reset_cluster()
+            raise
+
         with self._cluster_thread_lock:
-            try:
-                self._load_cluster()
-            except Exception:
-                self._cluster = None
-                raise
-            return self._cluster
+            self._cluster = cluster
+            self._cluster_valid_till = time.time() + self.ttl
+            return cluster
 
     @property
     def cluster(self):
         with self._cluster_thread_lock:
-            return self._cluster
+            return self._cluster if self._cluster_valid_till > time.time() else None
 
     def reset_cluster(self):
         with self._cluster_thread_lock:
             self._cluster = None
+            self._cluster_valid_till = 0
 
     @abc.abstractmethod
     def _write_leader_optime(self, last_operation):
@@ -494,7 +671,7 @@ class AbstractDCS(object):
         You have to use CAS (Compare And Swap) operation in order to update leader key,
         for example for etcd `prevValue` parameter must be used."""
 
-    def update_leader(self, last_operation):
+    def update_leader(self, last_operation, access_is_restricted=False):
         """Update leader key (or session) ttl and optime/leader
 
         :param last_operation: absolute xlog location in bytes
@@ -538,7 +715,7 @@ class AbstractDCS(object):
         """Create or update `/config` key"""
 
     @abc.abstractmethod
-    def touch_member(self, data, ttl=None, permanent=False):
+    def touch_member(self, data, permanent=False):
         """Update member key in DCS.
         This method should create or update key with the name = '/members/' + `~self._name`
         and value = data in a given DCS.

patroni/dcs/consul.py

@@ -2,19 +2,21 @@ from __future__ import absolute_import
 import json
 import logging
 import os
+import re
 import socket
 import ssl
 import time
 import urllib3
 
 from consul import ConsulException, NotFound, base
-from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
-from patroni.exceptions import DCSError
-from patroni.utils import deep_compare, parse_bool, Retry, RetryFailedError, split_host_port
 from urllib3.exceptions import HTTPError
-from six.moves.urllib.parse import urlencode, urlparse
+from six.moves.urllib.parse import urlencode, urlparse, quote
 from six.moves.http_client import HTTPException
 
+from . import AbstractDCS, Cluster, ClusterConfig, Failover, Leader, Member, SyncState, TimelineHistory
+from ..exceptions import DCSError
+from ..utils import deep_compare, parse_bool, Retry, RetryFailedError, split_host_port, uri, USER_AGENT
+
 logger = logging.getLogger(__name__)
 
 
@@ -26,16 +28,20 @@ class ConsulInternalError(ConsulException):
     """An internal Consul server error occurred"""
 
 
-class InvalidSessionTTL(ConsulInternalError):
+class InvalidSessionTTL(ConsulException):
     """Session TTL is too small or too big"""
 
 
+class InvalidSession(ConsulException):
+    """invalid session"""
+
+
 class HTTPClient(object):
 
     def __init__(self, host='127.0.0.1', port=8500, token=None, scheme='http', verify=True, cert=None, ca_cert=None):
         self.token = token
         self._read_timeout = 10
-        self.base_uri = '{0}://{1}:{2}'.format(scheme, host, port)
+        self.base_uri = uri(scheme, (host, port))
         kwargs = {}
         if cert:
             if isinstance(cert, tuple):
@@ -71,6 +77,8 @@ class HTTPClient(object):
             msg = '{0} {1}'.format(response.status, data)
             if data.startswith('Invalid Session TTL'):
                 raise InvalidSessionTTL(msg)
+            elif data.startswith('invalid session'):
+                raise InvalidSession(msg)
             else:
                 raise ConsulInternalError(msg)
         return base.Response(response.status, response.headers, data)
@@ -91,14 +99,22 @@ class HTTPClient(object):
                     data = '{' + ttl + '}'
                 else:
                     data = data[:-1] + ', ' + ttl + '}'
+            if isinstance(params, list):  # starting from v1.1.0 python-consul switched from `dict` to `list` for params
+                params = {k: v for k, v in params}
             kwargs = {'retries': 0, 'preload_content': False, 'body': data}
             if method == 'get' and isinstance(params, dict) and 'index' in params:
-                kwargs['timeout'] = (float(params['wait'][:-1]) if 'wait' in params else 300) + 1
+                timeout = float(params['wait'][:-1]) if 'wait' in params else 300
+                # According to the documentation a small random amount of additional wait time is added to the
+                # supplied maximum wait time to spread out the wake up time of any concurrent requests. This adds
+                # up to wait / 16 additional time to the maximum duration. Since our goal is actually getting a
+                # response rather read timeout we will add to the timeout a sligtly bigger value.
+                kwargs['timeout'] = timeout + max(timeout/15.0, 1)
             else:
                 kwargs['timeout'] = self._read_timeout
             token = params.pop('token', self.token) if isinstance(params, dict) else self.token
+            kwargs['headers'] = urllib3.make_headers(user_agent=USER_AGENT)
             if token:
-                kwargs['headers'] = {'X-Consul-Token': token}
+                kwargs['headers']['X-Consul-Token'] = token
             return callback(self.response(self.http.request(method.upper(), self.uri(path, params), **kwargs)))
         return wrapper
 
@@ -108,7 +124,7 @@ class ConsulClient(base.Consul):
     def __init__(self, *args, **kwargs):
         self._cert = kwargs.pop('cert', None)
         self._ca_cert = kwargs.pop('ca_cert', None)
-        self._token = kwargs.get('token')
+        self.token = kwargs.get('token')
         super(ConsulClient, self).__init__(*args, **kwargs)
 
     def connect(self, *args, **kwargs):
@@ -117,10 +133,15 @@ class ConsulClient(base.Consul):
             kwargs['cert'] = self._cert
         if self._ca_cert:
             kwargs['ca_cert'] = self._ca_cert
-        if self._token:
-            kwargs['token'] = self._token
+        if self.token:
+            kwargs['token'] = self.token
         return HTTPClient(**kwargs)
 
+    def reload_config(self, config):
+        self.http.token = self.token = config.get('token')
+        self.consistency = config.get('consistency', 'default')
+        self.dc = config.get('dc')
+
 
 def catch_consul_errors(func):
     def wrapper(*args, **kwargs):
@@ -131,6 +152,31 @@ def catch_consul_errors(func):
     return wrapper
 
 
+def force_if_last_failed(func):
+    def wrapper(*args, **kwargs):
+        if wrapper.last_result is False:
+            kwargs['force'] = True
+        wrapper.last_result = func(*args, **kwargs)
+        return wrapper.last_result
+
+    wrapper.last_result = None
+    return wrapper
+
+
+def service_name_from_scope_name(scope_name):
+    """Translate scope name to service name which can be used in dns.
+
+    230 = 253 - len('replica.') - len('.service.consul')
+    """
+
+    def replace_char(match):
+        c = match.group(0)
+        return '-' if c in '. _' else "u{:04d}".format(ord(c))
+
+    service_name = re.sub(r'[^a-z0-9\-]', replace_char, scope_name.lower())
+    return service_name[0:230]
+
+
 class Consul(AbstractDCS):
 
     def __init__(self, config):
@@ -142,7 +188,6 @@ class Consul(AbstractDCS):
                             retry_exceptions=(ConsulInternalError, HTTPException,
                                               HTTPError, socket.error, socket.timeout))
 
-        self._my_member_data = {}
         kwargs = {}
         if 'url' in config:
             r = urlparse(config['url'])
@@ -159,7 +204,7 @@ class Consul(AbstractDCS):
         if config.get('key') and config.get('cert'):
             config['cert'] = (config['cert'], config['key'])
 
-        config_keys = ('host', 'port', 'token', 'scheme', 'cert', 'ca_cert', 'dc')
+        config_keys = ('host', 'port', 'token', 'scheme', 'cert', 'ca_cert', 'dc', 'consistency')
         kwargs = {p: config.get(p) for p in config_keys if config.get(p)}
 
         verify = config.get('verify')
@@ -173,6 +218,13 @@ class Consul(AbstractDCS):
         self.set_ttl(config.get('ttl') or 30)
         self._last_session_refresh = 0
         self.__session_checks = config.get('checks')
+        self._register_service = config.get('register_service', False)
+        if self._register_service:
+            self._service_name = service_name_from_scope_name(self._scope)
+            if self._scope != self._service_name:
+                logger.warning('Using %s as consul service name instead of scope name %s', self._service_name,
+                               self._scope)
+        self._service_check_interval = config.get('service_check_interval', '5s')
         if not self._ctl:
             self.create_session()
 
@@ -187,11 +239,19 @@ class Consul(AbstractDCS):
                 logger.info('waiting on consul')
                 time.sleep(5)
 
+    def reload_config(self, config):
+        super(Consul, self).reload_config(config)
+        self._client.reload_config(config.get('consul', {}))
+
     def set_ttl(self, ttl):
         if self._client.http.set_ttl(ttl/2.0):  # Consul multiplies the TTL by 2x
             self._session = None
             self.__do_not_watch = True
 
+    @property
+    def ttl(self):
+        return self._client.http.ttl
+
     def set_retry_timeout(self, retry_timeout):
         self._retry.deadline = retry_timeout
         self._client.http.set_read_timeout(retry_timeout)
@@ -254,7 +314,7 @@ class Consul(AbstractDCS):
             nodes = {}
             for node in results:
                 node['Value'] = (node['Value'] or b'').decode('utf-8')
-                nodes[os.path.relpath(node['Key'], path)] = node
+                nodes[node['Key'][len(path):].lstrip('/')] = node
 
             # get initialize flag
             initialize = nodes.get(self._INITIALIZE)
@@ -297,48 +357,111 @@ class Consul(AbstractDCS):
             sync = nodes.get(self._SYNC)
             sync = SyncState.from_node(sync and sync['ModifyIndex'], sync and sync['Value'])
 
-            self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+            return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
         except NotFound:
-            self._cluster = Cluster(None, None, None, None, [], None, None, None)
+            return Cluster(None, None, None, None, [], None, None, None)
         except Exception:
             logger.exception('get_cluster')
             raise ConsulError('Consul is not responding properly')
 
-    def touch_member(self, data, ttl=None, permanent=False):
+    @catch_consul_errors
+    def touch_member(self, data, permanent=False):
         cluster = self.cluster
         member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
         create_member = not permanent and self.refresh_session()
 
         if member and (create_member or member.session != self._session):
-            try:
-                self._client.kv.delete(self.member_path)
-                create_member = True
-            except Exception:
-                return False
+            self._client.kv.delete(self.member_path)
+            create_member = True
 
-        if not create_member and member and deep_compare(data, self._my_member_data):
+        if not create_member and member and deep_compare(data, member.data):
             return True
 
         try:
             args = {} if permanent else {'acquire': self._session}
             self._client.kv.put(self.member_path, json.dumps(data, separators=(',', ':')), **args)
-            self._my_member_data = data
+            if self._register_service:
+                self.update_service(not create_member and member and member.data or {}, data)
             return True
+        except InvalidSession:
+            self._session = None
+            logger.error('Our session disappeared from Consul, can not "touch_member"')
         except Exception:
             logger.exception('touch_member')
         return False
 
     @catch_consul_errors
-    def _do_attempt_to_acquire_leader(self, kwargs):
-        return self.retry(self._client.kv.put, self.leader_path, self._name, **kwargs)
+    def register_service(self, service_name, **kwargs):
+        logger.info('Register service %s, params %s', service_name, kwargs)
+        return self._client.agent.service.register(service_name, **kwargs)
+
+    @catch_consul_errors
+    def deregister_service(self, service_id):
+        logger.info('Deregister service %s', service_id)
+        # service_id can contain special characters, but is used as part of uri in deregister request
+        service_id = quote(service_id)
+        return self._client.agent.service.deregister(service_id)
+
+    def _update_service(self, data):
+        service_name = self._service_name
+        role = data['role'].replace('_', '-')
+        state = data['state']
+        api_parts = urlparse(data['api_url'])
+        api_parts = api_parts._replace(path='/{0}'.format(role))
+        conn_parts = urlparse(data['conn_url'])
+        check = base.Check.http(api_parts.geturl(), self._service_check_interval,
+                                deregister='{0}s'.format(self._client.http.ttl * 10))
+        params = {
+            'service_id': '{0}/{1}'.format(self._scope, self._name),
+            'address': conn_parts.hostname,
+            'port': conn_parts.port,
+            'check': check,
+            'tags': [role]
+        }
+
+        if state == 'stopped':
+            return self.deregister_service(params['service_id'])
+
+        if role in ['master', 'replica', 'standby-leader']:
+            if state != 'running':
+                return
+            return self.register_service(service_name, **params)
+
+        logger.warning('Could not register service: unknown role type %s', role)
+
+    @force_if_last_failed
+    def update_service(self, old_data, new_data, force=False):
+        update = False
+
+        for key in ['role', 'api_url', 'conn_url', 'state']:
+            if key not in new_data:
+                logger.warning('Could not register service: not enough params in member data')
+                return
+            if old_data.get(key) != new_data[key]:
+                update = True
+
+        if force or update:
+            return self._update_service(new_data)
+
+    @catch_consul_errors
+    def _do_attempt_to_acquire_leader(self, permanent):
+        try:
+            kwargs = {} if permanent else {'acquire': self._session}
+            return self.retry(self._client.kv.put, self.leader_path, self._name, **kwargs)
+        except InvalidSession:
+            self._session = None
+            logger.error('Our session disappeared from Consul. Will try to get a new one and retry attempt')
+            self.refresh_session()
+            return self.retry(self._client.kv.put, self.leader_path, self._name, acquire=self._session)
 
     def attempt_to_acquire_leader(self, permanent=False):
         if not self._session and not permanent:
             self.refresh_session()
 
-        ret = self._do_attempt_to_acquire_leader({} if permanent else {'acquire': self._session})
+        ret = self._do_attempt_to_acquire_leader(permanent)
         if not ret:
             logger.info('Could not take out TTL lock')
+
         return ret
 
     def take_leader(self):
@@ -395,6 +518,7 @@ class Consul(AbstractDCS):
         return self.retry(self._client.kv.delete, self.sync_path, cas=index)
 
     def watch(self, leader_index, timeout):
+        self._last_session_refresh = 0
         if self.__do_not_watch:
             self.__do_not_watch = False
             return True
@@ -406,7 +530,7 @@ class Consul(AbstractDCS):
                     idx, _ = self._client.kv.get(self.leader_path, index=leader_index, wait=str(timeout) + 's')
                     return str(idx) != str(leader_index)
                 except (ConsulException, HTTPException, HTTPError, socket.error, socket.timeout):
-                    logging.exception('watch')
+                    logger.exception('watch')
 
                 timeout = end_time - time.time()
 

patroni/dcs/etcd.py

@@ -5,28 +5,28 @@ import logging
 import os
 import urllib3.util.connection
 import random
-import requests
 import six
 import socket
 import time
 
 from dns.exception import DNSException
 from dns import resolver
-from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
-from patroni.exceptions import DCSError
-from patroni.utils import Retry, RetryFailedError, split_host_port
-from urllib3.exceptions import HTTPError, ReadTimeoutError
-from requests.exceptions import RequestException
+from urllib3.exceptions import HTTPError, ReadTimeoutError, ProtocolError
 from six.moves.queue import Queue
 from six.moves.http_client import HTTPException
 from six.moves.urllib_parse import urlparse
 from threading import Thread
 
+from . import AbstractDCS, Cluster, ClusterConfig, Failover, Leader, Member, SyncState, TimelineHistory
+from ..exceptions import DCSError
+from ..request import get as requests_get
+from ..utils import Retry, RetryFailedError, split_host_port, uri, USER_AGENT
+
 logger = logging.getLogger(__name__)
 
 
-def uri(protocol, host, port, endpoint=''):
-    return '{0}://{1}:{2}{3}'.format(protocol, host, port, endpoint)
+class EtcdRaftInternal(etcd.EtcdException):
+    """Raft Internal Error"""
 
 
 class EtcdError(DCSError):
@@ -87,25 +87,57 @@ class Client(etcd.Client):
         args = {p: config.get(p) for p in ('host', 'port', 'protocol', 'use_proxies', 'username', 'password',
                                            'cert', 'ca_cert') if config.get(p)}
         super(Client, self).__init__(read_timeout=config['retry_timeout'], **args)
+        # For some reason python3-etcd on debian and ubuntu are not based on the latest version
+        # Workaround for the case when https://github.com/jplana/python-etcd/pull/196 is not applied
+        self.http.connection_pool_kw.pop('ssl_version', None)
         self._config = config
         self._load_machines_cache()
-        self._allow_reconnect = not self._use_proxies
+        self._allow_reconnect = True
+        # allow passing retry argument to api_execute in params
+        self._comparison_conditions.add('retry')
+        self._read_options.add('retry')
+        self._del_conditions.add('retry')
 
-    def _build_request_parameters(self):
+    def _calculate_timeouts(self, etcd_nodes=None, timeout=None):
+        """Calculate a request timeout and number of retries per single etcd node.
+        In case if the timeout per node is too small (less than one second) we will reduce the number of nodes.
+        For the cluster with only one node we will try to do 2 retries.
+        For clusters with 2 nodes we will try to do 1 retry for every node.
+        No retries for clusters with 3 or more nodes. We better rely on switching to a different node."""
+
+        etcd_nodes = etcd_nodes or len(self._machines_cache) + 1
+        per_node_timeout = timeout = float(timeout or self.read_timeout)
+
+        max_retries = 4 - min(etcd_nodes, 3)
+        per_node_retries = 1
+        min_timeout = 1.0
+
+        while etcd_nodes > 0:
+            per_node_timeout = float(timeout) / etcd_nodes
+            if per_node_timeout >= min_timeout:
+                # for small clusters we will try to do more than on try on every node
+                while per_node_retries < max_retries and per_node_timeout / (per_node_retries + 1) >= min_timeout:
+                    per_node_retries += 1
+                per_node_timeout /= per_node_retries
+                break
+            # if the timeout per one node is to small try to reduce number of nodes
+            etcd_nodes -= 1
+            max_retries = 1
+
+        return etcd_nodes, per_node_timeout, per_node_retries - 1
+
+    def _get_headers(self):
+        basic_auth = ':'.join((self.username, self.password)) if self.username and self.password else None
+        return urllib3.make_headers(basic_auth=basic_auth, user_agent=USER_AGENT)
+
+    def _build_request_parameters(self, timeout=None):
         kwargs = {'headers': self._get_headers(), 'redirect': self.allow_redirect}
 
-        # calculate the number of retries and timeout *per node*
-        # actual number of retries depends on the number of nodes
-        etcd_nodes = len(self._machines_cache) + 1
-        kwargs['retries'] = 0 if etcd_nodes > 3 else (1 if etcd_nodes > 1 else 2)
-
-        # if etcd_nodes > 3:
-        #     kwargs.update({'retries': 0, 'timeout': float(self.read_timeout)/etcd_nodes})
-        # elif etcd_nodes > 1:
-        #     kwargs.update({'retries': 1, 'timeout': self.read_timeout/2.0/etcd_nodes})
-        # else:
-        #     kwargs.update({'retries': 2, 'timeout': self.read_timeout/3.0})
-        kwargs['timeout'] = self.read_timeout/float(kwargs['retries'] + 1)/etcd_nodes
+        if timeout is not None:
+            kwargs.update(retries=0, timeout=timeout)
+        else:
+            _, per_node_timeout, per_node_retries = self._calculate_timeouts()
+            kwargs.update(timeout=per_node_timeout, retries=per_node_retries)
         return kwargs
 
     def set_machines_cache_ttl(self, cache_ttl):
@@ -128,8 +160,11 @@ class Client(etcd.Client):
         while True:
             try:
                 response = self.http.request(self._MGET, self._base_uri + self.version_prefix + '/machines', **kwargs)
-                machines = [n.strip() for n in self._handle_server_response(response).data.decode('utf-8').split(',')]
+                data = self._handle_server_response(response).data.decode('utf-8')
+                machines = [m.strip() for m in data.split(',') if m.strip()]
                 logger.debug("Retrieved list of machines: %s", machines)
+                if not machines:
+                    raise etcd.EtcdException
                 random.shuffle(machines)
                 for url in machines:
                     r = urlparse(url)
@@ -160,8 +195,12 @@ class Client(etcd.Client):
             self._check_cluster_id(response)
         except (HTTPError, HTTPException, socket.error, socket.timeout) as e:
             if (isinstance(fields, dict) and fields.get("wait") == "true" and
-                    isinstance(e, ReadTimeoutError)):
+                    isinstance(e, (ReadTimeoutError, ProtocolError))):
                 logger.debug("Watch timed out.")
+                # switch to the next etcd node because we don't know exactly what happened,
+                # whether the key didn't received an update or there is a network problem.
+                self._machines_cache.insert(0, self._base_uri)
+                self._base_uri = self._next_server()
                 raise etcd.EtcdWatchTimedOut("Watch timed out: {0}".format(e), cause=e)
             logger.error("Request to server %s failed: %r", self._base_uri, e)
             logger.info("Reconnection allowed, looking for another server.")
@@ -173,6 +212,7 @@ class Client(etcd.Client):
         if not path.startswith('/'):
             raise ValueError('Path does not start with /')
 
+        retry = params.pop('retry', None) if isinstance(params, dict) else None
         kwargs = {'fields': params, 'preload_content': False}
 
         if method in [self._MGET, self._MDELETE]:
@@ -186,34 +226,46 @@ class Client(etcd.Client):
         # Update machines_cache if previous attempt of update has failed
         if self._update_machines_cache:
             self._load_machines_cache()
-        elif time.time() - self._machines_cache_updated > self._machines_cache_ttl:
-            self._machines_cache = self.machines
-            if self._base_uri in self._machines_cache:
-                self._machines_cache.remove(self._base_uri)
-            self._machines_cache_updated = time.time()
+        elif not self._use_proxies and time.time() - self._machines_cache_updated > self._machines_cache_ttl:
+            self._refresh_machines_cache()
 
-        kwargs.update(self._build_request_parameters())
+        kwargs.update(self._build_request_parameters(timeout))
 
-        if timeout is not None:
-            kwargs.update({'retries': 0, 'timeout': timeout})
+        if retry:
+            machines_cache = [self._base_uri] + self._machines_cache
 
         response = False
 
-        try:
-            some_request_failed = False
-            while not response:
-                response = self._do_http_request(request_executor, method, self._base_uri + path, **kwargs)
+        while True:
+            try:
+                some_request_failed = False
+                while not response:
+                    response = self._do_http_request(request_executor, method, self._base_uri + path, **kwargs)
+
+                    if response is False:
+                        if not retry:
+                            raise etcd.EtcdException('{0} {1} request failed'.format(method, path))
+                        some_request_failed = True
+                if some_request_failed:
+                    self._refresh_machines_cache()
+                if response:
+                    break
+            except etcd.EtcdConnectionFailed:
+                if not retry:
+                    raise
+                sleeptime = retry.sleeptime
+                remaining_time = retry.stoptime - sleeptime - time.time()
+                nodes, timeout, retries = self._calculate_timeouts(len(machines_cache), remaining_time)
+                if nodes == 0:
+                    self._update_machines_cache = True
+                    raise
+                retry.sleep_func(sleeptime)
+                retry.update_delay()
+                # We still have some time left. Partially restore `_machines_cache` and retry request
+                kwargs.update(timeout=timeout, retries=retries)
+                self._base_uri = machines_cache[0]
+                self._machines_cache = machines_cache[1:nodes]
 
-                if response is False:
-                    some_request_failed = True
-            if some_request_failed and not self._use_proxies:
-                self._machines_cache = self.machines
-                if self._base_uri in self._machines_cache:
-                    self._machines_cache.remove(self._base_uri)
-        except etcd.EtcdConnectionFailed:
-            self._update_machines_cache = True
-            if not response:
-                raise
         return self._handle_server_response(response)
 
     @staticmethod
@@ -233,15 +285,15 @@ class Client(etcd.Client):
             protocol = 'https' if '-ssl' in r else 'http'
             endpoint = '/members' if '-server' in r else ''
             for host, port in self.get_srv_record('_etcd{0}._tcp.{1}'.format(r, srv)):
-                url = uri(protocol, host, port, endpoint)
+                url = uri(protocol, (host, port), endpoint)
                 if endpoint:
                     try:
-                        response = requests.get(url, timeout=self.read_timeout, verify=False)
-                        if response.ok:
-                            for member in response.json():
+                        response = requests_get(url, timeout=self.read_timeout, verify=False)
+                        if response.status < 400:
+                            for member in json.loads(response.data.decode('utf-8')):
                                 ret.extend(member['clientURLs'])
                             break
-                    except RequestException:
+                    except Exception:
                         logger.exception('GET %s', url)
                 else:
                     ret.append(url)
@@ -255,15 +307,25 @@ class Client(etcd.Client):
     def _get_machines_cache_from_dns(self, host, port):
         """One host might be resolved into multiple ip addresses. We will make list out of it"""
         if self.protocol == 'http':
-            ret = []
-            for af, _, _, _, sa in self._dns_resolver.resolve(host, port):
-                host, port = sa[:2]
-                if af == socket.AF_INET6:
-                    host = '[{0}]'.format(host)
-                ret.append(uri(self.protocol, host, port))
+            ret = map(lambda res: uri(self.protocol, res[-1][:2]), self._dns_resolver.resolve(host, port))
             if ret:
                 return list(set(ret))
-        return [uri(self.protocol, host, port)]
+        return [uri(self.protocol, (host, port))]
+
+    def _get_machines_cache_from_config(self):
+        if 'proxy' in self._config:
+            return [uri(self.protocol, (self._config['host'], self._config['port']))]
+
+        machines_cache = []
+        if 'srv' in self._config:
+            machines_cache = self._get_machines_cache_from_srv(self._config['srv'])
+
+        if not machines_cache and 'hosts' in self._config:
+            machines_cache = list(self._config['hosts'])
+
+        if not machines_cache and 'host' in self._config:
+            machines_cache = self._get_machines_cache_from_dns(self._config['host'], self._config['port'])
+        return machines_cache
 
     def _load_machines_cache(self):
         """This method should fill up `_machines_cache` from scratch.
@@ -276,19 +338,7 @@ class Client(etcd.Client):
         if 'srv' not in self._config and 'host' not in self._config and 'hosts' not in self._config:
             raise Exception('Neither srv, hosts, host nor url are defined in etcd section of config')
 
-        if self._use_proxies:
-            self._machines_cache = [uri(self.protocol, self._config['host'], self._config['port'])]
-        else:
-            self._machines_cache = []
-
-            if 'srv' in self._config:
-                self._machines_cache = self._get_machines_cache_from_srv(self._config['srv'])
-
-            if not self._machines_cache and 'hosts' in self._config:
-                self._machines_cache = list(self._config['hosts'])
-
-            if not self._machines_cache and 'host' in self._config:
-                self._machines_cache = self._get_machines_cache_from_dns(self._config['host'], self._config['port'])
+        self._machines_cache = self._get_machines_cache_from_config()
 
         # Can not bootstrap list of etcd-cluster members, giving up
         if not self._machines_cache:
@@ -296,12 +346,15 @@ class Client(etcd.Client):
 
         # After filling up initial list of machines_cache we should ask etcd-cluster about actual list
         self._base_uri = self._next_server()
-        self._machines_cache = self.machines
+        self._refresh_machines_cache()
+        self._update_machines_cache = False
 
+    def _refresh_machines_cache(self):
+        self._machines_cache = self._get_machines_cache_from_config() if self._use_proxies else self.machines
         if self._base_uri in self._machines_cache:
             self._machines_cache.remove(self._base_uri)
-
-        self._update_machines_cache = False
+        elif self._machines_cache:
+            self._base_uri = self._next_server()
         self._machines_cache_updated = time.time()
 
 
@@ -311,15 +364,15 @@ class Etcd(AbstractDCS):
         super(Etcd, self).__init__(config)
         self._ttl = int(config.get('ttl') or 30)
         self._retry = Retry(deadline=config['retry_timeout'], max_delay=1, max_tries=-1,
-                            retry_exceptions=(etcd.EtcdLeaderElectionInProgress,
-                                              etcd.EtcdWatcherCleared,
-                                              etcd.EtcdEventIndexCleared))
+                            retry_exceptions=(etcd.EtcdLeaderElectionInProgress, EtcdRaftInternal))
         self._client = self.get_etcd_client(config)
         self.__do_not_watch = False
         self._has_failed = False
 
     def retry(self, *args, **kwargs):
-        return self._retry.copy()(*args, **kwargs)
+        retry = self._retry.copy()
+        kwargs['retry'] = retry
+        return retry(*args, **kwargs)
 
     def _handle_exception(self, e, name='', do_sleep=False, raise_ex=None):
         if not self._has_failed:
@@ -367,7 +420,7 @@ class Etcd(AbstractDCS):
             config['hosts'] = []
             for value in hosts:
                 if isinstance(value, six.string_types):
-                    config['hosts'].append(uri(protocol, *split_host_port(value, default_port)))
+                    config['hosts'].append(uri(protocol, split_host_port(value.strip(), default_port)))
         elif 'host' in config:
             host, port = split_host_port(config['host'], 2379)
             config['host'] = host
@@ -423,6 +476,8 @@ class Etcd(AbstractDCS):
         while not client:
             try:
                 client = Client(config, dns_resolver)
+                if 'use_proxies' in config and not client.machines:
+                    raise etcd.EtcdException
             except etcd.EtcdException:
                 logger.info('waiting on etcd')
                 time.sleep(5)
@@ -434,6 +489,10 @@ class Etcd(AbstractDCS):
         self._ttl = ttl
         self._client.set_machines_cache_ttl(ttl*10)
 
+    @property
+    def ttl(self):
+        return self._ttl
+
     def set_retry_timeout(self, retry_timeout):
         self._retry.deadline = retry_timeout
         self._client.set_read_timeout(retry_timeout)
@@ -443,9 +502,10 @@ class Etcd(AbstractDCS):
         return Member.from_node(node.modifiedIndex, os.path.basename(node.key), node.ttl, node.value)
 
     def _load_cluster(self):
+        cluster = None
         try:
             result = self.retry(self._client.read, self.client_path(''), recursive=True)
-            nodes = {os.path.relpath(node.key, result.key): node for node in result.leaves}
+            nodes = {node.key[len(result.key):].lstrip('/'): node for node in result.leaves}
 
             # get initialize flag
             initialize = nodes.get(self._INITIALIZE)
@@ -483,21 +543,22 @@ class Etcd(AbstractDCS):
             sync = nodes.get(self._SYNC)
             sync = SyncState.from_node(sync and sync.modifiedIndex, sync and sync.value)
 
-            self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+            cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
         except etcd.EtcdKeyNotFound:
-            self._cluster = Cluster(None, None, None, None, [], None, None, None)
+            cluster = Cluster(None, None, None, None, [], None, None, None)
         except Exception as e:
             self._handle_exception(e, 'get_cluster', raise_ex=EtcdError('Etcd is not responding properly'))
         self._has_failed = False
+        return cluster
 
     @catch_etcd_errors
-    def touch_member(self, data, ttl=None, permanent=False):
+    def touch_member(self, data, permanent=False):
         data = json.dumps(data, separators=(',', ':'))
-        return self.retry(self._client.set, self.member_path, data, None if permanent else ttl or self._ttl)
+        return self._client.set(self.member_path, data, None if permanent else self._ttl)
 
     @catch_etcd_errors
     def take_leader(self):
-        return self.retry(self._client.set, self.leader_path, self._name, self._ttl)
+        return self.retry(self._client.write, self.leader_path, self._name, ttl=self._ttl)
 
     def attempt_to_acquire_leader(self, permanent=False):
         try:
@@ -526,7 +587,7 @@ class Etcd(AbstractDCS):
 
     @catch_etcd_errors
     def _update_leader(self):
-        return self.retry(self._client.test_and_set, self.leader_path, self._name, self._name, self._ttl)
+        return self.retry(self._client.write, self.leader_path, self._name, prevValue=self._name, ttl=self._ttl)
 
     @catch_etcd_errors
     def initialize(self, create_new=True, sysid=""):
@@ -587,3 +648,6 @@ class Etcd(AbstractDCS):
             return super(Etcd, self).watch(None, timeout)
         finally:
             self.event.clear()
+
+
+etcd.EtcdError.error_exceptions[300] = EtcdRaftInternal

patroni/dcs/exhibitor.py

@@ -1,10 +1,11 @@
+import json
 import logging
 import random
-import requests
 import time
 
 from patroni.dcs.zookeeper import ZooKeeper
-from requests.exceptions import RequestException
+from patroni.request import get as requests_get
+from patroni.utils import uri
 
 logger = logging.getLogger(__name__)
 
@@ -46,12 +47,11 @@ class ExhibitorEnsembleProvider(object):
     def _query_exhibitors(self, exhibitors):
         random.shuffle(exhibitors)
         for host in exhibitors:
-            uri = 'http://{0}:{1}{2}'.format(host, self._exhibitor_port, self._uri_path)
             try:
-                response = requests.get(uri, timeout=self.TIMEOUT)
-                return response.json()
-            except RequestException:
-                pass
+                response = requests_get(uri('http', (host, self._exhibitor_port), self._uri_path), timeout=self.TIMEOUT)
+                return json.loads(response.data.decode('utf-8'))
+            except Exception:
+                logging.debug('Request to %s failed', host)
         return None
 
     @property

patroni/dcs/kubernetes.py

@@ -8,11 +8,14 @@ import sys
 import time
 
 from kubernetes import client as k8s_client, config as k8s_config, watch as k8s_watch
-from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
-from patroni.exceptions import DCSError
-from patroni.utils import deep_compare, tzutc, Retry, RetryFailedError
+from urllib3 import Timeout
 from urllib3.exceptions import HTTPError
 from six.moves.http_client import HTTPException
+from threading import Condition, Lock, Thread
+
+from . import AbstractDCS, Cluster, ClusterConfig, Failover, Leader, Member, SyncState, TimelineHistory
+from ..exceptions import DCSError
+from ..utils import deep_compare, Retry, RetryFailedError, tzutc, USER_AGENT
 
 logger = logging.getLogger(__name__)
 
@@ -29,10 +32,12 @@ class KubernetesRetriableException(k8s_client.rest.ApiException):
         self.headers = orig.headers
 
 
-class CoreV1Api(object):
+class CoreV1ApiProxy(object):
 
     def __init__(self, use_endpoints=False):
         self._api = k8s_client.CoreV1Api()
+        self._api.api_client.user_agent = USER_AGENT
+        self._api.api_client.rest_client.pool_manager.connection_pool_kw['maxsize'] = 10
         self._request_timeout = None
         self._use_endpoints = use_endpoints
 
@@ -55,6 +60,125 @@ class CoreV1Api(object):
         return wrapper
 
 
+def catch_kubernetes_errors(func):
+    def wrapper(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except k8s_client.rest.ApiException as e:
+            if e.status == 403:
+                logger.exception('Permission denied')
+            elif e.status != 409:  # Object exists or conflict in resource_version
+                logger.exception('Unexpected error from Kubernetes API')
+            return False
+        except (RetryFailedError, HTTPException, HTTPError, socket.error, socket.timeout):
+            return False
+    return wrapper
+
+
+class ObjectCache(Thread):
+
+    def __init__(self, dcs, func, retry, condition):
+        Thread.__init__(self)
+        self.daemon = True
+        self._api_client = k8s_client.ApiClient()
+        self._dcs = dcs
+        self._func = func
+        self._retry = retry
+        self._condition = condition
+        self._is_ready = False
+        self._object_cache = {}
+        self._object_cache_lock = Lock()
+        self._annotations_map = {self._dcs.leader_path: self._dcs._LEADER, self._dcs.config_path: self._dcs._CONFIG}
+        self.start()
+
+    def _list(self):
+        return self._func(_request_timeout=(self._retry.deadline, Timeout.DEFAULT_TIMEOUT))
+
+    def _watch(self, resource_version):
+        return self._func(_request_timeout=(self._retry.deadline, Timeout.DEFAULT_TIMEOUT),
+                          _preload_content=False, watch=True, resource_version=resource_version)
+
+    def set(self, name, value):
+        with self._object_cache_lock:
+            old_value = self._object_cache.get(name)
+            ret = not old_value or int(old_value.metadata.resource_version) < int(value.metadata.resource_version)
+            if ret:
+                self._object_cache[name] = value
+        return ret, old_value
+
+    def delete(self, name, resource_version):
+        with self._object_cache_lock:
+            old_value = self._object_cache.get(name)
+            ret = old_value and int(old_value.metadata.resource_version) < int(resource_version)
+            if ret:
+                del self._object_cache[name]
+        return not old_value or ret, old_value
+
+    def copy(self):
+        with self._object_cache_lock:
+            return self._object_cache.copy()
+
+    def _build_cache(self):
+        objects = self._list()
+        return_type = 'V1' + objects.kind[:-4]
+        with self._object_cache_lock:
+            self._object_cache = {item.metadata.name: item for item in objects.items}
+        with self._condition:
+            self._is_ready = True
+            self._condition.notify()
+
+        response = self._watch(objects.metadata.resource_version)
+        try:
+            for line in k8s_watch.watch.iter_resp_lines(response):
+                event = json.loads(line)
+                obj = event['object']
+                if obj.get('code') == 410:
+                    break
+
+                ev_type = event['type']
+                name = obj['metadata']['name']
+
+                if ev_type in ('ADDED', 'MODIFIED'):
+                    obj = k8s_watch.watch.SimpleNamespace(data=json.dumps(obj))
+                    obj = self._api_client.deserialize(obj, return_type)
+                    success, old_value = self.set(name, obj)
+                    if success:
+                        new_value = (obj.metadata.annotations or {}).get(self._annotations_map.get(name))
+                elif ev_type == 'DELETED':
+                    success, old_value = self.delete(name, obj['metadata']['resourceVersion'])
+                    new_value = None
+                else:
+                    logger.warning('Unexpected event type: %s', ev_type)
+                    continue
+
+                if success and return_type != 'V1Pod':
+                    if old_value:
+                        old_value = (old_value.metadata.annotations or {}).get(self._annotations_map.get(name))
+
+                    if old_value != new_value and \
+                            (name != self._dcs.config_path or old_value is not None and new_value is not None):
+                        logger.debug('%s changed from %s to %s', name, old_value, new_value)
+                        self._dcs.event.set()
+        finally:
+            with self._condition:
+                self._is_ready = False
+            response.close()
+            response.release_conn()
+
+    def run(self):
+        while True:
+            try:
+                self._build_cache()
+            except Exception as e:
+                with self._condition:
+                    self._is_ready = False
+                logger.error('ObjectCache.run %r', e)
+
+    def is_ready(self):
+        """Must be called only when holding the lock on `_condition`"""
+        return self._is_ready
+
+
 class Kubernetes(AbstractDCS):
 
     def __init__(self, config):
@@ -77,35 +201,37 @@ class Kubernetes(AbstractDCS):
         self.__subsets = None
         use_endpoints = config.get('use_endpoints') and (config.get('patronictl') or 'pod_ip' in config)
         if use_endpoints:
-            addresses = [k8s_client.V1EndpointAddress(ip=config['pod_ip'])]
+            addresses = [k8s_client.V1EndpointAddress(ip='127.0.0.1' if config.get('patronictl') else config['pod_ip'])]
             ports = []
             for p in config.get('ports', [{}]):
                 port = {'port': int(p.get('port', '5432'))}
                 port.update({n: p[n] for n in ('name', 'protocol') if p.get(n)})
                 ports.append(k8s_client.V1EndpointPort(**port))
             self.__subsets = [k8s_client.V1EndpointSubset(addresses=addresses, ports=ports)]
-        self._api = CoreV1Api(use_endpoints)
+            self._should_create_config_service = True
+        self._api = CoreV1ApiProxy(use_endpoints)
         self.set_retry_timeout(config['retry_timeout'])
         self.set_ttl(config.get('ttl') or 30)
         self._leader_observed_record = {}
         self._leader_observed_time = None
         self._leader_resource_version = None
         self._leader_observed_subsets = []
+        self._config_resource_version = None
         self.__do_not_watch = False
 
+        self._condition = Condition()
+
+        pods_func = functools.partial(self._api.list_namespaced_pod, self._namespace,
+                                      label_selector=self._label_selector)
+        self._pods = ObjectCache(self, pods_func, self._retry, self._condition)
+
+        kinds_func = functools.partial(self._api.list_namespaced_kind, self._namespace,
+                                       label_selector=self._label_selector)
+        self._kinds = ObjectCache(self, kinds_func, self._retry, self._condition)
+
     def retry(self, *args, **kwargs):
         return self._retry.copy()(*args, **kwargs)
 
-    def catch_kubernetes_errors(func):
-        @functools.wraps(func)
-        def wrapper(*args, **kwargs):
-            try:
-                return func(*args, **kwargs)
-            except (RetryFailedError, k8s_client.rest.ApiException,
-                    HTTPException, HTTPError, socket.error, socket.timeout):
-                return False
-        return wrapper
-
     def client_path(self, path):
         return super(Kubernetes, self).client_path(path)[1:].replace('/', '-')
 
@@ -118,6 +244,10 @@ class Kubernetes(AbstractDCS):
         self.__do_not_watch = self._ttl != ttl
         self._ttl = ttl
 
+    @property
+    def ttl(self):
+        return self._ttl
+
     def set_retry_timeout(self, retry_timeout):
         self._retry.deadline = retry_timeout
         self._api.set_timeout(retry_timeout)
@@ -129,17 +259,25 @@ class Kubernetes(AbstractDCS):
         member.data['pod_labels'] = pod.metadata.labels
         return member
 
+    def _wait_caches(self):
+        stop_time = time.time() + self._retry.deadline
+        while not (self._pods.is_ready() and self._kinds.is_ready()):
+            timeout = stop_time - time.time()
+            if timeout <= 0:
+                raise RetryFailedError('Exceeded retry deadline')
+            self._condition.wait(timeout)
+
     def _load_cluster(self):
         try:
-            # get list of members
-            response = self.retry(self._api.list_namespaced_pod, self._namespace, label_selector=self._label_selector)
-            members = [self.member(pod) for pod in response.items]
+            with self._condition:
+                self._wait_caches()
 
-            response = self.retry(self._api.list_namespaced_kind, self._namespace, label_selector=self._label_selector)
-            nodes = {item.metadata.name: item for item in response.items}
+                members = [self.member(pod) for pod in self._pods.copy().values()]
+                nodes = self._kinds.copy()
 
             config = nodes.get(self.config_path)
             metadata = config and config.metadata
+            self._config_resource_version = metadata.resource_version if metadata else None
             annotations = metadata and metadata.annotations or {}
 
             # get initialize flag
@@ -147,7 +285,8 @@ class Kubernetes(AbstractDCS):
 
             # get global dynamic configuration
             config = ClusterConfig.from_node(metadata and metadata.resource_version,
-                                             annotations.get(self._CONFIG) or '{}')
+                                             annotations.get(self._CONFIG) or '{}',
+                                             metadata.resource_version if self._CONFIG in annotations else 0)
 
             # get timeline history
             history = TimelineHistory.from_node(metadata and metadata.resource_version,
@@ -156,7 +295,7 @@ class Kubernetes(AbstractDCS):
             leader = nodes.get(self.leader_path)
             metadata = leader and leader.metadata
             self._leader_resource_version = metadata.resource_version if metadata else None
-            self._leader_observed_subsets = leader.subsets if self.__subsets and leader else []
+            self._leader_observed_subsets = leader.subsets if self.__subsets and leader and leader.subsets else []
             annotations = metadata and metadata.annotations or {}
 
             # get last leader operation
@@ -182,19 +321,20 @@ class Kubernetes(AbstractDCS):
             if metadata:
                 member = Member(-1, leader, None, {})
                 member = ([m for m in members if m.name == leader] or [member])[0]
-                leader = Leader(response.metadata.resource_version, None, member)
+                leader = Leader(metadata.resource_version, None, member)
 
             # failover key
             failover = nodes.get(self.failover_path)
             metadata = failover and failover.metadata
-            failover = Failover.from_node(metadata and metadata.resource_version, metadata and metadata.annotations)
+            failover = Failover.from_node(metadata and metadata.resource_version,
+                                          metadata and (metadata.annotations or {}).copy())
 
             # get synchronization state
             sync = nodes.get(self.sync_path)
             metadata = sync and sync.metadata
             sync = SyncState.from_node(metadata and metadata.resource_version,  metadata and metadata.annotations)
 
-            self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+            return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
         except Exception:
             logger.exception('get_cluster')
             raise KubernetesError('Kubernetes API is not responding properly')
@@ -266,7 +406,31 @@ class Kubernetes(AbstractDCS):
             body = k8s_client.V1Endpoints(**endpoints)
         else:
             body = k8s_client.V1ConfigMap(metadata=metadata)
-        return self.retry(func, self._namespace, body) if retry else func(self._namespace, body)
+        ret = self.retry(func, self._namespace, body) if retry else func(self._namespace, body)
+        if ret:
+            self._kinds.set(name, ret)
+        return ret
+
+    def patch_or_create_config(self, annotations, resource_version=None, patch=False, retry=True):
+        # SCOPE-config endpoint requires corresponding service otherwise it might be "cleaned" by k8s master
+        if self.__subsets and not patch and not resource_version:
+            self._should_create_config_service = True
+            self._create_config_service()
+        ret = self.patch_or_create(self.config_path, annotations, resource_version, patch, retry)
+        if ret:
+            self._config_resource_version = ret.metadata.resource_version
+        return ret
+
+    def _create_config_service(self):
+        metadata = k8s_client.V1ObjectMeta(namespace=self._namespace, name=self.config_path, labels=self._labels)
+        body = k8s_client.V1Service(metadata=metadata, spec=k8s_client.V1ServiceSpec(cluster_ip='None'))
+        try:
+            if not self._api.create_namespaced_service(self._namespace, body):
+                return
+        except Exception as e:
+            if not isinstance(e, k8s_client.rest.ApiException) or e.status != 409:  # Service already exists
+                return logger.exception('create_config_service failed')
+        self._should_create_config_service = False
 
     def _write_leader_optime(self, last_operation):
         """Unused"""
@@ -274,7 +438,7 @@ class Kubernetes(AbstractDCS):
     def _update_leader(self):
         """Unused"""
 
-    def update_leader(self, last_operation):
+    def update_leader(self, last_operation, access_is_restricted=False):
         now = datetime.datetime.now(tzutc).isoformat()
         annotations = {self._LEADER: self._name, 'ttl': str(self._ttl), 'renewTime': now,
                        'acquireTime': self._leader_observed_record.get('acquireTime') or now,
@@ -282,7 +446,9 @@ class Kubernetes(AbstractDCS):
         if last_operation:
             annotations[self._OPTIME] = last_operation
 
-        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, subsets=self.__subsets)
+        subsets = [] if access_is_restricted else self.__subsets
+
+        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, subsets=subsets)
         if ret:
             self._leader_resource_version = ret.metadata.resource_version
         return ret
@@ -302,7 +468,8 @@ class Kubernetes(AbstractDCS):
             else:
                 annotations['acquireTime'] = self._leader_observed_record.get('acquireTime') or now
             annotations['transitions'] = str(transitions)
-        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, subsets=self.__subsets)
+        subsets = [] if self.__subsets else None
+        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, subsets=subsets)
         if ret:
             self._leader_resource_version = ret.metadata.resource_version
         else:
@@ -316,19 +483,19 @@ class Kubernetes(AbstractDCS):
         """Unused"""
 
     def manual_failover(self, leader, candidate, scheduled_at=None, index=None):
-        annotations = {'leader': leader or None, 'member': candidate or None, 'scheduled_at': scheduled_at}
+        annotations = {'leader': leader or None, 'member': candidate or None,
+                       'scheduled_at': scheduled_at and scheduled_at.isoformat()}
         patch = bool(self.cluster and isinstance(self.cluster.failover, Failover) and self.cluster.failover.index)
         return self.patch_or_create(self.failover_path, annotations, index, bool(index or patch), False)
 
     def set_config_value(self, value, index=None):
-        patch = bool(index or self.cluster and self.cluster.config and self.cluster.config.index)
-        return self.patch_or_create(self.config_path, {self._CONFIG: value}, index, patch, False)
+        return self.patch_or_create_config({self._CONFIG: value}, index, bool(self._config_resource_version), False)
 
     @catch_kubernetes_errors
-    def touch_member(self, data, ttl=None, permanent=False):
+    def touch_member(self, data, permanent=False):
         cluster = self.cluster
         if cluster and cluster.leader and cluster.leader.name == self._name:
-            role = 'master'
+            role = 'promoted' if data['role'] in ('replica', 'promoted') else 'master'
         elif data['state'] == 'running' and data['role'] != 'master':
             role = data['role']
         else:
@@ -343,12 +510,14 @@ class Kubernetes(AbstractDCS):
                         'annotations': {'status': json.dumps(data, separators=(',', ':'))}}
             body = k8s_client.V1Pod(metadata=k8s_client.V1ObjectMeta(**metadata))
             ret = self._api.patch_namespaced_pod(self._name, self._namespace, body)
+        if self.__subsets and self._should_create_config_service:
+            self._create_config_service()
         return ret
 
     def initialize(self, create_new=True, sysid=""):
         cluster = self.cluster
         resource_version = cluster.config.index if cluster and cluster.config and cluster.config.index else None
-        return self.patch_or_create(self.config_path, {self._INITIALIZE: sysid}, resource_version)
+        return self.patch_or_create_config({self._INITIALIZE: sysid}, resource_version)
 
     def delete_leader(self):
         if self.cluster and isinstance(self.cluster.leader, Leader) and self.cluster.leader.name == self._name:
@@ -356,16 +525,14 @@ class Kubernetes(AbstractDCS):
             self.reset_cluster()
 
     def cancel_initialization(self):
-        self.patch_or_create(self.config_path, {self._INITIALIZE: None}, self.cluster.config.index, True)
+        self.patch_or_create_config({self._INITIALIZE: None}, self._config_resource_version, True)
 
     @catch_kubernetes_errors
     def delete_cluster(self):
         self.retry(self._api.delete_collection_namespaced_kind, self._namespace, label_selector=self._label_selector)
 
-    @catch_kubernetes_errors
     def set_history_value(self, value):
-        patch = bool(self.cluster and self.cluster.config and self.cluster.config.index)
-        return self.patch_or_create(self.config_path, {self._HISTORY: value}, None, patch, False)
+        return self.patch_or_create_config({self._HISTORY: value}, None, bool(self._config_resource_version), False)
 
     def set_sync_state_value(self, value, index=None):
         """Unused"""
@@ -381,24 +548,6 @@ class Kubernetes(AbstractDCS):
             self.__do_not_watch = False
             return True
 
-        if leader_index:
-            end_time = time.time() + timeout
-            w = k8s_watch.Watch()
-            while timeout >= 1:
-                try:
-                    for event in w.stream(self._api.list_namespaced_kind, self._namespace,
-                                          resource_version=leader_index, timeout_seconds=int(timeout + 0.5),
-                                          field_selector='metadata.name=' + self.leader_path,
-                                          _request_timeout=(1, timeout + 1)):
-                        return event['raw_object'].get('metadata', {}).get('resourceVersion') != leader_index
-                    return False
-                except KeyboardInterrupt:
-                    raise
-                except Exception:
-                    logging.exception('watch')
-
-                timeout = end_time - time.time()
-
         try:
             return super(Kubernetes, self).watch(None, timeout)
         finally:

patroni/dcs/zookeeper.py

@@ -1,5 +1,6 @@
 import json
 import logging
+import select
 import time
 
 from kazoo.client import KazooClient, KazooState, KazooRetry
@@ -37,12 +38,21 @@ class PatroniSequentialThreadingHandler(SequentialThreadingHandler):
                      `connect_timeout` (negotiated session timeout) as the second element."""
 
         args = list(args)
-        if len(args) == 1:
+        if len(args) == 0:  # kazoo 2.6.0 slightly changed the way how it calls create_connection method
+            kwargs['timeout'] = max(self._connect_timeout, kwargs.get('timeout', self._connect_timeout*10)/10.0)
+        elif len(args) == 1:
             args.append(self._connect_timeout)
         else:
             args[1] = max(self._connect_timeout, args[1]/10.0)
         return super(PatroniSequentialThreadingHandler, self).create_connection(*args, **kwargs)
 
+    def select(self, *args, **kwargs):
+        """Python3 raises `ValueError` if socket is closed, because fd == -1"""
+        try:
+            return super(PatroniSequentialThreadingHandler, self).select(*args, **kwargs)
+        except ValueError as e:
+            raise select.error(9, str(e))
+
 
 class ZooKeeper(AbstractDCS):
 
@@ -59,7 +69,6 @@ class ZooKeeper(AbstractDCS):
                                    max_delay=1, max_tries=-1, sleep_func=time.sleep))
         self._client.add_listener(self.session_listener)
 
-        self._my_member_data = {}
         self._fetch_cluster = True
 
         self._orig_kazoo_connect = self._client._connection._connect
@@ -117,6 +126,10 @@ class ZooKeeper(AbstractDCS):
             self._client.restart()
             return True
 
+    @property
+    def ttl(self):
+        return self._client._session_timeout
+
     def set_retry_timeout(self, retry_timeout):
         retry = self._client.retry if isinstance(self._client.retry, KazooRetry) else self._client._retry
         retry.deadline = retry_timeout
@@ -197,62 +210,74 @@ class ZooKeeper(AbstractDCS):
         failover = self.get_node(self.failover_path, watch=self.cluster_watcher) if self._FAILOVER in nodes else None
         failover = failover and Failover.from_node(failover[1].version, failover[0])
 
-        self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+        return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
 
     def _load_cluster(self):
-        if self._fetch_cluster or self._cluster is None:
+        cluster = self.cluster
+        if self._fetch_cluster or cluster is None:
             try:
-                self._client.retry(self._inner_load_cluster)
+                cluster = self._client.retry(self._inner_load_cluster)
             except Exception:
                 logger.exception('get_cluster')
                 self.cluster_watcher(None)
                 raise ZooKeeperError('ZooKeeper in not responding properly')
+        return cluster
 
-    def _create(self, path, value, **kwargs):
+    def _create(self, path, value, retry=False, ephemeral=False):
         try:
-            self._client.retry(self._client.create, path, value.encode('utf-8'), **kwargs)
+            if retry:
+                self._client.retry(self._client.create, path, value, makepath=True, ephemeral=ephemeral)
+            else:
+                self._client.create_async(path, value, makepath=True, ephemeral=ephemeral).get(timeout=1)
             return True
         except Exception:
-            return False
+            logger.exception('Failed to create %s', path)
+        return False
 
     def attempt_to_acquire_leader(self, permanent=False):
-        ret = self._create(self.leader_path, self._name, makepath=True, ephemeral=not permanent)
+        ret = self._create(self.leader_path, self._name.encode('utf-8'), retry=True, ephemeral=not permanent)
         if not ret:
             logger.info('Could not take out TTL lock')
         return ret
 
-    def __set_failover_or_sync_state_value(self, key, value, index=None):
+    def _set_or_create(self, key, value, index=None, retry=False, do_not_create_empty=False):
+        value = value.encode('utf-8')
         try:
-            self._client.retry(self._client.set, key, value.encode('utf-8'), version=index or -1)
+            if retry:
+                self._client.retry(self._client.set, key, value, version=index or -1)
+            else:
+                self._client.set_async(key, value, version=index or -1).get(timeout=1)
             return True
         except NoNodeError:
-            return value == '' or (index is None and self._create(key, value))
+            if do_not_create_empty and not value:
+                return True
+            elif index is None:
+                return self._create(key, value, retry)
+            else:
+                return False
         except Exception:
-            logging.exception('set_failover_value')
-            return False
+            logger.exception('Failed to update %s', key)
+        return False
 
     def set_failover_value(self, value, index=None):
-        return self.__set_failover_or_sync_state_value(self.failover_path, value, index)
+        return self._set_or_create(self.failover_path, value, index)
 
     def set_config_value(self, value, index=None):
-        try:
-            self._client.retry(self._client.set, self.config_path, value.encode('utf-8'), version=index or -1)
-            return True
-        except NoNodeError:
-            return index is None and self._create(self.config_path, value)
-        except Exception:
-            logging.exception('set_config_value')
-            return False
+        return self._set_or_create(self.config_path, value, index, retry=True)
 
     def initialize(self, create_new=True, sysid=""):
-        return self._create(self.initialize_path, sysid, makepath=True) if create_new \
-            else self._client.retry(self._client.set, self.initialize_path, sysid.encode("utf-8"))
+        sysid = sysid.encode('utf-8')
+        return self._create(self.initialize_path, sysid, retry=True) if create_new \
+            else self._client.retry(self._client.set, self.initialize_path, sysid)
 
-    def touch_member(self, data, ttl=None, permanent=False):
+    def touch_member(self, data, permanent=False):
         cluster = self.cluster
         member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
         encoded_data = json.dumps(data, separators=(',', ':')).encode('utf-8')
-        if member and self._client.client_id is not None and member.session != self._client.client_id[0]:
+        if member and (self._client.client_id is not None and member.session != self._client.client_id[0] or
+                       not (deep_compare(member.data.get('tags', {}), data.get('tags', {})) and
+                            member.data.get('version') == data.get('version') and
+                            member.data.get('checkpoint_after_promote') == data.get('checkpoint_after_promote'))):
             try:
                 self._client.delete_async(self.member_path).get(timeout=1)
             except NoNodeError:
@@ -262,13 +287,12 @@ class ZooKeeper(AbstractDCS):
             member = None
 
         if member:
-            if deep_compare(data, self._my_member_data):
+            if deep_compare(data, member.data):
                 return True
         else:
             try:
                 self._client.create_async(self.member_path, encoded_data, makepath=True,
                                           ephemeral=not permanent).get(timeout=1)
-                self._my_member_data = data
                 return True
             except Exception as e:
                 if not isinstance(e, NodeExistsError):
@@ -276,7 +300,6 @@ class ZooKeeper(AbstractDCS):
                     return False
         try:
             self._client.set_async(self.member_path, encoded_data).get(timeout=1)
-            self._my_member_data = data
             return True
         except Exception:
             logger.exception('touch_member')
@@ -286,30 +309,14 @@ class ZooKeeper(AbstractDCS):
     def take_leader(self):
         return self.attempt_to_acquire_leader()
 
-    def __write_leader_optime_or_history_value(self, key, value):
-        value = value.encode('utf-8')
-        try:
-            self._client.set_async(key, value).get(timeout=1)
-            return True
-        except NoNodeError:
-            try:
-                self._client.create_async(key, value, makepath=True).get(timeout=1)
-                return True
-            except Exception:
-                logger.exception('Failed to create %s', key)
-        except Exception:
-            logger.exception('Failed to update %s', key)
-        return False
-
     def _write_leader_optime(self, last_operation):
-        return self.__write_leader_optime_or_history_value(self.leader_optime_path, last_operation)
+        return self._set_or_create(self.leader_optime_path, last_operation)
 
     def _update_leader(self):
         return True
 
     def delete_leader(self):
         self._client.restart()
-        self._my_member_data = None
         return True
 
     def _cancel_initialization(self):
@@ -330,10 +337,10 @@ class ZooKeeper(AbstractDCS):
             return True
 
     def set_history_value(self, value):
-        return self.__write_leader_optime_or_history_value(self.history_path, value)
+        return self._set_or_create(self.history_path, value)
 
     def set_sync_state_value(self, value, index=None):
-        return self.__set_failover_or_sync_state_value(self.sync_path, value, index)
+        return self._set_or_create(self.sync_path, value, index, retry=True, do_not_create_empty=True)
 
     def delete_sync_state(self, index=None):
         return self.set_sync_state_value("{}", index)

patroni/exceptions.py

@@ -27,3 +27,7 @@ class PostgresConnectionException(PostgresException):
 
 class WatchdogError(PatroniException):
     pass
+
+
+class ConfigParseError(PatroniException):
+    pass

patroni/ha.py

@@ -3,40 +3,46 @@ import functools
 import json
 import logging
 import psycopg2
-import requests
 import sys
 import time
+import uuid
 
 from collections import namedtuple
 from multiprocessing.pool import ThreadPool
 from patroni.async_executor import AsyncExecutor, CriticalTask
 from patroni.exceptions import DCSError, PostgresConnectionException, PatroniException
-from patroni.postgresql import ACTION_ON_START
-from patroni.utils import polling_loop, tzutc
+from patroni.postgresql import ACTION_ON_START, ACTION_ON_ROLE_CHANGE
+from patroni.postgresql.misc import postgres_version_to_int
+from patroni.postgresql.rewind import Rewind
+from patroni.utils import polling_loop, tzutc, is_standby_cluster as _is_standby_cluster
+from patroni.dcs import RemoteMember
 from threading import RLock
 
 logger = logging.getLogger(__name__)
 
 
-class _MemberStatus(namedtuple('_MemberStatus', 'member,reachable,in_recovery,wal_position,tags,watchdog_failed')):
+class _MemberStatus(namedtuple('_MemberStatus', ['member', 'reachable', 'in_recovery', 'timeline',
+                                                 'wal_position', 'tags', 'watchdog_failed'])):
     """Node status distilled from API response:
 
         member - dcs.Member object of the node
         reachable - `!False` if the node is not reachable or is not responding with correct JSON
         in_recovery - `!True` if pg_is_in_recovery() == true
-        wal_position - value of `replayed_location` or `location` from JSON, dependin on its role.
+        timeline - timeline value from JSON
+        wal_position - maximum value of `replayed_location` or `received_location` from JSON
         tags - dictionary with values of different tags (i.e. nofailover)
         watchdog_failed - indicates that watchdog is required by configuration but not available or failed
     """
     @classmethod
     def from_api_response(cls, member, json):
         is_master = json['role'] == 'master'
+        timeline = json.get('timeline', 0)
         wal = not is_master and max(json['xlog'].get('received_location', 0), json['xlog'].get('replayed_location', 0))
-        return cls(member, True, not is_master, wal, json.get('tags', {}), json.get('watchdog_failed', False))
+        return cls(member, True, not is_master, timeline, wal, json.get('tags', {}), json.get('watchdog_failed', False))
 
     @classmethod
     def unknown(cls, member):
-        return cls(member, False, None, 0, {}, False)
+        return cls(member, False, None, 0, 0, {}, False)
 
     def failover_limitation(self):
         """Returns reason why this node can't promote or None if everything is ok."""
@@ -54,15 +60,20 @@ class Ha(object):
     def __init__(self, patroni):
         self.patroni = patroni
         self.state_handler = patroni.postgresql
+        self._rewind = Rewind(self.state_handler)
         self.dcs = patroni.dcs
         self.cluster = None
         self.old_cluster = None
+        self._is_leader = False
+        self._is_leader_lock = RLock()
+        self._leader_access_is_restricted = False
+        self._was_paused = False
         self._leader_timeline = None
         self.recovering = False
         self._post_bootstrap_task = None
         self._crash_recovery_executed = False
         self._start_timeout = None
-        self._async_executor = AsyncExecutor(self.state_handler, self.wakeup)
+        self._async_executor = AsyncExecutor(self.state_handler.cancellable, self.wakeup)
         self.watchdog = patroni.watchdog
 
         # Each member publishes various pieces of information to the DCS using touch_member. This lock protects
@@ -72,8 +83,44 @@ class Ha(object):
         # standby. Changes protected by _member_state_lock.
         self._disable_sync = 0
 
+        # We need following property to avoid shutdown of postgres when join of Patroni to the postgres
+        # already running as replica was aborted due to cluster not beeing initialized in DCS.
+        self._join_aborted = False
+
+    def check_mode(self, mode):
+        # Try to protect from the case when DCS was wiped out during pause
+        if self.cluster and self.cluster.config and self.cluster.config.modify_index:
+            return self.cluster.check_mode(mode)
+        else:
+            return self.patroni.config.check_mode(mode)
+
     def is_paused(self):
-        return self.cluster and self.cluster.is_paused()
+        return self.check_mode('pause')
+
+    def check_timeline(self):
+        return self.check_mode('check_timeline')
+
+    def get_standby_cluster_config(self):
+        if self.cluster and self.cluster.config and self.cluster.config.modify_index:
+            config = self.cluster.config.data
+        else:
+            config = self.patroni.config.dynamic_configuration
+        return config.get('standby_cluster')
+
+    def is_standby_cluster(self):
+        return _is_standby_cluster(self.get_standby_cluster_config())
+
+    def is_leader(self):
+        with self._is_leader_lock:
+            return self._is_leader > time.time() and not self._leader_access_is_restricted
+
+    def set_is_leader(self, value):
+        with self._is_leader_lock:
+            self._is_leader = time.time() + self.dcs.ttl if value else 0
+
+    def set_leader_access_is_restricted(self, value):
+        with self._is_leader_lock:
+            self._leader_access_is_restricted = value
 
     def load_cluster_from_dcs(self):
         cluster = self.dcs.get_cluster()
@@ -83,10 +130,16 @@ class Ha(object):
             self.old_cluster = cluster
         self.cluster = cluster
 
+        if not self.has_lock(False):
+            self.set_is_leader(False)
+
         self._leader_timeline = None if cluster.is_unlocked() else cluster.leader.timeline
 
     def acquire_lock(self):
-        return self.dcs.attempt_to_acquire_leader()
+        self.set_leader_access_is_restricted(self.cluster.has_permanent_logical_slots(self.state_handler.name))
+        ret = self.dcs.attempt_to_acquire_leader()
+        self.set_is_leader(ret)
+        return ret
 
     def update_lock(self, write_leader_optime=False):
         last_operation = None
@@ -95,14 +148,16 @@ class Ha(object):
                 last_operation = self.state_handler.last_operation()
             except Exception:
                 logger.exception('Exception when called state_handler.last_operation()')
-        ret = self.dcs.update_leader(last_operation)
+        ret = self.dcs.update_leader(last_operation, self._leader_access_is_restricted)
+        self.set_is_leader(ret)
         if ret:
             self.watchdog.keepalive()
         return ret
 
-    def has_lock(self):
+    def has_lock(self, info=True):
         lock_owner = self.cluster.leader and self.cluster.leader.name
-        logger.info('Lock owner: %s; I am %s', lock_owner, self.state_handler.name)
+        if info:
+            logger.info('Lock owner: %s; I am %s', lock_owner, self.state_handler.name)
         return lock_owner == self.state_handler.name
 
     def get_effective_tags(self):
@@ -119,8 +174,15 @@ class Ha(object):
                 'conn_url': self.state_handler.connection_string,
                 'api_url': self.patroni.api.connection_string,
                 'state': self.state_handler.state,
-                'role': self.state_handler.role
+                'role': self.state_handler.role,
+                'version': self.patroni.version
             }
+
+            # following two lines are mainly necessary for consul, to avoid creation of master service
+            if data['role'] == 'master' and not self.is_leader():
+                data['role'] = 'promoted'
+            if self.is_leader() and not self._rewind.checkpoint_after_promote():
+                data['checkpoint_after_promote'] = False
             tags = self.get_effective_tags()
             if tags:
                 data['tags'] = tags
@@ -148,7 +210,11 @@ class Ha(object):
             return self.dcs.touch_member(data)
 
     def clone(self, clone_member=None, msg='(without leader)'):
-        if self.state_handler.clone(clone_member):
+        if self.is_standby_cluster() and not isinstance(clone_member, RemoteMember):
+            clone_member = self.get_remote_member(clone_member)
+
+        self._rewind.reset_state()
+        if self.state_handler.bootstrap.clone(clone_member):
             logger.info('bootstrapped %s', msg)
             cluster = self.dcs.get_cluster()
             node_to_follow = self._get_node_to_follow(cluster)
@@ -162,37 +228,59 @@ class Ha(object):
             clone_member = self.cluster.get_clone_member(self.state_handler.name)
             member_role = 'leader' if clone_member == self.cluster.leader else 'replica'
             msg = "from {0} '{1}'".format(member_role, clone_member.name)
-            self._async_executor.schedule('bootstrap {0}'.format(msg))
-            self._async_executor.run_async(self.clone, args=(clone_member, msg))
-            return 'trying to bootstrap {0}'.format(msg)
+            ret = self._async_executor.try_run_async('bootstrap {0}'.format(msg), self.clone, args=(clone_member, msg))
+            return ret or 'trying to bootstrap {0}'.format(msg)
+
         # no initialize key and node is allowed to be master and has 'bootstrap' section in a configuration file
         elif self.cluster.initialize is None and not self.patroni.nofailover and 'bootstrap' in self.patroni.config:
             if self.dcs.initialize(create_new=True):  # race for initialization
                 self.state_handler.bootstrapping = True
                 self._post_bootstrap_task = CriticalTask()
-                self._async_executor.schedule('bootstrap')
-                self._async_executor.run_async(self.state_handler.bootstrap, args=(self.patroni.config['bootstrap'],))
-                return 'trying to bootstrap a new cluster'
+
+                if self.is_standby_cluster():
+                    ret = self._async_executor.try_run_async('bootstrap_standby_leader', self.bootstrap_standby_leader)
+                    return ret or 'trying to bootstrap a new standby leader'
+                else:
+                    ret = self._async_executor.try_run_async('bootstrap', self.state_handler.bootstrap.bootstrap,
+                                                             args=(self.patroni.config['bootstrap'],))
+                    return ret or 'trying to bootstrap a new cluster'
             else:
                 return 'failed to acquire initialize lock'
         else:
-            if self.state_handler.can_create_replica_without_replication_connection():
+            create_replica_methods = self.get_standby_cluster_config().get('create_replica_methods', []) \
+                                     if self.is_standby_cluster() else None
+            if self.state_handler.can_create_replica_without_replication_connection(create_replica_methods):
                 msg = 'bootstrap (without leader)'
-                self._async_executor.schedule(msg)
-                self._async_executor.run_async(self.clone)
-                return 'trying to ' + msg
-            return 'waiting for leader to bootstrap'
+                return self._async_executor.try_run_async(msg, self.clone) or 'trying to ' + msg
+            return 'waiting for {0}leader to bootstrap'.format('standby_' if self.is_standby_cluster() else '')
 
-    def _handle_rewind(self):
-        if self.state_handler.rewind_needed_and_possible(self.cluster.leader):
-            self._async_executor.schedule('running pg_rewind from ' + self.cluster.leader.name)
-            self._async_executor.run_async(self.state_handler.rewind, (self.cluster.leader,))
-            return True
+    def bootstrap_standby_leader(self):
+        """ If we found 'standby' key in the configuration, we need to bootstrap
+            not a real master, but a 'standby leader', that will take base backup
+            from a remote master and start follow it.
+        """
+        clone_source = self.get_remote_master()
+        msg = 'clone from remote master {0}'.format(clone_source.conn_url)
+        result = self.clone(clone_source, msg)
+        self._post_bootstrap_task.complete(result)
+        if result:
+            self.state_handler.set_role('standby_leader')
 
-    def _start_crash_recovery(self, msg):
-        self._async_executor.schedule(msg)
-        self._async_executor.run_async(self.state_handler.fix_cluster_state)
-        return msg
+        return result
+
+    def _handle_rewind_or_reinitialize(self):
+        leader = self.get_remote_master() if self.is_standby_cluster() else self.cluster.leader
+        if not self._rewind.rewind_or_reinitialize_needed_and_possible(leader):
+            return None
+
+        if self._rewind.can_rewind:
+            msg = 'running pg_rewind from ' + leader.name
+            return self._async_executor.try_run_async(msg, self._rewind.execute, args=(leader,)) or msg
+
+        # remove_data_directory_on_diverged_timelines is set
+        if not self.is_standby_cluster():
+            msg = 'reinitializing due to diverged timelines'
+            return self._async_executor.try_run_async(msg, self._do_reinitialize, args=(self.cluster,)) or msg
 
     def recover(self):
         # Postgres is not running and we will restart in standby mode. Watchdog is not needed until we promote.
@@ -214,44 +302,52 @@ class Ha(object):
             timeout = None
 
         data = self.state_handler.controldata()
-        if data.get('Database cluster state') == 'in production' and not self._crash_recovery_executed and \
-                (self.cluster.is_unlocked() or self.state_handler.can_rewind):
+        logger.info('pg_controldata:\n%s\n', '\n'.join('  {0}: {1}'.format(k, v) for k, v in data.items()))
+        if data.get('Database cluster state') in ('in production', 'shutting down', 'in crash recovery') \
+                and not self._crash_recovery_executed and \
+                (self.cluster.is_unlocked() or self._rewind.can_rewind):
             self._crash_recovery_executed = True
-            return self._start_crash_recovery('doing crash recovery in a single user mode')
+            msg = 'doing crash recovery in a single user mode'
+            return self._async_executor.try_run_async(msg, self.state_handler.fix_cluster_state) or msg
 
         self.load_cluster_from_dcs()
 
-        if self.has_lock():
+        role = 'replica'
+        if self.is_standby_cluster() or not self.has_lock():
+            if not self._rewind.executed:
+                self._rewind.trigger_check_diverged_lsn()
+            msg = self._handle_rewind_or_reinitialize()
+            if msg:
+                return msg
+
+            if self.has_lock():  # in standby cluster
+                msg = "starting as a standby leader because i had the session lock"
+                role = 'standby_leader'
+                node_to_follow = self._get_node_to_follow(self.cluster)
+            elif self.is_standby_cluster() and self.cluster.is_unlocked():
+                msg = "trying to follow a remote master because standby cluster is unhealthy"
+                node_to_follow = self.get_remote_master()
+            else:
+                msg = "starting as a secondary"
+                node_to_follow = self._get_node_to_follow(self.cluster)
+        elif self.has_lock():
             msg = "starting as readonly because i had the session lock"
             node_to_follow = None
-        else:
-            if not self.state_handler.rewind_executed:
-                self.state_handler.trigger_check_diverged_lsn()
-            if self._handle_rewind():
-                return self._async_executor.scheduled_action
-            msg = "starting as a secondary"
-            node_to_follow = self._get_node_to_follow(self.cluster)
 
-        # once we already tried to start postgres but failed, single user mode is a rescue in this case
-        if self.recovering and not self.state_handler.rewind_executed \
-                and not self._crash_recovery_executed and self.state_handler.can_rewind \
-                and data.get('Database cluster state') not in ('shut down', 'shut down in recovery'):
-            self.recovering = False
-            return self._start_crash_recovery('fixing cluster state in a single user mode')
-
-        self.recovering = True
-
-        self._async_executor.schedule('restarting after failure')
-        self._async_executor.run_async(self.state_handler.follow, (node_to_follow, timeout))
+        if self._async_executor.try_run_async('restarting after failure', self.state_handler.follow,
+                                              args=(node_to_follow, role, timeout)) is None:
+            self.recovering = True
         return msg
 
     def _get_node_to_follow(self, cluster):
         # determine the node to follow. If replicatefrom tag is set,
         # try to follow the node mentioned there, otherwise, follow the leader.
-        if not self.patroni.replicatefrom or self.patroni.replicatefrom == self.state_handler.name:
-            node_to_follow = cluster.leader
-        else:
+        if self.is_standby_cluster() and (self.cluster.is_unlocked() or self.has_lock(False)):
+            node_to_follow = self.get_remote_master()
+        elif self.patroni.replicatefrom and self.patroni.replicatefrom != self.state_handler.name:
             node_to_follow = cluster.get_member(self.patroni.replicatefrom)
+        else:
+            node_to_follow = cluster.leader
 
         return node_to_follow if node_to_follow and node_to_follow.name != self.state_handler.name else None
 
@@ -264,7 +360,8 @@ class Ha(object):
         node_to_follow = self._get_node_to_follow(self.cluster)
 
         if self.is_paused():
-            if not (self.state_handler.need_rewind and self.state_handler.can_rewind) or self.cluster.is_unlocked():
+            if not (self._rewind.is_needed and self._rewind.can_rewind_or_reinitialize_allowed)\
+                    or self.cluster.is_unlocked():
                 self.state_handler.set_role('master' if is_leader else 'replica')
                 if is_leader:
                     return 'continue to run as master without lock'
@@ -274,20 +371,34 @@ class Ha(object):
             self.demote('immediate-nolock')
             return demote_reason
 
-        if self._handle_rewind():
-            return self._async_executor.scheduled_action
+        msg = self._handle_rewind_or_reinitialize()
+        if msg:
+            return msg
 
-        if not self.state_handler.check_recovery_conf(node_to_follow):
-            self._async_executor.schedule('changing primary_conninfo and restarting')
-            self._async_executor.run_async(self.state_handler.follow, (node_to_follow,))
+        role = 'standby_leader' if isinstance(node_to_follow, RemoteMember) and self.has_lock(False) else 'replica'
+        # It might happen that leader key in the standby cluster references non-exiting member.
+        # In this case it is safe to continue running without changing recovery.conf
+        if self.is_standby_cluster() and role == 'replica' and not (node_to_follow and node_to_follow.conn_url):
+            return 'continue following the old known standby leader'
+        else:
+            change_required, restart_required = self.state_handler.config.check_recovery_conf(node_to_follow)
+            if change_required:
+                if restart_required:
+                    self._async_executor.try_run_async('changing primary_conninfo and restarting',
+                                                       self.state_handler.follow, args=(node_to_follow, role))
+                else:
+                    self.state_handler.follow(node_to_follow, role, do_reload=True)
+            elif role == 'standby_leader' and self.state_handler.role != role:
+                self.state_handler.set_role(role)
+                self.state_handler.call_nowait(ACTION_ON_ROLE_CHANGE)
 
         return follow_reason
 
     def is_synchronous_mode(self):
-        return bool(self.cluster and self.cluster.is_synchronous_mode())
+        return self.check_mode('synchronous_mode')
 
     def is_synchronous_mode_strict(self):
-        return bool(self.cluster and self.cluster.is_synchronous_mode_strict())
+        return self.check_mode('synchronous_mode_strict')
 
     def process_sync_replication(self):
         """Process synchronous standby beahvior.
@@ -314,14 +425,17 @@ class Ha(object):
                     logger.warning("No standbys available!")
 
                 logger.info("Assigning synchronous standby status to %s", picked)
-                self.state_handler.set_synchronous_standby(picked)
+                self.state_handler.config.set_synchronous_standby(picked)
 
                 if picked and picked != '*' and not allow_promote:
                     # Wait for PostgreSQL to enable synchronous mode and see if we can immediately set sync_standby
                     time.sleep(2)
                     picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster)
                 if allow_promote:
-                    cluster = self.dcs.get_cluster()
+                    try:
+                        cluster = self.dcs.get_cluster()
+                    except DCSError:
+                        return logger.warning("Could not get cluster state from DCS during process_sync_replication()")
                     if cluster.sync.leader and cluster.sync.leader != self.state_handler.name:
                         logger.info("Synchronous replication key updated by someone else")
                         return
@@ -332,7 +446,7 @@ class Ha(object):
         else:
             if self.cluster.sync.leader and self.dcs.delete_sync_state(index=self.cluster.sync.index):
                 logger.info("Disabled synchronous replication")
-            self.state_handler.set_synchronous_standby(None)
+            self.state_handler.config.set_synchronous_standby(None)
 
     def is_sync_standby(self, cluster):
         return cluster.leader and cluster.sync.leader == cluster.leader.name \
@@ -393,6 +507,10 @@ class Ha(object):
                         line.append(cluster_history[line[0]][3])
                 self.dcs.set_history_value(json.dumps(history, separators=(',', ':')))
 
+    def enforce_follow_remote_master(self, message):
+        demote_reason = 'cannot be a real master in standby cluster'
+        return self.follow(demote_reason, message)
+
     def enforce_master_role(self, message, promote_message):
         if not self.is_paused() and not self.watchdog.is_running and not self.watchdog.activate():
             if self.state_handler.is_leader():
@@ -420,24 +538,31 @@ class Ha(object):
                     # Somebody else updated sync state, it may be due to us losing the lock. To be safe, postpone
                     # promotion until next cycle. TODO: trigger immediate retry of run_cycle
                     return 'Postponing promotion because synchronous replication state was updated by somebody else'
-                self.state_handler.set_synchronous_standby('*' if self.is_synchronous_mode_strict() else None)
+                self.state_handler.config.set_synchronous_standby('*' if self.is_synchronous_mode_strict() else None)
             if self.state_handler.role != 'master':
-                self._async_executor.schedule('promote')
-                self._async_executor.run_async(self.state_handler.promote, args=(self.dcs.loop_wait,))
+                self.set_leader_access_is_restricted(self.cluster.has_permanent_logical_slots(self.state_handler.name))
+
+                def on_success():
+                    self._rewind.reset_state()
+                    logger.info("cleared rewind state after becoming the leader")
+
+                self._async_executor.try_run_async('promote', self.state_handler.promote,
+                                                   args=(self.dcs.loop_wait, on_success,
+                                                         self._leader_access_is_restricted))
             return promote_message
 
-    @staticmethod
-    def fetch_node_status(member):
+    def fetch_node_status(self, member):
         """This function perform http get request on member.api_url and fetches its status
         :returns: `_MemberStatus` object
         """
 
         try:
-            response = requests.get(member.api_url, timeout=2, verify=False)
-            logger.info('Got response from %s %s: %s', member.name, member.api_url, response.content)
-            return _MemberStatus.from_api_response(member, response.json())
+            response = self.patroni.request(member, timeout=2, retries=0)
+            data = response.data.decode('utf-8')
+            logger.info('Got response from %s %s: %s', member.name, member.api_url, data)
+            return _MemberStatus.from_api_response(member, json.loads(data))
         except Exception as e:
-            logger.warning("request failed: GET %s (%s)", member.api_url, e)
+            logger.warning("Request failed to %s: GET %s (%s)", member.name, member.api_url, e)
         return _MemberStatus.unknown(member)
 
     def fetch_nodes_statuses(self, members):
@@ -454,15 +579,24 @@ class Ha(object):
         :returns True when node is lagging
         """
         lag = (self.cluster.last_leader_operation or 0) - wal_position
-        return lag > self.state_handler.config.get('maximum_lag_on_failover', 0)
+        return lag > self.patroni.config.get('maximum_lag_on_failover', 0)
 
     def _is_healthiest_node(self, members, check_replication_lag=True):
         """This method tries to determine whether I am healthy enough to became a new leader candidate or not."""
 
+        # We don't call `last_operation()` here because it returns a string
         _, my_wal_position = self.state_handler.timeline_wal_position()
         if check_replication_lag and self.is_lagging(my_wal_position):
+            logger.info('My wal position exceeds maximum replication lag')
             return False  # Too far behind last reported wal position on master
 
+        if not self.is_standby_cluster() and self.check_timeline():
+            cluster_timeline = self.cluster.timeline
+            my_timeline = self.state_handler.replica_cached_timeline(cluster_timeline)
+            if my_timeline < cluster_timeline:
+                logger.info('My timeline %s is behind last known cluster timeline %s', my_timeline, cluster_timeline)
+                return False
+
         # Prepare list of nodes to run check against
         members = [m for m in members if m.name != self.state_handler.name and not m.nofailover and m.api_url]
 
@@ -473,11 +607,17 @@ class Ha(object):
                         logger.warning('Master (%s) is still alive', st.member.name)
                         return False
                     if my_wal_position < st.wal_position:
-                        return False
+                        logger.info('Wal position of %s is ahead of my wal position', st.member.name)
+                        # In synchronous mode the former leader might be still accessible and even be ahead of us.
+                        # We should not disqualify himself from the leader race in such a situation.
+                        if not self.is_synchronous_mode() or st.member.name != self.cluster.sync.leader:
+                            return False
+                        logger.info('Ignoring the former leader being ahead of us')
         return True
 
     def is_failover_possible(self, members):
         ret = False
+        cluster_timeline = self.cluster.timeline
         members = [m for m in members if m.name != self.state_handler.name and not m.nofailover and m.api_url]
         if members:
             for st in self.fetch_nodes_statuses(members):
@@ -486,6 +626,9 @@ class Ha(object):
                     logger.info('Member %s is %s', st.member.name, not_allowed_reason)
                 elif self.is_lagging(st.wal_position):
                     logger.info('Member %s exceeds maximum replication lag', st.member.name)
+                elif self.check_timeline() and (not st.timeline or st.timeline < cluster_timeline):
+                    logger.info('Timeline %s of member %s is behind the cluster timeline %s',
+                                st.timeline, st.member.name, cluster_timeline)
                 else:
                     ret = True
         else:
@@ -577,10 +720,14 @@ class Ha(object):
 
         return self._is_healthiest_node(members.values())
 
-    def release_leader_key_voluntarily(self):
+    def _delete_leader(self):
+        self.set_is_leader(False)
         self.dcs.delete_leader()
-        self.touch_member()
         self.dcs.reset_cluster()
+
+    def release_leader_key_voluntarily(self):
+        self._delete_leader()
+        self.touch_member()
         logger.info("Leader key released")
 
     def demote(self, mode):
@@ -595,19 +742,21 @@ class Ha(object):
                 PostgreSQL as quickly as possible without regard for data durability. May only be called synchronously.
         """
         mode_control = {
-            'offline':          dict(stop='fast', checkpoint=False, release=False, offline=True, async=False),
-            'graceful':         dict(stop='fast', checkpoint=True, release=True, offline=False, async=False),
-            'immediate':        dict(stop='immediate', checkpoint=False, release=True, offline=False, async=True),
-            'immediate-nolock': dict(stop='immediate', checkpoint=False, release=False, offline=False, async=True),
+            'offline':          dict(stop='fast', checkpoint=False, release=False, offline=True, async_req=False),
+            'graceful':         dict(stop='fast', checkpoint=True, release=True, offline=False, async_req=False),
+            'immediate':        dict(stop='immediate', checkpoint=False, release=True, offline=False, async_req=True),
+            'immediate-nolock': dict(stop='immediate', checkpoint=False, release=False, offline=False, async_req=True),
         }[mode]
 
-        self.state_handler.trigger_check_diverged_lsn()
+        self._rewind.trigger_check_diverged_lsn()
         self.state_handler.stop(mode_control['stop'], checkpoint=mode_control['checkpoint'],
                                 on_safepoint=self.watchdog.disable if self.watchdog.is_running else None)
         self.state_handler.set_role('demoted')
+        self.set_is_leader(False)
 
         if mode_control['release']:
-            self.release_leader_key_voluntarily()
+            with self._async_executor:
+                self.release_leader_key_voluntarily()
             time.sleep(2)  # Give a time to somebody to take the leader lock
         if mode_control['offline']:
             node_to_follow, leader = None, None
@@ -618,13 +767,12 @@ class Ha(object):
         # FIXME: with mode offline called from DCS exception handler and handle_long_action_in_progress
         # there could be an async action already running, calling follow from here will lead
         # to racy state handler state updates.
-        if mode_control['async']:
-            self._async_executor.schedule('starting after demotion')
-            self._async_executor.run_async(self.state_handler.follow, (node_to_follow,))
+        if mode_control['async_req']:
+            self._async_executor.try_run_async('starting after demotion', self.state_handler.follow, (node_to_follow,))
         else:
             if self.is_synchronous_mode():
-                self.state_handler.set_synchronous_standby(None)
-            if self.state_handler.rewind_needed_and_possible(leader):
+                self.state_handler.config.set_synchronous_standby(None)
+            if self._rewind.rewind_or_reinitialize_needed_and_possible(leader):
                 return False  # do not start postgres, but run pg_rewind on the next iteration
             self.state_handler.follow(node_to_follow)
 
@@ -693,9 +841,8 @@ class Ha(object):
                         members = [m for m in self.cluster.members
                                    if not failover.candidate or m.name == failover.candidate]
                     if self.is_failover_possible(members):  # check that there are healthy members
-                        self._async_executor.schedule('manual failover: demote')
-                        self._async_executor.run_async(self.demote, ('graceful',))
-                        return 'manual failover: demoting myself'
+                        ret = self._async_executor.try_run_async('manual failover: demote', self.demote, ('graceful',))
+                        return ret or 'manual failover: demoting myself'
                     else:
                         logger.warning('manual failover: no healthy members found, failover is not possible')
             else:
@@ -721,8 +868,18 @@ class Ha(object):
                         logger.info('Cleaning up failover key after acquiring leader lock...')
                         self.dcs.manual_failover('', '')
                 self.load_cluster_from_dcs()
-                return self.enforce_master_role('acquired session lock as a leader',
-                                                'promoted self to leader by acquiring session lock')
+
+                if self.is_standby_cluster():
+                    # standby leader disappeared, and this is a healthiest
+                    # replica, so it should become a new standby leader.
+                    # This imply that we need to start following a remote master
+                    msg = 'promoted self to a standby leader by acquiring session lock'
+                    return self.enforce_follow_remote_master(msg)
+                else:
+                    return self.enforce_master_role(
+                        'acquired session lock as a leader',
+                        'promoted self to leader by acquiring session lock'
+                    )
             else:
                 return self.follow('demoted self after trying and failing to obtain lock',
                                    'following new leader after trying and failing to obtain lock')
@@ -730,7 +887,7 @@ class Ha(object):
             # when we are doing manual failover there is no guaranty that new leader is ahead of any other node
             # node tagged as nofailover can be ahead of the new leader either, but it is always excluded from elections
             if bool(self.cluster.failover) or self.patroni.nofailover:
-                self.state_handler.trigger_check_diverged_lsn()
+                self._rewind.trigger_check_diverged_lsn()
                 time.sleep(2)  # Give a time to somebody to take the leader lock
 
             if self.patroni.nofailover:
@@ -745,27 +902,50 @@ class Ha(object):
                 if self.cluster.failover and self.cluster.failover.candidate == self.state_handler.name:
                     return 'waiting to become master after promote...'
 
-                self.dcs.delete_leader()
-                self.dcs.reset_cluster()
+                self._delete_leader()
                 return 'removed leader lock because postgres is not running as master'
 
+            if self.state_handler.is_leader() and self._leader_access_is_restricted:
+                self.state_handler.slots_handler.sync_replication_slots(self.cluster)
+                self.state_handler.call_nowait(ACTION_ON_ROLE_CHANGE)
+                self.set_leader_access_is_restricted(False)
+
             if self.update_lock(True):
                 msg = self.process_manual_failover_from_leader()
                 if msg is not None:
                     return msg
 
-                return self.enforce_master_role('no action.  i am the leader with the lock',
-                                                'promoted self to leader because i had the session lock')
+                # check if the node is ready to be used by pg_rewind
+                self._rewind.check_for_checkpoint_after_promote()
+
+                if self.is_standby_cluster():
+                    # in case of standby cluster we don't really need to
+                    # enforce anything, since the leader is not a master.
+                    # So just remind the role.
+                    msg = 'no action.  i am the standby leader with the lock' \
+                          if self.state_handler.role == 'standby_leader' else \
+                          'promoted self to a standby leader because i had the session lock'
+                    return self.enforce_follow_remote_master(msg)
+                else:
+                    return self.enforce_master_role(
+                        'no action.  i am the leader with the lock',
+                        'promoted self to leader because i had the session lock'
+                    )
             else:
                 # Either there is no connection to DCS or someone else acquired the lock
                 logger.error('failed to update leader lock')
                 if self.state_handler.is_leader():
+                    if self.is_paused():
+                        return 'continue to run as master after failing to update leader lock in DCS'
                     self.demote('immediate-nolock')
                     return 'demoted self because failed to update leader lock in DCS'
                 else:
                     return 'not promoting because failed to update leader lock in DCS'
         else:
             logger.info('does not have lock')
+        if self.is_standby_cluster():
+            return self.follow('cannot be a real master in standby cluster',
+                               'no action.  i am a secondary and i am following a standby leader', refresh=False)
         return self.follow('demoting self because i do not have the lock and i was a leader',
                            'no action.  i am a secondary and i am following a leader', refresh=False)
 
@@ -802,8 +982,7 @@ class Ha(object):
         if role and role != self.state_handler.role:
             reason_to_cancel = "host role mismatch"
 
-        if (postgres_version and
-           self.state_handler.postgres_version_to_int(postgres_version) <= int(self.state_handler.server_version)):
+        if postgres_version and postgres_version_to_int(postgres_version) <= int(self.state_handler.server_version):
             reason_to_cancel = "postgres version mismatch"
 
         if pending_restart and not self.state_handler.pending_restart:
@@ -883,7 +1062,8 @@ class Ha(object):
 
     def _do_reinitialize(self, cluster):
         self.state_handler.stop('immediate')
-        self.state_handler.remove_data_directory()
+        # Commented redundant data directory cleanup here
+        # self.state_handler.remove_data_directory()
 
         clone_member = self.cluster.get_clone_member(self.state_handler.name)
         member_role = 'leader' if clone_member == self.cluster.leader else 'replica'
@@ -896,7 +1076,7 @@ class Ha(object):
             if self.cluster.is_unlocked():
                 return 'Cluster has no leader, can not reinitialize'
 
-            if self.cluster.leader.name == self.state_handler.name:
+            if self.has_lock(False):
                 return 'I am the leader, can not reinitialize'
 
         if force:
@@ -942,8 +1122,7 @@ class Ha(object):
             self.watchdog.disable()
             if self.has_lock():
                 self.state_handler.set_role('demoted')
-                self.dcs.delete_leader()
-                self.dcs.reset_cluster()
+                self._delete_leader()
                 return 'removed leader key after trying and failing to start postgres'
             return 'failed to start postgres'
         self._crash_recovery_executed = False
@@ -966,19 +1145,21 @@ class Ha(object):
                 return 'waiting for end of recovery after bootstrap'
 
             self.state_handler.set_role('master')
-            self._async_executor.schedule('post_bootstrap')
-            self._async_executor.run_async(self.state_handler.post_bootstrap,
-                                           args=(self.patroni.config['bootstrap'], self._post_bootstrap_task))
-            return 'running post_bootstrap'
+            ret = self._async_executor.try_run_async('post_bootstrap', self.state_handler.bootstrap.post_bootstrap,
+                                                     args=(self.patroni.config['bootstrap'], self._post_bootstrap_task))
+            return ret or 'running post_bootstrap'
 
         self.state_handler.bootstrapping = False
         self.dcs.set_config_value(json.dumps(self.patroni.config.dynamic_configuration, separators=(',', ':')))
         if not self.watchdog.activate():
             logger.error('Cancelling bootstrap because watchdog activation failed')
             self.cancel_initialization()
+        self.state_handler.slots_handler.sync_replication_slots(self.cluster)
         self.dcs.take_leader()
+        self.set_is_leader(True)
         self.state_handler.call_nowait(ACTION_ON_START)
         self.load_cluster_from_dcs()
+
         return 'initialized a new cluster'
 
     def handle_starting_instance(self):
@@ -1034,6 +1215,11 @@ class Ha(object):
 
             if self.is_paused():
                 self.watchdog.disable()
+                self._was_paused = True
+            else:
+                if self._was_paused:
+                    self.state_handler.schedule_sanity_checks_after_pause()
+                self._was_paused = False
 
             if not self.cluster.has_member(self.state_handler.name):
                 self.touch_member()
@@ -1057,7 +1243,7 @@ class Ha(object):
             if self.state_handler.bootstrapping:
                 return self.post_bootstrap()
 
-            if self.recovering and not self.state_handler.need_rewind:
+            if self.recovering and not self._rewind.is_needed:
                 self.recovering = False
                 # Check if we tried to recover and failed
                 msg = self.post_recover()
@@ -1077,24 +1263,40 @@ class Ha(object):
                     return 'released leader key voluntarily as data dir empty and currently leader'
 
                 return self.bootstrap()  # new node
-            # "bootstrap", but data directory is not empty
-            elif not self.sysid_valid(self.cluster.initialize) and self.cluster.is_unlocked() and not self.is_paused():
-                self.dcs.initialize(create_new=(self.cluster.initialize is None), sysid=self.state_handler.sysid)
             else:
                 # check if we are allowed to join
-                if self.sysid_valid(self.cluster.initialize) and self.cluster.initialize != self.state_handler.sysid:
-                    logger.fatal("system ID mismatch, node %s belongs to a different cluster: %s != %s",
-                                 self.state_handler.name, self.cluster.initialize, self.state_handler.sysid)
-                    sys.exit(1)
+                data_sysid = self.state_handler.sysid
+                if not self.sysid_valid(data_sysid):
+                    # data directory is not empty, but no valid sysid, cluster must be broken, suggest reinit
+                    return "data dir for the cluster is not empty, but system ID is invalid; consider doing reinitalize"
+
+                if self.sysid_valid(self.cluster.initialize):
+                    if self.cluster.initialize != data_sysid:
+                        logger.fatal("system ID mismatch, node %s belongs to a different cluster: %s != %s",
+                                     self.state_handler.name, self.cluster.initialize, data_sysid)
+                        sys.exit(1)
+                elif self.cluster.is_unlocked() and not self.is_paused():
+                    # "bootstrap", but data directory is not empty
+                    if not self.state_handler.cb_called and self.state_handler.is_running() \
+                            and not self.state_handler.is_leader():
+                        self._join_aborted = True
+                        logger.error('No initialize key in DCS and PostgreSQL is running as replica, aborting start')
+                        logger.error('Please first start Patroni on the node running as master')
+                        sys.exit(1)
+                    self.dcs.initialize(create_new=(self.cluster.initialize is None), sysid=data_sysid)
 
             if not self.state_handler.is_healthy():
                 if self.is_paused():
                     if self.has_lock():
-                        self.dcs.delete_leader()
-                        self.dcs.reset_cluster()
+                        self._delete_leader()
                         return 'removed leader lock because postgres is not running'
-                    elif not (self.state_handler.rewind_executed or
-                              self.state_handler.need_rewind and self.state_handler.can_rewind):
+                    # Normally we don't start Postgres in a paused state. We make an exception for the demoted primary
+                    # that needs to be started after it had been stopped by demote. When there is no need to call rewind
+                    # the demote code follows through to starting Postgres right away, however, in the rewind case
+                    # it returns from demote and reaches this point to start PostgreSQL again after rewind. In that
+                    # case it makes no sense to continue to recover() unless rewind has finished successfully.
+                    elif self._rewind.failed or not self._rewind.executed and not \
+                            (self._rewind.is_needed and self._rewind.can_rewind_or_reinitialize_allowed):
                         return 'postgres is not running'
 
                 # try to start dead postgres
@@ -1111,11 +1313,11 @@ class Ha(object):
                 # stops PostgreSQL, therefore, we only reload replication slots if no
                 # asynchronous processes are running (should be always the case for the master)
                 if not self._async_executor.busy and not self.state_handler.is_starting():
+                    self.state_handler.slots_handler.sync_replication_slots(self.cluster)
                     if not self.state_handler.cb_called:
                         if not self.state_handler.is_leader():
-                            self.state_handler.trigger_check_diverged_lsn()
+                            self._rewind.trigger_check_diverged_lsn()
                         self.state_handler.call_nowait(ACTION_ON_START)
-                    self.state_handler.sync_replication_slots(self.cluster)
         except DCSError:
             dcs_failed = True
             logger.error('Error communicating with DCS')
@@ -1138,7 +1340,7 @@ class Ha(object):
         if self.is_paused():
             logger.info('Leader key is not deleted and Postgresql is not stopped due paused state')
             self.watchdog.disable()
-        else:
+        elif not self._join_aborted:
             # FIXME: If stop doesn't reach safepoint quickly enough keepalive is triggered. If shutdown checkpoint
             # takes longer than ttl, then leader key is lost and replication might not have sent out all xlog.
             # This might not be the desired behavior of users, as a graceful shutdown of the host can mean lost data.
@@ -1148,6 +1350,7 @@ class Ha(object):
             if not self.state_handler.is_running():
                 if self.has_lock():
                     self.dcs.delete_leader()
+                self.touch_member()
             else:
                 # XXX: what about when Patroni is started as the wrong user that has access to the watchdog device
                 # but cannot shut down PostgreSQL. Root would be the obvious example. Would be nice to not kill the
@@ -1156,13 +1359,11 @@ class Ha(object):
                              (" Leaving watchdog running." if self.watchdog.is_running else ""))
 
     def watch(self, timeout):
-        cluster = self.cluster
         # watch on leader key changes if the postgres is running and leader is known and current node is not lock owner
-        if not self._async_executor.busy and cluster and cluster.leader \
-                and cluster.leader.name != self.state_handler.name:
-            leader_index = cluster.leader.index
-        else:
+        if self._async_executor.busy or self.cluster.is_unlocked() or self.has_lock(False):
             leader_index = None
+        else:
+            leader_index = self.cluster.leader.index
 
         return self.dcs.watch(leader_index, timeout)
 
@@ -1171,3 +1372,25 @@ class Ha(object):
         no "active" leader watch request in progress.
         This usually happens on the master or if the node is running async action"""
         self.dcs.event.set()
+
+    def get_remote_member(self, member=None):
+        """ In case of standby cluster this will tel us from which remote
+            master to stream. Config can be both patroni config or
+            cluster.config.data
+        """
+        cluster_params = self.get_standby_cluster_config()
+
+        if cluster_params:
+            name = member.name if member else 'remote_master:{}'.format(uuid.uuid1())
+
+            data = {k: v for k, v in cluster_params.items() if k in RemoteMember.allowed_keys()}
+            data['no_replication_slot'] = 'primary_slot_name' not in cluster_params
+            conn_kwargs = member.conn_kwargs() if member else \
+                {k: cluster_params[k] for k in ('host', 'port') if k in cluster_params}
+            if conn_kwargs:
+                data['conn_kwargs'] = conn_kwargs
+
+            return RemoteMember(name, data)
+
+    def get_remote_master(self):
+        return self.get_remote_member()

patroni/log.py

@@ -0,0 +1,194 @@
+import logging
+import os
+import sys
+
+from copy import deepcopy
+from logging.handlers import RotatingFileHandler
+from patroni.utils import deep_compare
+from six.moves.queue import Queue, Full
+from threading import Lock, Thread
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def debug_exception(logger_obj, msg, *args, **kwargs):
+    kwargs.pop("exc_info", False)
+    if logger_obj.isEnabledFor(logging.DEBUG):
+        logger_obj.debug(msg, *args, exc_info=True, **kwargs)
+    else:
+        msg = "{0}, DETAIL: '{1}'".format(msg, sys.exc_info()[1])
+        logger_obj.error(msg, *args, exc_info=False, **kwargs)
+
+
+def error_exception(logger_obj, msg, *args, **kwargs):
+    exc_info = kwargs.pop("exc_info", True)
+    logger_obj.error(msg, *args, exc_info=exc_info, **kwargs)
+
+
+class QueueHandler(logging.Handler):
+
+    def __init__(self):
+        logging.Handler.__init__(self)
+        self.queue = Queue()
+        self._records_lost = 0
+
+    def _put_record(self, record):
+        self.format(record)
+        record.msg = record.message
+        record.args = None
+        record.exc_info = None
+        self.queue.put_nowait(record)
+
+    def _try_to_report_lost_records(self):
+        if self._records_lost:
+            try:
+                record = _LOGGER.makeRecord(_LOGGER.name, logging.WARNING, __file__, 0,
+                                            'QueueHandler has lost %s log records',
+                                            (self._records_lost,), None, 'emit')
+                self._put_record(record)
+                self._records_lost = 0
+            except Exception:
+                pass
+
+    def emit(self, record):
+        try:
+            self._put_record(record)
+            self._try_to_report_lost_records()
+        except Exception:
+            self._records_lost += 1
+
+    @property
+    def records_lost(self):
+        return self._records_lost
+
+
+class ProxyHandler(logging.Handler):
+
+    def __init__(self, patroni_logger):
+        logging.Handler.__init__(self)
+        self.patroni_logger = patroni_logger
+
+    def emit(self, record):
+        self.patroni_logger.log_handler.handle(record)
+
+
+class PatroniLogger(Thread):
+
+    DEFAULT_LEVEL = 'INFO'
+    DEFAULT_TRACEBACK_LEVEL = 'ERROR'
+    DEFAULT_FORMAT = '%(asctime)s %(levelname)s: %(message)s'
+
+    NORMAL_LOG_QUEUE_SIZE = 2  # When everything goes normal Patroni writes only 2 messages per HA loop
+    DEFAULT_MAX_QUEUE_SIZE = 1000
+    LOGGING_BROKEN_EXIT_CODE = 5
+
+    def __init__(self):
+        super(PatroniLogger, self).__init__()
+        self._queue_handler = QueueHandler()
+        self._root_logger = logging.getLogger()
+        self._config = None
+        self.log_handler = None
+        self.log_handler_lock = Lock()
+        self._old_handlers = []
+        self.reload_config({'level': 'DEBUG'})
+        # We will switch to the QueueHandler only when thread was started.
+        # This is necessary to protect from the cases when Patroni constructor
+        # failed and PatroniLogger thread remain running and prevent shutdown.
+        self._proxy_handler = ProxyHandler(self)
+        self._root_logger.addHandler(self._proxy_handler)
+
+    def update_loggers(self):
+        loggers = deepcopy(self._config.get('loggers') or {})
+        for name, logger in self._root_logger.manager.loggerDict.items():
+            if not isinstance(logger, logging.PlaceHolder):
+                level = loggers.pop(name, logging.NOTSET)
+                logger.setLevel(level)
+
+        for name, level in loggers.items():
+            logger = self._root_logger.manager.getLogger(name)
+            logger.setLevel(level)
+
+    def reload_config(self, config):
+        if self._config is None or not deep_compare(self._config, config):
+            with self._queue_handler.queue.mutex:
+                self._queue_handler.queue.maxsize = config.get('max_queue_size', self.DEFAULT_MAX_QUEUE_SIZE)
+
+            self._root_logger.setLevel(config.get('level', PatroniLogger.DEFAULT_LEVEL))
+            if config.get('traceback_level', PatroniLogger.DEFAULT_TRACEBACK_LEVEL).lower() == 'debug':
+                logging.Logger.exception = debug_exception
+            else:
+                logging.Logger.exception = error_exception
+
+            new_handler = None
+            if 'dir' in config:
+                if not isinstance(self.log_handler, RotatingFileHandler):
+                    new_handler = RotatingFileHandler(os.path.join(config['dir'], __name__))
+                handler = new_handler or self.log_handler
+                handler.maxBytes = int(config.get('file_size', 25000000))
+                handler.backupCount = int(config.get('file_num', 4))
+            else:
+                if self.log_handler is None or isinstance(self.log_handler, RotatingFileHandler):
+                    new_handler = logging.StreamHandler()
+                handler = new_handler or self.log_handler
+
+            oldlogformat = (self._config or {}).get('format', PatroniLogger.DEFAULT_FORMAT)
+            logformat = config.get('format', PatroniLogger.DEFAULT_FORMAT)
+
+            olddateformat = (self._config or {}).get('dateformat') or None
+            dateformat = config.get('dateformat') or None  # Convert empty string to `None`
+
+            if oldlogformat != logformat or olddateformat != dateformat or new_handler:
+                handler.setFormatter(logging.Formatter(logformat, dateformat))
+
+            if new_handler:
+                with self.log_handler_lock:
+                    if self.log_handler:
+                        self._old_handlers.append(self.log_handler)
+                    self.log_handler = new_handler
+
+            self._config = config.copy()
+            self.update_loggers()
+
+    def _close_old_handlers(self):
+        while True:
+            with self.log_handler_lock:
+                if not self._old_handlers:
+                    break
+                handler = self._old_handlers.pop()
+            try:
+                handler.close()
+            except Exception:
+                _LOGGER.exception('Failed to close the old log handler %s', handler)
+
+    def run(self):
+        # switch to QueueHandler only when the thread was started
+        with self.log_handler_lock:
+            self._root_logger.addHandler(self._queue_handler)
+            self._root_logger.removeHandler(self._proxy_handler)
+
+        while True:
+            self._close_old_handlers()
+
+            record = self._queue_handler.queue.get(True)
+            if record is None:
+                break
+
+            self.log_handler.handle(record)
+            self._queue_handler.queue.task_done()
+
+    def shutdown(self):
+        try:
+            self._queue_handler.queue.put_nowait(None)
+        except Full:  # Queue is full.
+            # It seems that logging is not working, exiting with non-standard exit-code is the best we can do.
+            sys.exit(self.LOGGING_BROKEN_EXIT_CODE)
+        self.join()
+        logging.shutdown()
+
+    @property
+    def queue_size(self):
+        return self._queue_handler.queue.qsize()
+
+    @property
+    def records_lost(self):
+        return self._queue_handler.records_lost

patroni/postgresql/__init__.py

@@ -0,0 +1,883 @@
+import logging
+import os
+import psycopg2
+import shlex
+import shutil
+import subprocess
+import time
+
+from contextlib import contextmanager
+from copy import deepcopy
+from patroni.postgresql.callback_executor import CallbackExecutor
+from patroni.postgresql.bootstrap import Bootstrap
+from patroni.postgresql.cancellable import CancellableSubprocess
+from patroni.postgresql.config import ConfigHandler
+from patroni.postgresql.connection import Connection, get_connection_cursor
+from patroni.postgresql.misc import parse_history, postgres_major_version_to_int
+from patroni.postgresql.postmaster import PostmasterProcess
+from patroni.postgresql.slots import SlotsHandler
+from patroni.exceptions import PostgresConnectionException
+from patroni.utils import Retry, RetryFailedError, polling_loop
+from threading import current_thread, Lock
+
+
+logger = logging.getLogger(__name__)
+
+ACTION_ON_START = "on_start"
+ACTION_ON_STOP = "on_stop"
+ACTION_ON_RESTART = "on_restart"
+ACTION_ON_RELOAD = "on_reload"
+ACTION_ON_ROLE_CHANGE = "on_role_change"
+ACTION_NOOP = "noop"
+
+STATE_RUNNING = 'running'
+STATE_REJECT = 'rejecting connections'
+STATE_NO_RESPONSE = 'not responding'
+STATE_UNKNOWN = 'unknown'
+
+STOP_POLLING_INTERVAL = 1
+
+
+@contextmanager
+def null_context():
+    yield
+
+
+class Postgresql(object):
+
+    def __init__(self, config):
+        self.name = config['name']
+        self.scope = config['scope']
+        self._data_dir = config['data_dir']
+        self._database = config.get('database', 'postgres')
+        self._version_file = os.path.join(self._data_dir, 'PG_VERSION')
+        self._pg_control = os.path.join(self._data_dir, 'global', 'pg_control')
+        self._major_version = self.get_major_version()
+
+        self._state_lock = Lock()
+        self.set_state('stopped')
+
+        self._pending_restart = False
+        self._connection = Connection()
+        self.config = ConfigHandler(self, config)
+
+        self._bin_dir = config.get('bin_dir') or ''
+        self.bootstrap = Bootstrap(self)
+        self.bootstrapping = False
+        self.__thread_ident = current_thread().ident
+
+        self.slots_handler = SlotsHandler(self)
+
+        self._callback_executor = CallbackExecutor()
+        self.__cb_called = False
+        self.__cb_pending = None
+
+        self.cancellable = CancellableSubprocess()
+
+        self._sysid = None
+        self.retry = Retry(max_tries=-1, deadline=config['retry_timeout']/2.0, max_delay=1,
+                           retry_exceptions=PostgresConnectionException)
+
+        # Retry 'pg_is_in_recovery()' only once
+        self._is_leader_retry = Retry(max_tries=1, deadline=config['retry_timeout']/2.0, max_delay=1,
+                                      retry_exceptions=PostgresConnectionException)
+
+        self._role_lock = Lock()
+        self.set_role(self.get_postgres_role_from_data_directory())
+        self._state_entry_timestamp = None
+
+        self._cluster_info_state = {}
+        self._cached_replica_timeline = None
+
+        # Last known running process
+        self._postmaster_proc = None
+
+        if self.is_running():
+            self.set_state('running')
+            self.set_role('master' if self.is_leader() else 'replica')
+            self.config.write_postgresql_conf()  # we are "joining" already running postgres
+            hba_saved = self.config.replace_pg_hba()
+            ident_saved = self.config.replace_pg_ident()
+            if hba_saved or ident_saved:
+                self.reload()
+        elif self.role == 'master':
+            self.set_role('demoted')
+
+    @property
+    def create_replica_methods(self):
+        return self.config.get('create_replica_methods', []) or self.config.get('create_replica_method', [])
+
+    @property
+    def major_version(self):
+        return self._major_version
+
+    @property
+    def database(self):
+        return self._database
+
+    @property
+    def data_dir(self):
+        return self._data_dir
+
+    @property
+    def callback(self):
+        return self.config.get('callbacks') or {}
+
+    @property
+    def wal_name(self):
+        return 'wal' if self._major_version >= 100000 else 'xlog'
+
+    @property
+    def lsn_name(self):
+        return 'lsn' if self._major_version >= 100000 else 'location'
+
+    @property
+    def cluster_info_query(self):
+        return ("SELECT CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0 "
+                "ELSE ('x' || pg_catalog.substr(pg_catalog.pg_{0}file_name("
+                "pg_catalog.pg_current_{0}_{1}()), 1, 8))::bit(32)::int END, "
+                "CASE WHEN pg_catalog.pg_is_in_recovery() THEN GREATEST("
+                " pg_catalog.pg_{0}_{1}_diff(COALESCE("
+                "pg_catalog.pg_last_{0}_receive_{1}(), '0/0'), '0/0')::bigint,"
+                " pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_last_{0}_replay_{1}(), '0/0')::bigint)"
+                "ELSE pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_current_{0}_{1}(), '0/0')::bigint "
+                "END").format(self.wal_name, self.lsn_name)
+
+    def _version_file_exists(self):
+        return not self.data_directory_empty() and os.path.isfile(self._version_file)
+
+    def get_major_version(self):
+        if self._version_file_exists():
+            try:
+                with open(self._version_file) as f:
+                    return postgres_major_version_to_int(f.read().strip())
+            except Exception:
+                logger.exception('Failed to read PG_VERSION from %s', self._data_dir)
+        return 0
+
+    def pgcommand(self, cmd):
+        """Returns path to the specified PostgreSQL command"""
+        return os.path.join(self._bin_dir, cmd)
+
+    def pg_ctl(self, cmd, *args, **kwargs):
+        """Builds and executes pg_ctl command
+
+        :returns: `!True` when return_code == 0, otherwise `!False`"""
+
+        pg_ctl = [self.pgcommand('pg_ctl'), cmd]
+        return subprocess.call(pg_ctl + ['-D', self._data_dir] + list(args), **kwargs) == 0
+
+    def pg_isready(self):
+        """Runs pg_isready to see if PostgreSQL is accepting connections.
+
+        :returns: 'ok' if PostgreSQL is up, 'reject' if starting up, 'no_resopnse' if not up."""
+
+        r = self.config.local_connect_kwargs
+        cmd = [self.pgcommand('pg_isready'), '-p', r['port'], '-d', self._database]
+
+        # Host is not set if we are connecting via default unix socket
+        if 'host' in r:
+            cmd.extend(['-h', r['host']])
+
+        # We only need the username because pg_isready does not try to authenticate
+        if 'user' in r:
+            cmd.extend(['-U', r['user']])
+
+        ret = subprocess.call(cmd)
+        return_codes = {0: STATE_RUNNING,
+                        1: STATE_REJECT,
+                        2: STATE_NO_RESPONSE,
+                        3: STATE_UNKNOWN}
+        return return_codes.get(ret, STATE_UNKNOWN)
+
+    def reload_config(self, config, sighup=False):
+        self.config.reload_config(config, sighup)
+        self._is_leader_retry.deadline = self.retry.deadline = config['retry_timeout']/2.0
+
+    @property
+    def pending_restart(self):
+        return self._pending_restart
+
+    def set_pending_restart(self, value):
+        self._pending_restart = value
+
+    @property
+    def sysid(self):
+        if not self._sysid and not self.bootstrapping:
+            data = self.controldata()
+            self._sysid = data.get('Database system identifier', "")
+        return self._sysid
+
+    def get_postgres_role_from_data_directory(self):
+        if self.data_directory_empty() or not self.controldata():
+            return 'uninitialized'
+        elif self.config.recovery_conf_exists():
+            return 'replica'
+        else:
+            return 'master'
+
+    @property
+    def server_version(self):
+        return self._connection.server_version
+
+    def connection(self):
+        return self._connection.get()
+
+    def set_connection_kwargs(self, kwargs):
+        self._connection.set_conn_kwargs(kwargs)
+
+    def _query(self, sql, *params):
+        """We are always using the same cursor, therefore this method is not thread-safe!!!
+        You can call it from different threads only if you are holding explicit `AsyncExecutor` lock,
+        because the main thread is always holding this lock when running HA cycle."""
+        cursor = None
+        try:
+            cursor = self._connection.cursor()
+            cursor.execute(sql, params)
+            return cursor
+        except psycopg2.Error as e:
+            if cursor and cursor.connection.closed == 0:
+                # When connected via unix socket, psycopg2 can't recoginze 'connection lost'
+                # and leaves `_cursor_holder.connection.closed == 0`, but psycopg2.OperationalError
+                # is still raised (what is correct). It doesn't make sense to continiue with existing
+                # connection and we will close it, to avoid its reuse by the `cursor` method.
+                if isinstance(e, psycopg2.OperationalError):
+                    self._connection.close()
+                else:
+                    raise e
+            if self.state == 'restarting':
+                raise RetryFailedError('cluster is being restarted')
+            raise PostgresConnectionException('connection problems')
+
+    def query(self, sql, *args, **kwargs):
+        if not kwargs.get('retry', True):
+            return self._query(sql, *args)
+        try:
+            return self.retry(self._query, sql, *args)
+        except RetryFailedError as e:
+            raise PostgresConnectionException(str(e))
+
+    def pg_control_exists(self):
+        return os.path.isfile(self._pg_control)
+
+    def data_directory_empty(self):
+        if self.pg_control_exists():
+            return False
+        if not os.path.exists(self._data_dir):
+            return True
+        return all(os.name != 'nt' and (n.startswith('.') or n == 'lost+found') for n in os.listdir(self._data_dir))
+
+    def replica_method_options(self, method):
+        return deepcopy(self.config.get(method, {}))
+
+    def replica_method_can_work_without_replication_connection(self, method):
+        return method != 'basebackup' and self.replica_method_options(method).get('no_master')
+
+    def can_create_replica_without_replication_connection(self, replica_methods=None):
+        """ go through the replication methods to see if there are ones
+            that does not require a working replication connection.
+        """
+        if replica_methods is None:
+            replica_methods = self.create_replica_methods
+        return any(self.replica_method_can_work_without_replication_connection(m) for m in replica_methods)
+
+    def reset_cluster_info_state(self):
+        self._cluster_info_state = {}
+
+    def _cluster_info_state_get(self, name):
+        if not self._cluster_info_state:
+            try:
+                result = self._is_leader_retry(self._query, self.cluster_info_query).fetchone()
+                self._cluster_info_state = dict(zip(['timeline', 'wal_position'], result))
+            except RetryFailedError as e:  # SELECT failed two times
+                self._cluster_info_state = {'error': str(e)}
+                if not self.is_starting() and self.pg_isready() == STATE_REJECT:
+                    self.set_state('starting')
+
+        if 'error' in self._cluster_info_state:
+            raise PostgresConnectionException(self._cluster_info_state['error'])
+
+        return self._cluster_info_state.get(name)
+
+    def is_leader(self):
+        return bool(self._cluster_info_state_get('timeline'))
+
+    def is_running(self):
+        """Returns PostmasterProcess if one is running on the data directory or None. If most recently seen process
+        is running updates the cached process based on pid file."""
+        if self._postmaster_proc:
+            if self._postmaster_proc.is_running():
+                return self._postmaster_proc
+            self._postmaster_proc = None
+
+        # we noticed that postgres was restarted, force syncing of replication
+        self.slots_handler.schedule()
+
+        self._postmaster_proc = PostmasterProcess.from_pidfile(self._data_dir)
+        return self._postmaster_proc
+
+    @property
+    def cb_called(self):
+        return self.__cb_called
+
+    def call_nowait(self, cb_name):
+        """ pick a callback command and call it without waiting for it to finish """
+        if self.bootstrapping:
+            return
+        if cb_name in (ACTION_ON_START, ACTION_ON_STOP, ACTION_ON_RESTART, ACTION_ON_ROLE_CHANGE):
+            self.__cb_called = True
+
+        if self.callback and cb_name in self.callback:
+            cmd = self.callback[cb_name]
+            try:
+                cmd = shlex.split(self.callback[cb_name]) + [cb_name, self.role, self.scope]
+                self._callback_executor.call(cmd)
+            except Exception:
+                logger.exception('callback %s %s %s %s failed', cmd, cb_name, self.role, self.scope)
+
+    @property
+    def role(self):
+        with self._role_lock:
+            return self._role
+
+    def set_role(self, value):
+        with self._role_lock:
+            self._role = value
+
+    @property
+    def state(self):
+        with self._state_lock:
+            return self._state
+
+    def set_state(self, value):
+        with self._state_lock:
+            self._state = value
+            self._state_entry_timestamp = time.time()
+
+    def time_in_state(self):
+        return time.time() - self._state_entry_timestamp
+
+    def is_starting(self):
+        return self.state == 'starting'
+
+    def wait_for_port_open(self, postmaster, timeout):
+        """Waits until PostgreSQL opens ports."""
+        for _ in polling_loop(timeout):
+            if self.cancellable.is_cancelled:
+                return False
+
+            if not postmaster.is_running():
+                logger.error('postmaster is not running')
+                self.set_state('start failed')
+                return False
+
+            isready = self.pg_isready()
+            if isready != STATE_NO_RESPONSE:
+                if isready not in [STATE_REJECT, STATE_RUNNING]:
+                    logger.warning("Can't determine PostgreSQL startup status, assuming running")
+                return True
+
+        logger.warning("Timed out waiting for PostgreSQL to start")
+        return False
+
+    def start(self, timeout=None, task=None, block_callbacks=False, role=None):
+        """Start PostgreSQL
+
+        Waits for postmaster to open ports or terminate so pg_isready can be used to check startup completion
+        or failure.
+
+        :returns: True if start was initiated and postmaster ports are open, False if start failed"""
+        # make sure we close all connections established against
+        # the former node, otherwise, we might get a stalled one
+        # after kill -9, which would report incorrect data to
+        # patroni.
+        self._connection.close()
+
+        if self.is_running():
+            logger.error('Cannot start PostgreSQL because one is already running.')
+            self.set_state('starting')
+            return True
+
+        if not block_callbacks:
+            self.__cb_pending = ACTION_ON_START
+
+        self.set_role(role or self.get_postgres_role_from_data_directory())
+
+        self.set_state('starting')
+        self._pending_restart = False
+
+        configuration = self.config.effective_configuration
+        self.config.write_postgresql_conf(configuration)
+        self.config.resolve_connection_addresses()
+        self.config.replace_pg_hba()
+        self.config.replace_pg_ident()
+
+        options = ['--{0}={1}'.format(p, configuration[p]) for p in self.config.CMDLINE_OPTIONS
+                   if p in configuration and p != 'wal_keep_segments']
+
+        if self.cancellable.is_cancelled:
+            return False
+
+        with task or null_context():
+            if task and task.is_cancelled:
+                logger.info("PostgreSQL start cancelled.")
+                return False
+
+            self._postmaster_proc = PostmasterProcess.start(self.pgcommand('postgres'),
+                                                            self._data_dir,
+                                                            self.config.postgresql_conf,
+                                                            options)
+
+            if task:
+                task.complete(self._postmaster_proc)
+
+        start_timeout = timeout
+        if not start_timeout:
+            try:
+                start_timeout = float(self.config.get('pg_ctl_timeout', 60))
+            except ValueError:
+                start_timeout = 60
+
+        # We want postmaster to open ports before we continue
+        if not self._postmaster_proc or not self.wait_for_port_open(self._postmaster_proc, start_timeout):
+            return False
+
+        ret = self.wait_for_startup(start_timeout)
+        if ret is not None:
+            return ret
+        elif timeout is not None:
+            return False
+        else:
+            return None
+
+    def checkpoint(self, connect_kwargs=None):
+        check_not_is_in_recovery = connect_kwargs is not None
+        connect_kwargs = connect_kwargs or self.config.local_connect_kwargs
+        for p in ['connect_timeout', 'options']:
+            connect_kwargs.pop(p, None)
+        try:
+            with get_connection_cursor(**connect_kwargs) as cur:
+                cur.execute("SET statement_timeout = 0")
+                if check_not_is_in_recovery:
+                    cur.execute('SELECT pg_catalog.pg_is_in_recovery()')
+                    if cur.fetchone()[0]:
+                        return 'is_in_recovery=true'
+                return cur.execute('CHECKPOINT')
+        except psycopg2.Error:
+            logger.exception('Exception during CHECKPOINT')
+            return 'not accessible or not healty'
+
+    def stop(self, mode='fast', block_callbacks=False, checkpoint=None, on_safepoint=None):
+        """Stop PostgreSQL
+
+        Supports a callback when a safepoint is reached. A safepoint is when no user backend can return a successful
+        commit to users. Currently this means we wait for user backends to close. But in the future alternate mechanisms
+        could be added.
+
+        :param on_safepoint: This callback is called when no user backends are running.
+        """
+        if checkpoint is None:
+            checkpoint = False if mode == 'immediate' else True
+
+        success, pg_signaled = self._do_stop(mode, block_callbacks, checkpoint, on_safepoint)
+        if success:
+            # block_callbacks is used during restart to avoid
+            # running start/stop callbacks in addition to restart ones
+            if not block_callbacks:
+                self.set_state('stopped')
+                if pg_signaled:
+                    self.call_nowait(ACTION_ON_STOP)
+        else:
+            logger.warning('pg_ctl stop failed')
+            self.set_state('stop failed')
+        return success
+
+    def _do_stop(self, mode, block_callbacks, checkpoint, on_safepoint):
+        postmaster = self.is_running()
+        if not postmaster:
+            if on_safepoint:
+                on_safepoint()
+            return True, False
+
+        if checkpoint and not self.is_starting():
+            self.checkpoint()
+
+        if not block_callbacks:
+            self.set_state('stopping')
+
+        # Send signal to postmaster to stop
+        success = postmaster.signal_stop(mode)
+        if success is not None:
+            if success and on_safepoint:
+                on_safepoint()
+            return success, True
+
+        # We can skip safepoint detection if we don't have a callback
+        if on_safepoint:
+            # Wait for our connection to terminate so we can be sure that no new connections are being initiated
+            self._wait_for_connection_close(postmaster)
+            postmaster.wait_for_user_backends_to_close()
+            on_safepoint()
+
+        postmaster.wait()
+
+        return True, True
+
+    @staticmethod
+    def terminate_starting_postmaster(postmaster):
+        """Terminates a postmaster that has not yet opened ports or possibly even written a pid file. Blocks
+        until the process goes away."""
+        postmaster.signal_stop('immediate')
+        postmaster.wait()
+
+    def _wait_for_connection_close(self, postmaster):
+        try:
+            with self.connection().cursor() as cur:
+                while postmaster.is_running():  # Need a timeout here?
+                    cur.execute("SELECT 1")
+                    time.sleep(STOP_POLLING_INTERVAL)
+        except psycopg2.Error:
+            pass
+
+    def reload(self):
+        ret = self.pg_ctl('reload')
+        if ret:
+            self.call_nowait(ACTION_ON_RELOAD)
+        return ret
+
+    def check_for_startup(self):
+        """Checks PostgreSQL status and returns if PostgreSQL is in the middle of startup."""
+        return self.is_starting() and not self.check_startup_state_changed()
+
+    def check_startup_state_changed(self):
+        """Checks if PostgreSQL has completed starting up or failed or still starting.
+
+        Should only be called when state == 'starting'
+
+        :returns: True if state was changed from 'starting'
+        """
+        ready = self.pg_isready()
+
+        if ready == STATE_REJECT:
+            return False
+        elif ready == STATE_NO_RESPONSE:
+            ret = not self.is_running()
+            if ret:
+                self.set_state('start failed')
+                self.slots_handler.schedule(False)  # TODO: can remove this?
+                self.config.save_configuration_files(True)  # TODO: maybe remove this?
+            return ret
+        else:
+            if ready != STATE_RUNNING:
+                # Bad configuration or unexpected OS error. No idea of PostgreSQL status.
+                # Let the main loop of run cycle clean up the mess.
+                logger.warning("%s status returned from pg_isready",
+                               "Unknown" if ready == STATE_UNKNOWN else "Invalid")
+            self.set_state('running')
+            self.slots_handler.schedule()
+            self.config.save_configuration_files(True)
+            # TODO: __cb_pending can be None here after PostgreSQL restarts on its own. Do we want to call the callback?
+            # Previously we didn't even notice.
+            action = self.__cb_pending or ACTION_ON_START
+            self.call_nowait(action)
+            self.__cb_pending = None
+
+            return True
+
+    def wait_for_startup(self, timeout=None):
+        """Waits for PostgreSQL startup to complete or fail.
+
+        :returns: True if start was successful, False otherwise"""
+        if not self.is_starting():
+            # Should not happen
+            logger.warning("wait_for_startup() called when not in starting state")
+
+        while not self.check_startup_state_changed():
+            if self.cancellable.is_cancelled or timeout and self.time_in_state() > timeout:
+                return None
+            time.sleep(1)
+
+        return self.state == 'running'
+
+    def restart(self, timeout=None, task=None, block_callbacks=False, role=None):
+        """Restarts PostgreSQL.
+
+        When timeout parameter is set the call will block either until PostgreSQL has started, failed to start or
+        timeout arrives.
+
+        :returns: True when restart was successful and timeout did not expire when waiting.
+        """
+        self.set_state('restarting')
+        if not block_callbacks:
+            self.__cb_pending = ACTION_ON_RESTART
+        ret = self.stop(block_callbacks=True) and self.start(timeout, task, True, role)
+        if not ret and not self.is_starting():
+            self.set_state('restart failed ({0})'.format(self.state))
+        return ret
+
+    def is_healthy(self):
+        if not self.is_running():
+            logger.warning('Postgresql is not running.')
+            return False
+        return True
+
+    def controldata(self):
+        """ return the contents of pg_controldata, or non-True value if pg_controldata call failed """
+        result = {}
+        # Don't try to call pg_controldata during backup restore
+        if self._version_file_exists() and self.state != 'creating replica':
+            try:
+                env = os.environ.copy()
+                env.update(LANG='C', LC_ALL='C')
+                data = subprocess.check_output([self.pgcommand('pg_controldata'), self._data_dir], env=env)
+                if data:
+                    data = data.decode('utf-8').splitlines()
+                    # pg_controldata output depends on major verion. Some of parameters are prefixed by 'Current '
+                    result = {l.split(':')[0].replace('Current ', '', 1): l.split(':', 1)[1].strip() for l in data
+                              if l and ':' in l}
+            except subprocess.CalledProcessError:
+                logger.exception("Error when calling pg_controldata")
+        return result
+
+    @contextmanager
+    def get_replication_connection_cursor(self, host='localhost', port=5432, database=None, **kwargs):
+        conn_kwargs = self.config.replication.copy()
+        conn_kwargs.update(host=host, port=int(port), database=database or self._database, connect_timeout=3,
+                           user=conn_kwargs.pop('username'), replication=1, options='-c statement_timeout=2000')
+        with get_connection_cursor(**conn_kwargs) as cur:
+            yield cur
+
+    def get_local_timeline_lsn_from_replication_connection(self):
+        timeline = lsn = None
+        try:
+            with self.get_replication_connection_cursor(**self.config.local_replication_address) as cur:
+                cur.execute('IDENTIFY_SYSTEM')
+                timeline, lsn = cur.fetchone()[1:3]
+        except Exception:
+            logger.exception('Can not fetch local timeline and lsn from replication connection')
+        return timeline, lsn
+
+    def get_replica_timeline(self):
+        return self.get_local_timeline_lsn_from_replication_connection()[0]
+
+    def replica_cached_timeline(self, master_timeline):
+        if not self._cached_replica_timeline or not master_timeline or self._cached_replica_timeline != master_timeline:
+            self._cached_replica_timeline = self.get_replica_timeline()
+        return self._cached_replica_timeline
+
+    def get_master_timeline(self):
+        return self._cluster_info_state_get('timeline')
+
+    def get_history(self, timeline):
+        history_path = 'pg_{0}/{1:08X}.history'.format(self.wal_name, timeline)
+        try:
+            cursor = self._connection.cursor()
+            cursor.execute('SELECT isdir, modification FROM pg_catalog.pg_stat_file(%s)', (history_path,))
+            isdir, modification = cursor.fetchone()
+            if not isdir:
+                cursor.execute('SELECT pg_catalog.pg_read_file(%s)', (history_path,))
+                history = list(parse_history(cursor.fetchone()[0]))
+                if history[-1][0] == timeline - 1:
+                    history[-1].append(modification.isoformat())
+                return history
+        except Exception:
+            logger.exception('Failed to read and parse %s', (history_path,))
+
+    def follow(self, member, role='replica', timeout=None, do_reload=False):
+        recovery_params = self.config.build_recovery_params(member)
+        self.config.write_recovery_conf(recovery_params)
+
+        # When we demoting the master or standby_leader to replica or promoting replica to a standby_leader
+        # and we know for sure that postgres was already running before, we will only execute on_role_change
+        # callback and prevent execution of on_restart/on_start callback.
+        # If the role remains the same (replica or standby_leader), we will execute on_start or on_restart
+        change_role = self.cb_called and (self.role in ('master', 'demoted') or
+                                          not {'standby_leader', 'replica'} - {self.role, role})
+        if change_role:
+            self.__cb_pending = ACTION_NOOP
+
+        if self.is_running():
+            if do_reload:
+                self.config.write_postgresql_conf()
+                self.reload()
+            else:
+                self.restart(block_callbacks=change_role, role=role)
+        else:
+            self.start(timeout=timeout, block_callbacks=change_role, role=role)
+
+        if change_role:
+            # TODO: postpone this until start completes, or maybe do even earlier
+            self.call_nowait(ACTION_ON_ROLE_CHANGE)
+        return True
+
+    def _wait_promote(self, wait_seconds):
+        for _ in polling_loop(wait_seconds):
+            data = self.controldata()
+            if data.get('Database cluster state') == 'in production':
+                return True
+
+    def promote(self, wait_seconds, on_success=None, access_is_restricted=False):
+        if self.role == 'master':
+            return True
+        ret = self.pg_ctl('promote', '-W')
+        if ret:
+            self.set_role('master')
+            if on_success is not None:
+                on_success()
+            if not access_is_restricted:
+                self.call_nowait(ACTION_ON_ROLE_CHANGE)
+            ret = self._wait_promote(wait_seconds)
+        return ret
+
+    def timeline_wal_position(self):
+        # This method could be called from different threads (simultaneously with some other `_query` calls).
+        # If it is called not from main thread we will create a new cursor to execute statement.
+        if current_thread().ident == self.__thread_ident:
+            return self._cluster_info_state_get('timeline'), self._cluster_info_state_get('wal_position')
+
+        with self.connection().cursor() as cursor:
+            cursor.execute(self.cluster_info_query)
+            return cursor.fetchone()[:2]
+
+    def postmaster_start_time(self):
+        try:
+            query = "SELECT pg_catalog.to_char(pg_catalog.pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ')"
+            if current_thread().ident == self.__thread_ident:
+                return self.query(query).fetchone()[0]
+            with self.connection().cursor() as cursor:
+                cursor.execute(query)
+                return cursor.fetchone()[0]
+        except psycopg2.Error:
+            return None
+
+    def last_operation(self):
+        return str(self._cluster_info_state_get('wal_position'))
+
+    def configure_server_parameters(self):
+        self._major_version = self.get_major_version()
+        self.config.setup_server_parameters()
+        return True
+
+    def move_data_directory(self):
+        if os.path.isdir(self._data_dir) and not self.is_running():
+            try:
+                new_name = '{0}_{1}'.format(self._data_dir, time.strftime('%Y-%m-%d-%H-%M-%S'))
+                logger.info('renaming data directory to %s', new_name)
+                os.rename(self._data_dir, new_name)
+            except OSError:
+                logger.exception("Could not rename data directory %s", self._data_dir)
+
+    def remove_data_directory(self):
+        self.set_role('uninitialized')
+        logger.info('Removing data directory: %s', self._data_dir)
+        try:
+            if os.path.islink(self._data_dir):
+                os.unlink(self._data_dir)
+            elif not os.path.exists(self._data_dir):
+                return
+            elif os.path.isfile(self._data_dir):
+                os.remove(self._data_dir)
+            elif os.path.isdir(self._data_dir):
+
+                # let's see if pg_xlog|pg_wal is a symlink, in this case we
+                # should clean the target
+                for pg_wal_dir in ('pg_xlog', 'pg_wal'):
+                    pg_wal_path = os.path.join(self._data_dir, pg_wal_dir)
+                    if os.path.exists(pg_wal_path) and os.path.islink(pg_wal_path):
+                        pg_wal_realpath = os.path.realpath(pg_wal_path)
+                        logger.info('Removing WAL directory: %s', pg_wal_realpath)
+                        shutil.rmtree(pg_wal_realpath)
+
+                shutil.rmtree(self._data_dir)
+        except (IOError, OSError):
+            logger.exception('Could not remove data directory %s', self._data_dir)
+            self.move_data_directory()
+
+    def pick_synchronous_standby(self, cluster):
+        """Finds the best candidate to be the synchronous standby.
+
+        Current synchronous standby is always preferred, unless it has disconnected or does not want to be a
+        synchronous standby any longer.
+
+        :returns tuple of candidate name or None, and bool showing if the member is the active synchronous standby.
+        """
+        current = cluster.sync.sync_standby
+        current = current.lower() if current else current
+        members = {m.name.lower(): m for m in cluster.members}
+        candidates = []
+        # Pick candidates based on who has flushed WAL farthest.
+        # TODO: for synchronous_commit = remote_write we actually want to order on write_location
+        for app_name, state, sync_state in self.query(
+                "SELECT pg_catalog.lower(application_name), state, sync_state"
+                " FROM pg_catalog.pg_stat_replication"
+                " ORDER BY flush_{0} DESC".format(self.lsn_name)):
+            member = members.get(app_name)
+            if state != 'streaming' or not member or member.tags.get('nosync', False):
+                continue
+            if sync_state == 'sync':
+                return app_name, True
+            if sync_state == 'potential' and app_name == current:
+                # Prefer current even if not the best one any more to avoid indecisivness and spurious swaps.
+                return cluster.sync.sync_standby, False
+            if sync_state in ('async', 'potential'):
+                candidates.append(member.name)
+
+        if candidates:
+            return candidates[0], False
+        return None, False
+
+    def read_postmaster_opts(self):
+        """returns the list of option names/values from postgres.opts, Empty dict if read failed or no file"""
+        result = {}
+        try:
+            with open(os.path.join(self._data_dir, 'postmaster.opts')) as f:
+                data = f.read()
+                for opt in data.split('" "'):
+                    if '=' in opt and opt.startswith('--'):
+                        name, val = opt.split('=', 1)
+                        result[name.strip('-')] = val.rstrip('"\n')
+        except IOError:
+            logger.exception('Error when reading postmaster.opts')
+        return result
+
+    def single_user_mode(self, command=None, options=None):
+        """run a given command in a single-user mode. If the command is empty - then just start and stop"""
+        cmd = [self.pgcommand('postgres'), '--single', '-D', self._data_dir]
+        for opt, val in sorted((options or {}).items()):
+            cmd.extend(['-c', '{0}={1}'.format(opt, val)])
+        # need a database name to connect
+        cmd.append(self._database)
+        return self.cancellable.call(cmd, communicate_input=command)
+
+    def cleanup_archive_status(self):
+        status_dir = os.path.join(self._data_dir, 'pg_' + self.wal_name, 'archive_status')
+        try:
+            for f in os.listdir(status_dir):
+                path = os.path.join(status_dir, f)
+                try:
+                    if os.path.islink(path):
+                        os.unlink(path)
+                    elif os.path.isfile(path):
+                        os.remove(path)
+                except OSError:
+                    logger.exception('Unable to remove %s', path)
+        except OSError:
+            logger.exception('Unable to list %s', status_dir)
+
+    def fix_cluster_state(self):
+        self.cleanup_archive_status()
+
+        # Start in a single user mode and stop to produce a clean shutdown
+        opts = self.read_postmaster_opts()
+        opts.update({'archive_mode': 'on', 'archive_command': 'false'})
+        self.config.remove_recovery_conf()
+        return self.single_user_mode(options=opts) == 0 or None
+
+    def schedule_sanity_checks_after_pause(self):
+        """
+            After coming out of pause we have to:
+            1. sync replication slots, because it might happen that slots were removed
+            2. get new 'Database system identifier' to make sure that it wasn't changed
+        """
+        self.slots_handler.schedule()
+        self._sysid = None

patroni/postgresql/bootstrap.py

@@ -0,0 +1,370 @@
+import logging
+import os
+import shlex
+import tempfile
+import time
+
+from patroni.dcs import RemoteMember
+from patroni.utils import deep_compare
+from six import string_types
+
+logger = logging.getLogger(__name__)
+
+
+class Bootstrap(object):
+
+    def __init__(self, postgresql):
+        self._postgresql = postgresql
+        self._running_custom_bootstrap = False
+
+    @property
+    def running_custom_bootstrap(self):
+        return self._running_custom_bootstrap
+
+    @property
+    def keep_existing_recovery_conf(self):
+        return self._running_custom_bootstrap and self._keep_existing_recovery_conf
+
+    @staticmethod
+    def process_user_options(tool, options, not_allowed_options, error_handler):
+        user_options = []
+
+        def option_is_allowed(name):
+            ret = name not in not_allowed_options
+            if not ret:
+                error_handler('{0} option for {1} is not allowed'.format(name, tool))
+            return ret
+
+        if isinstance(options, dict):
+            for k, v in options.items():
+                if k and v:
+                    user_options.append('--{0}={1}'.format(k, v))
+        elif isinstance(options, list):
+            for opt in options:
+                if isinstance(opt, string_types) and option_is_allowed(opt):
+                    user_options.append('--{0}'.format(opt))
+                elif isinstance(opt, dict):
+                    keys = list(opt.keys())
+                    if len(keys) != 1 or not isinstance(opt[keys[0]], string_types) or not option_is_allowed(keys[0]):
+                        error_handler('Error when parsing {0} key-value option {1}: only one key-value is allowed'
+                                      ' and value should be a string'.format(tool, opt[keys[0]]))
+                    user_options.append('--{0}={1}'.format(keys[0], opt[keys[0]]))
+                else:
+                    error_handler('Error when parsing {0} option {1}: value should be string value'
+                                  ' or a single key-value pair'.format(tool, opt))
+        else:
+            error_handler('{0} options must be list ot dict'.format(tool))
+        return user_options
+
+    def _initdb(self, config):
+        self._postgresql.set_state('initalizing new cluster')
+        not_allowed_options = ('pgdata', 'nosync', 'pwfile', 'sync-only', 'version')
+
+        def error_handler(e):
+            raise Exception(e)
+
+        options = self.process_user_options('initdb', config or [], not_allowed_options, error_handler)
+        pwfile = None
+
+        if self._postgresql.config.superuser:
+            if 'username' in self._postgresql.config.superuser:
+                options.append('--username={0}'.format(self._postgresql.config.superuser['username']))
+            if 'password' in self._postgresql.config.superuser:
+                (fd, pwfile) = tempfile.mkstemp()
+                os.write(fd, self._postgresql.config.superuser['password'].encode('utf-8'))
+                os.close(fd)
+                options.append('--pwfile={0}'.format(pwfile))
+        options = ['-o', ' '.join(options)] if options else []
+
+        ret = self._postgresql.pg_ctl('initdb', *options)
+        if pwfile:
+            os.remove(pwfile)
+        if ret:
+            self._postgresql.configure_server_parameters()
+        else:
+            self._postgresql.set_state('initdb failed')
+        return ret
+
+    def _post_restore(self):
+        self._postgresql.config.restore_configuration_files()
+        self._postgresql.configure_server_parameters()
+
+        # make sure there is no trigger file or postgres will be automatically promoted
+        trigger_file = 'promote_trigger_file' if self._postgresql.major_version >= 120000 else 'trigger_file'
+        trigger_file = self._postgresql.config.get('recovery_conf', {}).get(trigger_file) or 'promote'
+        trigger_file = os.path.abspath(os.path.join(self._postgresql.data_dir, trigger_file))
+        if os.path.exists(trigger_file):
+            os.unlink(trigger_file)
+
+    def _custom_bootstrap(self, config):
+        self._postgresql.set_state('running custom bootstrap script')
+        params = ['--scope=' + self._postgresql.scope, '--datadir=' + self._postgresql.data_dir]
+        try:
+            logger.info('Running custom bootstrap script: %s', config['command'])
+            if self._postgresql.cancellable.call(shlex.split(config['command']) + params) != 0:
+                self._postgresql.set_state('custom bootstrap failed')
+                return False
+        except Exception:
+            logger.exception('Exception during custom bootstrap')
+            return False
+        self._post_restore()
+
+        if 'recovery_conf' in config:
+            self._postgresql.config.write_recovery_conf(config['recovery_conf'])
+        elif not self.keep_existing_recovery_conf:
+            self._postgresql.config.remove_recovery_conf()
+        return True
+
+    def call_post_bootstrap(self, config):
+        """
+        runs a script after initdb or custom bootstrap script is called and waits until completion.
+        """
+        cmd = config.get('post_bootstrap') or config.get('post_init')
+        if cmd:
+            r = self._postgresql.config.local_connect_kwargs
+            connstring = self._postgresql.config.format_dsn(r, True)
+            if 'host' not in r:
+                # https://www.postgresql.org/docs/current/static/libpq-pgpass.html
+                # A host name of localhost matches both TCP (host name localhost) and Unix domain socket
+                # (pghost empty or the default socket directory) connections coming from the local machine.
+                r['host'] = 'localhost'  # set it to localhost to write into pgpass
+
+            env = self._postgresql.config.write_pgpass(r) if 'password' in r else None
+
+            try:
+                ret = self._postgresql.cancellable.call(shlex.split(cmd) + [connstring], env=env)
+            except OSError:
+                logger.error('post_init script %s failed', cmd)
+                return False
+            if ret != 0:
+                logger.error('post_init script %s returned non-zero code %d', cmd, ret)
+                return False
+        return True
+
+    def create_replica(self, clone_member):
+        """
+            create the replica according to the replica_method
+            defined by the user.  this is a list, so we need to
+            loop through all methods the user supplies
+        """
+
+        self._postgresql.set_state('creating replica')
+        self._postgresql.schedule_sanity_checks_after_pause()
+
+        is_remote_master = isinstance(clone_member, RemoteMember)
+
+        # get list of replica methods either from clone member or from
+        # the config. If there is no configuration key, or no value is
+        # specified, use basebackup
+        replica_methods = (clone_member.create_replica_methods if is_remote_master
+                           else self._postgresql.create_replica_methods) or ['basebackup']
+
+        if clone_member and clone_member.conn_url:
+            r = clone_member.conn_kwargs(self._postgresql.config.replication)
+            # add the credentials to connect to the replica origin to pgpass.
+            env = self._postgresql.config.write_pgpass(r)
+            connstring = self._postgresql.config.format_dsn(r, True)
+        else:
+            connstring = ''
+            env = os.environ.copy()
+            # if we don't have any source, leave only replica methods that work without it
+            replica_methods = [r for r in replica_methods
+                               if self._postgresql.replica_method_can_work_without_replication_connection(r)]
+
+        # go through them in priority order
+        ret = 1
+        for replica_method in replica_methods:
+            if self._postgresql.cancellable.is_cancelled:
+                break
+
+            method_config = self._postgresql.replica_method_options(replica_method)
+
+            # if the method is basebackup, then use the built-in
+            if replica_method == "basebackup":
+                ret = self.basebackup(connstring, env, method_config)
+                if ret == 0:
+                    logger.info("replica has been created using basebackup")
+                    # if basebackup succeeds, exit with success
+                    break
+            else:
+                if not self._postgresql.data_directory_empty():
+                    if method_config.get('keep_data', False):
+                        logger.info('Leaving data directory uncleaned')
+                    else:
+                        self._postgresql.remove_data_directory()
+
+                cmd = replica_method
+                # user-defined method; check for configuration
+                # not required, actually
+                if method_config:
+                    # look to see if the user has supplied a full command path
+                    # if not, use the method name as the command
+                    cmd = method_config.pop('command', cmd)
+
+                # add the default parameters
+                if not method_config.get('no_params', False):
+                    method_config.update({"scope": self._postgresql.scope,
+                                          "role": "replica",
+                                          "datadir": self._postgresql.data_dir,
+                                          "connstring": connstring})
+                else:
+                    for param in ('no_params', 'no_master', 'keep_data'):
+                        method_config.pop(param, None)
+                params = ["--{0}={1}".format(arg, val) for arg, val in method_config.items()]
+                try:
+                    # call script with the full set of parameters
+                    ret = self._postgresql.cancellable.call(shlex.split(cmd) + params, env=env)
+                    # if we succeeded, stop
+                    if ret == 0:
+                        logger.info('replica has been created using %s', replica_method)
+                        break
+                    else:
+                        logger.error('Error creating replica using method %s: %s exited with code=%s',
+                                     replica_method, cmd, ret)
+                except Exception:
+                    logger.exception('Error creating replica using method %s', replica_method)
+                    ret = 1
+
+        self._postgresql.set_state('stopped')
+        return ret
+
+    def basebackup(self, conn_url, env, options):
+        # creates a replica data dir using pg_basebackup.
+        # this is the default, built-in create_replica_methods
+        # tries twice, then returns failure (as 1)
+        # uses "stream" as the xlog-method to avoid sync issues
+        # supports additional user-supplied options, those are not validated
+        maxfailures = 2
+        ret = 1
+        not_allowed_options = ('pgdata', 'format', 'wal-method', 'xlog-method', 'gzip',
+                               'version', 'compress', 'dbname', 'host', 'port', 'username', 'password')
+        user_options = self.process_user_options('basebackup', options, not_allowed_options, logger.error)
+
+        for bbfailures in range(0, maxfailures):
+            if self._postgresql.cancellable.is_cancelled:
+                break
+            if not self._postgresql.data_directory_empty():
+                self._postgresql.remove_data_directory()
+            try:
+                ret = self._postgresql.cancellable.call([self._postgresql.pgcommand('pg_basebackup'),
+                                                         '--pgdata=' + self._postgresql.data_dir, '-X', 'stream',
+                                                         '--dbname=' + conn_url] + user_options, env=env)
+                if ret == 0:
+                    break
+                else:
+                    logger.error('Error when fetching backup: pg_basebackup exited with code=%s', ret)
+
+            except Exception as e:
+                logger.error('Error when fetching backup with pg_basebackup: %s', e)
+
+            if bbfailures < maxfailures - 1:
+                logger.warning('Trying again in 5 seconds')
+                time.sleep(5)
+
+        return ret
+
+    def clone(self, clone_member):
+        """
+             - initialize the replica from an existing member (master or replica)
+             - initialize the replica using the replica creation method that
+               works without the replication connection (i.e. restore from on-disk
+               base backup)
+        """
+
+        ret = self.create_replica(clone_member) == 0
+        if ret:
+            self._post_restore()
+        return ret
+
+    def bootstrap(self, config):
+        """ Initialize a new node from scratch and start it. """
+        pg_hba = config.get('pg_hba', [])
+        method = config.get('method') or 'initdb'
+        if method != 'initdb' and method in config and 'command' in config[method]:
+            self._keep_existing_recovery_conf = config[method].get('keep_existing_recovery_conf')
+            self._running_custom_bootstrap = True
+            do_initialize = self._custom_bootstrap
+        else:
+            method = 'initdb'
+            do_initialize = self._initdb
+        return do_initialize(config.get(method)) and self._postgresql.config.append_pg_hba(pg_hba) \
+            and self._postgresql.config.save_configuration_files() and self._postgresql.start()
+
+    def create_or_update_role(self, name, password, options):
+        options = list(map(str.upper, options))
+        if 'NOLOGIN' not in options and 'LOGIN' not in options:
+            options.append('LOGIN')
+
+        params = [name]
+        if password:
+            options.extend(['PASSWORD', '%s'])
+            params.extend([password, password])
+
+        sql = """DO $$
+BEGIN
+    SET local synchronous_commit = 'local';
+    PERFORM * FROM pg_authid WHERE rolname = %s;
+    IF FOUND THEN
+        ALTER ROLE "{0}" WITH {1};
+    ELSE
+        CREATE ROLE "{0}" WITH {1};
+    END IF;
+END;$$""".format(name, ' '.join(options))
+        self._postgresql.query(sql, *params)
+
+    def post_bootstrap(self, config, task):
+        try:
+            postgresql = self._postgresql
+            superuser = postgresql.config.superuser
+            if 'username' in superuser and 'password' in superuser:
+                self.create_or_update_role(superuser['username'], superuser['password'], ['SUPERUSER'])
+
+            task.complete(self.call_post_bootstrap(config))
+            if task.result:
+                replication = postgresql.config.replication
+                self.create_or_update_role(replication['username'], replication.get('password'), ['REPLICATION'])
+
+                rewind = postgresql.config.rewind_credentials
+                if not deep_compare(rewind, superuser):
+                    self.create_or_update_role(rewind['username'], rewind.get('password'), [])
+                    for f in ('pg_ls_dir(text, boolean, boolean)', 'pg_stat_file(text, boolean)',
+                              'pg_read_binary_file(text)', 'pg_read_binary_file(text, bigint, bigint, boolean)'):
+                        sql = """DO $$
+BEGIN
+    SET local synchronous_commit = 'local';
+    GRANT EXECUTE ON function pg_catalog.{0} TO "{1}";
+END;$$""".format(f, rewind['username'])
+                        postgresql.query(sql)
+
+                for name, value in (config.get('users') or {}).items():
+                    if all(name != a.get('username') for a in (superuser, replication, rewind)):
+                        self.create_or_update_role(name, value.get('password'), value.get('options', []))
+
+                # We were doing a custom bootstrap instead of running initdb, therefore we opened trust
+                # access from certain addresses to be able to reach cluster and change password
+                if self._running_custom_bootstrap:
+                    self._running_custom_bootstrap = False
+                    # If we don't have custom configuration for pg_hba.conf we need to restore original file
+                    if not postgresql.config.get('pg_hba'):
+                        os.unlink(postgresql.config.pg_hba_conf)
+                        postgresql.config.restore_configuration_files()
+                    postgresql.config.write_postgresql_conf()
+                    postgresql.config.replace_pg_ident()
+
+                    # at this point there should be no recovery.conf
+                    postgresql.config.remove_recovery_conf()
+
+                    if postgresql.config.hba_file and postgresql.config.hba_file != postgresql.config.pg_hba_conf:
+                        postgresql.restart()
+                    else:
+                        postgresql.config.replace_pg_hba()
+                        if postgresql.pending_restart:
+                            postgresql.restart()
+                        else:
+                            postgresql.reload()
+                            time.sleep(1)  # give a time to postgres to "reload" configuration files
+                            postgresql.connection().close()  # close connection to reconnect with a new password
+        except Exception:
+            logger.exception('post_bootstrap')
+            task.complete(False)
+        return task.result

patroni/postgresql/callback_executor.py

@@ -0,0 +1,36 @@
+import logging
+
+from patroni.postgresql.cancellable import CancellableExecutor
+from threading import Condition, Thread
+
+logger = logging.getLogger(__name__)
+
+
+class CallbackExecutor(CancellableExecutor, Thread):
+
+    def __init__(self):
+        CancellableExecutor.__init__(self)
+        Thread.__init__(self)
+        self.daemon = True
+        self._cmd = None
+        self._condition = Condition()
+        self.start()
+
+    def call(self, cmd):
+        self._kill_process()
+        with self._condition:
+            self._cmd = cmd
+            self._condition.notify()
+
+    def run(self):
+        while True:
+            with self._condition:
+                if self._cmd is None:
+                    self._condition.wait()
+                cmd, self._cmd = self._cmd, None
+
+            with self._lock:
+                if not self._start_process(cmd, close_fds=True):
+                    continue
+            self._process.wait()
+            self._kill_children()

patroni/postgresql/cancellable.py

@@ -0,0 +1,129 @@
+import logging
+import os
+import psutil
+import subprocess
+
+from patroni.exceptions import PostgresException
+from patroni.utils import polling_loop
+from six import string_types
+from threading import Lock
+
+logger = logging.getLogger(__name__)
+
+
+class CancellableExecutor(object):
+
+    def __init__(self):
+        self._process = None
+        self._process_cmd = None
+        self._process_children = []
+        self._lock = Lock()
+
+    def _start_process(self, cmd, *args, **kwargs):
+        """This method must be executed only when the `_lock` is acquired"""
+
+        try:
+            self._process_children = []
+            self._process_cmd = cmd
+            self._process = psutil.Popen(cmd, *args, **kwargs)
+        except Exception:
+            return logger.exception('Failed to execute %s',  cmd)
+        return True
+
+    def _kill_process(self):
+        with self._lock:
+            if self._process is not None and self._process.is_running() and not self._process_children:
+                try:
+                    self._process.suspend()  # Suspend the process before getting list of childrens
+                except psutil.Error as e:
+                    logger.info('Failed to suspend the process: %s', e.msg)
+
+                try:
+                    self._process_children = self._process.children(recursive=True)
+                except psutil.Error:
+                    pass
+
+                try:
+                    self._process.kill()
+                    logger.warning('Killed %s because it was still running', self._process_cmd)
+                except psutil.NoSuchProcess:
+                    pass
+                except psutil.AccessDenied as e:
+                    logger.warning('Failed to kill the process: %s', e.msg)
+
+    def _kill_children(self):
+        waitlist = []
+        with self._lock:
+            for child in self._process_children:
+                try:
+                    child.kill()
+                except psutil.NoSuchProcess:
+                    continue
+                except psutil.AccessDenied as e:
+                    logger.info('Failed to kill child process: %s', e.msg)
+                waitlist.append(child)
+        psutil.wait_procs(waitlist)
+
+
+class CancellableSubprocess(CancellableExecutor):
+
+    def __init__(self):
+        super(CancellableSubprocess, self).__init__()
+        self._is_cancelled = False
+
+    def call(self, *args, **kwargs):
+        for s in ('stdin', 'stdout', 'stderr'):
+            kwargs.pop(s, None)
+
+        communicate_input = 'communicate_input' in kwargs
+        if communicate_input:
+            input_data = kwargs.pop('communicate_input', None)
+            if not isinstance(input_data, string_types):
+                input_data = ''
+            if input_data and input_data[-1] != '\n':
+                input_data += '\n'
+            kwargs['stdin'] = subprocess.PIPE
+            kwargs['stdout'] = open(os.devnull, 'w')
+            kwargs['stderr'] = subprocess.STDOUT
+
+        try:
+            with self._lock:
+                if self._is_cancelled:
+                    raise PostgresException('cancelled')
+
+                self._is_cancelled = False
+                started = self._start_process(*args, **kwargs)
+
+            if started:
+                if communicate_input:
+                    if input_data:
+                        self._process.communicate(input_data)
+                    self._process.stdin.close()
+                return self._process.wait()
+        finally:
+            with self._lock:
+                self._process = None
+            self._kill_children()
+
+    def reset_is_cancelled(self):
+        with self._lock:
+            self._is_cancelled = False
+
+    @property
+    def is_cancelled(self):
+        with self._lock:
+            return self._is_cancelled
+
+    def cancel(self):
+        with self._lock:
+            self._is_cancelled = True
+            if self._process is None or not self._process.is_running():
+                return
+            self._process.terminate()
+
+        for _ in polling_loop(10):
+            with self._lock:
+                if self._process is None or not self._process.is_running():
+                    return
+
+        self._kill_process()

patroni/postgresql/connection.py

@@ -0,0 +1,46 @@
+import logging
+import psycopg2
+
+from contextlib import contextmanager
+from threading import Lock
+
+logger = logging.getLogger(__name__)
+
+
+class Connection(object):
+
+    def __init__(self):
+        self._lock = Lock()
+        self._connection = None
+        self._cursor_holder = None
+
+    def set_conn_kwargs(self, conn_kwargs):
+        self._conn_kwargs = conn_kwargs
+
+    def get(self):
+        with self._lock:
+            if not self._connection or self._connection.closed != 0:
+                self._connection = psycopg2.connect(**self._conn_kwargs)
+                self._connection.autocommit = True
+                self.server_version = self._connection.server_version
+        return self._connection
+
+    def cursor(self):
+        if not self._cursor_holder or self._cursor_holder.closed or self._cursor_holder.connection.closed != 0:
+            logger.info("establishing a new patroni connection to the postgres cluster")
+            self._cursor_holder = self.get().cursor()
+        return self._cursor_holder
+
+    def close(self):
+        if self._connection and self._connection.closed == 0:
+            self._connection.close()
+            logger.info("closed patroni connection to the postgresql cluster")
+        self._cursor_holder = self._connection = None
+
+
+@contextmanager
+def get_connection_cursor(**kwargs):
+    with psycopg2.connect(**kwargs) as conn:
+        conn.autocommit = True
+        with conn.cursor() as cur:
+            yield cur

patroni/postgresql/misc.py

@@ -0,0 +1,70 @@
+import logging
+
+from patroni.exceptions import PostgresException
+
+logger = logging.getLogger(__name__)
+
+
+def postgres_version_to_int(pg_version):
+    """Convert the server_version to integer
+
+    >>> postgres_version_to_int('9.5.3')
+    90503
+    >>> postgres_version_to_int('9.3.13')
+    90313
+    >>> postgres_version_to_int('10.1')
+    100001
+    >>> postgres_version_to_int('10')  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+        ...
+    PostgresException: 'Invalid PostgreSQL version format: X.Y or X.Y.Z is accepted: 10'
+    >>> postgres_version_to_int('9.6')  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+        ...
+    PostgresException: 'Invalid PostgreSQL version format: X.Y or X.Y.Z is accepted: 9.6'
+    >>> postgres_version_to_int('a.b.c')  # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+        ...
+    PostgresException: 'Invalid PostgreSQL version: a.b.c'
+    """
+
+    try:
+        components = list(map(int, pg_version.split('.')))
+    except ValueError:
+        raise PostgresException('Invalid PostgreSQL version: {0}'.format(pg_version))
+
+    if len(components) < 2 or len(components) == 2 and components[0] < 10 or len(components) > 3:
+        raise PostgresException('Invalid PostgreSQL version format: X.Y or X.Y.Z is accepted: {0}'.format(pg_version))
+
+    if len(components) == 2:
+        # new style verion numbers, i.e. 10.1 becomes 100001
+        components.insert(1, 0)
+
+    return int(''.join('{0:02d}'.format(c) for c in components))
+
+
+def postgres_major_version_to_int(pg_version):
+    """
+    >>> postgres_major_version_to_int('10')
+    100000
+    >>> postgres_major_version_to_int('9.6')
+    90600
+    """
+    return postgres_version_to_int(pg_version + '.0')
+
+
+def parse_lsn(lsn):
+    t = lsn.split('/')
+    return int(t[0], 16) * 0x100000000 + int(t[1], 16)
+
+
+def parse_history(data):
+    for line in data.split('\n'):
+        values = line.strip().split('\t')
+        if len(values) == 3:
+            try:
+                values[0] = int(values[0])
+                values[1] = parse_lsn(values[1])
+                yield values
+            except (IndexError, ValueError):
+                logger.exception('Exception when parsing timeline history line "%s"', values)

patroni/postgresql/postmaster.py

@@ -0,0 +1,197 @@
+import logging
+import multiprocessing
+import os
+import psutil
+import re
+import signal
+import subprocess
+import sys
+
+from patroni import PATRONI_ENV_PREFIX
+
+# avoid spawning the resource tracker process
+if sys.version_info >= (3, 8):  # pragma: no cover
+    import multiprocessing.resource_tracker
+    multiprocessing.resource_tracker.getfd = lambda: 0
+elif sys.version_info >= (3, 4):  # pragma: no cover
+    import multiprocessing.semaphore_tracker
+    multiprocessing.semaphore_tracker.getfd = lambda: 0
+
+logger = logging.getLogger(__name__)
+
+STOP_SIGNALS = {
+    'smart': signal.SIGTERM,
+    'fast': signal.SIGINT,
+    'immediate': signal.SIGQUIT if os.name != 'nt' else signal.SIGABRT,
+}
+
+
+def pg_ctl_start(conn, cmdline, env):
+    if os.name != 'nt':
+        os.setsid()
+    try:
+        postmaster = subprocess.Popen(cmdline, close_fds=True, env=env)
+        conn.send(postmaster.pid)
+    except Exception:
+        logger.exception('Failed to execute %s', cmdline)
+        conn.send(None)
+    conn.close()
+
+
+class PostmasterProcess(psutil.Process):
+
+    def __init__(self, pid):
+        self.is_single_user = False
+        if pid < 0:
+            pid = -pid
+            self.is_single_user = True
+        super(PostmasterProcess, self).__init__(pid)
+
+    @staticmethod
+    def _read_postmaster_pidfile(data_dir):
+        """Reads and parses postmaster.pid from the data directory
+
+        :returns dictionary of values if successful, empty dictionary otherwise
+        """
+        pid_line_names = ['pid', 'data_dir', 'start_time', 'port', 'socket_dir', 'listen_addr', 'shmem_key']
+        try:
+            with open(os.path.join(data_dir, 'postmaster.pid')) as f:
+                return {name: line.rstrip('\n') for name, line in zip(pid_line_names, f)}
+        except IOError:
+            return {}
+
+    def _is_postmaster_process(self):
+        try:
+            start_time = int(self._postmaster_pid.get('start_time', 0))
+            if start_time and abs(self.create_time() - start_time) > 3:
+                logger.info('Process %s is not postmaster, too much difference between PID file start time %s and '
+                            'process start time %s', self.pid, self.create_time(), start_time)
+                return False
+        except ValueError:
+            logger.warning('Garbage start time value in pid file: %r', self._postmaster_pid.get('start_time'))
+
+        # Extra safety check. The process can't be ourselves, our parent or our direct child.
+        if self.pid == os.getpid() or self.pid == os.getppid() or self.ppid() == os.getpid():
+            logger.info('Patroni (pid=%s, ppid=%s), "fake postmaster" (pid=%s, ppid=%s)',
+                        os.getpid(), os.getppid(), self.pid, self.ppid())
+            return False
+
+        return True
+
+    @classmethod
+    def _from_pidfile(cls, data_dir):
+        postmaster_pid = PostmasterProcess._read_postmaster_pidfile(data_dir)
+        try:
+            pid = int(postmaster_pid.get('pid', 0))
+            if pid:
+                proc = cls(pid)
+                proc._postmaster_pid = postmaster_pid
+                return proc
+        except ValueError:
+            pass
+
+    @staticmethod
+    def from_pidfile(data_dir):
+        try:
+            proc = PostmasterProcess._from_pidfile(data_dir)
+            return proc if proc and proc._is_postmaster_process() else None
+        except psutil.NoSuchProcess:
+            return None
+
+    @classmethod
+    def from_pid(cls, pid):
+        try:
+            return cls(pid)
+        except psutil.NoSuchProcess:
+            return None
+
+    def signal_stop(self, mode):
+        """Signal postmaster process to stop
+
+        :returns None if signaled, True if process is already gone, False if error
+        """
+        if self.is_single_user:
+            logger.warning("Cannot stop server; single-user server is running (PID: {0})".format(self.pid))
+            return False
+        try:
+            self.send_signal(STOP_SIGNALS[mode])
+        except psutil.NoSuchProcess:
+            return True
+        except psutil.AccessDenied as e:
+            logger.warning("Could not send stop signal to PostgreSQL (error: {0})".format(e))
+            return False
+
+        return None
+
+    def wait_for_user_backends_to_close(self):
+        # These regexps are cross checked against versions PostgreSQL 9.1 .. 11
+        aux_proc_re = re.compile("(?:postgres:)( .*:)? (?:(?:archiver|startup|autovacuum launcher|autovacuum worker|"
+                                 "checkpointer|logger|stats collector|wal receiver|wal writer|writer)(?: process  )?|"
+                                 "walreceiver|wal sender process|walsender|walwriter|background writer|"
+                                 "logical replication launcher|logical replication worker for|bgworker:) ")
+
+        try:
+            children = self.children()
+        except psutil.Error:
+            return logger.debug('Failed to get list of postmaster children')
+
+        user_backends = []
+        user_backends_cmdlines = []
+        for child in children:
+            try:
+                cmdline = child.cmdline()[0]
+                if not aux_proc_re.match(cmdline):
+                    user_backends.append(child)
+                    user_backends_cmdlines.append(cmdline)
+            except psutil.NoSuchProcess:
+                pass
+        if user_backends:
+            logger.debug('Waiting for user backends %s to close', ', '.join(user_backends_cmdlines))
+            psutil.wait_procs(user_backends)
+        logger.debug("Backends closed")
+
+    @staticmethod
+    def start(pgcommand, data_dir, conf, options):
+        # Unfortunately `pg_ctl start` does not return postmaster pid to us. Without this information
+        # it is hard to know the current state of postgres startup, so we had to reimplement pg_ctl start
+        # in python. It will start postgres, wait for port to be open and wait until postgres will start
+        # accepting connections.
+        # Important!!! We can't just start postgres using subprocess.Popen, because in this case it
+        # will be our child for the rest of our live and we will have to take care of it (`waitpid`).
+        # So we will use the same approach as pg_ctl uses: start a new process, which will start postgres.
+        # This process will write postmaster pid to stdout and exit immediately. Now it's responsibility
+        # of init process to take care about postmaster.
+        # In order to make everything portable we can't use fork&exec approach here, so  we will call
+        # ourselves and pass list of arguments which must be used to start postgres.
+        # On Windows, in order to run a side-by-side assembly the specified env must include a valid SYSTEMROOT.
+        env = {p: os.environ[p] for p in os.environ if not p.startswith(PATRONI_ENV_PREFIX)}
+        try:
+            proc = PostmasterProcess._from_pidfile(data_dir)
+            if proc and not proc._is_postmaster_process():
+                # Upon start postmaster process performs various safety checks if there is a postmaster.pid
+                # file in the data directory. Although Patroni already detected that the running process
+                # corresponding to the postmaster.pid is not a postmaster, the new postmaster might fail
+                # to start, because it thinks that postmaster.pid is already locked.
+                # Important!!! Unlink of postmaster.pid isn't an option, because it has a lot of nasty race conditions.
+                # Luckily there is a workaround to this problem, we can pass the pid from postmaster.pid
+                # in the `PG_GRANDPARENT_PID` environment variable and postmaster will ignore it.
+                logger.info("Telling pg_ctl that it is safe to ignore postmaster.pid for process %s", proc.pid)
+                env['PG_GRANDPARENT_PID'] = str(proc.pid)
+        except psutil.NoSuchProcess:
+            pass
+        cmdline = [pgcommand, '-D', data_dir, '--config-file={}'.format(conf)] + options
+        logger.debug("Starting postgres: %s", " ".join(cmdline))
+        ctx = multiprocessing.get_context('spawn') if sys.version_info >= (3, 4) else multiprocessing
+        parent_conn, child_conn = ctx.Pipe(False)
+        proc = ctx.Process(target=pg_ctl_start, args=(child_conn, cmdline, env))
+        proc.start()
+        pid = parent_conn.recv()
+        proc.join()
+        if pid is None:
+            return
+        logger.info('postmaster pid=%s', pid)
+
+        # TODO: In an extremely unlikely case, the process could have exited and the pid reassigned. The start
+        # initiation time is not accurate enough to compare to create time as start time would also likely
+        # be relatively close. We need the subprocess extract pid+start_time in a race free manner.
+        return PostmasterProcess.from_pid(pid)

patroni/postgresql/rewind.py

@@ -0,0 +1,209 @@
+import logging
+import os
+import subprocess
+
+from patroni.dcs import Leader
+from patroni.postgresql.connection import get_connection_cursor
+from patroni.postgresql.misc import parse_history, parse_lsn
+
+logger = logging.getLogger(__name__)
+
+REWIND_STATUS = type('Enum', (), {'INITIAL': 0, 'CHECKPOINT': 1, 'CHECK': 2, 'NEED': 3,
+                                  'NOT_NEED': 4, 'SUCCESS': 5, 'FAILED': 6})
+
+
+class Rewind(object):
+
+    def __init__(self, postgresql):
+        self._postgresql = postgresql
+        self.reset_state()
+
+    @staticmethod
+    def configuration_allows_rewind(data):
+        return data.get('wal_log_hints setting', 'off') == 'on' or data.get('Data page checksum version', '0') != '0'
+
+    @property
+    def can_rewind(self):
+        """ check if pg_rewind executable is there and that pg_controldata indicates
+            we have either wal_log_hints or checksums turned on
+        """
+        # low-hanging fruit: check if pg_rewind configuration is there
+        if not self._postgresql.config.get('use_pg_rewind'):
+            return False
+
+        cmd = [self._postgresql.pgcommand('pg_rewind'), '--help']
+        try:
+            ret = subprocess.call(cmd, stdout=open(os.devnull, 'w'), stderr=subprocess.STDOUT)
+            if ret != 0:  # pg_rewind is not there, close up the shop and go home
+                return False
+        except OSError:
+            return False
+        return self.configuration_allows_rewind(self._postgresql.controldata())
+
+    @property
+    def can_rewind_or_reinitialize_allowed(self):
+        return self._postgresql.config.get('remove_data_directory_on_diverged_timelines') or self.can_rewind
+
+    def trigger_check_diverged_lsn(self):
+        if self.can_rewind_or_reinitialize_allowed and self._state != REWIND_STATUS.NEED:
+            self._state = REWIND_STATUS.CHECK
+
+    def check_leader_is_not_in_recovery(self, **kwargs):
+        if not kwargs.get('database'):
+            kwargs['database'] = self._postgresql.database
+        try:
+            with get_connection_cursor(connect_timeout=3, options='-c statement_timeout=2000', **kwargs) as cur:
+                cur.execute('SELECT pg_catalog.pg_is_in_recovery()')
+                if not cur.fetchone()[0]:
+                    return True
+                logger.info('Leader is still in_recovery and therefore can\'t be used for rewind')
+        except Exception:
+            return logger.exception('Exception when working with leader')
+
+    def _get_local_timeline_lsn_from_controldata(self):
+        timeline = lsn = None
+        data = self._postgresql.controldata()
+        try:
+            if data.get('Database cluster state') == 'shut down in recovery':
+                lsn = data.get('Minimum recovery ending location')
+                timeline = int(data.get("Min recovery ending loc's timeline"))
+                if lsn == '0/0' or timeline == 0:  # it was a master when it crashed
+                    data['Database cluster state'] = 'shut down'
+            if data.get('Database cluster state') == 'shut down':
+                lsn = data.get('Latest checkpoint location')
+                timeline = int(data.get("Latest checkpoint's TimeLineID"))
+        except (TypeError, ValueError):
+            logger.exception('Failed to get local timeline and lsn from pg_controldata output')
+        return timeline, lsn
+
+    def _get_local_timeline_lsn(self):
+        if self._postgresql.is_running():  # if postgres is running - get timeline and lsn from replication connection
+            timeline, lsn = self._postgresql.get_local_timeline_lsn_from_replication_connection()
+        else:  # otherwise analyze pg_controldata output
+            timeline, lsn = self._get_local_timeline_lsn_from_controldata()
+        logger.info('Local timeline=%s lsn=%s', timeline, lsn)
+        return timeline, lsn
+
+    def _check_timeline_and_lsn(self, leader):
+        local_timeline, local_lsn = self._get_local_timeline_lsn()
+        if local_timeline is None or local_lsn is None:
+            return
+
+        if isinstance(leader, Leader):
+            if leader.member.data.get('role') != 'master':
+                return
+        # standby cluster
+        elif not self.check_leader_is_not_in_recovery(**leader.conn_kwargs(self._postgresql.config.replication)):
+            return
+
+        history = need_rewind = None
+        try:
+            with self._postgresql.get_replication_connection_cursor(**leader.conn_kwargs()) as cur:
+                cur.execute('IDENTIFY_SYSTEM')
+                master_timeline = cur.fetchone()[1]
+                logger.info('master_timeline=%s', master_timeline)
+                if local_timeline > master_timeline:  # Not always supported by pg_rewind
+                    need_rewind = True
+                elif master_timeline > 1:
+                    cur.execute('TIMELINE_HISTORY %s', (master_timeline,))
+                    history = bytes(cur.fetchone()[1]).decode('utf-8')
+                    logger.info('master: history=%s', history)
+                else:  # local_timeline == master_timeline == 1
+                    need_rewind = False
+        except Exception:
+            return logger.exception('Exception when working with master via replication connection')
+
+        if history is not None:
+            for parent_timeline, switchpoint, _ in parse_history(history):
+                if parent_timeline == local_timeline:
+                    try:
+                        need_rewind = parse_lsn(local_lsn) >= switchpoint
+                    except (IndexError, ValueError):
+                        logger.exception('Exception when parsing lsn')
+                    break
+                elif parent_timeline > local_timeline:
+                    break
+
+        self._state = need_rewind and REWIND_STATUS.NEED or REWIND_STATUS.NOT_NEED
+
+    def rewind_or_reinitialize_needed_and_possible(self, leader):
+        if leader and leader.name != self._postgresql.name and leader.conn_url and self._state == REWIND_STATUS.CHECK:
+            self._check_timeline_and_lsn(leader)
+        return leader and leader.conn_url and self._state == REWIND_STATUS.NEED
+
+    def check_for_checkpoint_after_promote(self):
+        if self._state == REWIND_STATUS.INITIAL and self._postgresql.is_leader():
+            try:
+                timeline = int(self._postgresql.controldata().get("Latest checkpoint's TimeLineID"))
+                if self._postgresql.get_master_timeline() == timeline:
+                    self._state = REWIND_STATUS.CHECKPOINT
+            except (TypeError, ValueError):
+                logger.exception('Failed to parse timeline from pg_controldata output')
+
+    def checkpoint_after_promote(self):
+        return self._state == REWIND_STATUS.CHECKPOINT
+
+    def pg_rewind(self, r):
+        # prepare pg_rewind connection
+        env = self._postgresql.config.write_pgpass(r)
+        env['PGOPTIONS'] = '-c statement_timeout=0'
+        dsn = self._postgresql.config.format_dsn(r, True)
+        logger.info('running pg_rewind from %s', dsn)
+        try:
+            return self._postgresql.cancellable.call([self._postgresql.pgcommand('pg_rewind'), '-D',
+                                                      self._postgresql.data_dir, '--source-server', dsn], env=env) == 0
+        except OSError:
+            return False
+
+    def execute(self, leader):
+        if self._postgresql.is_running() and not self._postgresql.stop(checkpoint=False):
+            return logger.warning('Can not run pg_rewind because postgres is still running')
+
+        # prepare pg_rewind connection
+        r = leader.conn_kwargs(self._postgresql.config.rewind_credentials)
+
+        # 1. make sure that we are really trying to rewind from the master
+        # 2. make sure that pg_control contains the new timeline by:
+        #   running a checkpoint or
+        #   waiting until Patroni on the master will expose checkpoint_after_promote=True
+        checkpoint_status = leader.checkpoint_after_promote if isinstance(leader, Leader) else None
+        if checkpoint_status is None:  # master still runs the old Patroni
+            leader_status = self._postgresql.checkpoint(leader.conn_kwargs(self._postgresql.config.superuser))
+            if leader_status:
+                return logger.warning('Can not use %s for rewind: %s', leader.name, leader_status)
+        elif not checkpoint_status:
+            return logger.info('Waiting for checkpoint on %s before rewind', leader.name)
+        elif not self.check_leader_is_not_in_recovery(**r):
+            return
+
+        if self.pg_rewind(r):
+            self._state = REWIND_STATUS.SUCCESS
+        elif not self.check_leader_is_not_in_recovery(**r):
+            logger.warning('Failed to rewind because master %s become unreachable', leader.name)
+        else:
+            logger.error('Failed to rewind from healty master: %s', leader.name)
+
+            for name in ('remove_data_directory_on_rewind_failure', 'remove_data_directory_on_diverged_timelines'):
+                if self._postgresql.config.get(name):
+                    logger.warning('%s is set. removing...', name)
+                    self._postgresql.remove_data_directory()
+                    self._state = REWIND_STATUS.INITIAL
+                    break
+            else:
+                self._state = REWIND_STATUS.FAILED
+        return False
+
+    def reset_state(self):
+        self._state = REWIND_STATUS.INITIAL
+
+    @property
+    def is_needed(self):
+        return self._state in (REWIND_STATUS.CHECK, REWIND_STATUS.NEED)
+
+    @property
+    def executed(self):
+        return self._state > REWIND_STATUS.NOT_NEED
+
+    @property
+    def failed(self):
+        return self._state == REWIND_STATUS.FAILED

patroni/postgresql/slots.py

@@ -0,0 +1,103 @@
+import logging
+
+from patroni.postgresql.connection import get_connection_cursor
+from collections import defaultdict
+
+logger = logging.getLogger(__name__)
+
+
+def compare_slots(s1, s2):
+    return s1['type'] == s2['type'] and (s1['type'] == 'physical' or
+                                         s1['database'] == s2['database'] and s1['plugin'] == s2['plugin'])
+
+
+class SlotsHandler(object):
+
+    def __init__(self, postgresql):
+        self._postgresql = postgresql
+        self._replication_slots = {}  # already existing replication slots
+        self.schedule()
+
+    def _query(self, sql, *params):
+        return self._postgresql.query(sql, *params, retry=False)
+
+    def load_replication_slots(self):
+        if self._postgresql.major_version >= 90400 and self._schedule_load_slots:
+            replication_slots = {}
+            cursor = self._query('SELECT slot_name, slot_type, plugin, database FROM pg_catalog.pg_replication_slots')
+            for r in cursor:
+                value = {'type': r[1]}
+                if r[1] == 'logical':
+                    value.update({'plugin': r[2], 'database': r[3]})
+                replication_slots[r[0]] = value
+            self._replication_slots = replication_slots
+            self._schedule_load_slots = False
+
+    def drop_replication_slot(self, name):
+        cursor = self._query(('SELECT pg_catalog.pg_drop_replication_slot(%s) WHERE EXISTS (SELECT 1 ' +
+                              'FROM pg_catalog.pg_replication_slots WHERE slot_name = %s AND NOT active)'), name, name)
+        # In normal situation rowcount should be 1, otherwise either slot doesn't exists or it is still active
+        return cursor.rowcount == 1
+
+    def sync_replication_slots(self, cluster):
+        if self._postgresql.major_version >= 90400:
+            try:
+                self.load_replication_slots()
+
+                slots = cluster.get_replication_slots(self._postgresql.name, self._postgresql.role)
+
+                # drop old replication slots which are not presented in desired slots
+                for name in set(self._replication_slots) - set(slots):
+                    if not self.drop_replication_slot(name):
+                        logger.error("Failed to drop replication slot '%s'", name)
+                        self._schedule_load_slots = True
+
+                immediately_reserve = ', true' if self._postgresql.major_version >= 90600 else ''
+
+                logical_slots = defaultdict(dict)
+                for name, value in slots.items():
+                    if name in self._replication_slots and not compare_slots(value, self._replication_slots[name]):
+                        logger.info("Trying to drop replication slot '%s' because value is changing from %s to %s",
+                                    name, self._replication_slots[name], value)
+                        if not self.drop_replication_slot(name):
+                            logger.error("Failed to drop replication slot '%s'", name)
+                            self._schedule_load_slots = True
+                            continue
+                        self._replication_slots.pop(name)
+                    if name not in self._replication_slots:
+                        if value['type'] == 'physical':
+                            try:
+                                self._query(("SELECT pg_catalog.pg_create_physical_replication_slot(%s{0})" +
+                                             " WHERE NOT EXISTS (SELECT 1 FROM pg_catalog.pg_replication_slots" +
+                                             " WHERE slot_type = 'physical' AND slot_name = %s)").format(
+                                                 immediately_reserve), name, name)
+                            except Exception:
+                                logger.exception("Failed to create physical replication slot '%s'", name)
+                                self._schedule_load_slots = True
+                        elif value['type'] == 'logical' and name not in self._replication_slots:
+                            logical_slots[value['database']][name] = value
+
+                # create new logical slots
+                for database, values in logical_slots.items():
+                    conn_kwargs = self._postgresql.config.local_connect_kwargs
+                    conn_kwargs['database'] = database
+                    with get_connection_cursor(**conn_kwargs) as cur:
+                        for name, value in values.items():
+                            try:
+                                cur.execute("SELECT pg_catalog.pg_create_logical_replication_slot(%s, %s)" +
+                                            " WHERE NOT EXISTS (SELECT 1 FROM pg_catalog.pg_replication_slots" +
+                                            " WHERE slot_type = 'logical' AND slot_name = %s)",
+                                            (name, value['plugin'], name))
+                            except Exception:
+                                logger.exception("Failed to create logical replication slot '%s' plugin='%s'",
+                                                 name, value['plugin'])
+                                self._schedule_load_slots = True
+                self._replication_slots = slots
+            except Exception:
+                logger.exception('Exception when changing replication slots')
+                self._schedule_load_slots = True
+
+    def schedule(self, value=None):
+        if value is None:
+            value = self._postgresql.major_version >= 90400
+        self._schedule_load_slots = value

patroni/postmaster.py

@@ -1,115 +0,0 @@
-import logging
-import os
-import psutil
-import re
-import signal
-import subprocess
-
-from patroni import call_self
-
-logger = logging.getLogger(__name__)
-
-STOP_SIGNALS = {
-    'smart': signal.SIGTERM,
-    'fast': signal.SIGINT,
-    'immediate': signal.SIGQUIT,
-}
-
-
-class PostmasterProcess(psutil.Process):
-    def __init__(self, pid):
-        self.is_single_user = False
-        if pid < 0:
-            pid = -pid
-            self.is_single_user = True
-        super(PostmasterProcess, self).__init__(pid)
-
-    @classmethod
-    def from_pidfile(cls, pidfile):
-        try:
-            pid = int(pidfile.get('pid', 0))
-            if not pid:
-                return None
-        except ValueError:
-            return None
-
-        try:
-            proc = cls(pid)
-        except psutil.NoSuchProcess:
-            return None
-
-        try:
-            start_time = int(pidfile.get('start_time', 0))
-            if start_time and abs(proc.create_time() - start_time) > 3:
-                return None
-        except ValueError:
-            logger.warning("Garbage start time value in pid file: %r", pidfile.get('start_time'))
-
-        # Extra safety check. The process can't be ourselves, our parent or our direct child.
-        if proc.pid == os.getpid() or proc.pid == os.getppid() or proc.parent() == os.getpid():
-            return None
-
-        return proc
-
-    @classmethod
-    def from_pid(cls, pid):
-        try:
-            return cls(pid)
-        except psutil.NoSuchProcess:
-            return None
-
-    def signal_stop(self, mode):
-        """Signal postmaster process to stop
-
-        :returns None if signaled, True if process is already gone, False if error
-        """
-        if self.is_single_user:
-            logger.warning("Cannot stop server; single-user server is running (PID: {0})".format(self.pid))
-            return False
-        try:
-            self.send_signal(STOP_SIGNALS[mode])
-        except psutil.NoSuchProcess:
-            return True
-        except psutil.AccessDenied as e:
-            logger.warning("Could not send stop signal to PostgreSQL (error: {0})".format(e))
-            return False
-
-        return None
-
-    def wait_for_user_backends_to_close(self):
-        # These regexps are cross checked against versions PostgreSQL 9.1 .. 9.6
-        aux_proc_re = re.compile("(?:postgres:)( .*:)? (?:""(?:startup|logger|checkpointer|writer|wal writer|"
-                                 "autovacuum launcher|autovacuum worker|stats collector|wal receiver|archiver|"
-                                 "wal sender) process|bgworker: )")
-
-        user_backends = [p for p in self.children() if not aux_proc_re.match(p.cmdline()[0])]
-        logger.debug("Waiting for user backends {0} to close".format(
-            ",".join(p.cmdline()[0] for p in user_backends)))
-        psutil.wait_procs(user_backends)
-        logger.debug("Backends closed")
-
-    @classmethod
-    def start(cls, pgcommand, data_dir, conf, options):
-        # Unfortunately `pg_ctl start` does not return postmaster pid to us. Without this information
-        # it is hard to know the current state of postgres startup, so we had to reimplement pg_ctl start
-        # in python. It will start postgres, wait for port to be open and wait until postgres will start
-        # accepting connections.
-        # Important!!! We can't just start postgres using subprocess.Popen, because in this case it
-        # will be our child for the rest of our live and we will have to take care of it (`waitpid`).
-        # So we will use the same approach as pg_ctl uses: start a new process, which will start postgres.
-        # This process will write postmaster pid to stdout and exit immediately. Now it's responsibility
-        # of init process to take care about postmaster.
-        # In order to make everything portable we can't use fork&exec approach here, so  we will call
-        # ourselves and pass list of arguments which must be used to start postgres.
-        proc = call_self(['pg_ctl_start', pgcommand, '-D', data_dir,
-                          '--config-file={}'.format(conf)] + options, close_fds=True,
-                         preexec_fn=os.setsid, stdout=subprocess.PIPE,
-                         env={p: os.environ[p] for p in ('PATH', 'LC_ALL', 'LANG') if p in os.environ})
-        pid = int(proc.stdout.readline().strip())
-        proc.wait()
-        logger.info('postmaster pid=%s', pid)
-
-        # TODO: In an extremely unlikely case, the process could have exited and the pid reassigned. The start
-        # initiation time is not accurate enough to compare to create time as start time would also likely
-        # be relatively close. We need the subprocess extract pid+start_time in a race free manner.
-        return PostmasterProcess.from_pid(pid)

patroni/request.py

@@ -0,0 +1,58 @@
+import json
+import urllib3
+import six
+
+from six.moves.urllib_parse import urlparse, urlunparse
+
+from .utils import USER_AGENT
+
+
+class PatroniRequest(object):
+
+    def __init__(self, config, insecure=False):
+        cert_reqs = 'CERT_NONE' if insecure or config.get('ctl', {}).get('insecure', False) else 'CERT_REQUIRED'
+        self._pool = urllib3.PoolManager(num_pools=10, maxsize=10, cert_reqs=cert_reqs)
+        self.reload_config(config)
+
+    @staticmethod
+    def _get_cfg_value(config, name):
+        return config.get('ctl', {}).get(name) or config.get('restapi', {}).get(name)
+
+    def _apply_pool_param(self, param, value):
+        if value:
+            self._pool.connection_pool_kw[param] = value
+        else:
+            self._pool.connection_pool_kw.pop(param, None)
+
+    def _apply_ssl_file_param(self, config, name):
+        value = self._get_cfg_value(config, name + 'file')
+        self._apply_pool_param(name + '_file', value)
+        return value
+
+    def reload_config(self, config):
+        self._pool.headers = urllib3.make_headers(basic_auth=self._get_cfg_value(config, 'auth'), user_agent=USER_AGENT)
+
+        if self._apply_ssl_file_param(config, 'cert'):
+            self._apply_ssl_file_param(config, 'key')
+        else:
+            self._pool.connection_pool_kw.pop('key_file', None)
+
+        cacert = config.get('ctl', {}).get('cacert') or config.get('restapi', {}).get('cafile')
+        self._apply_pool_param('ca_certs', cacert)
+
+    def request(self, method, url, body=None, **kwargs):
+        if body is not None and not isinstance(body, six.string_types):
+            body = json.dumps(body)
+        return self._pool.request(method.upper(), url, body=body, **kwargs)
+
+    def __call__(self, member, method='GET', endpoint=None, data=None, **kwargs):
+        url = member.api_url
+        if endpoint:
+            scheme, netloc, _, _, _, _ = urlparse(url)
+            url = urlunparse((scheme, netloc, endpoint, '', '', ''))
+        return self.request(method, url, data, **kwargs)
+
+
+def get(url, verify=True, **kwargs):
+    http = PatroniRequest({}, not verify)
+    return http.request('GET', url, **kwargs)

patroni/scripts/aws.py

@@ -1,12 +1,12 @@
 #!/usr/bin/env python
 
+import json
 import logging
-import requests
-from requests.exceptions import RequestException
 import sys
 import boto.ec2
 
 from patroni.utils import Retry, RetryFailedError
+from patroni.request import get as requests_get
 
 logger = logging.getLogger(__name__)
 
@@ -19,14 +19,14 @@ class AWSConnection(object):
         self._retry = Retry(deadline=300, max_delay=30, max_tries=-1, retry_exceptions=(boto.exception.StandardError,))
         try:
             # get the instance id
-            r = requests.get('http://169.254.169.254/latest/dynamic/instance-identity/document', timeout=2.1)
-        except RequestException:
+            r = requests_get('http://169.254.169.254/latest/dynamic/instance-identity/document', timeout=2.1)
+        except Exception:
             logger.error('cannot query AWS meta-data')
             return
 
-        if r.ok:
+        if r.status < 400:
             try:
-                content = r.json()
+                content = json.loads(r.data.decode('utf-8'))
                 self.instance_id = content['instanceId']
                 self.region = content['region']
             except Exception:

patroni/scripts/wale_restore.py

@@ -224,13 +224,12 @@ class WALERestore(object):
                             lsn_name = 'location'
                         con.autocommit = True
                         with con.cursor() as cur:
-                            cur.execute("""SELECT CASE WHEN pg_is_in_recovery()
-                                                       THEN GREATEST(
-                                                                pg_{0}_{1}_diff(COALESCE(
-                                                                  pg_last_{0}_receive_{1}(), '0/0'), %s)::bigint,
-                                                                pg_{0}_{1}_diff(pg_last_{0}_replay_{1}(), %s)::bigint)
-                                                       ELSE pg_{0}_{1}_diff(pg_current_{0}_{1}(), %s)::bigint
-                                                   END""".format(wal_name, lsn_name),
+                            cur.execute(("SELECT CASE WHEN pg_catalog.pg_is_in_recovery()"
+                                         " THEN GREATEST(pg_catalog.pg_{0}_{1}_diff(COALESCE("
+                                         "pg_last_{0}_receive_{1}(), '0/0'), %s)::bigint, "
+                                         "pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_last_{0}_replay_{1}(), %s)::bigint)"
+                                         " ELSE pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_current_{0}_{1}(), %s)::bigint"
+                                         " END").format(wal_name, lsn_name),
                                         (backup_start_lsn, backup_start_lsn, backup_start_lsn))
 
                             diff_in_bytes = int(cur.fetchone()[0])

patroni/utils.py

@@ -1,11 +1,24 @@
+import logging
+import platform
 import random
+import re
 import time
 
 from dateutil import tz
-from patroni.exceptions import PatroniException
+
+from .exceptions import PatroniException
+from .version import __version__
 
 tzutc = tz.tzutc()
 
+logger = logging.getLogger(__name__)
+
+USER_AGENT = 'Patroni/{0} Python/{1} {2}'.format(__version__, platform.python_version(), platform.system())
+OCT_RE = re.compile(r'^[-+]?0[0-7]*')
+DEC_RE = re.compile(r'^[-+]?(0|[1-9][0-9]*)')
+HEX_RE = re.compile(r'^[-+]?0x[0-9a-fA-F]+')
+DBL_RE = re.compile(r'^[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?')
+
 
 def deep_compare(obj1, obj2):
     """
@@ -88,42 +101,77 @@ def strtol(value, strict=True):
     True
     >>> strtol(' d ') == (None, 'd')
     True
+    >>> strtol(' 1 d ') == (1, ' d')
+    True
     >>> strtol('9s', False) == (9, 's')
     True
     >>> strtol(' s ', False) == (1, 's')
     True
     """
     value = str(value).strip()
-    ln = len(value)
-    i = 0
-    # skip sign:
-    if i < ln and value[i] in ('-', '+'):
-        i += 1
+    for regex, base in ((HEX_RE, 16), (OCT_RE, 8), (DEC_RE, 10)):
+        match = regex.match(value)
+        if match:
+            end = match.end()
+            return int(value[:end], base), value[end:]
+    return (None if strict else 1), value
 
-    # we always expect to get digit in the beginning
-    if i < ln and value[i].isdigit():
-        if value[i] == '0':
-            i += 1
-            if i < ln and value[i] in ('x', 'X'):  # '0' followed by 'x': HEX
-                base = 16
-                i += 1
-            else:  # just starts with '0': OCT
-                base = 8
-        else:  # any other digit: DEC
-            base = 10
 
-        ret = None
-        while i <= ln:
-            try:  # try to find maximally long number
-                i += 1  # by giving to `int` longer and longer strings
-                ret = int(value[:i], base)
-            except ValueError:  # until we will not get an exception or end of the string
-                i -= 1
-                break
-        if ret is not None:  # yay! there is a number in the beginning of the string
-            return ret, value[i:].strip()  # return the number and the "rest"
+def strtod(value):
+    """As most as possible close equivalent of strtod(3) function used by postgres to parse parameter values.
+    >>> strtod(' A ') == (None, 'A')
+    True
+    """
+    value = str(value).strip()
+    match = DBL_RE.match(value)
+    if match:
+        end = match.end()
+        return float(value[:end]), value[end:]
+    return None, value
 
-    return (None if strict else 1), value.strip()
+
+def rint(value):
+    """
+    >>> rint(0.5) == 0
+    True
+    >>> rint(0.501) == 1
+    True
+    >>> rint(1.5) == 2
+    True
+    """
+
+    ret = round(value)
+    return 2.0 * round(value / 2.0) if abs(ret - value) == 0.5 else ret
+
+
+def convert_to_base_unit(value, unit, base_unit):
+    convert = {
+        'B': {'B': 1, 'kB': 1024, 'MB': 1024 * 1024, 'GB': 1024 * 1024 * 1024, 'TB': 1024 * 1024 * 1024 * 1024},
+        'kB': {'B': 1.0 / 1024, 'kB': 1, 'MB': 1024, 'GB': 1024 * 1024, 'TB': 1024 * 1024 * 1024},
+        'MB': {'B': 1.0 / (1024 * 1024), 'kB': 1.0 / 1024, 'MB': 1, 'GB': 1024, 'TB': 1024 * 1024},
+        'ms': {'us': 1.0 / 1000, 'ms': 1, 's': 1000, 'min': 1000 * 60, 'h': 1000 * 60 * 60, 'd': 1000 * 60 * 60 * 24},
+        's': {'us': 1.0 / (1000 * 1000), 'ms': 1.0 / 1000, 's': 1, 'min': 60, 'h': 60 * 60, 'd': 60 * 60 * 24},
+        'min': {'us': 1.0 / (1000 * 1000 * 60), 'ms': 1.0 / (1000 * 60), 's': 1.0 / 60, 'min': 1, 'h': 60, 'd': 60 * 24}
+    }
+
+    round_order = {
+        'TB': 'GB', 'GB': 'MB', 'MB': 'kB', 'kB': 'B',
+        'd': 'h', 'h': 'min', 'min': 's', 's': 'ms', 'ms': 'us'
+    }
+
+    if base_unit and base_unit not in convert:
+        base_value, base_unit = strtol(base_unit, False)
+    else:
+        base_value = 1
+
+    if base_unit in convert and unit in convert[base_unit]:
+        value *= convert[base_unit][unit] / float(base_value)
+
+        if unit in round_order:
+            multiplier = convert[base_unit][round_order[unit]]
+            value = rint(value / float(multiplier)) * multiplier
+
+        return value
 
 
 def parse_int(value, base_unit=None):
@@ -136,56 +184,71 @@ def parse_int(value, base_unit=None):
     True
     >>> parse_int('1000 ms', 's') == 1
     True
-    >>> parse_int('1GB', 'MB') is None
+    >>> parse_int('1TB', 'GB') is None
     True
     >>> parse_int(0) == 0
     True
+    >>> parse_int('6GB', '16MB') == 384
+    True
+    >>> parse_int('4097.4kB', 'kB') == 4097
+    True
+    >>> parse_int('4097.5kB', 'kB') == 4098
+    True
     """
 
-    convert = {
-        'kB': {'kB': 1, 'MB': 1024, 'GB': 1024 * 1024, 'TB': 1024 * 1024 * 1024},
-        'ms': {'ms': 1, 's': 1000, 'min': 1000 * 60, 'h': 1000 * 60 * 60, 'd': 1000 * 60 * 60 * 24},
-        's': {'ms': -1000, 's': 1, 'min': 60, 'h': 60 * 60, 'd': 60 * 60 * 24},
-        'min': {'ms': -1000 * 60, 's': -60, 'min': 1, 'h': 60, 'd': 60 * 24}
-    }
+    val, unit = strtol(value)
+    if val is None and unit.startswith('.') or unit and unit[0] in ('.', 'e', 'E'):
+        val, unit = strtod(value)
 
-    value, unit = strtol(value)
-    if value is not None:
+    if val is not None:
+        unit = unit.strip()
         if not unit:
-            return value
+            return int(rint(val))
 
-        if base_unit and base_unit not in convert:
-            base_value, base_unit = strtol(base_unit, False)
-        else:
-            base_value = 1
-        if base_unit in convert and unit in convert[base_unit]:
-            multiplier = convert[base_unit][unit]
-            if multiplier < 0:
-                value /= -multiplier
-            else:
-                value *= multiplier
-            return int(value/base_value)
+        val = convert_to_base_unit(val, unit, base_unit)
+        if val is not None:
+            return int(rint(val))
+
+
+def parse_real(value, base_unit=None):
+    """
+    >>> parse_real(' +0.0005 ') == 0.0005
+    True
+    >>> parse_real('0.0005ms', 'ms') == 0.0
+    True
+    >>> parse_real('0.00051ms', 'ms') == 0.001
+    True
+    """
+    val, unit = strtod(value)
+
+    if val is not None:
+        unit = unit.strip()
+        if not unit:
+            return val
+
+        return convert_to_base_unit(val, unit, base_unit)
 
 
 def compare_values(vartype, unit, old_value, new_value):
     """
     >>> compare_values('enum', None, 'remote_write', 'REMOTE_WRITE')
     True
-    >>> compare_values('real', None, '1.23', 1.23)
+    >>> compare_values('real', None, '1e-06', 0.000001)
     True
     """
 
-    # if the integer or bool new_value is not correct this function will return False
-    if vartype == 'bool':
-        old_value = parse_bool(old_value)
-        new_value = parse_bool(new_value)
-    elif vartype == 'integer':
-        old_value = parse_int(old_value)
-        new_value = parse_int(new_value, unit)
-    elif vartype == 'enum':
-        return str(old_value).lower() == str(new_value).lower()
-    else:  # ('string', 'real')
-        return str(old_value) == str(new_value)
+    converters = {
+        'bool': lambda v1, v2: parse_bool(v1),
+        'integer': parse_int,
+        'real': parse_real,
+        'enum': lambda v1, v2: str(v1).lower(),
+        'string': lambda v1, v2: str(v1)
+    }
+
+    convert = converters.get(vartype) or converters['string']
+    old_value = convert(old_value, None)
+    new_value = convert(new_value, unit)
+
     return old_value is not None and new_value is not None and old_value == new_value
 
 
@@ -237,6 +300,17 @@ class Retry(object):
                      max_jitter=self.max_jitter / 100.0, max_delay=self.max_delay, sleep_func=self.sleep_func,
                      deadline=self.deadline, retry_exceptions=self.retry_exceptions)
 
+    @property
+    def sleeptime(self):
+        return self._cur_delay + (random.randint(0, self.max_jitter) / 100.0)
+
+    def update_delay(self):
+        self._cur_delay = min(self._cur_delay * self.backoff, self.max_delay)
+
+    @property
+    def stoptime(self):
+        return self._cur_stoptime
+
     def __call__(self, func, *args, **kwargs):
         """Call a function with arguments until it completes without throwing a `retry_exceptions`
 
@@ -252,18 +326,20 @@ class Retry(object):
                 if self.deadline is not None and self._cur_stoptime is None:
                     self._cur_stoptime = time.time() + self.deadline
                 return func(*args, **kwargs)
-            except self.retry_exceptions:
+            except self.retry_exceptions as e:
                 # Note: max_tries == -1 means infinite tries.
                 if self._attempts == self.max_tries:
+                    logger.warning('Retry got exception: %s', e)
                     raise RetryFailedError("Too many retry attempts")
                 self._attempts += 1
-                sleeptime = self._cur_delay + (random.randint(0, self.max_jitter) / 100.0)
+                sleeptime = self.sleeptime
 
                 if self._cur_stoptime is not None and time.time() + sleeptime >= self._cur_stoptime:
+                    logger.warning('Retry got exception: %s', e)
                     raise RetryFailedError("Exceeded retry deadline")
-                else:
-                    self.sleep_func(sleeptime)
-                self._cur_delay = min(self._cur_delay * self.backoff, self.max_delay)
+                logger.debug('Retry got exception: %s', e)
+                self.sleep_func(sleeptime)
+                self.update_delay()
 
 
 def polling_loop(timeout, interval=1):
@@ -281,3 +357,62 @@ def split_host_port(value, default_port):
     t = value.rsplit(':', 1)
     t.append(default_port)
     return t[0], int(t[1])
+
+
+def uri(proto, netloc, path='', user=None):
+    host, port = netloc if isinstance(netloc, (list, tuple)) else split_host_port(netloc, 0)
+    if host and ':' in host and host[0] != '[' and host[-1] != ']':
+        host = '[{0}]'.format(host)
+    port = ':{0}'.format(port) if port else ''
+    path = '/{0}'.format(path) if path and not path.startswith('/') else path
+    user = '{0}@'.format(user) if user else ''
+    return '{0}://{1}{2}{3}{4}'.format(proto, user, host, port, path)
+
+
+def is_standby_cluster(config):
+    # Check whether or not provided configuration describes a standby cluster
+    return isinstance(config, dict) and (config.get('host') or config.get('port') or config.get('restore_command'))
+
+
+def cluster_as_json(cluster):
+    leader_name = cluster.leader.name if cluster.leader else None
+    xlog_location_cluster = cluster.last_leader_operation or 0
+
+    ret = {'members': []}
+    for m in cluster.members:
+        if m.name == leader_name:
+            config = cluster.config.data if cluster.config and cluster.config.modify_index else {}
+            role = 'standby_leader' if is_standby_cluster(config.get('standby_cluster')) else 'leader'
+        elif m.name == cluster.sync.sync_standby:
+            role = 'sync_standby'
+        else:
+            role = 'replica'
+
+        conn_kwargs = m.conn_kwargs()
+        member = {'name': m.name, 'host': conn_kwargs['host'], 'port': int(conn_kwargs['port']),
+                  'role': role, 'state': m.data.get('state', ''), 'api_url': m.api_url}
+        optional_attributes = ('timeline', 'pending_restart', 'scheduled_restart', 'tags')
+        member.update({n: m.data[n] for n in optional_attributes if n in m.data})
+
+        if m.name != leader_name:
+            xlog_location = m.data.get('xlog_location')
+            if xlog_location is None:
+                member['lag'] = 'unknown'
+            elif xlog_location_cluster >= xlog_location:
+                member['lag'] = xlog_location_cluster - xlog_location
+            else:
+                member['lag'] = 0
+
+        ret['members'].append(member)
+
+    # sort members by name for consistency
+    ret['members'].sort(key=lambda m: m['name'])
+    if cluster.is_paused():
+        ret['pause'] = True
+    if cluster.failover and cluster.failover.scheduled_at:
+        ret['scheduled_switchover'] = {'at': cluster.failover.scheduled_at.isoformat()}
+        if cluster.failover.leader:
+            ret['scheduled_switchover']['from'] = cluster.failover.leader
+        if cluster.failover.candidate:
+            ret['scheduled_switchover']['to'] = cluster.failover.candidate
+    return ret

patroni/version.py

@@ -1 +1 @@
-__version__ = '1.4'
+__version__ = '1.6.3'

patroni/watchdog/base.py

@@ -57,7 +57,7 @@ class WatchdogConfig(object):
         return not self == other
 
     def get_impl(self):
-        if self.driver == 'testing':
+        if self.driver == 'testing':  # pragma: no cover
             from patroni.watchdog.linux import TestingWatchdogDevice
             return TestingWatchdogDevice.from_config(self.driver_config)
         elif platform.system() == 'Linux' and self.driver == 'default':

patroni/watchdog/linux.py

@@ -1,6 +1,5 @@
 import collections
 import ctypes
-import fcntl
 import os
 import platform
 from patroni.watchdog.base import WatchdogBase, WatchdogError
@@ -17,11 +16,11 @@ IOC_DIRBITS = 2
 
 # Non-generic platform special cases
 machine = platform.machine()
-if machine in ['mips', 'sparc', 'powerpc', 'ppc64']:
+if machine in ['mips', 'sparc', 'powerpc', 'ppc64']:  # pragma: no cover
     IOC_SIZEBITS = 13
     IOC_DIRBITS = 3
     IOC_NONE, IOC_WRITE, IOC_READ = 1, 2, 4
-elif machine == 'parisc':
+elif machine == 'parisc':  # pragma: no cover
     IOC_WRITE, IOC_READ = 2, 1
 
 IOC_NRSHIFT = 0
@@ -162,7 +161,9 @@ class LinuxWatchdogDevice(WatchdogBase):
         Raises OSError or IOError (Python 2) when the ioctl fails."""
         if self._fd is None:
             raise WatchdogError("Watchdog device is closed")
-        fcntl.ioctl(self._fd, func, arg, True)
+        if os.name != 'nt':
+            import fcntl
+            fcntl.ioctl(self._fd, func, arg, True)
 
     def get_support(self):
         if self._support_cache is None:
@@ -217,7 +218,7 @@ class LinuxWatchdogDevice(WatchdogBase):
         return timeout.value
 
 
-class TestingWatchdogDevice(LinuxWatchdogDevice):
+class TestingWatchdogDevice(LinuxWatchdogDevice):  # pragma: no cover
     """Converts timeout ioctls to regular writes that can be intercepted from a named pipe."""
     timeout = 60
 

postgres0.yml

@@ -11,8 +11,24 @@ restapi:
 #    username: username
 #    password: password
 
+# ctl:
+#   insecure: false # Allow connections to SSL sites without certs
+#   certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
+#   cacert: /etc/ssl/certs/ssl-cacert-snakeoil.pem
+
 etcd:
+  #Provide host to do the initial discovery of the cluster topology:
   host: 127.0.0.1:2379
+  #Or use "hosts" to provide multiple endpoints
+  #Could be a comma separated string:
+  #hosts: host1:port1,host2:port2
+  #or an actual yaml list:
+  #hosts:
+  #- host1:port1
+  #- host2:port2
+  #Once discovery is complete Patroni will use the list of advertised clientURLs
+  #It is possible to change this behavior through by setting:
+  #use_proxies: true
 
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
@@ -24,6 +40,10 @@ bootstrap:
     maximum_lag_on_failover: 1048576
 #    master_start_timeout: 300
 #    synchronous_mode: false
+    #standby_cluster:
+      #host: 127.0.0.1
+      #port: 1111
+      #primary_slot_name: patroni
     postgresql:
       use_pg_rewind: true
 #      use_slots: true
@@ -31,8 +51,8 @@ bootstrap:
 #        wal_level: hot_standby
 #        hot_standby: "on"
 #        wal_keep_segments: 8
-#        max_wal_senders: 5
-#        max_replication_slots: 5
+#        max_wal_senders: 10
+#        max_replication_slots: 10
 #        wal_log_hints: "on"
 #        archive_mode: "on"
 #        archive_timeout: 1800s
@@ -46,6 +66,9 @@ bootstrap:
   - data-checksums
 
   pg_hba:  # Add following lines to pg_hba.conf after running 'initdb'
+  # For kerberos gss based connectivity (discard @.*$)
+  #- host replication replicator 127.0.0.1/32 gss include_realm=0
+  #- host all all 0.0.0.0/0 gss include_realm=0
   - host replication replicator 127.0.0.1/32 md5
   - host all all 0.0.0.0/0 md5
 #  - hostssl all all 0.0.0.0/0 md5
@@ -75,7 +98,15 @@ postgresql:
     superuser:
       username: postgres
       password: zalando
+    rewind:  # Has no effect on postgres 10 and lower
+      username: rewind_user
+      password: rewind_password
+  # Server side kerberos spn
+#  krbsrvname: postgres
   parameters:
+    # Fully qualified kerberos ticket file for the running user
+    # same as KRB5CCNAME used by the GSS
+#   krb_server_keyfile: /var/spool/keytabs/postgres
     unix_socket_directories: '.'
 
 #watchdog:

postgres1.yml

@@ -11,8 +11,24 @@ restapi:
 #    username: username
 #    password: password
 
+# ctl:
+#   insecure: false # Allow connections to SSL sites without certs
+#   certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
+#   cacert: /etc/ssl/certs/ssl-cacert-snakeoil.pem
+
 etcd:
+  #Provide host to do the initial discovery of the cluster topology:
   host: 127.0.0.1:2379
+  #Or use "hosts" to provide multiple endpoints
+  #Could be a comma separated string:
+  #hosts: host1:port1,host2:port2
+  #or an actual yaml list:
+  #hosts:
+  #- host1:port1
+  #- host2:port2
+  #Once discovery is complete Patroni will use the list of advertised clientURLs
+  #It is possible to change this behavior through by setting:
+  #use_proxies: true
 
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
@@ -29,8 +45,8 @@ bootstrap:
 #        wal_level: hot_standby
 #        hot_standby: "on"
 #        wal_keep_segments: 8
-#        max_wal_senders: 5
-#        max_replication_slots: 5
+#        max_wal_senders: 10
+#        max_replication_slots: 10
 #        wal_log_hints: "on"
 #        archive_mode: "on"
 #        archive_timeout: 1800s
@@ -44,6 +60,9 @@ bootstrap:
   - data-checksums
 
   pg_hba:  # Add following lines to pg_hba.conf after running 'initdb'
+  # For kerberos gss based connectivity (discard @.*$)
+  #- host replication replicator 127.0.0.1/32 gss include_realm=0
+  #- host all all 0.0.0.0/0 gss include_realm=0
   - host replication replicator 127.0.0.1/32 md5
   - host all all 0.0.0.0/0 md5
 #  - hostssl all all 0.0.0.0/0 md5
@@ -73,8 +92,19 @@ postgresql:
     superuser:
       username: postgres
       password: zalando
+    rewind:  # Has no effect on postgres 10 and lower
+      username: rewind_user
+      password: rewind_password
+  # Server side kerberos spn
+#  krbsrvname: postgres
   parameters:
+    # Fully qualified kerberos ticket file for the running user
+    # same as KRB5CCNAME used by the GSS
+#    krb_server_keyfile: /var/spool/keytabs/postgres
     unix_socket_directories: '.'
+  basebackup:
+      - verbose
+      - max-rate: 100M
 tags:
     nofailover: false
     noloadbalance: false

postgres2.yml

@@ -11,8 +11,24 @@ restapi:
     username: username
     password: password
 
+# ctl:
+#   insecure: false # Allow connections to SSL sites without certs
+#   certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
+#   cacert: /etc/ssl/certs/ssl-cacert-snakeoil.pem
+
 etcd:
+  #Provide host to do the initial discovery of the cluster topology:
   host: 127.0.0.1:2379
+  #Or use "hosts" to provide multiple endpoints
+  #Could be a comma separated string:
+  #hosts: host1:port1,host2:port2
+  #or an actual yaml list:
+  #hosts:
+  #- host1:port1
+  #- host2:port2
+  #Once discovery is complete Patroni will use the list of advertised clientURLs
+  #It is possible to change this behavior through by setting:
+  #use_proxies: true
 
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
@@ -29,8 +45,8 @@ bootstrap:
 #        wal_level: hot_standby
 #        hot_standby: "on"
 #        wal_keep_segments: 8
-#        max_wal_senders: 5
-#        max_replication_slots: 5
+#        max_wal_senders: 10
+#        max_replication_slots: 10
 #        wal_log_hints: "on"
 #        archive_mode: "on"
 #        archive_timeout: 1800s
@@ -44,6 +60,9 @@ bootstrap:
   - data-checksums
 
   pg_hba:  # Add following lines to pg_hba.conf after running 'initdb'
+  # For kerberos gss based connectivity (discard @.*$)
+  #- host replication replicator 127.0.0.1/32 gss include_realm=0
+  #- host all all 0.0.0.0/0 gss include_realm=0
   - host replication replicator 127.0.0.1/32 md5
   - host all all 0.0.0.0/0 md5
 #  - hostssl all all 0.0.0.0/0 md5
@@ -70,7 +89,15 @@ postgresql:
     superuser:
       username: postgres
       password: zalando
+    rewind:  # Has no effect on postgres 10 and lower
+      username: rewind_user
+      password: rewind_password
+  # Server side kerberos spn
+#  krbsrvname: postgres
   parameters:
+    # Fully qualified kerberos ticket file for the running user
+    # same as KRB5CCNAME used by the GSS
+#    krb_server_keyfile: /var/spool/keytabs/postgres
     unix_socket_directories: '.'
 tags:
     nofailover: false

requirements.txt

@@ -1,16 +1,14 @@
 urllib3>=1.19.1,!=1.21
 boto
-psycopg2>=2.5.4
 PyYAML
-requests
 six >= 1.7
 kazoo>=1.3.1
 python-etcd>=0.4.3,<0.5
-python-consul>=0.7.0
+python-consul>=0.7.1
 click>=4.1
 prettytable>=0.7
 tzlocal
 python-dateutil
-psutil
+psutil>=2.0.0
 cdiff
-kubernetes==3.0.0
+kubernetes>=2.0.0,<=10.0.1,!=4.0.*,!=5.0.*

setup.py

@@ -8,51 +8,44 @@ import inspect
 import os
 import sys
 
-from setuptools.command.test import test as TestCommand
-from setuptools import find_packages, setup
-
-if sys.version_info < (2, 7, 0):
-    sys.stderr.write('FATAL: patroni needs to be run with Python 2.7+\n')
-    sys.exit(1)
+from setuptools import Command, find_packages, setup
 
 __location__ = os.path.join(os.getcwd(), os.path.dirname(inspect.getfile(inspect.currentframe())))
 
-
-def read_version(package):
-    data = {}
-    with open(os.path.join(package, 'version.py'), 'r') as fd:
-        exec(fd.read(), data)
-    return data['__version__']
-
-
 NAME = 'patroni'
 MAIN_PACKAGE = NAME
-SCRIPTS = 'scripts'
-VERSION = read_version(MAIN_PACKAGE)
 DESCRIPTION = 'PostgreSQL High-Available orchestrator and CLI'
 LICENSE = 'The MIT License'
 URL = 'https://github.com/zalando/patroni'
-AUTHOR = 'Alexander Kukushkin, Oleksii Kliukin, Feike Steenbergen'
-AUTHOR_EMAIL = '[email protected], [email protected], [email protected]'
-KEYWORDS = 'etcd governor patroni postgresql postgres ha haproxy confd zookeeper exhibitor consul streaming replication'
+AUTHOR = 'Alexander Kukushkin, Dmitrii Dolgov, Oleksii Kliukin'
+AUTHOR_EMAIL = '[email protected], [email protected], [email protected]'
+KEYWORDS = 'etcd governor patroni postgresql postgres ha haproxy confd' +\
+    ' zookeeper exhibitor consul streaming replication kubernetes k8s'
 
+EXTRAS_REQUIRE = {'aws': ['boto'], 'etcd': ['python-etcd'], 'consul': ['python-consul'],
+                  'exhibitor': ['kazoo'], 'zookeeper': ['kazoo'], 'kubernetes': ['kubernetes']}
 COVERAGE_XML = True
 COVERAGE_HTML = False
-JUNIT_XML = True
 
 # Add here all kinds of additional classifiers as defined under
 # https://pypi.python.org/pypi?%3Aaction=list_classifiers
 CLASSIFIERS = [
-    'Development Status :: 4 - Beta',
+    'Development Status :: 5 - Production/Stable',
     'Environment :: Console',
     'Intended Audience :: Developers',
     'Intended Audience :: System Administrators',
     'License :: OSI Approved :: MIT License',
+    'Operating System :: MacOS',
     'Operating System :: POSIX :: Linux',
+    'Operating System :: POSIX :: BSD :: FreeBSD',
+    'Operating System :: Microsoft :: Windows',
     'Programming Language :: Python',
     'Programming Language :: Python :: 2.7',
+    'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3.4',
     'Programming Language :: Python :: 3.5',
+    'Programming Language :: Python :: 3.6',
+    'Programming Language :: Python :: 3.7',
     'Programming Language :: Python :: Implementation :: CPython',
 ]
 
@@ -62,80 +55,74 @@ CONSOLE_SCRIPTS = ['patroni = patroni:main',
                    "patroni_aws = patroni.scripts.aws:main"]
 
 
-class PyTest(TestCommand):
+class PyTest(Command):
 
-    user_options = [('cov=', None, 'Run coverage'), ('cov-xml=', None, 'Generate junit xml report'), ('cov-html=',
-                    None, 'Generate junit html report'), ('junitxml=', None, 'Generate xml of test results')]
+    user_options = [('cov=', None, 'Run coverage'), ('cov-xml=', None, 'Generate junit xml report'),
+                    ('cov-html=', None, 'Generate junit html report')]
 
     def initialize_options(self):
-        TestCommand.initialize_options(self)
+        self.cov = []
         self.cov_xml = False
         self.cov_html = False
-        self.junitxml = None
 
     def finalize_options(self):
-        TestCommand.finalize_options(self)
         if self.cov_xml or self.cov_html:
             self.cov = ['--cov', MAIN_PACKAGE, '--cov-report', 'term-missing']
             if self.cov_xml:
                 self.cov.extend(['--cov-report', 'xml'])
             if self.cov_html:
                 self.cov.extend(['--cov-report', 'html'])
-        if self.junitxml is not None:
-            self.junitxml = ['--junitxml', self.junitxml]
 
     def run_tests(self):
         try:
             import pytest
         except Exception:
             raise RuntimeError('py.test is not installed, run: pip install pytest')
-        params = {'args': self.test_args}
-        if self.cov:
-            params['args'] += self.cov
-        if self.junitxml:
-            params['args'] += self.junitxml
-        params['args'] += ['--doctest-modules', MAIN_PACKAGE, '-vv']
 
         import logging
         silence = logging.WARNING
         logging.basicConfig(format='%(asctime)s %(levelname)s: %(message)s', level=os.getenv('LOGLEVEL', silence))
-        params['args'] += ['-s' if logging.getLogger().getEffectiveLevel() < silence else '--capture=fd']
-        errno = pytest.main(**params)
+
+        args = ['--verbose', 'tests', '--doctest-modules', MAIN_PACKAGE] +\
+            ['-s' if logging.getLogger().getEffectiveLevel() < silence else '--capture=fd']
+        if self.cov:
+            args += self.cov
+
+        errno = pytest.main(args=args)
         sys.exit(errno)
 
-
-def get_install_requirements(path):
-    content = open(os.path.join(__location__, path)).read()
-    return [req for req in content.split('\n') if req != '']
+    def run(self):
+        from pkg_resources import evaluate_marker
+        requirements = self.distribution.install_requires + ['mock>=2.0.0', 'pytest-cov', 'pytest'] +\
+            [v for k, v in self.distribution.extras_require.items() if not k.startswith(':') or evaluate_marker(k[1:])]
+        self.distribution.fetch_build_eggs(requirements)
+        self.run_tests()
 
 
 def read(fname):
-    return open(os.path.join(__location__, fname)).read()
+    with open(os.path.join(__location__, fname)) as fd:
+        return fd.read()
 
 
-def setup_package():
+def setup_package(version):
     # Assemble additional setup commands
     cmdclass = {'test': PyTest}
 
-    # Some helper variables
-    version = os.getenv('GO_PIPELINE_LABEL', VERSION)
-
     install_requires = []
-    extras_require = {'aws': ['boto'], 'etcd': ['python-etcd'], 'consul': ['python-consul'],
-                      'exhibitor': ['kazoo'], 'zookeeper': ['kazoo'], 'kubernetes': ['kubernetes']}
 
-    for r in get_install_requirements('requirements.txt'):
+    for r in read('requirements.txt').split('\n'):
+        r = r.strip()
+        if r == '':
+            continue
         extra = False
-        for e, v in extras_require.items():
+        for e, v in EXTRAS_REQUIRE.items():
             if r.startswith(v[0]):
-                extras_require[e] = [r]
+                EXTRAS_REQUIRE[e] = [r]
                 extra = True
         if not extra:
             install_requires.append(r)
 
-    command_options = {'test': {'test_suite': ('setup.py', 'tests')}}
-    if JUNIT_XML:
-        command_options['test']['junitxml'] = 'setup.py', 'junit.xml'
+    command_options = {'test': {}}
     if COVERAGE_XML:
         command_options['test']['cov_xml'] = 'setup.py', True
     if COVERAGE_HTML:
@@ -152,17 +139,28 @@ def setup_package():
         keywords=KEYWORDS,
         long_description=read('README.rst'),
         classifiers=CLASSIFIERS,
-        test_suite='tests',
         packages=find_packages(exclude=['tests', 'tests.*']),
         package_data={MAIN_PACKAGE: ["*.json"]},
+        python_requires='>=2.7',
         install_requires=install_requires,
-        extras_require=extras_require,
+        extras_require=EXTRAS_REQUIRE,
+        setup_requires='flake8',
         cmdclass=cmdclass,
-        tests_require=['flake8', 'mock>=2.0.0', 'pytest-cov', 'pytest'],
         command_options=command_options,
         entry_points={'console_scripts': CONSOLE_SCRIPTS},
     )
 
 
 if __name__ == '__main__':
-    setup_package()
+    old_modules = sys.modules.copy()
+    try:
+        from patroni import check_psycopg2, fatal, __version__
+    finally:
+        sys.modules.clear()
+        sys.modules.update(old_modules)
+
+    if sys.version_info < (2, 7, 0):
+        fatal('Patroni needs to be run with Python 2.7+')
+    check_psycopg2()
+
+    setup_package(__version__)

tests/__init__.py

@@ -0,0 +1,208 @@
+import datetime
+import os
+import shutil
+import unittest
+
+from mock import Mock, patch
+
+import psycopg2
+import urllib3
+
+from patroni.dcs import Leader, Member
+from patroni.postgresql import Postgresql
+from patroni.postgresql.config import ConfigHandler
+from patroni.utils import RetryFailedError
+
+
+class SleepException(Exception):
+    pass
+
+
+class MockResponse(object):
+
+    def __init__(self, status_code=200):
+        self.status_code = status_code
+        self.content = '{}'
+
+    @property
+    def data(self):
+        return self.content.encode('utf-8')
+
+    @property
+    def status(self):
+        return self.status_code
+
+    @staticmethod
+    def getheader(*args):
+        return ''
+
+
+def requests_get(url, **kwargs):
+    members = '[{"id":14855829450254237642,"peerURLs":["http://localhost:2380","http://localhost:7001"],' +\
+              '"name":"default","clientURLs":["http://localhost:2379","http://localhost:4001"]}]'
+    response = MockResponse()
+    if url.startswith('http://local'):
+        raise urllib3.exceptions.HTTPError()
+    elif ':8011/patroni' in url:
+        response.content = '{"role": "replica", "xlog": {"received_location": 0}, "tags": {}}'
+    elif url.endswith('/members'):
+        response.content = '[{}]' if url.startswith('http://error') else members
+    elif url.startswith('http://exhibitor'):
+        response.content = '{"servers":["127.0.0.1","127.0.0.2","127.0.0.3"],"port":2181}'
+    elif url.endswith(':8011/reinitialize'):
+        data = kwargs.get('data', '')
+        if ' false}' in data:
+            response.status_code = 503
+            response.content = 'restarting after failure already in progress'
+    else:
+        response.status_code = 404
+    return response
+
+
+class MockPostmaster(object):
+    def __init__(self, is_running=True, is_single_master=False):
+        self.is_running = Mock(return_value=is_running)
+        self.is_single_master = Mock(return_value=is_single_master)
+        self.wait_for_user_backends_to_close = Mock()
+        self.signal_stop = Mock(return_value=None)
+        self.wait = Mock()
+
+
+class MockCursor(object):
+
+    def __init__(self, connection):
+        self.connection = connection
+        self.closed = False
+        self.rowcount = 0
+        self.results = []
+
+    def execute(self, sql, *params):
+        if sql.startswith('blabla'):
+            raise psycopg2.ProgrammingError()
+        elif sql == 'CHECKPOINT' or sql.startswith('SELECT pg_catalog.pg_create_'):
+            raise psycopg2.OperationalError()
+        elif sql.startswith('RetryFailedError'):
+            raise RetryFailedError('retry')
+        elif sql.startswith('SELECT slot_name'):
+            self.results = [('blabla', 'physical'), ('foobar', 'physical'), ('ls', 'logical', 'a', 'b')]
+        elif sql.startswith('SELECT CASE WHEN pg_catalog.pg_is_in_recovery()'):
+            self.results = [(1, 2)]
+        elif sql.startswith('SELECT pg_catalog.pg_is_in_recovery()'):
+            self.results = [(False, 2)]
+        elif sql.startswith('SELECT pg_catalog.to_char'):
+            replication_info = '[{"application_name":"walreceiver","client_addr":"1.2.3.4",' +\
+                               '"state":"streaming","sync_state":"async","sync_priority":0}]'
+            self.results = [('', 0, '', '', '', '', False, replication_info)]
+        elif sql.startswith('SELECT name, setting'):
+            self.results = [('wal_segment_size', '2048', '8kB', 'integer', 'internal'),
+                            ('wal_block_size', '8192', None, 'integer', 'internal'),
+                            ('shared_buffers', '16384', '8kB', 'integer', 'postmaster'),
+                            ('wal_buffers', '-1', '8kB', 'integer', 'postmaster'),
+                            ('search_path', 'public', None, 'string', 'user'),
+                            ('port', '5433', None, 'integer', 'postmaster'),
+                            ('listen_addresses', '*', None, 'string', 'postmaster'),
+                            ('autovacuum', 'on', None, 'bool', 'sighup'),
+                            ('unix_socket_directories', '/tmp', None, 'string', 'postmaster')]
+        elif sql.startswith('IDENTIFY_SYSTEM'):
+            self.results = [('1', 2, '0/402EEC0', '')]
+        elif sql.startswith('SELECT isdir, modification'):
+            self.results = [(False, datetime.datetime.now())]
+        elif sql.startswith('SELECT pg_catalog.pg_read_file'):
+            self.results = [('1\t0/40159C0\tno recovery target specified\n\n'
+                             '2\t1/40159C0\tno recovery target specified\n',)]
+        elif sql.startswith('TIMELINE_HISTORY '):
+            self.results = [('', b'x\t0/40159C0\tno recovery target specified\n\n'
+                                 b'1\t0/40159C0\tno recovery target specified\n\n'
+                                 b'2\t0/402DD98\tno recovery target specified\n\n'
+                                 b'3\t0/403DD98\tno recovery target specified\n')]
+        else:
+            self.results = [(None, None, None, None, None, None, None, None, None, None)]
+
+    def fetchone(self):
+        return self.results[0]
+
+    def fetchall(self):
+        return self.results
+
+    def __iter__(self):
+        for i in self.results:
+            yield i
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        pass
+
+
+class MockConnect(object):
+
+    server_version = 99999
+    autocommit = False
+    closed = 0
+
+    def cursor(self):
+        return MockCursor(self)
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        pass
+
+    @staticmethod
+    def close():
+        pass
+
+
+def psycopg2_connect(*args, **kwargs):
+    return MockConnect()
+
+
+class PostgresInit(unittest.TestCase):
+    _PARAMETERS = {'wal_level': 'hot_standby', 'max_replication_slots': 5, 'f.oo': 'bar',
+                   'search_path': 'public', 'hot_standby': 'on', 'max_wal_senders': 5,
+                   'wal_keep_segments': 8, 'wal_log_hints': 'on', 'max_locks_per_transaction': 64,
+                   'max_worker_processes': 8, 'max_connections': 100, 'max_prepared_transactions': 0,
+                   'track_commit_timestamp': 'off', 'unix_socket_directories': '/tmp', 'trigger_file': 'bla'}
+
+    @patch('psycopg2.connect', psycopg2_connect)
+    @patch.object(ConfigHandler, 'write_postgresql_conf', Mock())
+    @patch.object(ConfigHandler, 'replace_pg_hba', Mock())
+    @patch.object(ConfigHandler, 'replace_pg_ident', Mock())
+    @patch.object(Postgresql, 'get_postgres_role_from_data_directory', Mock(return_value='master'))
+    def setUp(self):
+        data_dir = os.path.join('data', 'test0')
+        self.p = Postgresql({'name': 'postgresql0', 'scope': 'batman', 'data_dir': data_dir,
+                             'config_dir': data_dir, 'retry_timeout': 10,
+                             'krbsrvname': 'postgres', 'pgpass': os.path.join(data_dir, 'pgpass0'),
+                             'listen': '127.0.0.2, 127.0.0.3:5432', 'connect_address': '127.0.0.2:5432',
+                             'authentication': {'superuser': {'username': 'foo', 'password': 'test'},
+                                                'replication': {'username': '', 'password': 'rep-pass'}},
+                             'remove_data_directory_on_rewind_failure': True,
+                             'use_pg_rewind': True, 'pg_ctl_timeout': 'bla',
+                             'parameters': self._PARAMETERS,
+                             'recovery_conf': {'foo': 'bar'},
+                             'pg_hba': ['host all all 0.0.0.0/0 md5'],
+                             'pg_ident': ['krb realm postgres'],
+                             'callbacks': {'on_start': 'true', 'on_stop': 'true', 'on_reload': 'true',
+                                           'on_restart': 'true', 'on_role_change': 'true'}})
+
+
+class BaseTestPostgresql(PostgresInit):
+
+    def setUp(self):
+        super(BaseTestPostgresql, self).setUp()
+
+        if not os.path.exists(self.p.data_dir):
+            os.makedirs(self.p.data_dir)
+
+        self.leadermem = Member(0, 'leader', 28, {'conn_url': 'postgres://replicator:[email protected]:5435/postgres'})
+        self.leader = Leader(-1, 28, self.leadermem)
+        self.other = Member(0, 'test-1', 28, {'conn_url': 'postgres://replicator:[email protected]:5433/postgres',
+                                              'tags': {'replicatefrom': 'leader'}})
+        self.me = Member(0, 'test0', 28, {'conn_url': 'postgres://replicator:[email protected]:5434/postgres'})
+
+    def tearDown(self):
+        if os.path.exists(self.p.data_dir):
+            shutil.rmtree(self.p.data_dir)

tests/test_api.py

@@ -2,6 +2,7 @@ import datetime
 import json
 import psycopg2
 import unittest
+import socket
 
 from mock import Mock, PropertyMock, patch
 from patroni.api import RestApiHandler, RestApiServer
@@ -10,7 +11,8 @@ from patroni.ha import _MemberStatus
 from patroni.utils import tzutc
 from six import BytesIO as IO
 from six.moves import BaseHTTPServer
-from test_postgresql import psycopg2_connect, MockCursor
+from . import psycopg2_connect, MockCursor
+from .test_ha import get_cluster_initialized_without_leader
 
 
 future_restart_time = datetime.datetime.now(tzutc) + datetime.timedelta(days=5)
@@ -51,12 +53,16 @@ class MockHa(object):
     state_handler = MockPostgresql()
     watchdog = MockWatchdog()
 
+    @staticmethod
+    def is_leader():
+        return False
+
     @staticmethod
     def reinitialize(_):
         return 'reinitialize'
 
     @staticmethod
-    def restart():
+    def restart(*args, **kwargs):
         return (True, '')
 
     @staticmethod
@@ -69,7 +75,7 @@ class MockHa(object):
 
     @staticmethod
     def fetch_nodes_statuses(members):
-        return [_MemberStatus(None, True, None, None, {}, False)]
+        return [_MemberStatus(None, True, None, 0, None, {}, False)]
 
     @staticmethod
     def schedule_future_restart(data):
@@ -91,6 +97,17 @@ class MockHa(object):
     def is_paused():
         return True
 
+    @staticmethod
+    def is_standby_cluster():
+        return False
+
+
+class MockLogger(object):
+
+    NORMAL_LOG_QUEUE_SIZE = 2
+    queue_size = 3
+    records_lost = 1
+
 
 class MockPatroni(object):
 
@@ -98,6 +115,7 @@ class MockPatroni(object):
     config = Mock()
     postgresql = ha.state_handler
     dcs = Mock()
+    logger = MockLogger()
     tags = {}
     version = '0.00'
     noloadbalance = PropertyMock(return_value=False)
@@ -123,38 +141,41 @@ class MockRequest(object):
 
 class MockRestApiServer(RestApiServer):
 
-    def __init__(self, Handler, request):
+    def __init__(self, Handler, request, config=None):
         self.socket = 0
         self.serve_forever = Mock()
-        BaseHTTPServer.HTTPServer.__init__ = Mock()
         MockRestApiServer._BaseServer__is_shut_down = Mock()
         MockRestApiServer._BaseServer__shutdown_request = True
-        config = {'listen': '127.0.0.1:8008', 'auth': 'test:test'}
+        config = config or {'listen': '127.0.0.1:8008', 'auth': 'test:test', 'certfile': 'dumb', 'verify_client': 'a'}
         super(MockRestApiServer, self).__init__(MockPatroni(), config)
-        config['certfile'] = 'dumb'
-        self.reload_config(config)
         Handler(MockRequest(request), ('0.0.0.0', 8080), self)
 
 
-@patch('ssl.wrap_socket', Mock(return_value=0))
+@patch('ssl.SSLContext.load_cert_chain', Mock())
+@patch('ssl.SSLContext.wrap_socket', Mock(return_value=0))
+@patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
 class TestRestApiHandler(unittest.TestCase):
 
     _authorization = '\nAuthorization: Basic dGVzdDp0ZXN0'
 
     def test_do_GET(self):
         MockRestApiServer(RestApiHandler, 'GET /replica')
+        MockRestApiServer(RestApiHandler, 'GET /read-only')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={})):
             MockRestApiServer(RestApiHandler, 'GET /replica')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
             MockRestApiServer(RestApiHandler, 'GET /replica')
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'state': 'running'})):
+            MockRestApiServer(RestApiHandler, 'GET /health')
         MockRestApiServer(RestApiHandler, 'GET /master')
         MockPatroni.dcs.cluster.sync.sync_standby = MockPostgresql.name
         MockPatroni.dcs.cluster.is_synchronous_mode = Mock(return_value=True)
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'replica'})):
             MockRestApiServer(RestApiHandler, 'GET /synchronous')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'replica'})):
+            MockPatroni.dcs.cluster.sync.sync_standby = ''
             MockRestApiServer(RestApiHandler, 'GET /asynchronous')
-        MockPatroni.dcs.cluster.leader.name = MockPostgresql.name
+        MockPatroni.ha.is_leader = Mock(return_value=True)
         MockRestApiServer(RestApiHandler, 'GET /replica')
         MockPatroni.dcs.cluster = None
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
@@ -164,6 +185,8 @@ class TestRestApiHandler(unittest.TestCase):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /master'))
         with patch.object(RestApiServer, 'query', Mock(return_value=[('', 1, '', '', '', '', False, '')])):
             self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))
+        with patch.object(MockHa, 'is_standby_cluster', Mock(return_value=True)):
+            MockRestApiServer(RestApiHandler, 'GET /standby_leader')
 
     def test_do_OPTIONS(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'OPTIONS / HTTP/1.0'))
@@ -176,6 +199,17 @@ class TestRestApiHandler(unittest.TestCase):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'POST /restart HTTP/1.0'))
         MockRestApiServer(RestApiHandler, 'POST /restart HTTP/1.0\nAuthorization:')
 
+    @patch.object(MockPatroni, 'dcs')
+    def test_do_GET_cluster(self, mock_dcs):
+        mock_dcs.cluster = get_cluster_initialized_without_leader()
+        mock_dcs.cluster.members[1].data['xlog_location'] = 11
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /cluster'))
+
+    @patch.object(MockPatroni, 'dcs')
+    def test_do_GET_history(self, mock_dcs):
+        mock_dcs.cluster = get_cluster_initialized_without_leader()
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /history'))
+
     @patch.object(MockPatroni, 'dcs')
     def test_do_GET_config(self, mock_dcs):
         mock_dcs.cluster.config.data = {}
@@ -212,11 +246,8 @@ class TestRestApiHandler(unittest.TestCase):
         mock_dcs.get_cluster.return_value.config = ClusterConfig.from_node(1, config)
         MockRestApiServer(RestApiHandler, request)
 
-    @patch.object(MockPatroni, 'sighup_handler', Mock(side_effect=Exception))
+    @patch.object(MockPatroni, 'sighup_handler', Mock())
     def test_do_POST_reload(self):
-        with patch.object(MockPatroni, 'config') as mock_config:
-            mock_config.reload_local_configuration.return_value = False
-            MockRestApiServer(RestApiHandler, 'POST /reload HTTP/1.0' + self._authorization)
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'POST /reload HTTP/1.0' + self._authorization))
 
     @patch.object(MockPatroni, 'dcs')
@@ -339,6 +370,7 @@ class TestRestApiHandler(unittest.TestCase):
 
         cluster2 = cluster.copy()
         cluster2.leader.name = 'postgresql0'
+        cluster2.is_unlocked.return_value = False
         dcs.get_cluster.side_effect = [cluster, cluster2]
         MockRestApiServer(RestApiHandler, request)
 
@@ -379,3 +411,34 @@ class TestRestApiHandler(unittest.TestCase):
         post = 'POST /failover HTTP/1.0' + self._authorization + '\nContent-Length: '
         MockRestApiServer(RestApiHandler, post + '14\n\n{"leader":"1"}')
         MockRestApiServer(RestApiHandler, post + '37\n\n{"candidate":"2","scheduled_at": "1"}')
+
+
+@patch('ssl.SSLContext.load_cert_chain', Mock())
+@patch('ssl.SSLContext.wrap_socket', Mock(return_value=0))
+@patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
+class TestRestApiServer(unittest.TestCase):
+
+    def test_reload_config(self):
+        bad_config = {'listen': 'foo'}
+        self.assertRaises(ValueError, MockRestApiServer, None, '', bad_config)
+        srv = MockRestApiServer(Mock(), '', {'listen': '*:8008', 'certfile': 'a', 'verify_client': 'required'})
+        self.assertRaises(ValueError, srv.reload_config, bad_config)
+        self.assertRaises(ValueError, srv.reload_config, {})
+        with patch.object(socket.socket, 'setsockopt', Mock(side_effect=socket.error)):
+            srv.reload_config({'listen': ':8008'})
+
+    def test_check_auth(self):
+        srv = MockRestApiServer(Mock(), '', {'listen': '*:8008', 'certfile': 'a', 'verify_client': 'required'})
+        mock_rh = Mock()
+        mock_rh.request.getpeercert.return_value = None
+        self.assertIsNot(srv.check_auth(mock_rh), True)
+
+    def test_handle_error(self):
+        try:
+            raise Exception()
+        except Exception:
+            self.assertIsNone(MockRestApiServer.handle_error(None, ('127.0.0.1', 55555)))
+
+    def test_socket_error(self):
+        with patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock(side_effect=socket.error)):
+            self.assertRaises(socket.error, MockRestApiServer, Mock(), '', {'listen': '*:8008'})

tests/test_aws.py

@@ -1,11 +1,11 @@
 import boto.ec2
 import sys
 import unittest
+import urllib3
 
 from mock import Mock, patch
 from collections import namedtuple
 from patroni.scripts.aws import AWSConnection, main as _main
-from requests.exceptions import RequestException
 
 
 class MockEc2Connection(object):
@@ -22,28 +22,11 @@ class MockEc2Connection(object):
         return True
 
 
-class MockResponse(object):
-    ok = True
-
-    def __init__(self, content):
-        self.content = content
-
-    def json(self):
-        return self.content
-
-
-def requests_get(url, **kwargs):
-    if url.split('/')[-1] == 'document':
-        result = {"instanceId": "012345", "region": "eu-west-1"}
-    else:
-        result = 'foo'
-    return MockResponse(result)
-
-
 @patch('boto.ec2.connect_to_region', Mock(return_value=MockEc2Connection()))
 class TestAWSConnection(unittest.TestCase):
 
-    @patch('requests.get', requests_get)
+    @patch('patroni.scripts.aws.requests_get', Mock(return_value=urllib3.HTTPResponse(
+        status=200, body=b'{"instanceId": "012345", "region": "eu-west-1"}')))
     def setUp(self):
         self.conn = AWSConnection('test')
 
@@ -53,17 +36,18 @@ class TestAWSConnection(unittest.TestCase):
             self.conn._retry.max_tries = 1
             self.assertFalse(self.conn.on_role_change('master'))
 
-    @patch('requests.get', Mock(side_effect=RequestException('foo')))
+    @patch('patroni.scripts.aws.requests_get', Mock(side_effect=Exception('foo')))
     def test_non_aws(self):
         conn = AWSConnection('test')
         self.assertFalse(conn.on_role_change("master"))
 
-    @patch('requests.get', Mock(return_value=MockResponse('foo')))
+    @patch('patroni.scripts.aws.requests_get', Mock(return_value=urllib3.HTTPResponse(status=200, body=b'foo')))
     def test_aws_bizare_response(self):
         conn = AWSConnection('test')
         self.assertFalse(conn.aws_available())
 
-    @patch('requests.get', requests_get)
+    @patch('patroni.scripts.aws.requests_get', Mock(return_value=urllib3.HTTPResponse(
+        status=200, body=b'{"instanceId": "012345", "region": "eu-west-1"}')))
     @patch('sys.exit', Mock())
     def test_main(self):
         self.assertIsNone(_main())

tests/test_bootstrap.py

@@ -0,0 +1,227 @@
+import os
+
+from mock import Mock, PropertyMock, patch
+
+from patroni.async_executor import CriticalTask
+from patroni.postgresql import Postgresql
+from patroni.postgresql.bootstrap import Bootstrap
+from patroni.postgresql.cancellable import CancellableSubprocess
+from patroni.postgresql.config import ConfigHandler
+
+from . import psycopg2_connect, BaseTestPostgresql
+
+
+@patch('subprocess.call', Mock(return_value=0))
+@patch('psycopg2.connect', psycopg2_connect)
+@patch('os.rename', Mock())
+class TestBootstrap(BaseTestPostgresql):
+
+    @patch('patroni.postgresql.CallbackExecutor', Mock())
+    def setUp(self):
+        super(TestBootstrap, self).setUp()
+        self.b = self.p.bootstrap
+
+    @patch('time.sleep', Mock())
+    @patch.object(CancellableSubprocess, 'call')
+    @patch.object(Postgresql, 'remove_data_directory', Mock(return_value=True))
+    @patch.object(Postgresql, 'data_directory_empty', Mock(return_value=False))
+    @patch.object(Bootstrap, '_post_restore', Mock(side_effect=OSError))
+    def test_create_replica(self, mock_cancellable_subprocess_call):
+        self.p.config._config['create_replica_methods'] = ['pgBackRest']
+        self.p.config._config['pgBackRest'] = {'command': 'pgBackRest', 'keep_data': True, 'no_params': True}
+        mock_cancellable_subprocess_call.return_value = 0
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+
+        self.p.config._config['create_replica_methods'] = ['basebackup']
+        self.p.config._config['basebackup'] = [{'max_rate': '100M'}, 'no-sync']
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+
+        self.p.config._config['basebackup'] = [{'max_rate': '100M', 'compress': '9'}]
+        with patch('patroni.postgresql.bootstrap.logger.error', new_callable=Mock()) as mock_logger:
+            self.b.create_replica(self.leader)
+            mock_logger.assert_called_once()
+            self.assertTrue("only one key-value is allowed and value should be a string" in mock_logger.call_args[0][0],
+                            "not matching {0}".format(mock_logger.call_args[0][0]))
+
+        self.p.config._config['basebackup'] = [42]
+        with patch('patroni.postgresql.bootstrap.logger.error', new_callable=Mock()) as mock_logger:
+            self.b.create_replica(self.leader)
+            mock_logger.assert_called_once()
+            self.assertTrue("value should be string value or a single key-value pair" in mock_logger.call_args[0][0],
+                            "not matching {0}".format(mock_logger.call_args[0][0]))
+
+        self.p.config._config['basebackup'] = {"foo": "bar"}
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+
+        self.p.config._config['create_replica_methods'] = ['wale', 'basebackup']
+        del self.p.config._config['basebackup']
+        mock_cancellable_subprocess_call.return_value = 1
+        self.assertEqual(self.b.create_replica(self.leader), 1)
+
+        mock_cancellable_subprocess_call.side_effect = Exception('foo')
+        self.assertEqual(self.b.create_replica(self.leader), 1)
+
+        mock_cancellable_subprocess_call.side_effect = [1, 0]
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+
+        mock_cancellable_subprocess_call.side_effect = [Exception(), 0]
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+
+        self.p.cancellable.cancel()
+        self.assertEqual(self.b.create_replica(self.leader), 1)
+
+    @patch('time.sleep', Mock())
+    @patch.object(CancellableSubprocess, 'call')
+    @patch.object(Postgresql, 'remove_data_directory', Mock(return_value=True))
+    @patch.object(Bootstrap, '_post_restore', Mock(side_effect=OSError))
+    def test_create_replica_old_format(self, mock_cancellable_subprocess_call):
+        """ The same test as before but with old 'create_replica_method'
+            to test backward compatibility
+        """
+        self.p.config._config['create_replica_method'] = ['wale', 'basebackup']
+        self.p.config._config['wale'] = {'command': 'foo'}
+        mock_cancellable_subprocess_call.return_value = 0
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+        del self.p.config._config['wale']
+        self.assertEqual(self.b.create_replica(self.leader), 0)
+
+        self.p.config._config['create_replica_method'] = ['wale']
+        mock_cancellable_subprocess_call.return_value = 1
+        self.assertEqual(self.b.create_replica(self.leader), 1)
+
+    def test_basebackup(self):
+        self.p.cancellable.cancel()
+        self.b.basebackup(None, None, {'foo': 'bar'})
+
+    def test__initdb(self):
+        self.assertRaises(Exception, self.b.bootstrap, {'initdb': [{'pgdata': 'bar'}]})
+        self.assertRaises(Exception, self.b.bootstrap, {'initdb': [{'foo': 'bar', 1: 2}]})
+        self.assertRaises(Exception, self.b.bootstrap, {'initdb': [1]})
+        self.assertRaises(Exception, self.b.bootstrap, {'initdb': 1})
+
+    @patch.object(CancellableSubprocess, 'call', Mock())
+    @patch.object(Postgresql, 'is_running', Mock(return_value=True))
+    @patch.object(Postgresql, 'data_directory_empty', Mock(return_value=False))
+    @patch.object(Postgresql, 'controldata', Mock(return_value={'max_connections setting': 100,
+                                                                'max_prepared_xacts setting': 0,
+                                                                'max_locks_per_xact setting': 64}))
+    def test_bootstrap(self):
+        with patch('subprocess.call', Mock(return_value=1)):
+            self.assertFalse(self.b.bootstrap({}))
+
+        config = {'users': {'replicator': {'password': 'rep-pass', 'options': ['replication']}}}
+
+        with patch.object(Postgresql, 'is_running', Mock(return_value=False)),\
+                patch('multiprocessing.Process', Mock(side_effect=Exception)),\
+                patch('multiprocessing.get_context', Mock(side_effect=Exception), create=True):
+            self.assertRaises(Exception, self.b.bootstrap, config)
+        with open(os.path.join(self.p.data_dir, 'pg_hba.conf')) as f:
+            lines = f.readlines()
+            self.assertTrue('host all all 0.0.0.0/0 md5\n' in lines)
+
+        self.p.config._config.pop('pg_hba')
+        config.update({'post_init': '/bin/false',
+                       'pg_hba': ['host replication replicator 127.0.0.1/32 md5',
+                                  'hostssl all all 0.0.0.0/0 md5',
+                                  'host all all 0.0.0.0/0 md5']})
+        self.b.bootstrap(config)
+        with open(os.path.join(self.p.data_dir, 'pg_hba.conf')) as f:
+            lines = f.readlines()
+            self.assertTrue('host replication replicator 127.0.0.1/32 md5\n' in lines)
+
+    @patch.object(CancellableSubprocess, 'call')
+    @patch.object(Postgresql, 'get_major_version', Mock(return_value=90600))
+    @patch.object(Postgresql, 'controldata',  Mock(return_value={'Database cluster state': 'in production'}))
+    def test_custom_bootstrap(self, mock_cancellable_subprocess_call):
+        self.p.config._config.pop('pg_hba')
+        config = {'method': 'foo', 'foo': {'command': 'bar'}}
+
+        mock_cancellable_subprocess_call.return_value = 1
+        self.assertFalse(self.b.bootstrap(config))
+
+        mock_cancellable_subprocess_call.return_value = 0
+        with patch('multiprocessing.Process', Mock(side_effect=Exception("42"))),\
+                patch('multiprocessing.get_context', Mock(side_effect=Exception("42")), create=True),\
+                patch('os.path.isfile', Mock(return_value=True)),\
+                patch('os.unlink', Mock()),\
+                patch.object(ConfigHandler, 'save_configuration_files', Mock()),\
+                patch.object(ConfigHandler, 'restore_configuration_files', Mock()),\
+                patch.object(ConfigHandler, 'write_recovery_conf', Mock()):
+            with self.assertRaises(Exception) as e:
+                self.b.bootstrap(config)
+            self.assertEqual(str(e.exception), '42')
+
+            config['foo']['recovery_conf'] = {'foo': 'bar'}
+
+            with self.assertRaises(Exception) as e:
+                self.b.bootstrap(config)
+            self.assertEqual(str(e.exception), '42')
+
+        mock_cancellable_subprocess_call.side_effect = Exception
+        self.assertFalse(self.b.bootstrap(config))
+
+    @patch('time.sleep', Mock())
+    @patch('os.unlink', Mock())
+    @patch('shutil.copy', Mock())
+    @patch('os.path.isfile', Mock(return_value=True))
+    @patch.object(Bootstrap, 'call_post_bootstrap', Mock(return_value=True))
+    @patch.object(Bootstrap, '_custom_bootstrap', Mock(return_value=True))
+    @patch.object(Postgresql, 'start', Mock(return_value=True))
+    @patch.object(Postgresql, 'get_major_version', Mock(return_value=110000))
+    def test_post_bootstrap(self):
+        config = {'method': 'foo', 'foo': {'command': 'bar'}}
+        self.b.bootstrap(config)
+
+        task = CriticalTask()
+        with patch.object(Bootstrap, 'create_or_update_role', Mock(side_effect=Exception)):
+            self.b.post_bootstrap({}, task)
+            self.assertFalse(task.result)
+
+        self.p.config._config.pop('pg_hba')
+        self.b.post_bootstrap({}, task)
+        self.assertTrue(task.result)
+
+        self.b.bootstrap(config)
+        with patch.object(Postgresql, 'pending_restart', PropertyMock(return_value=True)), \
+                patch.object(Postgresql, 'restart', Mock()) as mock_restart:
+            self.b.post_bootstrap({}, task)
+            mock_restart.assert_called_once()
+
+        self.b.bootstrap(config)
+        self.p.set_state('stopped')
+        self.p.reload_config({'authentication': {'superuser': {'username': 'p', 'password': 'p'},
+                                                 'replication': {'username': 'r', 'password': 'r'},
+                                                 'rewind': {'username': 'rw', 'password': 'rw'}},
+                              'listen': '*', 'retry_timeout': 10, 'parameters': {'wal_level': '', 'hba_file': 'foo'}})
+        with patch.object(Postgresql, 'major_version', PropertyMock(return_value=110000)), \
+                patch.object(Postgresql, 'restart', Mock()) as mock_restart:
+            self.b.post_bootstrap({}, task)
+            mock_restart.assert_called_once()
+
+    @patch.object(CancellableSubprocess, 'call')
+    def test_call_post_bootstrap(self, mock_cancellable_subprocess_call):
+        mock_cancellable_subprocess_call.return_value = 1
+        self.assertFalse(self.b.call_post_bootstrap({'post_init': '/bin/false'}))
+
+        mock_cancellable_subprocess_call.return_value = 0
+        self.p.config.superuser.pop('username')
+        self.assertTrue(self.b.call_post_bootstrap({'post_init': '/bin/false'}))
+        mock_cancellable_subprocess_call.assert_called()
+        args, kwargs = mock_cancellable_subprocess_call.call_args
+        self.assertTrue('PGPASSFILE' in kwargs['env'])
+        self.assertEqual(args[0], ['/bin/false', 'dbname=postgres host=127.0.0.2 port=5432'])
+
+        mock_cancellable_subprocess_call.reset_mock()
+        self.p.config._local_address.pop('host')
+        self.assertTrue(self.b.call_post_bootstrap({'post_init': '/bin/false'}))
+        mock_cancellable_subprocess_call.assert_called()
+        self.assertEqual(mock_cancellable_subprocess_call.call_args[0][0], ['/bin/false', 'dbname=postgres port=5432'])
+
+        mock_cancellable_subprocess_call.side_effect = OSError
+        self.assertFalse(self.b.call_post_bootstrap({'post_init': '/bin/false'}))
+
+    @patch('os.path.exists', Mock(return_value=True))
+    @patch('os.unlink', Mock())
+    @patch.object(Bootstrap, 'create_replica', Mock(return_value=0))
+    def test_clone(self):
+        self.b.clone(self.leader)

tests/test_callback_executor.py

@@ -1,24 +1,34 @@
+import psutil
 import unittest
 
 from mock import Mock, patch
-from patroni.callback_executor import CallbackExecutor
+from patroni.postgresql.callback_executor import CallbackExecutor
 
 
 class TestCallbackExecutor(unittest.TestCase):
 
-    @patch('subprocess.Popen')
+    @patch('psutil.Popen')
     def test_callback_executor(self, mock_popen):
-        mock_popen.return_value.wait.side_effect = Exception
-        mock_popen.return_value.poll.return_value = None
+        mock_popen.return_value.children.return_value = []
+        mock_popen.return_value.is_running.return_value = True
 
         ce = CallbackExecutor()
+        ce._kill_children = Mock(side_effect=Exception)
         self.assertIsNone(ce.call([]))
         ce.join()
 
         self.assertIsNone(ce.call([]))
 
+        mock_popen.return_value.kill.side_effect = psutil.AccessDenied()
+        self.assertIsNone(ce.call([]))
+
+        ce._process_children = []
+        mock_popen.return_value.children.side_effect = psutil.Error()
+        mock_popen.return_value.kill.side_effect = psutil.NoSuchProcess(123)
+        self.assertIsNone(ce.call([]))
+
         mock_popen.side_effect = Exception
         ce = CallbackExecutor()
-        ce._callback_event.wait = Mock(side_effect=[None, Exception])
+        ce._condition.wait = Mock(side_effect=[None, Exception])
         self.assertIsNone(ce.call([]))
         ce.join()

tests/test_cancellable.py

@@ -0,0 +1,34 @@
+import psutil
+import unittest
+
+from mock import Mock, patch
+from patroni.exceptions import PostgresException
+from patroni.postgresql.cancellable import CancellableSubprocess
+
+
+class TestCancellableSubprocess(unittest.TestCase):
+
+    def setUp(self):
+        self.c = CancellableSubprocess()
+
+    def test_call(self):
+        self.c.cancel()
+        self.assertRaises(PostgresException, self.c.call, communicate_input=None)
+
+    def test__kill_children(self):
+        self.c._process_children = [Mock()]
+        self.c._kill_children()
+        self.c._process_children[0].kill.side_effect = psutil.AccessDenied()
+        self.c._kill_children()
+        self.c._process_children[0].kill.side_effect = psutil.NoSuchProcess(123)
+        self.c._kill_children()
+
+    @patch('patroni.postgresql.cancellable.polling_loop', Mock(return_value=[0, 0]))
+    def test_cancel(self):
+        self.c._process = Mock()
+        self.c._process.is_running.return_value = True
+        self.c._process.children.side_effect = psutil.Error()
+        self.c._process.suspend.side_effect = psutil.Error()
+        self.c.cancel()
+        self.c._process.is_running.side_effect = [True, False]
+        self.c.cancel()

tests/test_config.py

@@ -1,6 +1,6 @@
 import os
-import unittest
 import sys
+import unittest
 
 from mock import MagicMock, Mock, patch
 from patroni.config import Config
@@ -15,21 +15,20 @@ class TestConfig(unittest.TestCase):
     def setUp(self):
         sys.argv = ['patroni.py']
         os.environ[Config.PATRONI_CONFIG_VARIABLE] = 'restapi: {}\npostgresql: {data_dir: foo}'
-        self.config = Config()
-
-    def test_no_config(self):
-        self.assertRaises(SystemExit, Config)
+        self.config = Config(None)
 
     def test_set_dynamic_configuration(self):
         with patch.object(Config, '_build_effective_configuration', Mock(side_effect=Exception)):
             self.assertIsNone(self.config.set_dynamic_configuration({'foo': 'bar'}))
-        self.assertTrue(self.config.set_dynamic_configuration({'synchronous_mode': True}))
+        self.assertTrue(self.config.set_dynamic_configuration({'synchronous_mode': True, 'standby_cluster': {}}))
 
     def test_reload_local_configuration(self):
         os.environ.update({
             'PATRONI_NAME': 'postgres0',
             'PATRONI_NAMESPACE': '/patroni/',
             'PATRONI_SCOPE': 'batman2',
+            'PATRONI_LOGLEVEL': 'ERROR',
+            'PATRONI_LOG_LOGGERS': 'patroni.postmaster: WARNING, urllib3: DEBUG',
             'PATRONI_RESTAPI_USERNAME': 'username',
             'PATRONI_RESTAPI_PASSWORD': 'password',
             'PATRONI_RESTAPI_LISTEN': '0.0.0.0:8008',
@@ -49,7 +48,8 @@ class TestConfig(unittest.TestCase):
             'PATRONI_ETCD_CERT': '/cert',
             'PATRONI_ETCD_KEY': '/key',
             'PATRONI_CONSUL_HOST': '127.0.0.1:8500',
-            'PATRONI_KUBERNETES_LABELS': 'a:b:c',
+            'PATRONI_CONSUL_REGISTER_SERVICE': 'on',
+            'PATRONI_KUBERNETES_LABELS': 'a: b: c',
             'PATRONI_KUBERNETES_SCOPE_LABEL': 'a',
             'PATRONI_KUBERNETES_PORTS': '[{"name": "postgresql"}]',
             'PATRONI_ZOOKEEPER_HOSTS': "'host1:2181','host2:2181'",
@@ -63,19 +63,18 @@ class TestConfig(unittest.TestCase):
             'PATRONI_admin_PASSWORD': 'admin',
             'PATRONI_admin_OPTIONS': 'createrole,createdb'
         })
-        sys.argv = ['patroni.py', 'postgres0.yml']
-        config = Config()
+        config = Config('postgres0.yml')
         with patch.object(Config, '_load_config_file', Mock(return_value={'restapi': {}})):
             with patch.object(Config, '_build_effective_configuration', Mock(side_effect=Exception)):
-                self.assertRaises(Exception, config.reload_local_configuration, True)
-            self.assertTrue(config.reload_local_configuration(True))
+                config.reload_local_configuration()
             self.assertTrue(config.reload_local_configuration())
+            self.assertIsNone(config.reload_local_configuration())
 
     @patch('tempfile.mkstemp', Mock(return_value=[3000, 'blabla']))
     @patch('os.path.exists', Mock(return_value=True))
     @patch('os.remove', Mock(side_effect=IOError))
     @patch('os.close', Mock(side_effect=IOError))
-    @patch('os.rename', Mock(return_value=None))
+    @patch('shutil.move', Mock(return_value=None))
     @patch('json.dump', Mock())
     def test_save_cache(self):
         self.config.set_dynamic_configuration({'ttl': 30, 'postgresql': {'foo': 'bar'}})
@@ -83,3 +82,15 @@ class TestConfig(unittest.TestCase):
             self.config.save_cache()
         with patch('os.fdopen', MagicMock()):
             self.config.save_cache()
+
+    def test_standby_cluster_parameters(self):
+        dynamic_configuration = {
+            'standby_cluster': {
+                'create_replica_methods': ['wal_e', 'basebackup'],
+                'host': 'localhost',
+                'port': 5432
+            }
+        }
+        self.config.set_dynamic_configuration(dynamic_configuration)
+        for name, value in dynamic_configuration['standby_cluster'].items():
+            self.assertEqual(self.config['standby_cluster'][name], value)

tests/test_consul.py

@@ -4,8 +4,8 @@ import unittest
 from consul import ConsulException, NotFound
 from mock import Mock, patch
 from patroni.dcs.consul import AbstractDCS, Cluster, Consul, ConsulInternalError, \
-                                ConsulError, HTTPClient, InvalidSessionTTL
-from test_etcd import SleepException
+                                ConsulError, HTTPClient, InvalidSessionTTL, InvalidSession
+from . import SleepException
 
 
 def kv_get(self, key, **kwargs):
@@ -52,6 +52,8 @@ class TestHTTPClient(unittest.TestCase):
         self.assertRaises(ConsulInternalError, self.client.get, Mock(), '')
         self.client.http.request.return_value.data = b"Invalid Session TTL '3000000000', must be between [10s=24h0m0s]"
         self.assertRaises(InvalidSessionTTL, self.client.get, Mock(), '')
+        self.client.http.request.return_value.data = b"invalid session '16492f43-c2d6-5307-432f-e32d6f7bcbd0'"
+        self.assertRaises(InvalidSession, self.client.get, Mock(), '')
 
     def test_unknown_method(self):
         try:
@@ -62,7 +64,7 @@ class TestHTTPClient(unittest.TestCase):
 
     def test_put(self):
         self.client.put(Mock(), '/v1/session/create')
-        self.client.put(Mock(), '/v1/session/create', data='{"foo": "bar"}')
+        self.client.put(Mock(), '/v1/session/create', params=[], data='{"foo": "bar"}')
 
 
 @patch.object(consul.Consul.KV, 'get', kv_get)
@@ -74,12 +76,14 @@ class TestConsul(unittest.TestCase):
     @patch.object(consul.Consul.KV, 'delete', Mock())
     def setUp(self):
         Consul({'ttl': 30, 'scope': 't', 'name': 'p', 'url': 'https://l:1', 'retry_timeout': 10,
-                'verify': 'on', 'key': 'foo', 'cert': 'bar', 'cacert': 'buz', 'token': 'asd', 'dc': 'dc1'})
-        Consul({'ttl': 30, 'scope': 't', 'name': 'p', 'url': 'https://l:1', 'retry_timeout': 10,
-                'verify': 'on', 'cert': 'bar', 'cacert': 'buz'})
-        self.c = Consul({'ttl': 30, 'scope': 'test', 'name': 'postgresql1', 'host': 'localhost:1', 'retry_timeout': 10})
+                'verify': 'on', 'key': 'foo', 'cert': 'bar', 'cacert': 'buz', 'token': 'asd', 'dc': 'dc1',
+                'register_service': True})
+        Consul({'ttl': 30, 'scope': 't_', 'name': 'p', 'url': 'https://l:1', 'retry_timeout': 10,
+                'verify': 'on', 'cert': 'bar', 'cacert': 'buz', 'register_service': True})
+        self.c = Consul({'ttl': 30, 'scope': 'test', 'name': 'postgresql1', 'host': 'localhost:1', 'retry_timeout': 10,
+                         'register_service': True})
         self.c._base_path = '/service/good'
-        self.c._load_cluster()
+        self.c.get_cluster()
 
     @patch('time.sleep', Mock(side_effect=SleepException))
     @patch.object(consul.Consul.Session, 'create', Mock(side_effect=ConsulException))
@@ -108,17 +112,18 @@ class TestConsul(unittest.TestCase):
         self.c._session = 'fd4f44fe-2cac-bba5-a60b-304b51ff39b8'
         self.assertIsInstance(self.c.get_cluster(), Cluster)
 
-    @patch.object(consul.Consul.KV, 'delete', Mock(side_effect=[ConsulException, True, True]))
-    @patch.object(consul.Consul.KV, 'put', Mock(side_effect=[True, ConsulException]))
+    @patch.object(consul.Consul.KV, 'delete', Mock(side_effect=[ConsulException, True, True, True]))
+    @patch.object(consul.Consul.KV, 'put', Mock(side_effect=[True, ConsulException, InvalidSession]))
     def test_touch_member(self):
-        self.c.refresh_session = Mock(return_value=True)
-        self.c.touch_member({'balbla': 'blabla'})
-        self.c.touch_member({'balbla': 'blabla'})
-        self.c.touch_member({'balbla': 'blabla'})
         self.c.refresh_session = Mock(return_value=False)
-        self.c.touch_member({'balbla': 'blabla'})
+        self.c.touch_member({'conn_url': 'postgres://replicator:[email protected]:5433/postgres',
+                             'api_url': 'http://127.0.0.1:8009/patroni'})
+        self.c._register_service = True
+        self.c.refresh_session = Mock(return_value=True)
+        for _ in range(0, 4):
+            self.c.touch_member({'balbla': 'blabla'})
 
-    @patch.object(consul.Consul.KV, 'put', Mock(return_value=False))
+    @patch.object(consul.Consul.KV, 'put', Mock(side_effect=InvalidSession))
     def test_take_leader(self):
         self.c.set_ttl(20)
         self.c.refresh_session = Mock()
@@ -176,3 +181,22 @@ class TestConsul(unittest.TestCase):
     @patch.object(consul.Consul.KV, 'put', Mock(return_value=True))
     def test_set_history_value(self):
         self.assertTrue(self.c.set_history_value('{}'))
+
+    @patch.object(consul.Consul.Agent.Service, 'register', Mock(side_effect=(False, True)))
+    @patch.object(consul.Consul.Agent.Service, 'deregister', Mock(return_value=True))
+    def test_update_service(self):
+        d = {'role': 'replica', 'api_url': 'http://a/t', 'conn_url': 'pg://c:1', 'state': 'running'}
+        self.assertIsNone(self.c.update_service({}, {}))
+        self.assertFalse(self.c.update_service({}, d))
+        self.assertTrue(self.c.update_service(d, d))
+        self.assertIsNone(self.c.update_service(d, d))
+        d['state'] = 'stopped'
+        self.assertTrue(self.c.update_service(d, d, force=True))
+        d['state'] = 'unknown'
+        self.assertIsNone(self.c.update_service({}, d))
+        d['state'] = 'running'
+        d['role'] = 'bla'
+        self.assertIsNone(self.c.update_service({}, d))
+
+    def test_reload_config(self):
+        self.c.reload_config({'consul': {'token': 'foo'}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})

tests/test_ctl.py

@@ -1,22 +1,22 @@
 import etcd
 import os
-import requests
-import sys
 import unittest
 
 from click.testing import CliRunner
 from datetime import datetime, timedelta
 from mock import patch, Mock
-from patroni.ctl import ctl, store_config, load_config, output_members, request_patroni, get_dcs, parse_dcs, \
+from patroni.ctl import ctl, store_config, load_config, output_members, get_dcs, parse_dcs, \
     get_all_members, get_any_member, get_cursor, query_member, configure, PatroniCtlException, apply_config_changes, \
-    format_config_for_editing, show_diff, invoke_editor, format_pg_version
+    format_config_for_editing, show_diff, invoke_editor, format_pg_version, find_executable
 from patroni.dcs.etcd import Client, Failover
 from patroni.utils import tzutc
 from psycopg2 import OperationalError
-from test_etcd import etcd_read, requests_get, socket_getaddrinfo, MockResponse
-from test_ha import get_cluster_initialized_without_leader, get_cluster_initialized_with_leader, \
+from urllib3 import PoolManager
+
+from . import MockConnect, MockCursor, MockResponse, psycopg2_connect
+from .test_etcd import etcd_read, socket_getaddrinfo
+from .test_ha import get_cluster_initialized_without_leader, get_cluster_initialized_with_leader, \
     get_cluster_initialized_with_only_leader, get_cluster_not_initialized_without_leader, get_cluster, Member
-from test_postgresql import MockConnect, psycopg2_connect
 
 CONFIG_FILE_PATH = './test-ctl.yaml'
 
@@ -24,9 +24,8 @@ CONFIG_FILE_PATH = './test-ctl.yaml'
 def test_rw_config():
     runner = CliRunner()
     with runner.isolated_filesystem():
-        store_config({'etcd': {'host': 'localhost:2379'}}, CONFIG_FILE_PATH + '/dummy')
-        sys.argv = ['patronictl.py', '']
         load_config(CONFIG_FILE_PATH + '/dummy', None)
+        store_config({'etcd': {'host': 'localhost:2379'}}, CONFIG_FILE_PATH + '/dummy')
         load_config(CONFIG_FILE_PATH + '/dummy', '0.0.0.0')
         os.remove(CONFIG_FILE_PATH + '/dummy')
         os.rmdir(CONFIG_FILE_PATH)
@@ -34,7 +33,7 @@ def test_rw_config():
 
 @patch('patroni.ctl.load_config',
        Mock(return_value={'scope': 'alpha', 'postgresql': {'data_dir': '.', 'parameters': {}, 'retry_timeout': 5},
-                          'restapi': {'auth': 'u:p', 'listen': ''}, 'etcd': {'host': 'localhost:2379'}}))
+                          'restapi': {'listen': '::', 'certfile': 'a'}, 'etcd': {'host': 'localhost:2379'}}))
 class TestCtl(unittest.TestCase):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
@@ -74,7 +73,7 @@ class TestCtl(unittest.TestCase):
         self.assertIsNone(output_members(cluster, name='abc', fmt='tsv'))
 
     @patch('patroni.ctl.get_dcs')
-    @patch('patroni.ctl.request_patroni', Mock(return_value=MockResponse()))
+    @patch.object(PoolManager, 'request', Mock(return_value=MockResponse()))
     def test_switchover(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
@@ -89,10 +88,15 @@ class TestCtl(unittest.TestCase):
             result = self.runner.invoke(ctl, ['switchover', 'dummy', '--force', '--scheduled', '2015-01-01T12:00:00'])
             assert result.exit_code == 1
 
-        # Aborting switchover, as we anser NO to the confirmation
+        # Aborting switchover, as we answer NO to the confirmation
         result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\nN')
         assert result.exit_code == 1
 
+        # Aborting scheduled switchover, as we answer NO to the confirmation
+        result = self.runner.invoke(ctl, ['switchover', 'dummy', '--scheduled', '2015-01-01T12:00:00+01:00'],
+                                    input='leader\nother\n\nN')
+        assert result.exit_code == 1
+
         # Target and source are equal
         result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nleader\n\ny')
         assert result.exit_code == 1
@@ -119,13 +123,18 @@ class TestCtl(unittest.TestCase):
         result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='dummy')
         assert result.exit_code == 1
 
-        with patch('patroni.ctl.request_patroni', Mock(side_effect=Exception)):
+        with patch.object(PoolManager, 'request', Mock(side_effect=Exception)):
             # Non-responding patroni
             result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n2300-01-01T12:23:00\ny')
             assert 'falling back to DCS' in result.output
 
-        with patch('patroni.ctl.request_patroni') as mocked:
-            mocked.return_value.status_code = 500
+        with patch.object(PoolManager, 'request') as mocked:
+            mocked.return_value.status = 500
+            result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
+            assert 'Switchover failed' in result.output
+
+            mocked.return_value.status = 501
+            mocked.return_value.data = b'Server does not support this operation'
             result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
             assert 'Switchover failed' in result.output
 
@@ -140,7 +149,7 @@ class TestCtl(unittest.TestCase):
         assert result.exit_code == 1
 
     @patch('patroni.ctl.get_dcs')
-    @patch('patroni.ctl.request_patroni', Mock(return_value=MockResponse()))
+    @patch.object(PoolManager, 'request', Mock(return_value=MockResponse()))
     def test_failover(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
@@ -148,6 +157,7 @@ class TestCtl(unittest.TestCase):
         result = self.runner.invoke(ctl, ['failover', 'dummy'], input='\n')
         assert 'Failover could be performed only to a specific candidate' in result.output
 
+    @patch('patroni.dcs.dcs_modules', Mock(return_value=['patroni.dcs.dummy', 'patroni.dcs.etcd']))
     def test_get_dcs(self):
         self.assertRaises(PatroniCtlException, get_dcs, {'dummy': {}}, 'dummy')
 
@@ -187,24 +197,24 @@ class TestCtl(unittest.TestCase):
 
     def test_query_member(self):
         with patch('patroni.ctl.get_cursor', Mock(return_value=MockConnect().cursor())):
-            rows = query_member(None, None, None, 'master', 'SELECT pg_is_in_recovery()', {})
+            rows = query_member(None, None, None, 'master', 'SELECT pg_catalog.pg_is_in_recovery()', {})
             self.assertTrue('False' in str(rows))
 
-            rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()', {})
-            self.assertEquals(rows, (None, None))
+            rows = query_member(None, None, None, 'replica', 'SELECT pg_catalog.pg_is_in_recovery()', {})
+            self.assertEqual(rows, (None, None))
 
-            with patch('test_postgresql.MockCursor.execute', Mock(side_effect=OperationalError('bla'))):
-                rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()', {})
+            with patch.object(MockCursor, 'execute', Mock(side_effect=OperationalError('bla'))):
+                rows = query_member(None, None, None, 'replica', 'SELECT pg_catalog.pg_is_in_recovery()', {})
 
         with patch('patroni.ctl.get_cursor', Mock(return_value=None)):
-            rows = query_member(None, None, None, None, 'SELECT pg_is_in_recovery()', {})
+            rows = query_member(None, None, None, None, 'SELECT pg_catalog.pg_is_in_recovery()', {})
             self.assertTrue('No connection to' in str(rows))
 
-            rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()', {})
+            rows = query_member(None, None, None, 'replica', 'SELECT pg_catalog.pg_is_in_recovery()', {})
             self.assertTrue('No connection to' in str(rows))
 
         with patch('patroni.ctl.get_cursor', Mock(side_effect=OperationalError('bla'))):
-            rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()', {})
+            rows = query_member(None, None, None, 'replica', 'SELECT pg_catalog.pg_is_in_recovery()', {})
 
     @patch('patroni.ctl.get_dcs')
     def test_dsn(self, mock_get_dcs):
@@ -220,11 +230,28 @@ class TestCtl(unittest.TestCase):
         result = self.runner.invoke(ctl, ['dsn', 'alpha', '--member', 'dummy'])
         assert result.exit_code == 1
 
-    @patch('requests.post', requests_get)
+    @patch.object(PoolManager, 'request')
     @patch('patroni.ctl.get_dcs')
-    def test_restart_reinit(self, mock_get_dcs):
+    def test_reload(self, mock_get_dcs, mock_post):
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
-        result = self.runner.invoke(ctl, ['restart', 'alpha'], input='y\n\nnow')
+
+        result = self.runner.invoke(ctl, ['reload', 'alpha'], input='y')
+        assert 'Failed: reload for member' in result.output
+
+        mock_post.return_value.status = 200
+        result = self.runner.invoke(ctl, ['reload', 'alpha'], input='y')
+        assert 'No changes to apply on member' in result.output
+
+        mock_post.return_value.status = 202
+        result = self.runner.invoke(ctl, ['reload', 'alpha'], input='y')
+        assert 'Reload request received for member' in result.output
+
+    @patch.object(PoolManager, 'request')
+    @patch('patroni.ctl.get_dcs')
+    def test_restart_reinit(self, mock_get_dcs, mock_post):
+        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
+        mock_post.return_value.status = 503
+        result = self.runner.invoke(ctl, ['restart', 'alpha'], input='now\ny\n')
         assert 'Failed: restart for' in result.output
         assert result.exit_code == 0
 
@@ -236,76 +263,71 @@ class TestCtl(unittest.TestCase):
         assert result.exit_code == 0
 
         # Aborted restart
-        result = self.runner.invoke(ctl, ['restart', 'alpha'], input='N')
+        result = self.runner.invoke(ctl, ['restart', 'alpha'], input='now\nN')
         assert result.exit_code == 1
 
         result = self.runner.invoke(ctl, ['restart', 'alpha', '--pending', '--force'])
         assert result.exit_code == 0
 
+        # Aborted scheduled restart
+        result = self.runner.invoke(ctl, ['restart', 'alpha', '--scheduled', '2019-10-01T14:30'], input='N')
+        assert result.exit_code == 1
+
         # Not a member
-        result = self.runner.invoke(ctl, ['restart', 'alpha', 'dummy', '--any'], input='y')
+        result = self.runner.invoke(ctl, ['restart', 'alpha', 'dummy', '--any'], input='now\ny')
         assert result.exit_code == 1
 
         # Wrong pg version
-        result = self.runner.invoke(ctl, ['restart', 'alpha', '--any', '--pg-version', '9.1'], input='y')
+        result = self.runner.invoke(ctl, ['restart', 'alpha', '--any', '--pg-version', '9.1'], input='now\ny')
         assert 'Error: Invalid PostgreSQL version format' in result.output
         assert result.exit_code == 1
 
         result = self.runner.invoke(ctl, ['restart', 'alpha', '--pending', '--force', '--timeout', '10min'])
         assert result.exit_code == 0
 
-        with patch('requests.delete', Mock(return_value=MockResponse(500))):
-            # normal restart, the schedule is actually parsed, but not validated in patronictl
-            result = self.runner.invoke(ctl, ['restart', 'alpha', 'other', '--force',
-                                              '--scheduled', '2300-10-01T14:30'])
-            assert 'Failed: flush scheduled restart' in result.output
+        # normal restart, the schedule is actually parsed, but not validated in patronictl
+        result = self.runner.invoke(ctl, ['restart', 'alpha', 'other', '--force', '--scheduled', '2300-10-01T14:30'])
+        assert 'Failed: flush scheduled restart' in result.output
 
         with patch('patroni.dcs.Cluster.is_paused', Mock(return_value=True)):
             result = self.runner.invoke(ctl,
                                         ['restart', 'alpha', 'other', '--force', '--scheduled', '2300-10-01T14:30'])
             assert result.exit_code == 1
 
-        with patch('requests.post', Mock(return_value=MockResponse())):
-            # normal restart, the schedule is actually parsed, but not validated in patronictl
-            result = self.runner.invoke(ctl, ['restart', 'alpha', '--pg-version', '42.0.0',
-                                        '--scheduled', '2300-10-01T14:30'], input='y')
-            assert result.exit_code == 0
-
-        with patch('requests.post', Mock(return_value=MockResponse(204))):
-            # get restart with the non-200 return code
-            # normal restart, the schedule is actually parsed, but not validated in patronictl
-            result = self.runner.invoke(ctl, ['restart', 'alpha', '--pg-version', '42.0',
-                                        '--scheduled', '2300-10-01T14:30'], input='y')
-            assert result.exit_code == 0
-
         # force restart with restart already present
-        with patch('patroni.ctl.request_patroni', Mock(return_value=MockResponse(204))):
-            result = self.runner.invoke(ctl, ['restart', 'alpha', 'other', '--force',
-                                              '--scheduled', '2300-10-01T14:30'])
-            assert result.exit_code == 0
+        result = self.runner.invoke(ctl, ['restart', 'alpha', 'other', '--force', '--scheduled', '2300-10-01T14:30'])
+        assert result.exit_code == 0
 
-        with patch('requests.post', Mock(return_value=MockResponse(202))):
-            # get restart with the non-200 return code
-            # normal restart, the schedule is actually parsed, but not validated in patronictl
-            result = self.runner.invoke(
-                ctl, ['restart', 'alpha', '--pg-version', '99.0.0', '--scheduled', '2300-10-01T14:30'], input='y'
-            )
-            assert 'Success: restart scheduled' in result.output
-            assert result.exit_code == 0
+        ctl_args = ['restart', 'alpha', '--pg-version', '99.0', '--scheduled', '2300-10-01T14:30']
+        # normal restart, the schedule is actually parsed, but not validated in patronictl
+        mock_post.return_value.status = 200
+        result = self.runner.invoke(ctl, ctl_args, input='y')
+        assert result.exit_code == 0
 
-        with patch('requests.post', Mock(return_value=MockResponse(409))):
-            # get restart with the non-200 return code
-            # normal restart, the schedule is actually parsed, but not validated in patronictl
-            result = self.runner.invoke(
-                ctl, ['restart', 'alpha', '--pg-version', '99.0.0', '--scheduled', '2300-10-01T14:30'], input='y'
-            )
-            assert 'Failed: another restart is already' in result.output
-            assert result.exit_code == 0
+        # get restart with the non-200 return code
+        # normal restart, the schedule is actually parsed, but not validated in patronictl
+        mock_post.return_value.status = 204
+        result = self.runner.invoke(ctl, ctl_args, input='y')
+        assert result.exit_code == 0
+
+        # get restart with the non-200 return code
+        # normal restart, the schedule is actually parsed, but not validated in patronictl
+        mock_post.return_value.status = 202
+        result = self.runner.invoke(ctl, ctl_args, input='y')
+        assert 'Success: restart scheduled' in result.output
+        assert result.exit_code == 0
+
+        # get restart with the non-200 return code
+        # normal restart, the schedule is actually parsed, but not validated in patronictl
+        mock_post.return_value.status = 409
+        result = self.runner.invoke(ctl, ctl_args, input='y')
+        assert 'Failed: another restart is already' in result.output
+        assert result.exit_code == 0
 
     @patch('patroni.ctl.get_dcs')
     def test_remove(self, mock_get_dcs):
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
-        result = self.runner.invoke(ctl, ['remove', 'alpha'], input='alpha\nslave')
+        result = self.runner.invoke(ctl, ['-k', 'remove', 'alpha'], input='alpha\nslave')
         assert 'Please confirm' in result.output
         assert 'You are about to remove all' in result.output
         # Not typing an exact confirmation
@@ -322,11 +344,6 @@ class TestCtl(unittest.TestCase):
         result = self.runner.invoke(ctl, ['remove', 'alpha'], input='alpha\nYes I am aware\nleader')
         assert result.exit_code == 0
 
-    @patch('requests.post', Mock(side_effect=requests.exceptions.ConnectionError('foo')))
-    def test_request_patroni(self):
-        member = get_cluster_initialized_with_leader().leader.member
-        self.assertRaises(requests.exceptions.ConnectionError, request_patroni, member, 'post', 'dummy', {})
-
     def test_ctl(self):
         self.runner.invoke(ctl, ['list'])
 
@@ -337,20 +354,20 @@ class TestCtl(unittest.TestCase):
         self.assertIsNone(get_any_member(get_cluster_initialized_without_leader(), role='master'))
 
         m = get_any_member(get_cluster_initialized_with_leader(), role='master')
-        self.assertEquals(m.name, 'leader')
+        self.assertEqual(m.name, 'leader')
 
     def test_get_all_members(self):
-        self.assertEquals(list(get_all_members(get_cluster_initialized_without_leader(), role='master')), [])
+        self.assertEqual(list(get_all_members(get_cluster_initialized_without_leader(), role='master')), [])
 
         r = list(get_all_members(get_cluster_initialized_with_leader(), role='master'))
-        self.assertEquals(len(r), 1)
-        self.assertEquals(r[0].name, 'leader')
+        self.assertEqual(len(r), 1)
+        self.assertEqual(r[0].name, 'leader')
 
         r = list(get_all_members(get_cluster_initialized_with_leader(), role='replica'))
-        self.assertEquals(len(r), 1)
-        self.assertEquals(r[0].name, 'other')
+        self.assertEqual(len(r), 1)
+        self.assertEqual(r[0].name, 'other')
 
-        self.assertEquals(len(list(get_all_members(get_cluster_initialized_without_leader(), role='replica'))), 2)
+        self.assertEqual(len(list(get_all_members(get_cluster_initialized_without_leader(), role='replica'))), 2)
 
     @patch('patroni.ctl.get_dcs')
     def test_members(self, mock_get_dcs):
@@ -400,7 +417,7 @@ class TestCtl(unittest.TestCase):
         assert 'Scheduled restart' in result.output
 
     @patch('patroni.ctl.get_dcs')
-    @patch('requests.delete', Mock(return_value=MockResponse()))
+    @patch.object(PoolManager, 'request', Mock(return_value=MockResponse()))
     def test_flush(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
@@ -410,58 +427,58 @@ class TestCtl(unittest.TestCase):
 
         result = self.runner.invoke(ctl, ['flush', 'dummy', 'restart', '--force'])
         assert 'Success: flush scheduled restart' in result.output
-        with patch.object(requests, 'delete', return_value=MockResponse(404)):
+        with patch.object(PoolManager, 'request', return_value=MockResponse(404)):
             result = self.runner.invoke(ctl, ['flush', 'dummy', 'restart', '--force'])
             assert 'Failed: flush scheduled restart' in result.output
 
+    @patch.object(PoolManager, 'request')
     @patch('patroni.ctl.get_dcs')
     @patch('patroni.ctl.polling_loop', Mock(return_value=[1]))
-    def test_pause_cluster(self, mock_get_dcs):
+    def test_pause_cluster(self, mock_get_dcs, mock_post):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
 
-        with patch('requests.patch', Mock(return_value=MockResponse(500))):
-            result = self.runner.invoke(ctl, ['pause', 'dummy'])
-            assert 'Failed' in result.output
+        mock_post.return_value.status = 500
+        result = self.runner.invoke(ctl, ['pause', 'dummy'])
+        assert 'Failed' in result.output
 
-        with patch('requests.patch', Mock(return_value=MockResponse(200))),\
-                patch('patroni.dcs.Cluster.is_paused', Mock(return_value=True)):
+        mock_post.return_value.status = 200
+        with patch('patroni.dcs.Cluster.is_paused', Mock(return_value=True)):
             result = self.runner.invoke(ctl, ['pause', 'dummy'])
             assert 'Cluster is already paused' in result.output
 
-        with patch('requests.patch', Mock(return_value=MockResponse(200))):
-            result = self.runner.invoke(ctl, ['pause', 'dummy', '--wait'])
-            assert "'pause' request sent" in result.output
-            mock_get_dcs.return_value.get_cluster = Mock(side_effect=[get_cluster_initialized_with_leader(),
-                                                                      get_cluster(None, None, [], None, None)])
-            self.runner.invoke(ctl, ['pause', 'dummy', '--wait'])
-            member = Member(1, 'other', 28, {})
-            mock_get_dcs.return_value.get_cluster = Mock(side_effect=[get_cluster_initialized_with_leader(),
-                                                                      get_cluster(None, None, [member], None, None)])
-            self.runner.invoke(ctl, ['pause', 'dummy', '--wait'])
+        result = self.runner.invoke(ctl, ['pause', 'dummy', '--wait'])
+        assert "'pause' request sent" in result.output
+        mock_get_dcs.return_value.get_cluster = Mock(side_effect=[get_cluster_initialized_with_leader(),
+                                                                  get_cluster(None, None, [], None, None)])
+        self.runner.invoke(ctl, ['pause', 'dummy', '--wait'])
+        member = Member(1, 'other', 28, {})
+        mock_get_dcs.return_value.get_cluster = Mock(side_effect=[get_cluster_initialized_with_leader(),
+                                                                  get_cluster(None, None, [member], None, None)])
+        self.runner.invoke(ctl, ['pause', 'dummy', '--wait'])
 
+    @patch.object(PoolManager, 'request')
     @patch('patroni.ctl.get_dcs')
-    def test_resume_cluster(self, mock_get_dcs):
+    def test_resume_cluster(self, mock_get_dcs, mock_post):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
 
+        mock_post.return_value.status = 200
+        with patch('patroni.dcs.Cluster.is_paused', Mock(return_value=False)):
+            result = self.runner.invoke(ctl, ['resume', 'dummy'])
+            assert 'Cluster is not paused' in result.output
+
         with patch('patroni.dcs.Cluster.is_paused', Mock(return_value=True)):
-            with patch('requests.patch', Mock(return_value=MockResponse(200))):
-                result = self.runner.invoke(ctl, ['resume', 'dummy'])
-                assert 'Success' in result.output
+            result = self.runner.invoke(ctl, ['resume', 'dummy'])
+            assert 'Success' in result.output
 
-            with patch('requests.patch', Mock(return_value=MockResponse(500))):
-                result = self.runner.invoke(ctl, ['resume', 'dummy'])
-                assert 'Failed' in result.output
+            mock_post.return_value.status = 500
+            result = self.runner.invoke(ctl, ['resume', 'dummy'])
+            assert 'Failed' in result.output
 
-            with patch('requests.patch', Mock(return_value=MockResponse(200))),\
-                    patch('patroni.dcs.Cluster.is_paused', Mock(return_value=False)):
-                result = self.runner.invoke(ctl, ['resume', 'dummy'])
-                assert 'Cluster is not paused' in result.output
-
-            with patch('requests.patch', Mock(side_effect=Exception)):
-                result = self.runner.invoke(ctl, ['resume', 'dummy'])
-                assert 'Can not find accessible cluster member' in result.output
+            mock_post.side_effect = Exception
+            result = self.runner.invoke(ctl, ['resume', 'dummy'])
+            assert 'Can not find accessible cluster member' in result.output
 
     def test_apply_config_changes(self):
         config = {"postgresql": {"parameters": {"work_mem": "4MB"}, "use_pg_rewind": True}, "ttl": 30}
@@ -472,23 +489,23 @@ class TestCtl(unittest.TestCase):
         after_editing, changed_config = apply_config_changes(before_editing, config,
                                                              ["postgresql.parameters.work_mem = 5MB",
                                                               "ttl=15", "postgresql.use_pg_rewind=off", 'a.b=c'])
-        self.assertEquals(changed_config, {"a": {"b": "c"}, "postgresql": {"parameters": {"work_mem": "5MB"},
-                                                                           "use_pg_rewind": False}, "ttl": 15})
+        self.assertEqual(changed_config, {"a": {"b": "c"}, "postgresql": {"parameters": {"work_mem": "5MB"},
+                                                                          "use_pg_rewind": False}, "ttl": 15})
 
         # postgresql.parameters namespace is flattened
         after_editing, changed_config = apply_config_changes(before_editing, config,
                                                              ["postgresql.parameters.work_mem.sub = x"])
-        self.assertEquals(changed_config, {"postgresql": {"parameters": {"work_mem": "4MB", "work_mem.sub": "x"},
-                                                          "use_pg_rewind": True}, "ttl": 30})
+        self.assertEqual(changed_config, {"postgresql": {"parameters": {"work_mem": "4MB", "work_mem.sub": "x"},
+                                                         "use_pg_rewind": True}, "ttl": 30})
 
         # Setting to null deletes
         after_editing, changed_config = apply_config_changes(before_editing, config,
                                                              ["postgresql.parameters.work_mem=null"])
-        self.assertEquals(changed_config, {"postgresql": {"use_pg_rewind": True}, "ttl": 30})
+        self.assertEqual(changed_config, {"postgresql": {"use_pg_rewind": True}, "ttl": 30})
         after_editing, changed_config = apply_config_changes(before_editing, config,
                                                              ["postgresql.use_pg_rewind=null",
                                                               "postgresql.parameters.work_mem=null"])
-        self.assertEquals(changed_config, {"ttl": 30})
+        self.assertEqual(changed_config, {"ttl": 30})
 
         self.assertRaises(PatroniCtlException, apply_config_changes, before_editing, config, ['a'])
 
@@ -506,10 +523,12 @@ class TestCtl(unittest.TestCase):
         show_diff(b"foo:\n  bar: \xc3\xb6\xc3\xb6\n".decode('utf-8'),
                   b"foo:\n  bar: \xc3\xbc\xc3\xbc\n".decode('utf-8'))
 
-    def test_invoke_editor(self):
-        for e in ('', 'false'):
-            os.environ['EDITOR'] = e
-            self.assertRaises(PatroniCtlException, invoke_editor, 'foo: bar\n', 'test')
+    @patch('subprocess.call', return_value=1)
+    def test_invoke_editor(self, mock_subprocess_call):
+        os.environ.pop('EDITOR', None)
+        for e in ('', '/bin/vi'):
+            with patch('patroni.ctl.find_executable', Mock(return_value=e)):
+                self.assertRaises(PatroniCtlException, invoke_editor, 'foo: bar\n', 'test')
 
     @patch('patroni.ctl.get_dcs')
     def test_show_config(self, mock_get_dcs):
@@ -521,29 +540,53 @@ class TestCtl(unittest.TestCase):
     def test_edit_config(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
+        mock_get_dcs.return_value.set_config_value = Mock(return_value=False)
         os.environ['EDITOR'] = 'true'
         self.runner.invoke(ctl, ['edit-config', 'dummy'])
         self.runner.invoke(ctl, ['edit-config', 'dummy', '-s', 'foo=bar'])
         self.runner.invoke(ctl, ['edit-config', 'dummy', '--replace', 'postgres0.yml'])
         self.runner.invoke(ctl, ['edit-config', 'dummy', '--apply', '-'], input='foo: bar')
         self.runner.invoke(ctl, ['edit-config', 'dummy', '--force', '--apply', '-'], input='foo: bar')
-        mock_get_dcs.return_value.set_config_value = Mock(return_value=True)
+        mock_get_dcs.return_value.set_config_value.return_value = True
         self.runner.invoke(ctl, ['edit-config', 'dummy', '--force', '--apply', '-'], input='foo: bar')
 
     @patch('patroni.ctl.get_dcs')
     def test_version(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
-        with patch('patroni.ctl.request_patroni') as mocked:
+        with patch.object(PoolManager, 'request') as mocked:
             result = self.runner.invoke(ctl, ['version'])
             assert 'patronictl version' in result.output
-            mocked.return_value.json = lambda: {'patroni': {'version': '1.2.3'}, 'server_version': 100001}
+            mocked.return_value.data = b'{"patroni":{"version":"1.2.3"},"server_version": 100001}'
             result = self.runner.invoke(ctl, ['version', 'dummy'])
             assert '1.2.3' in result.output
-        with patch('requests.get', Mock(side_effect=Exception)):
+        with patch.object(PoolManager, 'request', Mock(side_effect=Exception)):
             result = self.runner.invoke(ctl, ['version', 'dummy'])
             assert 'failed to get version' in result.output
 
+    @patch('patroni.ctl.get_dcs')
+    def test_history(self, mock_get_dcs):
+        mock_get_dcs.return_value.get_cluster = Mock()
+        mock_get_dcs.return_value.get_cluster.return_value.history.lines = [[1, 67176, 'no recovery target specified']]
+        result = self.runner.invoke(ctl, ['history'])
+        assert 'Reason' in result.output
+
     def test_format_pg_version(self):
-        self.assertEquals(format_pg_version(100001), '10.1')
-        self.assertEquals(format_pg_version(90605), '9.6.5')
+        self.assertEqual(format_pg_version(100001), '10.1')
+        self.assertEqual(format_pg_version(90605), '9.6.5')
+
+    @patch('sys.platform', 'win32')
+    def test_find_executable(self):
+        with patch('os.path.isfile', Mock(return_value=True)):
+            self.assertEqual(find_executable('vim'), 'vim.exe')
+        with patch('os.path.isfile', Mock(return_value=False)):
+            self.assertIsNone(find_executable('vim'))
+        with patch('os.path.isfile', Mock(side_effect=[False, True])):
+            self.assertEqual(find_executable('vim', '/'), '/vim.exe')
+
+    @patch('patroni.ctl.get_dcs')
+    def test_get_members(self, mock_get_dcs):
+        mock_get_dcs.return_value = self.e
+        mock_get_dcs.return_value.get_cluster = get_cluster_not_initialized_without_leader
+        result = self.runner.invoke(ctl, ['reinit', 'dummy'])
+        assert "cluster doesn\'t have any members" in result.output

tests/test_etcd.py

@@ -1,7 +1,5 @@
 import etcd
-import json
 import urllib3.util.connection
-import requests
 import socket
 import unittest
 
@@ -9,58 +7,10 @@ from dns.exception import DNSException
 from mock import Mock, patch
 from patroni.dcs.etcd import AbstractDCS, Client, Cluster, Etcd, EtcdError, DnsCachingResolver
 from patroni.exceptions import DCSError
+from patroni.utils import Retry
 from urllib3.exceptions import ReadTimeoutError
 
-
-class MockResponse(object):
-
-    def __init__(self, status_code=200):
-        self.status_code = status_code
-        self.content = '{}'
-        self.ok = True
-
-    def json(self):
-        return json.loads(self.content)
-
-    @property
-    def data(self):
-        return self.content.encode('utf-8')
-
-    @property
-    def text(self):
-        return self.content
-
-    @property
-    def status(self):
-        return self.status_code
-
-    @staticmethod
-    def getheader(*args):
-        return ''
-
-
-def requests_get(url, **kwargs):
-    members = '[{"id":14855829450254237642,"peerURLs":["http://localhost:2380","http://localhost:7001"],' +\
-              '"name":"default","clientURLs":["http://localhost:2379","http://localhost:4001"]}]'
-    response = MockResponse()
-    if url.startswith('http://local'):
-        raise requests.exceptions.RequestException()
-    elif ':8011/patroni' in url:
-        response.content = '{"role": "replica", "xlog": {"received_location": 0}, "tags": {}}'
-    elif url.endswith('/members'):
-        response.content = '[{}]' if url.startswith('http://error') else members
-    elif url.startswith('http://exhibitor'):
-        response.content = '{"servers":["127.0.0.1","127.0.0.2","127.0.0.3"],"port":2181}'
-    elif url.endswith(':8011/reinitialize'):
-        data = kwargs.get('data', '')
-        if ' false}' in data:
-            response.status_code = 503
-            response.ok = False
-            response.content = 'restarting after failure already in progress'
-    else:
-        response.status_code = 404
-        response.ok = False
-    return response
+from . import SleepException, MockResponse, requests_get
 
 
 def etcd_watch(self, key, index=None, timeout=None, recursive=None):
@@ -90,7 +40,7 @@ def etcd_read(self, key, **kwargs):
         raise etcd.EtcdKeyNotFound
 
     response = {"action": "get", "node": {"key": "/service/batman5", "dir": True, "nodes": [
-                {"key": "/service/batman5/config", "value": '{"foo": "bar"}',
+                {"key": "/service/batman5/config", "value": '{"synchronous_mode": 0}',
                  "modifiedIndex": 1582, "createdIndex": 1582},
                 {"key": "/service/batman5/failover", "value": "",
                  "modifiedIndex": 1582, "createdIndex": 1582},
@@ -122,10 +72,6 @@ def etcd_read(self, key, **kwargs):
     return result
 
 
-class SleepException(Exception):
-    pass
-
-
 def dns_query(name, _):
     if '-server' not in name or '-ssl' in name:
         return []
@@ -148,13 +94,14 @@ def socket_getaddrinfo(*args):
 def http_request(method, url, **kwargs):
     if url == 'http://localhost:2379/timeout':
         raise ReadTimeoutError(None, None, None)
+    ret = MockResponse()
     if url == 'http://localhost:2379/v2/machines':
-        ret = MockResponse()
         ret.content = 'http://localhost:2379,http://localhost:4001'
-        return ret
-    if url == 'http://localhost:2379/':
-        return MockResponse()
-    raise socket.error
+    elif url == 'http://localhost:4001/v2/machines':
+        ret.content = ''
+    elif url != 'http://localhost:2379/':
+        raise socket.error
+    return ret
 
 
 class TestDnsCachingResolver(unittest.TestCase):
@@ -169,12 +116,12 @@ class TestDnsCachingResolver(unittest.TestCase):
 
 @patch('dns.resolver.query', dns_query)
 @patch('socket.getaddrinfo', socket_getaddrinfo)
-@patch('requests.get', requests_get)
+@patch('patroni.dcs.etcd.requests_get', requests_get)
 class TestClient(unittest.TestCase):
 
     @patch('dns.resolver.query', dns_query)
     @patch('socket.getaddrinfo', socket_getaddrinfo)
-    @patch('requests.get', requests_get)
+    @patch('patroni.dcs.etcd.requests_get', requests_get)
     def setUp(self):
         with patch.object(Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
@@ -203,19 +150,28 @@ class TestClient(unittest.TestCase):
         self.assertRaises(ValueError, self.client.api_execute, '', '')
         self.client._base_uri = 'http://localhost:4001'
         self.client._machines_cache = ['http://localhost:2379']
-        self.client.api_execute('/', 'POST', timeout=0)
+        self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'POST', timeout=0)
+        self.client._base_uri = 'http://localhost:4001'
+        self.client._machines_cache = ['http://localhost:2379']
+        rtry = Retry(deadline=10, max_delay=1, max_tries=-1, retry_exceptions=(etcd.EtcdLeaderElectionInProgress,))
+        rtry(self.client.api_execute, '/', 'POST', timeout=0, params={'retry': rtry})
         mock_machines.__get__ = Mock(return_value=['http://localhost:2379'])
         self.client._machines_cache_updated = 0
         self.client.api_execute('/', 'POST', timeout=0)
+        self.client._machines_cache = [self.client._base_uri]
+        self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
         self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
         self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', '')
-        self.client._update_machines_cache = True
-        with patch.object(Client, '_load_machines_cache', Mock(side_effect=etcd.EtcdException)):
+
+        with patch.object(Client, '_do_http_request', Mock(side_effect=etcd.EtcdConnectionFailed)):
+            with patch.object(Client, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])):
+                self.assertRaises(etcd.EtcdException, rtry, self.client.api_execute, '/', 'GET', params={'retry': rtry})
+            self.client._read_timeout = 0
             self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'GET')
 
     def test_get_srv_record(self):
-        self.assertEquals(self.client.get_srv_record('_etcd-server._tcp.blabla'), [])
-        self.assertEquals(self.client.get_srv_record('_etcd-server._tcp.exception'), [])
+        self.assertEqual(self.client.get_srv_record('_etcd-server._tcp.blabla'), [])
+        self.assertEqual(self.client.get_srv_record('_etcd-server._tcp.exception'), [])
 
     def test__get_machines_cache_from_srv(self):
         self.client._get_machines_cache_from_srv('foobar')
@@ -243,7 +199,7 @@ class TestClient(unittest.TestCase):
                           socket_options=[(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)])
 
 
-@patch('requests.get', requests_get)
+@patch('patroni.dcs.etcd.requests_get', requests_get)
 @patch('socket.getaddrinfo', socket_getaddrinfo)
 @patch.object(etcd.Client, 'write', etcd_write)
 @patch.object(etcd.Client, 'read', etcd_read)
@@ -258,24 +214,27 @@ class TestEtcd(unittest.TestCase):
                               'host': 'localhost:2379', 'scope': 'test', 'name': 'foo'})
 
     def test_base_path(self):
-        self.assertEquals(self.etcd._base_path, '/patroni/test')
+        self.assertEqual(self.etcd._base_path, '/patroni/test')
 
     @patch('dns.resolver.query', dns_query)
     def test_get_etcd_client(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch('time.sleep', Mock(side_effect=SleepException)),\
+                patch.object(Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(side_effect=etcd.EtcdException)
-            with patch('time.sleep', Mock(side_effect=SleepException)):
-                self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                                  {'discovery_srv': 'test', 'retry_timeout': 10, 'cacert': '1', 'key': '1', 'cert': 1})
-                self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                                  {'url': 'https://test:2379', 'retry_timeout': 10})
-                self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                                  {'proxy': 'https://user:password@test:2379', 'retry_timeout': 10})
-                self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                                  {'hosts': 'foo:4001,bar', 'retry_timeout': 10})
+            self.assertRaises(SleepException, self.etcd.get_etcd_client,
+                              {'discovery_srv': 'test', 'retry_timeout': 10, 'cacert': '1', 'key': '1', 'cert': 1})
+            self.assertRaises(SleepException, self.etcd.get_etcd_client,
+                              {'url': 'https://test:2379', 'retry_timeout': 10})
+            self.assertRaises(SleepException, self.etcd.get_etcd_client,
+                              {'hosts': 'foo:4001,bar', 'retry_timeout': 10})
+            mock_machines.__get__ = Mock(return_value=[])
+            self.assertRaises(SleepException, self.etcd.get_etcd_client,
+                              {'proxy': 'https://user:password@test:2379', 'retry_timeout': 10})
 
     def test_get_cluster(self):
-        self.assertIsInstance(self.etcd.get_cluster(), Cluster)
+        cluster = self.etcd.get_cluster()
+        self.assertIsInstance(cluster, Cluster)
+        self.assertFalse(cluster.is_synchronous_mode())
         self.etcd._base_path = '/service/nocluster'
         cluster = self.etcd.get_cluster()
         self.assertIsInstance(cluster, Cluster)

tests/test_exhibitor.py

@@ -1,13 +1,15 @@
 import unittest
+import urllib3
 
 from mock import Mock, patch
 from patroni.dcs.exhibitor import ExhibitorEnsembleProvider, Exhibitor
 from patroni.dcs.zookeeper import ZooKeeperError
-from test_etcd import SleepException, requests_get
-from test_zookeeper import MockKazooClient
+
+from . import SleepException, requests_get
+from .test_zookeeper import MockKazooClient
 
 
-@patch('requests.get', requests_get)
+@patch('patroni.dcs.exhibitor.requests_get', requests_get)
 @patch('time.sleep', Mock(side_effect=SleepException))
 class TestExhibitorEnsembleProvider(unittest.TestCase):
 
@@ -20,7 +22,8 @@ class TestExhibitorEnsembleProvider(unittest.TestCase):
 
 class TestExhibitor(unittest.TestCase):
 
-    @patch('requests.get', requests_get)
+    @patch('urllib3.PoolManager.request', Mock(return_value=urllib3.HTTPResponse(
+        status=200, body=b'{"servers":["127.0.0.1","127.0.0.2","127.0.0.3"],"port":2181}')))
     @patch('patroni.dcs.zookeeper.KazooClient', MockKazooClient)
     def setUp(self):
         self.e = Exhibitor({'hosts': ['localhost', 'exhibitor'], 'port': 8181, 'scope': 'test',

tests/test_ha.py

@@ -1,7 +1,7 @@
 import datetime
 import etcd
 import os
-import unittest
+import sys
 
 from mock import Mock, MagicMock, PropertyMock, patch
 from patroni.config import Config
@@ -10,10 +10,18 @@ from patroni.dcs.etcd import Client
 from patroni.exceptions import DCSError, PostgresConnectionException, PatroniException
 from patroni.ha import Ha, _MemberStatus
 from patroni.postgresql import Postgresql
-from patroni.watchdog import Watchdog
+from patroni.postgresql.bootstrap import Bootstrap
+from patroni.postgresql.cancellable import CancellableSubprocess
+from patroni.postgresql.config import ConfigHandler
+from patroni.postgresql.rewind import Rewind
+from patroni.postgresql.slots import SlotsHandler
 from patroni.utils import tzutc
-from test_etcd import socket_getaddrinfo, etcd_read, etcd_write, requests_get
-from test_postgresql import psycopg2_connect, MockPostmaster
+from patroni.watchdog import Watchdog
+
+from . import PostgresInit, MockPostmaster, psycopg2_connect, requests_get
+from .test_etcd import socket_getaddrinfo, etcd_read, etcd_write
+
+SYSID = '12345678901'
 
 
 def true(*args, **kwargs):
@@ -24,16 +32,19 @@ def false(*args, **kwargs):
     return False
 
 
-def get_cluster(initialize, leader, members, failover, sync):
-    history = TimelineHistory(1, [(1, 67197376, 'no recovery target specified', datetime.datetime.now().isoformat())])
-    return Cluster(initialize, ClusterConfig(1, {1: 2}, 1), leader, 10, members, failover, sync, history)
+def get_cluster(initialize, leader, members, failover, sync, cluster_config=None):
+    t = datetime.datetime.now().isoformat()
+    history = TimelineHistory(1, '[[1,67197376,"no recovery target specified","' + t + '"]]',
+                              [(1, 67197376, 'no recovery target specified', t)])
+    cluster_config = cluster_config or ClusterConfig(1, {'check_timeline': True}, 1)
+    return Cluster(initialize, cluster_config, leader, 10, members, failover, sync, history)
 
 
-def get_cluster_not_initialized_without_leader():
-    return get_cluster(None, None, [], None, SyncState(None, None, None))
+def get_cluster_not_initialized_without_leader(cluster_config=None):
+    return get_cluster(None, None, [], None, SyncState(None, None, None), cluster_config)
 
 
-def get_cluster_initialized_without_leader(leader=False, failover=None, sync=None):
+def get_cluster_initialized_without_leader(leader=False, failover=None, sync=None, cluster_config=None):
     m1 = Member(0, 'leader', 28, {'conn_url': 'postgres://replicator:[email protected]:5435/postgres',
                                   'api_url': 'http://127.0.0.1:8008/patroni', 'xlog_location': 4})
     leader = Leader(0, 0, m1) if leader else None
@@ -45,24 +56,36 @@ def get_cluster_initialized_without_leader(leader=False, failover=None, sync=Non
                                  'scheduled_restart': {'schedule': "2100-01-01 10:53:07.560445+00:00",
                                                        'postgres_version': '99.0.0'}})
     syncstate = SyncState(0 if sync else None, sync and sync[0], sync and sync[1])
-    return get_cluster(True, leader, [m1, m2], failover, syncstate)
+    return get_cluster(SYSID, leader, [m1, m2], failover, syncstate, cluster_config)
 
 
 def get_cluster_initialized_with_leader(failover=None, sync=None):
     return get_cluster_initialized_without_leader(leader=True, failover=failover, sync=sync)
 
 
-def get_cluster_initialized_with_only_leader(failover=None):
+def get_cluster_initialized_with_only_leader(failover=None, cluster_config=None):
     leader = get_cluster_initialized_without_leader(leader=True, failover=failover).leader
-    return get_cluster(True, leader, [leader], failover, None)
+    return get_cluster(True, leader, [leader], failover, None, cluster_config)
 
 
-def get_node_status(reachable=True, in_recovery=True, wal_position=10, nofailover=False, watchdog_failed=False):
+def get_standby_cluster_initialized_with_only_leader(failover=None, sync=None):
+    return get_cluster_initialized_with_only_leader(
+        cluster_config=ClusterConfig(1, {
+            "standby_cluster": {
+                "host": "localhost",
+                "port": 5432,
+                "primary_slot_name": "",
+            }}, 1)
+    )
+
+
+def get_node_status(reachable=True, in_recovery=True, timeline=2,
+                    wal_position=10, nofailover=False, watchdog_failed=False):
     def fetch_node_status(e):
         tags = {}
         if nofailover:
             tags['nofailover'] = True
-        return _MemberStatus(e, reachable, in_recovery, wal_position, tags, watchdog_failed)
+        return _MemberStatus(e, reachable, in_recovery, timeline, wal_position, tags, watchdog_failed)
     return fetch_node_status
 
 
@@ -95,7 +118,13 @@ zookeeper:
     hosts: [localhost]
     port: 8181
 """
-        self.config = Config()
+        # We rely on sys.argv in Config, so it's necessary to reset
+        # all the extra values that are coming from py.test
+        sys.argv = sys.argv[:1]
+
+        self.config = Config(None)
+        self.config.set_dynamic_configuration({'maximum_lag_on_failover': 5})
+        self.version = '1.5.7'
         self.postgresql = p
         self.dcs = d
         self.api = Mock()
@@ -108,10 +137,15 @@ zookeeper:
         self.scheduled_restart = {'schedule': future_restart_time,
                                   'postmaster_start_time': str(postmaster_start_time)}
         self.watchdog = Watchdog(self.config)
+        self.request = lambda member, **kwargs: requests_get(member.api_url, **kwargs)
 
 
 def run_async(self, func, args=()):
-    return func(*args) if args else func()
+    self.reset_scheduled_action()
+    if args:
+        func(*args)
+    else:
+        func()
 
 
 @patch.object(Postgresql, 'is_running', Mock(return_value=MockPostmaster()))
@@ -120,15 +154,18 @@ def run_async(self, func, args=()):
 @patch.object(Postgresql, '_cluster_info_state_get', Mock(return_value=3))
 @patch.object(Postgresql, 'call_nowait', Mock(return_value=True))
 @patch.object(Postgresql, 'data_directory_empty', Mock(return_value=False))
-@patch.object(Postgresql, 'controldata', Mock(return_value={'Database system identifier': '1234567890'}))
-@patch.object(Postgresql, 'sync_replication_slots', Mock())
-@patch.object(Postgresql, 'write_pg_hba', Mock())
-@patch.object(Postgresql, 'write_pgpass', Mock(return_value={}))
-@patch.object(Postgresql, 'write_recovery_conf', Mock())
+@patch.object(Postgresql, 'controldata', Mock(return_value={'Database system identifier': SYSID}))
+@patch.object(SlotsHandler, 'sync_replication_slots', Mock())
+@patch.object(ConfigHandler, 'append_pg_hba', Mock())
+@patch.object(ConfigHandler, 'write_pgpass', Mock(return_value={}))
+@patch.object(ConfigHandler, 'write_recovery_conf', Mock())
+@patch.object(ConfigHandler, 'write_postgresql_conf', Mock())
 @patch.object(Postgresql, 'query', Mock())
 @patch.object(Postgresql, 'checkpoint', Mock())
-@patch.object(Postgresql, 'call_nowait', Mock())
-@patch.object(Postgresql, 'cancellable_subprocess_call', Mock(return_value=0))
+@patch.object(CancellableSubprocess, 'call', Mock(return_value=0))
+@patch.object(Postgresql, 'get_local_timeline_lsn_from_replication_connection', Mock(return_value=[2, 10]))
+@patch.object(Postgresql, 'get_master_timeline', Mock(return_value=2))
+@patch.object(ConfigHandler, 'restore_configuration_files', Mock())
 @patch.object(etcd.Client, 'write', etcd_write)
 @patch.object(etcd.Client, 'read', etcd_read)
 @patch.object(etcd.Client, 'delete', Mock(side_effect=etcd.EtcdException))
@@ -137,22 +174,15 @@ def run_async(self, func, args=()):
 @patch('patroni.async_executor.AsyncExecutor.run_async', run_async)
 @patch('subprocess.call', Mock(return_value=0))
 @patch('time.sleep', Mock())
-class TestHa(unittest.TestCase):
+class TestHa(PostgresInit):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
-    @patch('psycopg2.connect', psycopg2_connect)
-    @patch('patroni.dcs.dcs_modules', Mock(return_value=['patroni.dcs.foo', 'patroni.dcs.etcd']))
+    @patch('patroni.dcs.dcs_modules', Mock(return_value=['patroni.dcs.etcd']))
     @patch.object(etcd.Client, 'read', etcd_read)
     def setUp(self):
+        super(TestHa, self).setUp()
         with patch.object(Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
-            self.p = Postgresql({'name': 'postgresql0', 'scope': 'dummy', 'listen': '127.0.0.1:5432',
-                                 'data_dir': 'data/postgresql0', 'retry_timeout': 10,
-                                 'maximum_lag_on_failover': 5,
-                                 'authentication': {'superuser': {'username': 'foo', 'password': 'bar'},
-                                                    'replication': {'username': '', 'password': ''}},
-                                 'parameters': {'wal_level': 'hot_standby', 'max_replication_slots': 5, 'foo': 'bar',
-                                                'hot_standby': 'on', 'max_wal_senders': 5, 'wal_keep_segments': 8}})
             self.p.set_state('running')
             self.p.set_role('replica')
             self.p.postmaster_start_time = MagicMock(return_value=str(postmaster_start_time))
@@ -161,7 +191,7 @@ class TestHa(unittest.TestCase):
                                        'name': 'foo', 'retry_timeout': 10}})
             self.ha = Ha(MockPatroni(self.p, self.e))
             self.ha.old_cluster = self.e.get_cluster()
-            self.ha.cluster = get_cluster_not_initialized_without_leader()
+            self.ha.cluster = get_cluster_initialized_without_leader()
             self.ha.load_cluster_from_dcs = Mock()
 
     def test_update_lock(self):
@@ -173,50 +203,77 @@ class TestHa(unittest.TestCase):
         self.p.replica_cached_timeline = Mock(side_effect=Exception)
         self.ha.touch_member()
 
+    def test_is_leader(self):
+        self.assertFalse(self.ha.is_leader())
+
     def test_start_as_replica(self):
         self.p.is_healthy = false
-        self.assertEquals(self.ha.run_cycle(), 'starting as a secondary')
+        self.assertEqual(self.ha.run_cycle(), 'starting as a secondary')
+
+    @patch('patroni.dcs.etcd.Etcd.initialize', return_value=True)
+    def test_bootstrap_as_standby_leader(self, initialize):
+        self.p.data_directory_empty = true
+        self.ha.cluster = get_cluster_not_initialized_without_leader(cluster_config=ClusterConfig(0, {}, 0))
+        self.ha.cluster.is_unlocked = true
+        self.ha.patroni.config._dynamic_configuration = {"standby_cluster": {"port": 5432}}
+        self.assertEqual(self.ha.run_cycle(), 'trying to bootstrap a new standby leader')
+
+    def test_bootstrap_waiting_for_standby_leader(self):
+        self.p.data_directory_empty = true
+        self.ha.cluster = get_cluster_initialized_without_leader()
+        self.ha.cluster.config.data.update({'standby_cluster': {'port': 5432}})
+        self.assertEqual(self.ha.run_cycle(), 'waiting for standby_leader to bootstrap')
+
+    @patch.object(Cluster, 'get_clone_member',
+                  Mock(return_value=Member(0, 'test', 1, {'api_url': 'http://127.0.0.1:8011/patroni',
+                                                          'conn_url': 'postgres://127.0.0.1:5432/postgres'})))
+    @patch.object(Bootstrap, 'create_replica', Mock(return_value=0))
+    def test_start_as_cascade_replica_in_standby_cluster(self):
+        self.p.data_directory_empty = true
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.ha.cluster.is_unlocked = false
+        self.assertEqual(self.ha.run_cycle(), "trying to bootstrap from replica 'test'")
 
     def test_recover_replica_failed(self):
-        self.p.controldata = lambda: {'Database cluster state': 'in recovery'}
+        self.p.controldata = lambda: {'Database cluster state': 'in recovery', 'Database system identifier': SYSID}
         self.p.is_running = false
         self.p.follow = false
-        self.assertEquals(self.ha.run_cycle(), 'starting as a secondary')
-        self.assertEquals(self.ha.run_cycle(), 'failed to start postgres')
+        self.assertEqual(self.ha.run_cycle(), 'starting as a secondary')
+        self.assertEqual(self.ha.run_cycle(), 'failed to start postgres')
 
     def test_recover_former_master(self):
         self.p.follow = false
         self.p.is_running = false
         self.p.name = 'leader'
         self.p.set_role('master')
-        self.p.controldata = lambda: {'Database cluster state': 'shut down'}
+        self.p.controldata = lambda: {'Database cluster state': 'shut down', 'Database system identifier': SYSID}
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.assertEquals(self.ha.run_cycle(), 'starting as readonly because i had the session lock')
+        self.assertEqual(self.ha.run_cycle(), 'starting as readonly because i had the session lock')
 
     @patch.object(Postgresql, 'fix_cluster_state', Mock())
     def test_crash_recovery(self):
         self.p.is_running = false
-        self.p.controldata = lambda: {'Database cluster state': 'in production'}
-        self.assertEquals(self.ha.run_cycle(), 'doing crash recovery in a single user mode')
+        self.p.controldata = lambda: {'Database cluster state': 'in production', 'Database system identifier': SYSID}
+        self.assertEqual(self.ha.run_cycle(), 'doing crash recovery in a single user mode')
 
-    @patch.object(Postgresql, 'rewind_needed_and_possible', Mock(return_value=True))
+    @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
+    @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
     def test_recover_with_rewind(self):
         self.p.is_running = false
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.assertEquals(self.ha.run_cycle(), 'running pg_rewind from leader')
+        self.assertEqual(self.ha.run_cycle(), 'running pg_rewind from leader')
 
-    @patch.object(Postgresql, 'can_rewind', PropertyMock(return_value=True))
-    @patch.object(Postgresql, 'fix_cluster_state', Mock())
-    def test_single_user_after_recover_failed(self):
-        self.p.controldata = lambda: {'Database cluster state': 'in recovery'}
+    @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
+    @patch.object(Bootstrap, 'create_replica', Mock(return_value=1))
+    def test_recover_with_reinitialize(self):
         self.p.is_running = false
-        self.p.follow = false
-        self.assertEquals(self.ha.run_cycle(), 'starting as a secondary')
-        self.assertEquals(self.ha.run_cycle(), 'fixing cluster state in a single user mode')
+        self.ha.cluster = get_cluster_initialized_with_leader()
+        self.assertEqual(self.ha.run_cycle(), 'reinitializing due to diverged timelines')
 
     @patch('sys.exit', return_value=1)
     @patch('patroni.ha.Ha.sysid_valid', MagicMock(return_value=True))
     def test_sysid_no_match(self, exit_mock):
+        self.p.controldata = lambda: {'Database cluster state': 'in recovery', 'Database system identifier': '123'}
         self.ha.run_cycle()
         exit_mock.assert_called_once_with(1)
 
@@ -225,129 +282,132 @@ class TestHa(unittest.TestCase):
         self.p.is_leader = false
         self.p.is_healthy = true
         self.ha.has_lock = true
-        self.p.controldata = lambda: {'Database cluster state': 'in production'}
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
+        self.p.controldata = lambda: {'Database cluster state': 'in production', 'Database system identifier': SYSID}
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
 
     @patch('psycopg2.connect', psycopg2_connect)
     def test_acquire_lock_as_master(self):
-        self.assertEquals(self.ha.run_cycle(), 'acquired session lock as a leader')
+        self.assertEqual(self.ha.run_cycle(), 'acquired session lock as a leader')
 
     def test_promoted_by_acquiring_lock(self):
         self.ha.is_healthiest_node = true
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
 
     def test_long_promote(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.p.is_leader = false
         self.p.set_role('master')
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
 
     def test_demote_after_failing_to_obtain_lock(self):
         self.ha.acquire_lock = false
-        self.assertEquals(self.ha.run_cycle(), 'demoted self after trying and failing to obtain lock')
+        self.assertEqual(self.ha.run_cycle(), 'demoted self after trying and failing to obtain lock')
 
     def test_follow_new_leader_after_failing_to_obtain_lock(self):
         self.ha.is_healthiest_node = true
         self.ha.acquire_lock = false
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'following new leader after trying and failing to obtain lock')
+        self.assertEqual(self.ha.run_cycle(), 'following new leader after trying and failing to obtain lock')
 
     def test_demote_because_not_healthiest(self):
         self.ha.is_healthiest_node = false
-        self.assertEquals(self.ha.run_cycle(), 'demoting self because i am not the healthiest node')
+        self.assertEqual(self.ha.run_cycle(), 'demoting self because i am not the healthiest node')
 
     def test_follow_new_leader_because_not_healthiest(self):
         self.ha.is_healthiest_node = false
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
 
     def test_promote_because_have_lock(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
 
     def test_promote_without_watchdog(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.p.is_leader = true
         with patch.object(Watchdog, 'activate', Mock(return_value=False)):
-            self.assertEquals(self.ha.run_cycle(), 'Demoting self because watchdog could not be activated')
+            self.assertEqual(self.ha.run_cycle(), 'Demoting self because watchdog could not be activated')
             self.p.is_leader = false
-            self.assertEquals(self.ha.run_cycle(), 'Not promoting self because watchdog could not be activated')
+            self.assertEqual(self.ha.run_cycle(), 'Not promoting self because watchdog could not be activated')
 
     def test_leader_with_lock(self):
+        self.ha.cluster = get_cluster_initialized_with_leader()
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
 
     def test_demote_because_not_having_lock(self):
         self.ha.cluster.is_unlocked = false
         with patch.object(Watchdog, 'is_running', PropertyMock(return_value=True)):
-            self.assertEquals(self.ha.run_cycle(), 'demoting self because i do not have the lock and i was a leader')
+            self.assertEqual(self.ha.run_cycle(), 'demoting self because i do not have the lock and i was a leader')
 
     def test_demote_because_update_lock_failed(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.ha.update_lock = false
-        self.assertEquals(self.ha.run_cycle(), 'demoted self because failed to update leader lock in DCS')
+        self.assertEqual(self.ha.run_cycle(), 'demoted self because failed to update leader lock in DCS')
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'not promoting because failed to update leader lock in DCS')
+        self.assertEqual(self.ha.run_cycle(), 'not promoting because failed to update leader lock in DCS')
 
     def test_follow(self):
         self.ha.cluster.is_unlocked = false
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
         self.ha.patroni.replicatefrom = "foo"
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
+        self.p.config.check_recovery_conf = Mock(return_value=(True, False))
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
 
     def test_follow_in_pause(self):
         self.ha.cluster.is_unlocked = false
         self.ha.is_paused = true
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: no action')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: no action')
 
-    @patch.object(Postgresql, 'rewind_needed_and_possible', Mock(return_value=True))
+    @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
+    @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
     def test_follow_triggers_rewind(self):
         self.p.is_leader = false
-        self.p.trigger_check_diverged_lsn()
+        self.ha._rewind.trigger_check_diverged_lsn()
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.assertEquals(self.ha.run_cycle(), 'running pg_rewind from leader')
+        self.assertEqual(self.ha.run_cycle(), 'running pg_rewind from leader')
 
     def test_no_etcd_connection_master_demote(self):
         self.ha.load_cluster_from_dcs = Mock(side_effect=DCSError('Etcd is not responding properly'))
-        self.assertEquals(self.ha.run_cycle(), 'demoted self because DCS is not accessible and i was a leader')
+        self.assertEqual(self.ha.run_cycle(), 'demoted self because DCS is not accessible and i was a leader')
 
     @patch('time.sleep', Mock())
     def test_bootstrap_from_another_member(self):
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.assertEquals(self.ha.bootstrap(), 'trying to bootstrap from replica \'other\'')
+        self.assertEqual(self.ha.bootstrap(), 'trying to bootstrap from replica \'other\'')
 
     def test_bootstrap_waiting_for_leader(self):
         self.ha.cluster = get_cluster_initialized_without_leader()
-        self.assertEquals(self.ha.bootstrap(), 'waiting for leader to bootstrap')
+        self.assertEqual(self.ha.bootstrap(), 'waiting for leader to bootstrap')
 
     def test_bootstrap_without_leader(self):
         self.ha.cluster = get_cluster_initialized_without_leader()
         self.p.can_create_replica_without_replication_connection = MagicMock(return_value=True)
-        self.assertEquals(self.ha.bootstrap(), 'trying to bootstrap (without leader)')
+        self.assertEqual(self.ha.bootstrap(), 'trying to bootstrap (without leader)')
 
     def test_bootstrap_initialize_lock_failed(self):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
-        self.assertEquals(self.ha.bootstrap(), 'failed to acquire initialize lock')
+        self.assertEqual(self.ha.bootstrap(), 'failed to acquire initialize lock')
 
     def test_bootstrap_initialized_new_cluster(self):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
         self.e.initialize = true
-        self.assertEquals(self.ha.bootstrap(), 'trying to bootstrap a new cluster')
+        self.assertEqual(self.ha.bootstrap(), 'trying to bootstrap a new cluster')
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'waiting for end of recovery after bootstrap')
+        self.assertEqual(self.ha.run_cycle(), 'waiting for end of recovery after bootstrap')
         self.p.is_leader = true
-        self.assertEquals(self.ha.run_cycle(), 'running post_bootstrap')
-        self.assertEquals(self.ha.run_cycle(), 'initialized a new cluster')
+        self.assertEqual(self.ha.run_cycle(), 'running post_bootstrap')
+        self.assertEqual(self.ha.run_cycle(), 'initialized a new cluster')
 
     def test_bootstrap_release_initialize_key_on_failure(self):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
@@ -363,7 +423,7 @@ class TestHa(unittest.TestCase):
         self.p.is_running.return_value = MockPostmaster()
         self.p.is_leader = true
         with patch.object(Watchdog, 'activate', Mock(return_value=False)):
-            self.assertEquals(self.ha.post_bootstrap(), 'running post_bootstrap')
+            self.assertEqual(self.ha.post_bootstrap(), 'running post_bootstrap')
             self.assertRaises(PatroniException, self.ha.post_bootstrap)
 
     @patch('psycopg2.connect', psycopg2_connect)
@@ -372,7 +432,7 @@ class TestHa(unittest.TestCase):
 
         self.ha.cluster = get_cluster_initialized_with_leader()
         self.assertIsNone(self.ha.reinitialize(True))
-
+        self.ha._async_executor.schedule('reinitialize')
         self.assertIsNotNone(self.ha.reinitialize())
 
         self.ha.state_handler.name = self.ha.cluster.leader.name
@@ -380,61 +440,62 @@ class TestHa(unittest.TestCase):
 
     @patch('time.sleep', Mock())
     def test_restart(self):
-        self.assertEquals(self.ha.restart({}), (True, 'restarted successfully'))
+        self.assertEqual(self.ha.restart({}), (True, 'restarted successfully'))
         self.p.restart = Mock(return_value=None)
-        self.assertEquals(self.ha.restart({}), (False, 'postgres is still starting'))
+        self.assertEqual(self.ha.restart({}), (False, 'postgres is still starting'))
         self.p.restart = false
-        self.assertEquals(self.ha.restart({}), (False, 'restart failed'))
+        self.assertEqual(self.ha.restart({}), (False, 'restart failed'))
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.ha.reinitialize()
-        self.assertEquals(self.ha.restart({}), (False, 'reinitialize already in progress'))
+        self.ha._async_executor.schedule('reinitialize')
+        self.assertEqual(self.ha.restart({}), (False, 'reinitialize already in progress'))
         with patch.object(self.ha, "restart_matches", return_value=False):
-            self.assertEquals(self.ha.restart({'foo': 'bar'}), (False, "restart conditions are not satisfied"))
+            self.assertEqual(self.ha.restart({'foo': 'bar'}), (False, "restart conditions are not satisfied"))
 
     @patch('os.kill', Mock())
     def test_restart_in_progress(self):
         with patch('patroni.async_executor.AsyncExecutor.busy', PropertyMock(return_value=True)):
-            self.ha.restart({}, run_async=True)
+            self.ha._async_executor.schedule('restart')
             self.assertTrue(self.ha.restart_scheduled())
-            self.assertEquals(self.ha.run_cycle(), 'restart in progress')
+            self.assertEqual(self.ha.run_cycle(), 'restart in progress')
 
             self.ha.cluster = get_cluster_initialized_with_leader()
-            self.assertEquals(self.ha.run_cycle(), 'restart in progress')
+            self.assertEqual(self.ha.run_cycle(), 'restart in progress')
 
             self.ha.has_lock = true
-            self.assertEquals(self.ha.run_cycle(), 'updated leader lock during restart')
+            self.assertEqual(self.ha.run_cycle(), 'updated leader lock during restart')
 
             self.ha.update_lock = false
             self.p.set_role('master')
             with patch('patroni.async_executor.CriticalTask.cancel', Mock(return_value=False)):
                 with patch('patroni.postgresql.Postgresql.terminate_starting_postmaster') as mock_terminate:
-                    self.assertEquals(self.ha.run_cycle(), 'lost leader lock during restart')
+                    self.assertEqual(self.ha.run_cycle(), 'lost leader lock during restart')
                     mock_terminate.assert_called()
 
-    @patch('requests.get', requests_get)
     def test_manual_failover_from_leader(self):
         self.ha.fetch_node_status = get_node_status()
         self.ha.has_lock = true
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', '', None))
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', self.p.name, None))
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', 'blabla', None))
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
         f = Failover(0, self.p.name, '', None)
         self.ha.cluster = get_cluster_initialized_with_leader(f)
-        self.assertEquals(self.ha.run_cycle(), 'manual failover: demoting myself')
-        self.p.rewind_needed_and_possible = true
-        self.assertEquals(self.ha.run_cycle(), 'manual failover: demoting myself')
+        self.assertEqual(self.ha.run_cycle(), 'manual failover: demoting myself')
+        self.ha._rewind.rewind_or_reinitialize_needed_and_possible = true
+        self.assertEqual(self.ha.run_cycle(), 'manual failover: demoting myself')
         self.ha.fetch_node_status = get_node_status(nofailover=True)
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
         self.ha.fetch_node_status = get_node_status(watchdog_failed=True)
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.ha.fetch_node_status = get_node_status(timeline=1)
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
         self.ha.fetch_node_status = get_node_status(wal_position=1)
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
         # manual failover from the previous leader to us won't happen if we hold the nofailover flag
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, None))
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
 
         # Failover scheduled time must include timezone
         scheduled = datetime.datetime.now()
@@ -443,31 +504,29 @@ class TestHa(unittest.TestCase):
 
         scheduled = datetime.datetime.utcnow().replace(tzinfo=tzutc)
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEquals('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
 
         scheduled = scheduled + datetime.timedelta(seconds=30)
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEquals('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
 
         scheduled = scheduled + datetime.timedelta(seconds=-600)
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEquals('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
 
         scheduled = None
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEquals('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
 
-    @patch('requests.get', requests_get)
     def test_manual_failover_from_leader_in_pause(self):
         self.ha.has_lock = true
         self.ha.is_paused = true
         scheduled = datetime.datetime.now()
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEquals('PAUSE: no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('PAUSE: no action.  i am the leader with the lock', self.ha.run_cycle())
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, self.p.name, '', None))
-        self.assertEquals('PAUSE: no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('PAUSE: no action.  i am the leader with the lock', self.ha.run_cycle())
 
-    @patch('requests.get', requests_get)
     def test_manual_failover_from_leader_in_synchronous_mode(self):
         self.p.is_leader = true
         self.ha.has_lock = true
@@ -475,48 +534,47 @@ class TestHa(unittest.TestCase):
         self.ha.is_failover_possible = false
         self.ha.process_sync_replication = Mock()
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, self.p.name, 'a', None), (self.p.name, None))
-        self.assertEquals('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, self.p.name, 'a', None), (self.p.name, 'a'))
         self.ha.is_failover_possible = true
-        self.assertEquals('manual failover: demoting myself', self.ha.run_cycle())
+        self.assertEqual('manual failover: demoting myself', self.ha.run_cycle())
 
-    @patch('requests.get', requests_get)
     def test_manual_failover_process_no_leader(self):
         self.p.is_leader = false
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', self.p.name, None))
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', 'leader', None))
         self.p.set_role('replica')
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
         self.ha.fetch_node_status = get_node_status()  # accessible, in_recovery
-        self.assertEquals(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, self.p.name, '', None))
-        self.assertEquals(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
         self.ha.fetch_node_status = get_node_status(reachable=False)  # inaccessible, in_recovery
         self.p.set_role('replica')
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
         # set failover flag to True for all members of the cluster
         # this should elect the current member, as we are not going to call the API for it.
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', 'other', None))
         self.ha.fetch_node_status = get_node_status(nofailover=True)  # accessible, in_recovery
         self.p.set_role('replica')
-        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
         # same as previous, but set the current member to nofailover. In no case it should be elected as a leader
         self.ha.patroni.nofailover = True
-        self.assertEquals(self.ha.run_cycle(), 'following a different leader because I am not allowed to promote')
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because I am not allowed to promote')
 
     def test_manual_failover_process_no_leader_in_pause(self):
         self.ha.is_paused = true
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', 'other', None))
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, 'leader', '', None))
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, 'leader', 'blabla', None))
-        self.assertEquals('PAUSE: acquired session lock as a leader', self.ha.run_cycle())
+        self.assertEqual('PAUSE: acquired session lock as a leader', self.ha.run_cycle())
         self.p.is_leader = false
         self.p.set_role('replica')
         self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, 'leader', self.p.name, None))
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: promoted self to leader by acquiring session lock')
 
     def test_is_healthiest_node(self):
         self.ha.state_handler.is_leader = false
@@ -531,6 +589,7 @@ class TestHa(unittest.TestCase):
         self.assertFalse(self.ha.is_healthiest_node())
 
     def test__is_healthiest_node(self):
+        self.ha.cluster = get_cluster_initialized_without_leader(sync=('postgresql1', self.p.name))
         self.assertTrue(self.ha._is_healthiest_node(self.ha.old_cluster.members))
         self.p.is_leader = false
         self.ha.fetch_node_status = get_node_status()  # accessible, in_recovery
@@ -539,13 +598,17 @@ class TestHa(unittest.TestCase):
         self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
         self.ha.fetch_node_status = get_node_status(wal_position=11)  # accessible, in_recovery, wal position ahead
         self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        # in synchronous_mode consider itself healthy if the former leader is accessible in read-only and ahead of us
+        with patch.object(Ha, 'is_synchronous_mode', Mock(return_value=True)):
+            self.assertTrue(self.ha._is_healthiest_node(self.ha.old_cluster.members))
         with patch('patroni.postgresql.Postgresql.timeline_wal_position', return_value=(1, 1)):
             self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        with patch('patroni.postgresql.Postgresql.replica_cached_timeline', return_value=1):
+            self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
         self.ha.patroni.nofailover = True
         self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
         self.ha.patroni.nofailover = False
 
-    @patch('requests.get', requests_get)
     def test_fetch_node_status(self):
         member = Member(0, 'test', 1, {'api_url': 'http://127.0.0.1:8011/patroni'})
         self.ha.fetch_node_status(member)
@@ -597,11 +660,11 @@ class TestHa(unittest.TestCase):
     def test_scheduled_restart(self):
         self.ha.cluster = get_cluster_initialized_with_leader()
         with patch.object(self.ha, "evaluate_scheduled_restart", Mock(return_value="restart scheduled")):
-            self.assertEquals(self.ha.run_cycle(), "restart scheduled")
+            self.assertEqual(self.ha.run_cycle(), "restart scheduled")
 
     def test_restart_matches(self):
         self.p._role = 'replica'
-        self.p.server_version = 90500
+        self.p._connection.server_version = 90500
         self.p._pending_restart = True
         self.assertFalse(self.ha.restart_matches("master", "9.5.0", True))
         self.assertFalse(self.ha.restart_matches("replica", "9.4.3", True))
@@ -614,21 +677,81 @@ class TestHa(unittest.TestCase):
         self.ha.is_paused = true
         self.p.name = 'leader'
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: removed leader lock because postgres is not running as master')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: removed leader lock because postgres is not running as master')
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', self.p.name, None))
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: waiting to become master after promote...')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: waiting to become master after promote...')
+
+    def test_process_healthy_standby_cluster_as_standby_leader(self):
+        self.p.is_leader = false
+        self.p.name = 'leader'
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.p.config.check_recovery_conf = Mock(return_value=(False, False))
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to a standby leader because i had the session lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the standby leader with the lock')
+
+    def test_process_healthy_standby_cluster_as_cascade_replica(self):
+        self.p.is_leader = false
+        self.p.name = 'replica'
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a standby leader')
+        with patch.object(Leader, 'conn_url', PropertyMock(return_value='')):
+            self.assertEqual(self.ha.run_cycle(), 'continue following the old known standby leader')
+
+    def test_process_unhealthy_standby_cluster_as_standby_leader(self):
+        self.p.is_leader = false
+        self.p.name = 'leader'
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.ha.cluster.is_unlocked = true
+        self.ha.sysid_valid = true
+        self.p._sysid = True
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to a standby leader by acquiring session lock')
+
+    @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
+    @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
+    def test_process_unhealthy_standby_cluster_as_cascade_replica(self):
+        self.p.is_leader = false
+        self.p.name = 'replica'
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.ha.is_unlocked = true
+        self.assertTrue(self.ha.run_cycle().startswith('running pg_rewind from remote_master:'))
+
+    def test_recover_unhealthy_leader_in_standby_cluster(self):
+        self.p.is_leader = false
+        self.p.name = 'leader'
+        self.p.is_running = false
+        self.p.follow = false
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.assertEqual(self.ha.run_cycle(), 'starting as a standby leader because i had the session lock')
+
+    def test_recover_unhealthy_unlocked_standby_cluster(self):
+        self.p.is_leader = false
+        self.p.name = 'leader'
+        self.p.is_running = false
+        self.p.follow = false
+        self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
+        self.ha.cluster.is_unlocked = true
+        self.ha.has_lock = false
+        self.assertEqual(self.ha.run_cycle(), 'trying to follow a remote master because standby cluster is unhealthy')
+
+    def test_failed_to_update_lock_in_pause(self):
+        self.ha.update_lock = false
+        self.ha.is_paused = true
+        self.p.name = 'leader'
+        self.ha.cluster = get_cluster_initialized_with_leader()
+        self.assertEqual(self.ha.run_cycle(),
+                         'PAUSE: continue to run as master after failing to update leader lock in DCS')
 
     def test_postgres_unhealthy_in_pause(self):
         self.ha.is_paused = true
         self.p.is_healthy = false
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: postgres is not running')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: postgres is not running')
         self.ha.has_lock = true
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: removed leader lock because postgres is not running')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: removed leader lock because postgres is not running')
 
     def test_no_etcd_connection_in_pause(self):
         self.ha.is_paused = true
         self.ha.load_cluster_from_dcs = Mock(side_effect=DCSError('Etcd is not responding properly'))
-        self.assertEquals(self.ha.run_cycle(), 'PAUSE: DCS is not accessible')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: DCS is not accessible')
 
     @patch('patroni.ha.Ha.update_lock', return_value=True)
     @patch('patroni.ha.Ha.demote')
@@ -644,26 +767,26 @@ class TestHa(unittest.TestCase):
         self.ha.cluster = get_cluster_initialized_with_leader()
         self.p.check_for_startup = true
         self.p.time_in_state = lambda: 30
-        self.assertEquals(self.ha.run_cycle(), 'PostgreSQL is still starting up, 270 seconds until timeout')
+        self.assertEqual(self.ha.run_cycle(), 'PostgreSQL is still starting up, 270 seconds until timeout')
         check_calls([(update_lock, True), (demote, False)])
 
         self.p.time_in_state = lambda: 350
         self.ha.fetch_node_status = get_node_status(reachable=False)  # inaccessible, in_recovery
-        self.assertEquals(self.ha.run_cycle(),
-                          'master start has timed out, but continuing to wait because failover is not possible')
+        self.assertEqual(self.ha.run_cycle(),
+                         'master start has timed out, but continuing to wait because failover is not possible')
         check_calls([(update_lock, True), (demote, False)])
 
         self.ha.fetch_node_status = get_node_status()  # accessible, in_recovery
-        self.assertEquals(self.ha.run_cycle(), 'stopped PostgreSQL because of startup timeout')
+        self.assertEqual(self.ha.run_cycle(), 'stopped PostgreSQL because of startup timeout')
         check_calls([(update_lock, True), (demote, True)])
 
         update_lock.return_value = False
-        self.assertEquals(self.ha.run_cycle(), 'stopped PostgreSQL while starting up because leader key was lost')
+        self.assertEqual(self.ha.run_cycle(), 'stopped PostgreSQL while starting up because leader key was lost')
         check_calls([(update_lock, True), (demote, True)])
 
         self.ha.has_lock = false
         self.p.is_leader = false
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
         check_calls([(update_lock, False), (demote, False)])
 
     def test_manual_failover_while_starting(self):
@@ -672,7 +795,7 @@ class TestHa(unittest.TestCase):
         f = Failover(0, self.p.name, '', None)
         self.ha.cluster = get_cluster_initialized_with_leader(f)
         self.ha.fetch_node_status = get_node_status()  # accessible, in_recovery
-        self.assertEquals(self.ha.run_cycle(), 'manual failover: demoting myself')
+        self.assertEqual(self.ha.run_cycle(), 'manual failover: demoting myself')
 
     @patch('patroni.ha.Ha.demote')
     def test_failover_immediately_on_zero_master_start_timeout(self, demote):
@@ -683,7 +806,7 @@ class TestHa(unittest.TestCase):
         self.ha.has_lock = true
         self.ha.update_lock = true
         self.ha.fetch_node_status = get_node_status()  # accessible, in_recovery
-        self.assertEquals(self.ha.run_cycle(), 'stopped PostgreSQL to fail over after a crash')
+        self.assertEqual(self.ha.run_cycle(), 'stopped PostgreSQL to fail over after a crash')
         demote.assert_called_once()
 
     @patch('patroni.postgresql.Postgresql.follow')
@@ -695,7 +818,7 @@ class TestHa(unittest.TestCase):
 
     def test_process_sync_replication(self):
         self.ha.has_lock = true
-        mock_set_sync = self.p.set_synchronous_standby = Mock()
+        mock_set_sync = self.p.config.set_synchronous_standby = Mock()
         self.p.name = 'leader'
 
         # Test sync key removed when sync mode disabled
@@ -745,18 +868,22 @@ class TestHa(unittest.TestCase):
         self.p.pick_synchronous_standby = Mock(return_value=('other2', True))
         self.ha.run_cycle()
         self.ha.dcs.get_cluster.assert_called_once()
-        self.assertEquals(self.ha.dcs.write_sync_state.call_count, 2)
+        self.assertEqual(self.ha.dcs.write_sync_state.call_count, 2)
 
         # Test updating sync standby key failed due to race
         self.ha.dcs.write_sync_state = Mock(side_effect=[True, False])
         self.ha.run_cycle()
-        self.assertEquals(self.ha.dcs.write_sync_state.call_count, 2)
+        self.assertEqual(self.ha.dcs.write_sync_state.call_count, 2)
+
+        # Test updating sync standby key failed due to DCS being not accessible
+        self.ha.dcs.write_sync_state = Mock(return_value=True)
+        self.ha.dcs.get_cluster = Mock(side_effect=DCSError('foo'))
+        self.ha.run_cycle()
 
         # Test changing sync standby failed due to race
-        self.ha.dcs.write_sync_state = Mock(return_value=True)
         self.ha.dcs.get_cluster = Mock(return_value=get_cluster_initialized_with_leader(sync=('somebodyelse', None)))
         self.ha.run_cycle()
-        self.assertEquals(self.ha.dcs.write_sync_state.call_count, 1)
+        self.assertEqual(self.ha.dcs.write_sync_state.call_count, 2)
 
         # Test sync set to '*' when synchronous_mode_strict is enabled
         mock_set_sync.reset_mock()
@@ -768,7 +895,7 @@ class TestHa(unittest.TestCase):
     def test_sync_replication_become_master(self):
         self.ha.is_synchronous_mode = true
 
-        mock_set_sync = self.p.set_synchronous_standby = Mock()
+        mock_set_sync = self.p.config.set_synchronous_standby = Mock()
         self.p.is_leader = false
         self.p.set_role('replica')
         self.ha.has_lock = true
@@ -777,7 +904,7 @@ class TestHa(unittest.TestCase):
         self.ha.cluster = get_cluster_initialized_with_leader(sync=('other', None))
 
         # When we just became master nobody is sync
-        self.assertEquals(self.ha.enforce_master_role('msg', 'promote msg'), 'promote msg')
+        self.assertEqual(self.ha.enforce_master_role('msg', 'promote msg'), 'promote msg')
         mock_set_sync.assert_called_once_with(None)
         mock_write_sync.assert_called_once_with('leader', None, index=0)
 
@@ -805,7 +932,7 @@ class TestHa(unittest.TestCase):
         self.ha.run_cycle()
         mock_acquire.assert_not_called()
         mock_follow.assert_called_once()
-        self.assertEquals(mock_follow.call_args[0][0], None)
+        self.assertEqual(mock_follow.call_args[0][0], None)
         mock_write_sync.assert_not_called()
 
         mock_follow.reset_mock()
@@ -856,15 +983,15 @@ class TestHa(unittest.TestCase):
 
     def test_effective_tags(self):
         self.ha._disable_sync = True
-        self.assertEquals(self.ha.get_effective_tags(), {'foo': 'bar', 'nosync': True})
+        self.assertEqual(self.ha.get_effective_tags(), {'foo': 'bar', 'nosync': True})
         self.ha._disable_sync = False
-        self.assertEquals(self.ha.get_effective_tags(), {'foo': 'bar'})
+        self.assertEqual(self.ha.get_effective_tags(), {'foo': 'bar'})
 
     def test_restore_cluster_config(self):
         self.ha.cluster.config.data.clear()
         self.ha.has_lock = true
         self.ha.cluster.is_unlocked = false
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
 
     def test_watch(self):
         self.ha.cluster = get_cluster_initialized_with_leader()
@@ -883,16 +1010,42 @@ class TestHa(unittest.TestCase):
         self.ha.cluster = get_cluster_initialized_with_leader()
         self.ha.has_lock = true
         self.p.data_directory_empty = true
-        self.assertEquals(self.ha.run_cycle(), 'released leader key voluntarily as data dir empty and currently leader')
-        self.assertEquals(self.p.role, 'uninitialized')
+        self.assertEqual(self.ha.run_cycle(), 'released leader key voluntarily as data dir empty and currently leader')
+        self.assertEqual(self.p.role, 'uninitialized')
 
         # as has_lock is mocked out, we need to fake the leader key release
         self.ha.has_lock = false
         # will not say bootstrap from leader as replica can't self elect
-        self.assertEquals(self.ha.run_cycle(), "trying to bootstrap from replica 'other'")
+        self.assertEqual(self.ha.run_cycle(), "trying to bootstrap from replica 'other'")
 
+    @patch('psycopg2.connect', psycopg2_connect)
     def test_update_cluster_history(self):
-        self.p.get_master_timeline = Mock(return_value=1)
         self.ha.has_lock = true
         self.ha.cluster.is_unlocked = false
-        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        for tl in (1, 3):
+            self.p.get_master_timeline = Mock(return_value=tl)
+            self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+
+    @patch('sys.exit', return_value=1)
+    def test_abort_join(self, exit_mock):
+        self.ha.cluster = get_cluster_not_initialized_without_leader()
+        self.p.is_leader = false
+        self.ha.run_cycle()
+        exit_mock.assert_called_once_with(1)
+
+    def test_after_pause(self):
+        self.ha.has_lock = true
+        self.ha.cluster.is_unlocked = false
+        self.ha.is_paused = true
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: no action.  i am the leader with the lock')
+        self.ha.is_paused = false
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+
+    @patch('psycopg2.connect', psycopg2_connect)
+    def test_permanent_logical_slots_after_promote(self):
+        config = ClusterConfig(1, {'slots': {'l': {'database': 'postgres', 'plugin': 'test_decoding'}}}, 1)
+        self.ha.cluster = get_cluster_initialized_without_leader(cluster_config=config)
+        self.assertEqual(self.ha.run_cycle(), 'acquired session lock as a leader')
+        self.ha.cluster = get_cluster_initialized_without_leader(leader=True, cluster_config=config)
+        self.ha.has_lock = true
+        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')