Release 1.5.4 (#931)

* Bump version
* Update release notes
* Make it possible to configure registration of Service in Consul via env variables

.gitignore

@@ -46,3 +46,11 @@ dummy
 
 pgpass
 scm-source.json
+
+# Sphinx-generated documentation
+docs/build/
+docs/source/_static/
+docs/source/_templates/
+
+# Pycharm IDE
+.idea/

.travis.yml

@@ -1,82 +1,153 @@
-sudo: false
+sudo: true
+dist: trusty
 language: python
-python:
-- "3.5"
-addons:
-  apt:
-    packages:
-    - postgresql-contrib-9.5
-  postgresql: "9.5"
 env:
   global:
-  - ETCDVERSION=2.3.2 ZKVERSION=3.4.6 CONSULVERSION=0.6.4
-  matrix:
-  - TEST_SUITE="python setup.py"
-  - DCS="etcd" TEST_SUITE="behave"
-  - DCS="exhibitor" TEST_SUITE="behave"
-  - DCS="consul" TEST_SUITE="behave"
+  - ETCDVERSION=3.0.17 ZKVERSION=3.4.11 CONSULVERSION=0.7.4
+  - PYVERSIONS="2.7 3.5 3.6"
+  - EXCLUDE_BEHAVE="3.5"
+  - BOTO_CONFIG=/doesnotexist
+matrix:
+  include:
+  - python: "3.5"
+    env: TEST_SUITE="python setup.py"
+  - python: "3.6"
+    env: DCS="etcd" TEST_SUITE="behave"
+  - python: "3.6"
+    env: DCS="exhibitor" TEST_SUITE="behave"
+  - python: "3.6"
+    env: DCS="consul" TEST_SUITE="behave"
+  - python: "3.6"
+    env: DCS="kubernetes" TEST_SUITE="behave"
+branches:
+  only:
+  - master
+  - /^v\d+\.\d+(\.\d+)?$/
 cache:
   directories:
-  - $HOME/virtualenv/python2.7.9
-  - $HOME/virtualenv/python3.4.2
-  - $HOME/virtualenv/python3.5.2
+  - $HOME/mycache
+before_cache:
+- |
+  rm -fr $HOME/mycache/python*
+  for pv in $PYVERSIONS; do
+      if [[ $TEST_SUITE != "behave" || $pv != $EXCLUDE_BEHAVE ]]; then
+          fpv=$(basename $(readlink $HOME/virtualenv/python${pv}))
+          mv $HOME/virtualenv/${fpv} $HOME/mycache/${fpv}
+      fi
+  done
 install:
   - |
     set -e
 
     if [[ $TEST_SUITE == "behave" ]]; then
-        if [[ $DCS == "consul" ]]; then
-            curl -L https://releases.hashicorp.com/consul/${CONSULVERSION}/consul_${CONSULVERSION}_linux_amd64.zip \
-                | gunzip > consul
-            chmod +x consul
-        fi
+        function get_consul() {
+            CC=~/mycache/consul_${CONSULVERSION}
+            if [[ ! -x $CC ]]; then
+                curl -L https://releases.hashicorp.com/consul/${CONSULVERSION}/consul_${CONSULVERSION}_linux_amd64.zip \
+                    | gunzip > $CC
+                [[ ${PIPESTATUS[0]} == 0 ]] || return 1
+                chmod +x $CC
+            fi
+            ln -s $CC consul
+        }
 
-        if [[ $DCS == "etcd" ]]; then
-            curl -L https://github.com/coreos/etcd/releases/download/v${ETCDVERSION}/etcd-v${ETCDVERSION}-linux-amd64.tar.gz \
-                | tar xz -C . --strip=1 --wildcards --no-anchored etcd
-        fi
+        function get_etcd() {
+            EC=~/mycache/etcd_${ETCDVERSION}
+            if [[ ! -x $EC ]]; then
+                curl -L https://github.com/coreos/etcd/releases/download/v${ETCDVERSION}/etcd-v${ETCDVERSION}-linux-amd64.tar.gz \
+                    | tar xz -C . --strip=1 --wildcards --no-anchored etcd
+                [[ ${PIPESTATUS[0]} == 0 ]] || return 1
+                mv etcd $EC
+            fi
+            ln -s $EC etcd
+        }
 
-        if [[ $DCS == "exhibitor" ]]; then
-            curl -L http://www.apache.org/dist/zookeeper/zookeeper-${ZKVERSION}/zookeeper-${ZKVERSION}.tar.gz | tar xz
-            mv zookeeper-${ZKVERSION}/conf/zoo_sample.cfg zookeeper-${ZKVERSION}/conf/zoo.cfg
-            zookeeper-${ZKVERSION}/bin/zkServer.sh start
+        function get_kubernetes() {
+            wget -O localkube "https://storage.googleapis.com/minikube/k8sReleases/v1.7.0/localkube-linux-amd64"
+            chmod +x localkube
+            sudo nohup ./localkube --logtostderr=true --enable-dns=false > localkube.log 2>&1 &
+
+            echo "Waiting for localkube to start..."
+            if ! timeout 120 sh -c "while ! curl -ks http://127.0.0.1:8080/ >/dev/null; do sleep 1; done"; then
+                sudo cat localkube.log
+                echo "localkube did not start"
+                exit 1
+            fi
+            echo "Check certificate permissions"
+            sudo chmod 644 /var/lib/localkube/certs/*
+            sudo ls -altr /var/lib/localkube/certs/
+
+            echo "Set up .kube/config"
+            mkdir ~/.kube
+            echo -e "apiVersion: v1\nclusters:\n- cluster:\n    certificate-authority: /var/lib/localkube/certs/ca.crt\n    server: https://127.0.0.1:8443\n  name: local\ncontexts:\n- context:\n    cluster: local\n    user: myself\n  name: local\ncurrent-context: local\nkind: Config\npreferences: {}\nusers:\n- name: myself\n  user:\n    client-certificate: /var/lib/localkube/certs/apiserver.crt\n    client-key: /var/lib/localkube/certs/apiserver.key\n" > ~/.kube/config
+        }
+
+        function get_exhibitor() {
+            ZC=~/mycache/zookeeper-${ZKVERSION}
+            if [[ ! -d $ZC ]]; then
+                curl -L http://www.apache.org/dist/zookeeper/zookeeper-${ZKVERSION}/zookeeper-${ZKVERSION}.tar.gz | tar xz
+                [[ ${PIPESTATUS[0]} == 0 ]] || return 1
+                mv zookeeper-${ZKVERSION}/conf/zoo_sample.cfg zookeeper-${ZKVERSION}/conf/zoo.cfg
+                mv zookeeper-${ZKVERSION} $ZC
+            fi
+            $ZC/bin/zkServer.sh start
             # following lines are 'emulating' exhibitor REST API
             while true; do
                 echo -e 'HTTP/1.0 200 OK\nContent-Type: application/json\n\n{"servers":["127.0.0.1"],"port":2181}' \
                     | nc -l 8181 &> /dev/null
             done&
-        fi
+        }
+
+        attempt_num=1
+        until get_${DCS}; do
+            [[ $attempt_num -ge 3 ]] && exit 1
+            echo "Attempt $attempt_num failed! Trying again in $attempt_num seconds..."
+            sleep $(( attempt_num++ ))
+        done
     fi
 
-    for pv in "2.7" "3.4" "3.5"; do
-        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==2.6.0 mock>=2.0.0 pytest-cov pytest'; do
-            pip install $p
-        done
+    for pv in $PYVERSIONS; do
+        if [[ $TEST_SUITE != "behave" || $pv != $EXCLUDE_BEHAVE ]]; then
+            fpv=$(basename $(readlink $HOME/virtualenv/python$pv))
+            if [[ -d ~/mycache/${fpv} ]]; then
+                mv ~/virtualenv/${fpv} ~/virtualenv/${fpv}.bckp
+                mv ~/mycache/${fpv} ~/virtualenv/${fpv}
+            fi
+            source ~/virtualenv/python${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
+                pip install $p --upgrade
+            done
+        fi
     done
 script:
   - |
-    for pv in "2.7" "3.4" "3.5"; do
+    for pv in $PYVERSIONS; do
+        if [[ $TEST_SUITE == "behave" && $pv == $EXCLUDE_BEHAVE ]]; then
+            continue
+        fi
+
         source ~/virtualenv/python${pv}/bin/activate
 
-        if [[ $TEST_SUITE == "behave" ]]; then
-            if [[ $pv != "3.4" ]]; then
-                echo Running acceptance tests using python${pv}
-                if ! PATH=.:$PATH $TEST_SUITE; then
-                    # output all log files when tests are failing
-                    grep . features/output/*/*postgres?.*
-                    exit 1
-                fi
-            fi
-        else
+        if [[ $TEST_SUITE != "behave" ]]; then
             echo Running unit tests using python${pv}
             $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
+                # output all log files when tests are failing
+                grep . features/output/*/*postgres?.*
+                exit 1
+            fi
         fi
     done
 
     set +e
 after_success:
+  # before_cache is executed earlier than after_success, so we need to restore one of virtualenv directories
+  - fpv=$(basename $(readlink $HOME/virtualenv/python3.6)) && mv $HOME/mycache/${fpv} $HOME/virtualenv/${fpv}
   - coveralls
   - if [[ $TEST_SUITE != "behave" ]]; then python-codacy-coverage -r coverage.xml; fi
+  - if [[ $DCS == "exhibitor" ]]; then ~/mycache/zookeeper-${ZKVERSION}/bin/zkServer.sh stop; fi
+  - sudo kill $(jobs -p)

.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

@@ -1,44 +1,45 @@
 ## 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 ubuntu:16.04
-MAINTAINER Feike Steenbergen <feike.steenberge[email protected]>
+FROM postgres:10
+MAINTAINER Alexander Kukushkin <alexander.kukushki[email protected]>
 
-RUN echo 'APT::Install-Recommends "0";' > /etc/apt/apt.conf.d/01norecommend \
-    && echo 'APT::Install-Suggests "0";' >> /etc/apt/apt.conf.d/01norecommend
-
-ENV PGVERSION 9.5
-ENV PATH /usr/lib/postgresql/${PGVERSION}/bin:$PATH
-RUN apt-get update -y \
+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 curl jq haproxy zookeeper postgresql-${PGVERSION} python-psycopg2 python-yaml \
-        python-requests python-six python-click python-dateutil python-tzlocal python-urllib3 \
-        python-dnspython python-pip python-setuptools python-kazoo python-prettytable python \
-    && pip install python-etcd==0.4.3 python-consul==0.6.0 --upgrade \
-    && apt-get remove -y python-pip python-setuptools \
+    # postgres:10 is based on debian, which has patroni package. We will install all required dependencies
+    && apt-get install -s patroni | sed -n -e '/^Inst patroni /d' -e 's/^Inst \([^ ]\+\) .*$/\1/p' \
+            | xargs apt-get install -y curl jq haproxy locales python3-etcd python3-kazoo \
+
+    ## 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 \
+
+    && mkdir -p /home/postgres \
+    && chown postgres:postgres /home/postgres \
+
+    # Clean up
+    && apt-get purge -y libpython2.7-stdlib libpython2.7-minimal \
     && apt-get autoremove -y \
-        # Clean up
     && apt-get clean -y \
     && rm -rf /var/lib/apt/lists/* /root/.cache
 
-ENV ETCDVERSION 2.3.6
+ENV ETCDVERSION 3.2.23
 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
 
-ENV CONFDVERSION 0.11.0
+ENV CONFDVERSION 0.16.0
 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
 
 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
 
-### 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/ \
-    && echo 1 > /etc/zookeeper/conf/myid
+RUN sed -i 's/env python/&3/' patroni*.py && ln -s /patronictl.py /usr/local/bin/patronictl && mkdir /data/ /run/haproxy \
+    && touch /pgpass /patroni.yml && chown postgres:postgres -R /patroni/ /data/ /pgpass /patroni.yml /etc/haproxy /var/run/ /var/lib/ /var/log/
 
 EXPOSE 2379 5432 8008
 
+ENV LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
 ENTRYPOINT ["/bin/bash", "/entrypoint.sh"]
 USER postgres

README.rst

@@ -1,55 +1,98 @@
 |Build Status| |Coverage Status|
 
 Patroni: A Template for PostgreSQL HA with ZooKeeper, etcd or Consul
-------------------------------------------------------------
+--------------------------------------------------------------------
+
+You can find a version of this documentation that is searchable and also easier to navigate at `patroni.readthedocs.io <https://patroni.readthedocs.io>`__.
+
+
 There are many ways to run high availability with PostgreSQL; for a list, see the `PostgreSQL Documentation <https://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling>`__.
 
-Patroni is a template for you to create your own customized, high-availability solution using Python and - for maximum accessibility - a distributed configuration store like `ZooKeeper <https://zookeeper.apache.org/>`__, `etcd <https://github.com/coreos/etcd>`__ or `Consul <https://github.com/hashicorp/consul>`__. Database engineers, DBAs, DevOps engineers, and SREs who are looking to quickly deploy HA PostgreSQL in the datacenter-or anywhere else-will hopefully find it useful.
+Patroni is a template for you to create your own customized, high-availability solution using Python and - for maximum accessibility - a distributed configuration store like `ZooKeeper <https://zookeeper.apache.org/>`__, `etcd <https://github.com/coreos/etcd>`__, `Consul <https://github.com/hashicorp/consul>`__ or `Kubernetes <https://kubernetes.io>`__. Database engineers, DBAs, DevOps engineers, and SREs who are looking to quickly deploy HA PostgreSQL in the datacenter-or anywhere else-will hopefully find it useful.
 
 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**: We're currently developing Patroni to be as useful as possible for teams running Kubernetes on top of Google Compute Engine; Patroni can be the HA solution for Postgres in such an environment. Please contact us via our Issues Tracker if this describes your team's current setup, and we'll follow up.
+**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:
     :depth: 1
     :backlinks: none
 
-==============
+=================
 How Patroni Works
-==============
+=================
 
-Patroni originated as a fork of `Governor <https://github.com/compose/governor>`__, the project from Compose. It includes plenty of new features. 
+Patroni originated as a fork of `Governor <https://github.com/compose/governor>`__, the project from Compose. It includes plenty of new features.
 
 For an example of a Docker-based deployment with Patroni, see `Spilo <https://github.com/zalando/spilo>`__, currently in use at Zalando.
 
 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
 * `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/>`__
 
-================
+==================
 Development Status
-================
+==================
 
-Patroni is in active development and accepts contributions. See our `Contributing <https://github.com/zalando/patroni/blob/master/README.rst#contributing>`__ section below for more details. 
+Patroni is in active development and accepts contributions. See our `Contributing <https://github.com/zalando/patroni/blob/master/docs/CONTRIBUTING.rst>`__ section below for more details.
 
-===========================
+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
-===========================
+===================================
 
-**For Mac**
+**Pre-requirements for Mac OS**
 
 To install requirements on a Mac, run the following:
 
 ::
 
     brew install postgresql etcd haproxy libyaml python
-    pip install psycopg2 pyyaml
 
-===================
+**General installation for pip**
+
+Patroni can be installed with pip:
+
+::
+
+    pip install patroni[dependencies]
+
+where dependencies can be either empty, or consist of one or more of the following:
+
+etcd
+    `python-etcd` module in order to use Etcd as DCS
+consul
+    `python-consul` module in order to use Consul as DCS
+zookeeper
+    `kazoo` module in order to use Zookeeper as DCS
+exhibitor
+    `kazoo` module in order to use Exhibitor as DCS (same dependencies as for Zookeeper)
+kubernetes
+    `kubernetes` module in order to use Kubernetes as DCS in Patroni
+aws
+    `boto` in order to use AWS callbacks
+
+For example, the command in order to install Patroni together with dependencies for Etcd as a DCS and AWS callbacks is:
+
+::
+
+    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 independently of Patroni.
+
+=======================
 Running and Configuring
-===================
+=======================
 
 To get started, do the following from different terminals:
 ::
@@ -73,11 +116,11 @@ run:
 
     > psql --host 127.0.0.1 --port 5000 postgres
 
-===============
+==================
 YAML Configuration
-===============
+==================
 
-Go `here <https://github.com/zalando/patroni/blob/master/docs/SETTINGS.rst>`__ for comprehensive information about settings for etcd, consul, and ZooKeeper. And for an example, see `postgres0.yml <https://github.com/zalando/patroni/blob/master/postgres0.yml>`__. 
+Go `here <https://github.com/zalando/patroni/blob/master/docs/SETTINGS.rst>`__ for comprehensive information about settings for etcd, consul, and ZooKeeper. And for an example, see `postgres0.yml <https://github.com/zalando/patroni/blob/master/postgres0.yml>`__.
 
 =========================
 Environment Configuration
@@ -85,43 +128,18 @@ Environment Configuration
 
 Go `here <https://github.com/zalando/patroni/blob/master/docs/ENVIRONMENT.rst>`__ for comprehensive information about configuring(overriding) settings via environment variables.
 
-===============
+===================
 Replication Choices
-===============
+===================
 
-Patroni uses Postgres' streaming replication, which is asynchronous by default. For more information, see the `Postgres documentation on streaming replication <http://www.postgresql.org/docs/current/static/warm-standby.html#STREAMING-REPLICATION>`__.
+Patroni uses Postgres' streaming replication, which is asynchronous by default. Patroni's asynchronous replication configuration allows for ``maximum_lag_on_failover`` settings. This setting ensures failover will not occur if a follower is more than a certain number of bytes behind the leader. This setting should be increased or decreased based on business requirements. It's also possible to use synchronous replication for better durability guarantees. See `replication modes documentation <https://github.com/zalando/patroni/blob/master/docs/replication_modes.rst>`__ for details.
 
-Patroni's asynchronous replication configuration allows for ``maximum_lag_on_failover`` settings. This setting ensures failover will not occur if a follower is more than a certain number of bytes behind the follower. This setting should be increased or decreased based on business requirements.
-
-When asynchronous replication is not optimal for your use case, investigate Postgres's `synchronous replication <http://www.postgresql.org/docs/current/static/warm-standby.html#SYNCHRONOUS-REPLICATION>`__. Synchronous replication ensures consistency across a cluster by confirming that writes are written to a secondary before returning to the connecting client with a success. The cost of synchronous replication: reduced throughput on writes. This throughput will be entirely based on network performance. 
-
-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:
-
-.. code:: YAML
-
-        synchronous_commit: "on"
-        synchronous_standby_names: "*"
-
-When using synchronous replication, use at least three Postgres data nodes to ensure write availability if one host fails.
-
-Choosing your replication schema is dependent on your business considerations. Investigate both async and sync replication, as well as other HA solutions, to determine which solution is best for you.
-
-===============================
+======================================
 Applications Should Not Use Superusers
-===============================
+======================================
 
 When connecting from an application, always use a non-superuser. Patroni requires access to the database to function properly. By using a superuser from an application, you can potentially use the entire connection pool, including the connections reserved for superusers, with the ``superuser_reserved_connections`` setting. If Patroni cannot access the Primary because the connection pool is full, behavior will be undesirable.
 
-================
-Contributing
-================
-Patroni accepts contributions from the open-source community; see the `Issues Tracker <https://github.com/zalando/patroni/issues>`__ for current needs. 
-
-Before making a contribution, please let us know by posting a comment to the relevant issue. 
-If you would like to propose a new feature, please first file a new issue explaining the feature you'd like to create.
-
 .. |Build Status| image:: https://travis-ci.org/zalando/patroni.svg?branch=master
    :target: https://travis-ci.org/zalando/patroni
 .. |Coverage Status| image:: https://coveralls.io/repos/zalando/patroni/badge.svg?branch=master

docker-compose.yml

@@ -15,7 +15,7 @@ dbnode1:
         - ./patroni:/patroni
     env_file: docker/patroni-secrets.env
     environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
+        PATRONI_ETCD_URL: http://patroni_etcd:2379
         PATRONI_NAME: dbnode1
         PATRONI_SCOPE: testcluster
 
@@ -28,7 +28,7 @@ dbnode2:
         - ./patroni:/patroni
     env_file: docker/patroni-secrets.env
     environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
+        PATRONI_ETCD_URL: http://patroni_etcd:2379
         PATRONI_NAME: dbnode2
         PATRONI_SCOPE: testcluster
 
@@ -41,7 +41,7 @@ dbnode3:
         - ./patroni:/patroni
     env_file: docker/patroni-secrets.env
     environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
+        PATRONI_ETCD_URL: http://patroni_etcd:2379
         PATRONI_NAME: dbnode3
         PATRONI_SCOPE: testcluster
 
@@ -50,9 +50,9 @@ haproxy:
     links:
         - patroni_etcd:patroni_etcd
     ports:
-        - "5000"
-        - "5001"
+        - "5000:5000"
+        - "5001:5001"
     environment:
-        PATRONI_ETCD_HOST: patroni_etcd:2379
+        PATRONI_ETCD_URL: http://patroni_etcd:2379
         PATRONI_SCOPE: testcluster
     command: --confd

docker/dev_patroni_cluster.sh

@@ -84,7 +84,7 @@ function docker_run()
 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"
+DOCKER_ARGS="--link=${ETCD_CONTAINER}:${ETCD_CONTAINER} -e PATRONI_SCOPE=${PATRONI_SCOPE} -e PATRONI_ETCD_URL=http://${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"
 

docker/entrypoint.sh

@@ -22,7 +22,7 @@ __EOF__
 
 DOCKER_IP=$(hostname --ip-address)
 PATRONI_SCOPE=${PATRONI_SCOPE:-batman}
-ETCD_ARGS="--data-dir /tmp/etcd.data -advertise-client-urls=http://${DOCKER_IP}:2379 -listen-client-urls=http://0.0.0.0:2379 -listen-peer-urls=http://0.0.0.0:2380"
+ETCD_ARGS="--data-dir /tmp/etcd.data -advertise-client-urls=http://${DOCKER_IP}:2379 -listen-client-urls=http://0.0.0.0:2379"
 
 optspec=":vh-:"
 while getopts "$optspec" optchar; do
@@ -38,10 +38,10 @@ while getopts "$optspec" optchar; do
                         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
+                        while ! curl -s ${PATRONI_ETCD_URL}/v2/members | jq -r '.members[0].clientURLs[0]' | grep -q http; do
                             sleep 1
                         done
-                        exec $CONFD etcd -node $PATRONI_ETCD_HOST
+                        exec $CONFD etcd -node $PATRONI_ETCD_URL
                     fi
                     ;;
                 etcd)
@@ -74,9 +74,9 @@ while getopts "$optspec" optchar; do
 done
 
 ## We start an etcd
-if [[ -z ${PATRONI_ETCD_HOST} && -z ${PATRONI_ZOOKEEPER_HOSTS} ]]; then
+if [[ -z ${PATRONI_ETCD_URL} && -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"
+    export PATRONI_ETCD_URL="http://127.0.0.1:2379"
 fi
 
 export PATRONI_SCOPE
@@ -108,7 +108,7 @@ __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
+[ -z $CHEAT ] && exec python3 /patroni.py /patroni.yml
 
 while true; do
     sleep 60

docs/CONTRIBUTING.rst

@@ -0,0 +1,29 @@
+.. _contributing:
+
+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
+----------------
+
+If you have a question about patroni or have a problem using it, please read the :ref:`README <readme>` before filing an issue.
+Also double check with the current issues on our `Issues Tracker <https://github.com/zalando/patroni/issues>`__.
+
+Contributing a pull request
+---------------------------
+
+1) Submit a comment to the relevant issue or create a new issue describing your proposed change.
+2) Do a fork, develop and test your code changes.
+3) Include documentation
+4) Submit a pull request.
+
+You'll get feedback about your pull request as soon as possible.
+
+Happy Patroni hacking ;-)

docs/ENVIRONMENT.rst

@@ -1,4 +1,5 @@
-==================================
+.. _environment:
+
 Environment Configuration Settings
 ==================================
 
@@ -10,6 +11,13 @@ Global/Universal
 -  **PATRONI\_NAME**: name of the node where the current instance of Patroni is running. Must be unique for the cluster.
 -  **PATRONI\_NAMESPACE**: path within the configuration store where Patroni will keep information about the cluster. Default value: "/service"
 -  **PATRONI\_SCOPE**: cluster name
+-  **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\_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\_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
 -----------------------
@@ -23,21 +31,53 @@ Example: defining ``PATRONI_admin_PASSWORD=strongpasswd`` and ``PATRONI_admin_OP
 Consul
 ------
 -  **PATRONI\_CONSUL\_HOST**: the host:port for the Consul endpoint.
+-  **PATRONI\_CONSUL\_URL**: url for the Consul, in format: http(s)://host:port
+-  **PATRONI\_CONSUL\_PORT**: (optional) Consul port
+-  **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 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\_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\_SRV**: Domain to search the SRV record(s) for cluster autodiscovery.
+-  **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.
 
 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.
 -  **PATRONI\_EXHIBITOR\_PORT**: Exhibitor port.
 
+.. _kubernetes_environment:
+
+Kubernetes
+----------
+-  **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 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
 ----------
 -  **PATRONI\_POSTGRESQL\_LISTEN**: IP address + port that Postgres listens to. 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.
 -  **PATRONI\_POSTGRESQL\_CONNECT\_ADDRESS**: IP address + port through which Postgres is accessible from other nodes and applications.
 -  **PATRONI\_POSTGRESQL\_DATA\_DIR**: The location of the Postgres data directory, either existing or to be initialized by Patroni.
+-  **PATRONI\_POSTGRESQL\_CONFIG\_DIR**: The location of the Postgres configuration directory, defaults to the data directory. Must be writable by Patroni.
 -  **PATRONI\_POSTGRESQL\_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.
 -  **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
@@ -46,7 +86,7 @@ PostgreSQL
 -  **PATRONI\_SUPERUSER\_PASSWORD**: password for the superuser, set during initialization (initdb).
 
 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.

docs/Makefile

@@ -0,0 +1,20 @@
+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+SPHINXPROJ    = Patroni
+SOURCEDIR     = .
+BUILDDIR      = build
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

docs/README.rst

@@ -0,0 +1,125 @@
+.. _readme:
+
+============
+Introduction
+============
+
+Patroni originated as a fork of `Governor <https://github.com/compose/governor>`__, the project from Compose. It includes plenty of new features.
+
+For an example of a Docker-based deployment with Patroni, see `Spilo <https://github.com/zalando/spilo>`__, currently in use at Zalando.
+
+For additional background info, see:
+
+* `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/>`__
+
+
+Development Status
+------------------
+
+Patroni is in active development and accepts contributions. See our :ref:`Contributing <contributing>` section below for more details.
+
+We report new releases information :ref:`here <releases>`.
+
+
+Technical Requirements/Installation
+-----------------------------------
+
+**Pre-requirements for Mac OS**
+
+To install requirements on a Mac, run the following:
+
+::
+
+    brew install postgresql etcd haproxy libyaml python
+
+**General installation for pip**
+
+Patroni can be installed with pip:
+
+::
+
+    pip install patroni[dependencies]
+
+where dependencies can be either empty, or consist of one or more of the following:
+
+etcd
+    `python-etcd` module in order to use Etcd as DCS
+consul
+    `python-consul` module in order to use Consul as DCS
+zookeeper
+    `kazoo` module in order to use Zookeeper as DCS
+exhibitor
+    `kazoo` module in order to use Exhibitor as DCS (same dependencies as for Zookeeper)
+kubernetes
+    `kubernetes` module in order to use Kubernetes as DCS in Patroni
+aws
+    `boto` in order to use AWS callbacks
+
+For example, the command in order to install Patroni together with dependencies for Etcd as a DCS and AWS callbacks is:
+
+::
+
+    pip install patroni[etcd,aws]
+
+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 and Configuring
+-----------------------
+
+The following section assumes Patroni repository as being cloned from https://github.com/zalando/patroni. Namely, you
+will need example configuration files `postgres0.yml` and `postgres1.yml`. If you installed Patroni with pip, you can
+obtain those files from the git repository and replace `./patroni.py` below with `patroni` command.
+
+To get started, do the following from different terminals:
+::
+
+    > etcd --data-dir=data/etcd
+    > ./patroni.py postgres0.yml
+    > ./patroni.py postgres1.yml
+
+You will then see a high-availability cluster start up. Test different settings in the YAML files to see how the cluster's behavior changes. Kill some of the components to see how the system behaves.
+
+Add more ``postgres*.yml`` files to create an even larger cluster.
+
+Patroni provides an `HAProxy <http://www.haproxy.org/>`__ configuration, which will give your application a single endpoint for connecting to the cluster's leader. To configure,
+run:
+
+::
+
+    > haproxy -f haproxy.cfg
+
+::
+
+    > psql --host 127.0.0.1 --port 5000 postgres
+
+
+YAML Configuration
+------------------
+
+Go :ref:`here <settings>` for comprehensive information about settings for etcd, consul, and ZooKeeper. And for an example, see `postgres0.yml <https://github.com/zalando/patroni/blob/master/postgres0.yml>`__.
+
+
+Environment Configuration
+-------------------------
+
+Go :ref:`here <environment>` for comprehensive information about configuring(overriding) settings via environment variables.
+
+
+Replication Choices
+-------------------
+
+Patroni uses Postgres' streaming replication, which is asynchronous by default. Patroni's asynchronous replication configuration allows for ``maximum_lag_on_failover`` settings. This setting ensures failover will not occur if a follower is more than a certain number of bytes behind the leader. This setting should be increased or decreased based on business requirements. It's also possible to use synchronous replication for better durability guarantees. See :ref:`replication modes documentation <replication_modes>` for details.
+
+
+Applications Should Not Use Superusers
+--------------------------------------
+
+When connecting from an application, always use a non-superuser. Patroni requires access to the database to function properly. By using a superuser from an application, you can potentially use the entire connection pool, including the connections reserved for superusers, with the ``superuser_reserved_connections`` setting. If Patroni cannot access the Primary because the connection pool is full, behavior will be undesirable.
+
+.. |Build Status| image:: https://travis-ci.org/zalando/patroni.svg?branch=master
+   :target: https://travis-ci.org/zalando/patroni
+.. |Coverage Status| image:: https://coveralls.io/repos/zalando/patroni/badge.svg?branch=master
+   :target: https://coveralls.io/r/zalando/patroni?branch=master

docs/SETTINGS.rst

@@ -1,3 +1,5 @@
+.. _settings:
+
 ===========================
 YAML Configuration Settings
 ===========================
@@ -8,17 +10,50 @@ Global/Universal
 -  **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>`_)
+-  **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>`_)
+-  **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 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 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
+        -  **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.
+    -  **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.
+-  **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.
 -  **initdb**: List options to be passed on to initdb.
         -  **- data-checksums**: Must be enabled when pg_rewind is needed on 9.3.
         -  **- encoding: UTF8**: default encoding for new databases.
@@ -26,20 +61,49 @@ 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
             -  **- createrole**
             -  **- createdb**
+-  **post\_bootstrap** or **post\_init**: An additional script that will be executed after initializing the cluster. The script receives a connection string URL (with the cluster superuser as a user name). The PGPASSFILE variable is set to the location of pgpass file.
+
+.. _consul_settings:
 
 Consul
 ------
--  **host**: the host:port for the Consul endpoint.
+Most of the parameters are optional, but you have to specify one of the **host** or **url**
+
+-  **host**: the host:port for the Consul endpoint, in format: http(s)://host:port
+-  **url**: url for the Consul endpoint
+-  **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 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.
+-  **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
 ----
+Most of the parameters are optional, but you have to specify one of the **host**, **hosts**, **url**, **proxy** or **srv**
+
 -  **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.
+-  **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
+-  **password**: (optional) password for etcd authentication.
+-  **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**.
 
 Exhibitor
 ---------
@@ -47,6 +111,20 @@ Exhibitor
 -  **poll\_interval**: how often the list of ZooKeeper and Exhibitor nodes should be updated from Exhibitor
 -  **port**: Exhibitor port.
 
+.. _kubernetes_settings:
+
+Kubernetes
+----------
+-  **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 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:
+
 PostgreSQL
 ----------
 -  **authentication**:
@@ -63,23 +141,32 @@ PostgreSQL
         -  **on\_start**: run this script when the cluster starts.
         -  **on\_stop**: run this script when the cluster stops.
 -  **connect\_address**: IP address + port through which Postgres is accessible from other nodes and applications.
--  **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.
+-  **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.
--  **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.
+-  **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.
 -  **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.
--  **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.
+-  **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.
+-  **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\_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".
+-  **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 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 addres (ie: "localhost" or "127.0.0.1"). It can serve as a 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.
@@ -88,6 +175,21 @@ 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.
 
+.. _patronictl_settings:
+
+CTL
+---
+-  **Optional**:
+    -  **insecure**: Allow connections to REST API without verifying SSL certs. 
+    -  **cacert**: Specifices the file with the CA_BUNDLE file or directory with certificates of trusted CAs to use while verifying REST API SSL certs.
+    -  **certfile**: Specifies the file with the certificate in the PEM format to use while verifying REST API SSL certs. If not provided patronictl will use the value provided for REST API "certfile" parameter.
+
 ZooKeeper
 ----------
 -  **hosts**: list of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+
+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 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.

docs/_static/custom.css

@@ -0,0 +1,3 @@
+li {
+   margin-bottom: 0.5em
+}

docs/conf.py

@@ -0,0 +1,197 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Patroni documentation build configuration file, created by
+# sphinx-quickstart on Mon Dec 19 16:54:09 2016.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+import os
+
+import sys
+sys.path.insert(0, os.path.abspath('..'))
+
+from patroni.version import __version__
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#
+# needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = ['sphinx.ext.intersphinx',
+    'sphinx.ext.todo',
+    'sphinx.ext.mathjax',
+    'sphinx.ext.ifconfig',
+    'sphinx.ext.viewcode']
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+#
+# source_suffix = ['.rst', '.md']
+source_suffix = '.rst'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = 'Patroni'
+copyright = '2015 Compose, Zalando SE'
+author = 'Zalando SE'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = __version__[:__version__.rfind('.')]
+# The full version, including alpha/beta/rc tags.
+release = __version__
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This patterns also effect to html_static_path and html_extra_path
+exclude_patterns = []
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# If true, `todo` and `todoList` produce output, else they produce nothing.
+todo_include_todos = True
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    import sphinx_rtd_theme
+    html_theme = 'sphinx_rtd_theme'
+    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#
+# html_theme_options = {}
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+
+# -- Options for HTMLHelp output ------------------------------------------
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'Patronidoc'
+
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+    # The paper size ('letterpaper' or 'a4paper').
+    #
+    # 'papersize': 'letterpaper',
+
+    # The font size ('10pt', '11pt' or '12pt').
+    #
+    # 'pointsize': '10pt',
+
+    # Additional stuff for the LaTeX preamble.
+    #
+    # 'preamble': '',
+
+    # Latex figure (float) alignment
+    #
+    # 'figure_align': 'htbp',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+    (master_doc, 'Patroni.tex', 'Patroni Documentation',
+     'Zalando SE', 'manual'),
+]
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'patroni', 'Patroni Documentation',
+     [author], 1)
+]
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    (master_doc, 'Patroni', 'Patroni Documentation',
+     author, 'Patroni', 'One line description of project.',
+     'Miscellaneous'),
+]
+
+
+
+# -- Options for Epub output ----------------------------------------------
+
+# Bibliographic Dublin Core info.
+epub_title = project
+epub_author = author
+epub_publisher = author
+epub_copyright = copyright
+
+# The unique identifier of the text. This can be a ISBN number
+# or the project homepage.
+#
+# epub_identifier = ''
+
+# A unique identification for the text.
+#
+# epub_uid = ''
+
+# A list of files that should not be packed into the epub file.
+epub_exclude_files = ['search.html']
+
+
+
+# Example configuration for intersphinx: refer to the Python standard library.
+intersphinx_mapping = {'https://docs.python.org/': None}
+
+# A possibility to have an own stylesheet, to add new rules or override existing ones
+# For the latter case, the CSS specificity of the rules should be higher than the default ones
+def setup(app):
+   app.add_stylesheet("custom.css")

docs/dynamic_configuration.rst

@@ -1,3 +1,5 @@
+.. _dynamic_configuration:
+
 Patroni configuration
 =====================
 
@@ -10,13 +12,13 @@ Patroni configuration is stored in the DCS (Distributed Configuration Store). Th
 	have changed), a special flag, ``pending_restart`` indicating this, is set in the members.data JSON.
 	Additionally, the node status also indicates this, by showing ``"restart_pending": true``.
 
-- Local `configuration <https://github.com/zalando/patroni/blob/master/docs/SETTINGS.rst>`__ (patroni.yml).
+- 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.
 
-- Environment `configuration <https://github.com/zalando/patroni/blob/master/docs/ENVIRONMENT.rst>`__ .
+- 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:
 
@@ -40,7 +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>`__
@@ -74,6 +76,7 @@ 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

docs/ha_loop_diagram.dot

@@ -0,0 +1,148 @@
+// Graphviz source for ha_loop_diagram.png
+// recompile with:
+// dot -Tpng ha_loop_diagram.dot -o ha_loop_diagram.png
+
+digraph G {
+  rankdir=TB;
+  fontname="sans-serif";
+  penwidth="0.3";
+  layout="dot";
+  newrank=true;
+  edge [fontname="sans-serif", 
+        fontsize=12, 
+        color=black, 
+        fontcolor=black];
+  node [fontname=serif, 
+        fontsize=12, 
+        fillcolor=white, 
+        color=black, 
+        fontcolor=black,
+        style=filled];
+  "start" [label=Start, shape="rectangle", fillcolor="green"]
+  "start" -> "load_cluster_from_dcs";
+  "update_member" [label="Persist node state in DCS"]
+  "update_member" -> "start"
+  
+  subgraph cluster_run_cycle {
+    label="run_cycle"
+    "load_cluster_from_dcs" [label="Load cluster from DCS"];
+    "touch_member" [label="Persist node in DCS"];
+    "cluster.has_member" [shape="diamond", label="Is node registered on DCS?"]
+    "cluster.has_member" -> "touch_member"  [label="no" color="red"]
+    "long_action_in_progress?" [shape="diamond" label="Is the PostgreSQL currently being\nstopping/starting/restarting/reinitializing?"]
+    "load_cluster_from_dcs" -> "cluster.has_member";
+    "touch_member" -> "long_action_in_progress?";
+    "cluster.has_member" -> "long_action_in_progress?"  [label="yes" color="green"];
+    "long_action_in_progress?" -> "recovering?" [label="no" color="red"]
+    "recovering?" [label="Was cluster recovering and failed?", shape="diamond"];
+    "recovering?" -> "post_recover" [label="yes" color="green"];
+    "recovering?" -> "data_directory_empty" [label="no" color="red"];
+    "post_recover" [label="Remove leader key (if I was the leader)"];
+    "data_directory_empty" [label="Is data folder empty?", shape="diamond"];
+    "data_directory_empty" -> "cluster_initialize" [label="no" color="red"];
+    "data_belongs_to_cluster" [label="Does data dir belong to cluster?", shape="diamond"];
+    "data_belongs_to_cluster" -> "exit" [label="no" color="red"];
+    "data_belongs_to_cluster" -> "is_healthy" [label="yes" color="green"]
+    "exit" [label="Fail and exit", fillcolor=red];
+    "cluster_initialize" [label="Is cluster initialized on DCS?" shape="diamond"]
+    "cluster_initialize" -> "cluster.has_leader" [label="no" color="red"]
+    "cluster.has_leader" [label="Does the cluster has leader?", shape="diamond"]
+    "cluster.has_leader" -> "dcs.initialize" [label="no", color="red"]
+    "cluster.has_leader" -> "is_healthy" [label="yes", color="green"]
+    "cluster_initialize" -> "data_belongs_to_cluster" [label="yes" color="green"]
+    "dcs.initialize" [label="Initialize new cluster"];
+    "dcs.initialize" -> "is_healthy"
+    "is_healthy" [label="Is node healthy?\n(running Postgres)", shape="diamond"];
+    "recover" [label="Start as read-only\nand set Recover flag"]
+    "is_healthy" -> "recover" [label="no" color="red"]; 
+    "is_healthy" -> "cluster.is_unlocked" [label="yes" color="green"]; 
+    "cluster.is_unlocked" [label="Does the cluster has a leader?", shape="diamond"]
+  }
+
+  "post_recover" -> "update_member"
+  "recover" -> "update_member"
+  "long_action_in_progress?" -> "async_has_lock?" [label="yes" color="green"];
+  "cluster.is_unlocked" -> "unhealthy_is_healthiest" [label="no" color="red"]
+  "cluster.is_unlocked" -> "healthy_has_lock" [label="yes" color="green"]
+  "data_directory_empty" -> "bootstrap.is_unlocked" [label="yes" color="green"]
+
+  subgraph cluster_async {
+    label = "Long action in progress\n(Start/Stop/Restart/Reinitialize)"
+    "async_has_lock?" [label="Do I have the leader lock?", shape="diamond"]
+    "async_update_lock" [label="Renew leader lock"]
+    "async_has_lock?" -> "async_update_lock" [label="yes" color="green"]
+  }
+  "async_update_lock" -> "update_member"
+  "async_has_lock?" -> "update_member" [label="no" color="red"]
+
+  subgraph cluster_bootstrap {
+    label = "Node bootstrap";
+    "bootstrap.is_unlocked" [label="Does the cluster has a leader?", shape="diamond"]
+    "bootstrap.is_initialized" [label="Does the cluster has an initialize key?", shape="diamond"]
+    "bootstrap.is_unlocked" -> "bootstrap.is_initialized" [label="no" color="red"]
+    "bootstrap.is_unlocked" -> "bootstrap.select_node" [label="yes" color="green"]
+    "bootstrap.select_node" [label="Select a node to take a backup from"]
+    "bootstrap.do_bootstrap" [label="Run pg_basebackup\n(async)"]
+    "bootstrap.select_node" -> "bootstrap.do_bootstrap"
+    "bootstrap.is_initialized" -> "bootstrap.initialization_race" [label="no" color="red"]
+    "bootstrap.is_initialized" -> "bootstrap.wait_for_leader" [label="yes" color="green"]
+    "bootstrap.initialization_race" [label="Race for initialize key"]
+    "bootstrap.initialization_race" -> "bootstrap.won_initialize_race?"
+    "bootstrap.won_initialize_race?" [label="Do I won initialize race?", shape="diamond"]
+    "bootstrap.won_initialize_race?" -> "bootstrap.initdb_and_start" [label="yes" color="green"]
+    "bootstrap.won_initialize_race?" -> "bootstrap.wait_for_leader" [label="no" color="red"]
+    "bootstrap.wait_for_leader" [label="Need to wait for leader key"]
+    "bootstrap.initdb_and_start" [label="Run initdb, start postgres and create roles"]
+    "bootstrap.initdb_and_start" -> "bootstrap.success?"
+    "bootstrap.success?" [label="Success", shape="diamond"]
+    "bootstrap.success?" -> "bootstrap.take_leader_key" [label="yes" color="green"]
+    "bootstrap.success?" -> "bootstrap.clean" [label="no" color="red"]
+    "bootstrap.clean" [label="Remove initialize key from DCS\nand data directory from filesystem"]
+    "bootstrap.take_leader_key" [label="Take a leader key in DCS"]
+  }
+
+  "bootstrap.do_bootstrap" -> "update_member"
+  "bootstrap.wait_for_leader" -> "update_member"
+  "bootstrap.clean" -> "update_member"
+  "bootstrap.take_leader_key" -> "update_member"
+
+  subgraph cluster_process_healthy_cluster {
+    label = "process_healthy_cluster"
+    "healthy_has_lock" [label="Am I the owner of the leader lock?", shape=diamond]
+    "healthy_is_leader" [label="Is Postgres running as master?", shape=diamond]
+    "healthy_no_lock" [label="Follow the leader (async,\ncreate/update recovery.conf and restart if necessary)"]
+    "healthy_has_lock" -> "healthy_no_lock" [label="no" color="red"]
+    "healthy_has_lock" -> "healthy_update_leader_lock" [label="yes" color="green"]
+    "healthy_update_leader_lock" [label="Try to update leader lock"]
+    "healthy_update_leader_lock" -> "healthy_update_success"
+    "healthy_update_success" [label="Success?", shape=diamond]
+    "healthy_update_success" -> "healthy_is_leader" [label="yes" color="green"]
+    "healthy_update_success" -> "healthy_demote" [label="no" color="red"]
+    "healthy_demote" [label="Demote (async,\nrestart in read-only)"]
+    "healthy_failover" [label="Promote Postgres to master"]
+    "healthy_is_leader" -> "healthy_failover" [label="no" color="red"]
+  }
+  "healthy_demote" -> "update_member"
+  "healthy_is_leader" -> "update_member" [label="yes" color="green"]
+  "healthy_failover" -> "update_member"
+  "healthy_no_lock" -> "update_member"
+
+  subgraph cluster_process_unhealthy_cluster {
+    label = "process_unhealthy_cluster"
+    "unhealthy_is_healthiest" [label="Am I the healthiest node?", shape="diamond"]
+    "unhealthy_is_healthiest" -> "unhealthy_leader_race" [label="yes", color="green"]
+    "unhealthy_leader_race" [label="Try to create leader key"]
+    "unhealthy_leader_race" -> "unhealthy_acquire_lock"
+    "unhealthy_acquire_lock" [label="Was I able to get the lock?", shape="diamond"]
+    "unhealthy_is_leader" [label="Is Postgres running as master?", shape=diamond]
+    "unhealthy_acquire_lock" -> "unhealthy_is_leader" [label="yes" color="green"]
+    "unhealthy_is_leader" -> "unhealthy_promote" [label="no" color="red"]
+    "unhealthy_promote" [label="Promote to master"]
+    "unhealthy_is_healthiest" -> "unhealthy_follow" [label="no" color="red"]
+    "unhealthy_follow" [label="try to follow somebody else()"]
+    "unhealthy_acquire_lock" -> "unhealthy_follow" [label="no" color="red"]
+  }
+  "unhealthy_follow" -> "update_member"
+  "unhealthy_promote" -> "update_member"
+  "unhealthy_is_leader" -> "update_member" [label="yes" color="green"]
+}

docs/index.rst

@@ -0,0 +1,37 @@
+.. Patroni documentation master file, created by
+   sphinx-quickstart on Mon Dec 19 16:54:09 2016.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Introduction
+============
+
+Patroni is a template for you to create your own customized, high-availability solution using Python and - for maximum accessibility - a distributed configuration store like `ZooKeeper <https://zookeeper.apache.org/>`__, `etcd <https://github.com/coreos/etcd>`__, `Consul <https://github.com/hashicorp/consul>`__ or `Kubernetes <https://kubernetes.io>`__. Database engineers, DBAs, DevOps engineers, and SREs who are looking to quickly deploy HA PostgreSQL in the datacenter-or anywhere else-will hopefully find it useful.
+
+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. There are many ways to run high availability with PostgreSQL; for a list, see the `PostgreSQL Documentation <https://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling>`__.
+
+**Note to Kubernetes users**: Patroni can run natively on top of Kubernetes. Take a look at the :ref:`Kubernetes <kubernetes>` chapter of the Patroni documentation.
+
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+   README
+   dynamic_configuration
+   ENVIRONMENT
+   SETTINGS
+   replica_bootstrap
+   replication_modes
+   pause
+   kubernetes
+   watchdog
+   releases
+   CONTRIBUTING
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`

docs/kubernetes.rst

@@ -0,0 +1,53 @@
+.. _kubernetes:
+
+Using Patroni with Kubernetes
+=============================
+
+Patroni can use Kubernetes objects in order to store the state of the cluster and manage the leader key. That makes it
+capable of operating Postgres in Kubernetes environment without any consistency store, namely, one doesn't
+need to run an extra Etcd deployment. There are two different type of Kubernetes objects Patroni can use to store the
+leader and the configuration keys, they are configured with the `kubernetes.use_endpoints` or `PATRONI_KUBERNETES_USE_ENDPOINTS`
+environment variable.
+
+Use Endpoints
+-------------
+
+Despite the fact that this is the recommended mode, it is turned off by default for compatibility reasons. When it is on, Patroni stores
+the cluster configuration and the leader key in the `metadata: annotations` fields of the respective `Endpoints` it creates.
+Changing the leader is safer than when using `ConfigMaps`, since both the annotations, containing the leader information, and the actual addresses
+pointing to the running leader pod are updated simultaneously in one go.
+
+Use ConfigMaps
+--------------
+
+In this mode, Patroni will create ConfigMaps instead of Endpoints and store keys inside meta-data of those ConfigMaps.
+Changing the leader takes at least two updates, one to the leader ConfigMap and another to the respective Endpoint.
+
+There are two ways to direct the traffic to the Postgres master:
+
+- use the `callback script <https://github.com/zalando/patroni/blob/master/kubernetes/callback.py>`_ provided by Patroni
+- configure the Kubernetes Postgres service to use the label selector with the `role_label` (configured in patroni configuration).
+
+Note that in some cases, for instance, when running on OpenShift, there is no alternative to using ConfigMaps.
+
+Configuration
+-------------
+
+Patroni Kubernetes :ref:`settings <kubernetes_settings>` and :ref:`environment variables <kubernetes_environment>` are described in the general chapters of the documentation.
+
+Examples
+--------
+
+- The `kubernetes <https://github.com/zalando/patroni/tree/master/kubernetes>`__ folder of the Patroni repository contains
+  examples of the Docker image, the Kubernetes manifest and the callback script in order to test Patroni Kubernetes setup.
+  Note that in the current state it will not be able to use PersistentVolumes because of permission issues.
+
+- 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/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
+  `postgres-operator <https://github.com/zalando-incubator/postgres-operator>`_ project. It implements the operator pattern
+  to manage Spilo clusters.

docs/pause.rst

@@ -1,3 +1,5 @@
+.. _pause:
+
 Pause/Resume mode for the cluster
 =================================
 
@@ -23,7 +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/replica_bootstrap.rst

@@ -0,0 +1,199 @@
+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 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:
+
+Bootstrap
+---------
+
+PostgreSQL provides ``initdb`` command to initialize a new cluster and Patroni calls it by default. In certain cases,
+particularly when creating a new cluster as a copy of an existing one, it is necessary to replace a built-in method with
+custom actions. Patroni supports executing user-defined scripts to bootstrap new clusters, supplying some required
+arguments to them, i.e. the name of the cluster and the path to the data directory. This is configured in the
+``bootstrap`` section of the Patroni configuration. For example:
+
+.. code:: YAML
+
+    bootstrap:
+        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
+                restore_command: <method_specific_restore_command>
+
+
+Each bootstrap method must define at least a ``name`` and a ``command``. A special ``initdb`` method is available to trigger
+the default behavior, in which case ``method`` parameter can be omitted altogether. The ``command`` can be specified using either
+an absolute path, or the one relative to the ``patroni`` command location. In addition to the fixed parameters defined
+in the configuration files, Patroni supplies two cluster-specific ones:
+
+--scope
+    Name of the cluster to be bootstrapped
+--datadir
+    Path to the data directory of the cluster instance to be bootstrapped
+
+If the bootstrap script returns 0, Patroni tries to configure and start the PostgreSQL instance produced by it. If any
+of the intermediate steps fail, or the script returns a non-zero value, Patroni assumes that the bootstrap has failed,
+cleans up after itself and releases the initialize lock to give another node the opportunity to bootstrap.
+
+If a ``recovery_conf`` block is defined in the same section as the custom bootstrap method, Patroni will generate a
+``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
+
+
+.. _custom_replica_creation:
+
+Building replicas
+-----------------
+
+Patroni uses tried and proven ``pg_basebackup`` in order to create new replicas. One downside of it is that it requires
+a running master node. Another one is the lack of 'on-the-fly' compression for the backup data and no built-in cleanup
+for outdated backup files. Some people prefer other backup solutions, such as ``WAL-E``, ``pgBackRest``, ``Barman`` and
+others, or simply roll their own scripts. In order to accommodate all those use-cases Patroni supports running custom
+scripts to clone a new replica. Those are configured in the ``postgresql`` configuration block:
+
+.. code:: YAML
+
+    postgresql:
+        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:
+            command: patroni_wale_restore
+            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_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
+--datadir
+    Path to the data directory of the replica
+--role
+    Always 'replica'
+--connstring
+    Connection string to connect to the cluster member to clone from (master or other replica). The user in the
+    connection string can execute SQL and replication protocol commands.
+
+A special ``no_master`` parameter, if defined, allows Patroni to call the replica creation method even if there is no
+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 instuct 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 different
+methods of creating a replica and recovery WAL records when a cluster is in the
+"standby mode", and after it was detached to function as a normal cluster.
+
+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
+
+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 permenant 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

@@ -0,0 +1,79 @@
+.. _replication_modes:
+
+=================
+Replication modes
+=================
+
+Patroni uses PostgreSQL streaming replication. For more information about streaming replication, see the `Postgres documentation <http://www.postgresql.org/docs/current/static/warm-standby.html#STREAMING-REPLICATION>`__. By default Patroni configures PostgreSQL for asynchronous replication. Choosing your replication schema is dependent on your business considerations. Investigate both async and sync replication, as well as other HA solutions, to determine which solution is best for you.
+
+Asynchronous mode durability
+----------------------------
+
+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 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
+----------------------------------
+
+You can use Postgres's `synchronous replication <http://www.postgresql.org/docs/current/static/warm-standby.html#SYNCHRONOUS-REPLICATION>`__ with Patroni. Synchronous replication ensures consistency across a cluster by confirming that writes are written to a secondary before returning to the connecting client with a success. The cost of synchronous replication: reduced throughput on writes. This throughput will be entirely based on network performance.
+
+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 following lines to the ``parameters`` section of your YAML configuration files:
+
+.. code:: YAML
+
+        synchronous_commit: "on"
+        synchronous_standby_names: "*"
+
+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 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 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, 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 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_node``. 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.
+
+Synchronous mode can be switched on and off via Patroni REST interface. See :ref:`dynamic configuration <dynamic_configuration>` for instructions.
+
+
+Synchronous mode implementation
+-------------------------------
+
+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.
+
+- A node must be set as the synchronous standby in PostgreSQL as long as it is published as the synchronous standby.
+
+- A node that is not the leader or current synchronous standby is not allowed to promote itself automatically.
+
+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 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 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/watchdog.rst

@@ -0,0 +1,39 @@
+.. _watchdog:
+
+Watchdog support
+================
+
+Having multiple PostgreSQL servers running as master can result in transactions lost due to diverging timelines. This situation is also called a split-brain problem. To avoid split-brain Patroni needs to ensure PostgreSQL will not accept any transaction commits after leader key expires in the DCS. Under normal circumstances Patroni will try to achieve this by stopping PostgreSQL when leader lock update fails for any reason. However, this may fail to happen due to various reasons:
+
+- Patroni has crashed due to a bug, out-of-memory condition or by being accidentally killed by a system administrator.
+
+- Shutting down PostgreSQL is too slow.
+
+- 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.
+
+Patroni will try to activate the watchdog before promoting PostgreSQL to master. If watchdog activation fails and watchdog mode is ``required`` then the node will refuse to become master. When deciding to participate in leader election Patroni will also check that watchdog configuration will allow it to become leader at all. After demoting PostgreSQL (for example due to a manual failover) Patroni will disable the watchdog again. Watchdog will also be disabled while Patroni is in paused state.
+
+By default Patroni will set up the watchdog to expire 5 seconds before TTL expires. With the default setup of ``loop_wait=10`` and ``ttl=30`` this gives HA loop at least 15 seconds (``ttl`` - ``safety_margin`` - ``loop_wait``) to complete before the system gets forcefully reset. By default accessing DCS is configured to time out after 10 seconds. This means that when DCS is unavailable, for example due to network issues, Patroni and PostgreSQL will have at least 5 seconds (``ttl`` - ``safety_margin`` - ``loop_wait`` - ``retry_timeout``) to come to a state where all client connections are terminated.
+
+Safety margin is the amount of time that Patroni reserves for time between leader key update and watchdog keepalive. Patroni will try to send a keepalive immediately after confirmation of leader key update. If Patroni process is suspended for extended amount of time at exactly the right moment the keepalive may be delayed for more than the safety margin without triggering the watchdog. This results in a window of time where watchdog will not trigger before leader key expiration, invalidating the guarantee. To be absolutely sure that watchdog will trigger under all circumstances set up the watchdog to expire after half of TTL by setting ``safety_margin`` to -1 to set watchdog timeout to ``ttl // 2``. If you need this guarantee you probably should increase ``ttl`` and/or reduce ``loop_wait`` and ``retry_timeout``.
+
+Currently watchdogs are only supported using Linux watchdog device interface.
+
+Setting up software watchdog on Linux
+-------------------------------------
+
+Default Patroni configuration will try to use ``/dev/watchdog`` on Linux if it is accessible to Patroni. For most use cases using software watchdog built into the Linux kernel is secure enough.
+
+To enable software watchdog issue the following commands as root before starting Patroni:
+
+.. code-block:: bash
+
+    modprobe softdog
+    # Replace postgres with the user you will be running patroni under
+    chown postgres /dev/watchdog
+
+For testing it may be helpful to disable rebooting by adding ``soft_noboot=1`` to the modprobe command line. In this case the watchdog will just log a line in kernel ring buffer, visible via `dmesg`.
+
+Patroni will log information about the watchdog when it is successfully enabled.

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/README.md

@@ -11,3 +11,12 @@ Upstart job for Ubuntu 12.04 or 14.04.  Requires Upstart > 1.4. Intended for sys
 
 ### patroni.service
 Systemd service file, to be copied to /etc/systemd/system/patroni.service, tested on Centos 7.1 with Patroni installed from pip. 
+
+### patroni
+Init.d service file for Debian-like distributions. Copy it to /etc/init.d/, make executable:
+```chmod 755 /etc/init.d/patroni``` and run with ```service patroni start```, or make it starting on boot with ```update-rc.d patroni defaults```. Also you might edit some configuration variables in it:
+PATRONI for patroni.py location
+CONF for configuration file
+LOGFILE for log (script creates it if does not exist)
+
+Note. If you have several versions of Postgres installed, please add to POSTGRES_VERSION the release number which you wish to run. Script uses this value to append PATH environment with correct path to Postgres bin.

extras/startup-scripts/patroni

@@ -0,0 +1,144 @@
+#!/bin/sh
+#
+### BEGIN INIT INFO
+# Provides:          patroni
+# Required-Start:    $remote_fs $syslog
+# Required-Stop:     $remote_fs $syslog
+# Default-Start:     2 3 4 5
+# Default-Stop:      0 1 6
+# Short-Description: Patroni init script
+# Description:       Runners to orchestrate a high-availability PostgreSQL
+### END INIT INFO
+
+### BEGIN USER CONFIGURATION
+
+CONF="/etc/patroni/postgres.yml"
+LOGFILE="/var/log/patroni.log"
+USER="postgres"
+GROUP="postgres"
+
+NAME=patroni
+PATRONI="/opt/patroni/$NAME.py"
+PIDFILE="/var/run/$NAME.pid"
+
+# Set this parameter, if you have several Postgres versions installed
+# POSTGRES_VERSION="9.4"
+POSTGRES_VERSION=""
+
+### END USER CONFIGURATION
+
+. /lib/lsb/init-functions
+
+# Loading this library for get_versions() function
+if test ! -e /usr/share/postgresql-common/init.d-functions; then
+  log_failure_msg "Probably postgresql-common does not installed."
+  exit 1
+else
+  . /usr/share/postgresql-common/init.d-functions
+fi
+
+# Is there Patroni executable?
+if test ! -e $PATRONI; then
+  log_failure_msg "Patroni executable $PATRONI does not exist."
+  exit 1
+fi
+
+# Is there Patroni configuration file?
+if test ! -e $CONF; then
+  log_failure_msg "Patroni configuration file $CONF does not exist."
+  exit 1
+fi
+
+# Create logfile if doesn't exist
+if test ! -e $LOGFILE; then
+  log_action_msg "Creating logfile for Patroni..."
+  touch $LOGFILE
+  chown $USER:$GROUP $LOGFILE
+fi
+
+prepare_pgpath() {
+  if [ "$POSTGRES_VERSION" != "" ]; then
+    if [ -x /usr/lib/postgresql/$POSTGRES_VERSION/bin/pg_ctl ]; then
+      PGPATH="/usr/lib/postgresql/$POSTGRES_VERSION/bin"
+    else
+      log_failure_msg "Postgres version incorrect, check POSTGRES_VERSION variable."
+      exit 0
+    fi
+  else
+    get_versions
+    if echo $versions | grep -q -e "\s"; then
+      log_warning_msg "You have several Postgres versions installed. Please, use POSTGRES_VERSION to define correct environment."
+    else
+      versions=`echo $versions | sed -e 's/^[ \t]*//'`
+      PGPATH="/usr/lib/postgresql/$versions/bin"
+    fi
+  fi
+}
+
+get_pid() {
+  if test -e $PIDFILE; then
+    PID=`cat $PIDFILE`
+    CHILDPID=`ps --ppid $PID -o %p --no-headers`
+  else
+    log_failure_msg "Could not find PID file. Patroni probably down."
+    exit 1
+  fi
+}
+
+
+case "$1" in
+  start)
+    prepare_pgpath
+    PGPATH=$PATH:$PGPATH
+    log_success_msg "Starting Patroni\n"
+    exec start-stop-daemon --start --quiet \
+        --background \
+        --pidfile $PIDFILE --make-pidfile \
+        --chuid $USER:$GROUP \
+        --chdir `eval echo ~$USER` \
+        --exec $PATRONI \
+        --startas /bin/sh -- \
+        -c "/usr/bin/env PATH=$PGPATH /usr/bin/python $PATRONI $CONF >> $LOGFILE 2>&1"
+    ;;
+
+  stop)
+    log_success_msg "Stopping Patroni"
+    get_pid
+    start-stop-daemon --stop --pid $CHILDPID
+    start-stop-daemon --stop --pidfile $PIDFILE --remove-pidfile --quiet
+    ;;
+
+  reload)
+    log_success_msg "Reloading Patroni configuration"
+    get_pid
+    kill -HUP $CHILDPID
+    ;;
+
+  status)
+    get_pid
+    if start-stop-daemon -T --pid $CHILDPID; then
+      log_success_msg "Patroni is running\n"
+      exit 0
+    else
+      log_warning_msg "Patroni in not running\n"
+    fi
+    ;;
+
+  restart)
+    $0 stop
+    $0 start
+    ;;
+
+  *)
+    echo "Usage: /etc/init.d/$NAME {start|stop|restart|reload|status}"
+    exit 1
+    ;;
+esac
+
+if [ $? -eq 0 ]; then
+        echo .
+        exit 0
+else
+        echo " failed"
+        exit 1
+fi

extras/startup-scripts/patroni.service

@@ -11,17 +11,31 @@ 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
 
 # Give a reasonable amount of time for the server to start up/shut down
-TimeoutSec=10
+TimeoutSec=30
 
 # Do not restart the service if it crashes, we want to manually inspect database on failure
 Restart=no

features/backup_create.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+while getopts ":-:" optchar; do
+    [[ "${optchar}" == "-" ]] || continue
+    case "${OPTARG}" in
+        datadir=* )
+            PGDATA=${OPTARG#*=}
+            ;;
+        dbname=* )
+            DBNAME=${OPTARG#*=}
+            ;;
+        walmethod=* )
+            WALMETHOD=${OPTARG#*=}
+            ;;
+    esac
+done
+
+[[ -z $PGDATA || -z $DBNAME || -z $WALMETHOD ]] && exit 1
+
+[[ $WALMETHOD != "none" ]] && WALMETHOD="-X $WALMETHOD" || WALMETHOD=""
+
+exec pg_basebackup -D $PGDATA $WALMETHOD -c fast -d $DBNAME

features/backup_restore.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -x
+
+while getopts ":-:" optchar; do
+    [[ "${optchar}" == "-" ]] || continue
+    case "${OPTARG}" in
+        datadir=* )
+            PGDATA=${OPTARG#*=}
+            ;;
+        sourcedir=* )
+            SOURCE=${OPTARG#*=}
+            ;;
+    esac
+done
+
+[[ -z $PGDATA || -z $SOURCE ]] && exit 1
+
+mkdir -p $(dirname $PGDATA)
+
+exec cp -af $SOURCE $PGDATA

features/basic_replication.feature

@@ -3,15 +3,51 @@ Feature: basic replication
 
   Scenario: check replication of a single table
     Given I start postgres0
-    And postgres0 is a leader after 10 seconds
-    And I start postgres1
-    When I add the table foo to postgres0
+    Then postgres0 is a leader after 10 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
+    And I configure and start postgres2 with a tag replicatefrom postgres0
+    And "sync" key in DCS has leader=postgres0 after 20 seconds
+    And I add the table foo to postgres0
     Then table foo is present on postgres1 after 20 seconds
+    Then table foo is present on postgres2 after 20 seconds
 
-  Scenario: check the basic failover
-    When I kill postgres0
-    Then postgres1 role is the primary after 32 seconds
-    When I start postgres0
+  Scenario: check restart of sync replica
+    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
+    When I issue a GET request to http://127.0.0.1:8009/async
+    Then I receive a response code 200
+
+  Scenario: check the basic failover in synchronous mode
+    Given I run patronictl.py pause batman
+    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
+    Then I receive a response returncode 0
+    And postgres2 role is the primary after 24 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
+
+  Scenario: check immediate failover when master_start_timeout=0
+    Given I kill postmaster on postgres2
+    Then postgres1 is a leader after 10 seconds
+    And postgres1 role is the primary after 10 seconds
+
+  Scenario: check rejoin of the former master with pg_rewind
+    Given I add the table splitbrain to postgres0
+    And I start postgres0
     Then postgres0 role is the secondary after 20 seconds
-    When I add the table bar to postgres1
-    Then table bar is present on postgres0 after 20 seconds
+    When I add the table buz to postgres1
+    Then table buz is present on postgres0 after 20 seconds

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/cascading_replication.feature

@@ -8,6 +8,7 @@ Scenario: check a base backup and streaming replication from a replica
 	And replication works from postgres0 to postgres1 after 20 seconds
 	And I create label with "postgres0" in postgres0 data directory
 	And I create label with "postgres1" in postgres1 data directory
+	And "members/postgres1" key in DCS has state=running after 12 seconds
 	And I configure and start postgres2 with a tag replicatefrom postgres1
 	Then replication works from postgres0 to postgres2 after 30 seconds
 	And there is a label with "postgres1" in postgres2 data directory

features/custom_bootstrap.feature

@@ -0,0 +1,17 @@
+Feature: custom bootstrap
+    We should check that patroni can bootstrap a new cluster from a backup
+
+Scenario: clone existing cluster using pg_basebackup
+    Given I start postgres0
+    Then postgres0 is a leader after 10 seconds
+    When I add the table foo to postgres0
+    And I start postgres1 in a cluster batman1 as a clone of postgres0
+    Then postgres1 is a leader of batman1 after 10 seconds
+    Then table foo is present on postgres1 after 10 seconds
+
+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
+    And table bar is present on postgres2 after 10 seconds

features/environment.py

@@ -1,14 +1,19 @@
 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 tempfile
+import threading
 import time
 import yaml
 
@@ -16,7 +21,8 @@ import yaml
 @six.add_metaclass(abc.ABCMeta)
 class AbstractController(object):
 
-    def __init__(self, name, work_directory, output_dir):
+    def __init__(self, context, name, work_directory, output_dir):
+        self._context = context
         self._name = name
         self._work_directory = work_directory
         self._output_dir = output_dir
@@ -46,6 +52,7 @@ class AbstractController(object):
 
         assert self._has_started(), "Process {0} is not running after being started".format(self._name)
 
+        max_wait_limit *= self._context.timeout_multiplier
         for _ in range(max_wait_limit):
             if self._is_accessible():
                 break
@@ -54,10 +61,11 @@ class AbstractController(object):
             assert False,\
                 "{0} instance is not available for queries after {1} seconds".format(self._name, max_wait_limit)
 
-    def stop(self, kill=False, timeout=15):
+    def stop(self, kill=False, timeout=15, _=False):
         term = False
         start_time = time.time()
 
+        timeout *= self._context.timeout_multiplier
         while self._handle and self._is_running():
             if kill:
                 self._handle.kill()
@@ -71,18 +79,29 @@ class AbstractController(object):
         if self._log:
             self._log.close()
 
+    def cancel_background(self):
+        pass
+
 
 class PatroniController(AbstractController):
     __PORT = 5440
     PATRONI_CONFIG = '{}.yml'
     """ starts and stops individual patronis"""
 
-    def __init__(self, dcs, name, work_directory, output_dir, tags=None):
-        super(PatroniController, self).__init__('patroni_' + name, work_directory, output_dir)
+    def __init__(self, context, name, work_directory, output_dir, custom_config=None):
+        super(PatroniController, self).__init__(context, 'patroni_' + name, work_directory, output_dir)
         PatroniController.__PORT += 1
         self._data_dir = os.path.join(work_directory, 'data', name)
         self._connstring = None
-        self._config = self._make_patroni_test_config(name, dcs, tags)
+        if custom_config and 'watchdog' in custom_config:
+            self.watchdog = WatchdogMonitor(name, work_directory, output_dir)
+            custom_config['watchdog'] = {'driver': 'testing', 'device': self.watchdog.fifo_path, 'mode': 'required'}
+        else:
+            self.watchdog = None
+
+        self._scope = (custom_config or {}).get('scope', 'batman')
+        self._config = self._make_patroni_test_config(name, custom_config)
+        self._closables = []
 
         self._conn = None
         self._curs = None
@@ -98,50 +117,89 @@ class PatroniController(AbstractController):
         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:
+            self.watchdog.start()
+        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],
                                 stdout=self._log, stderr=subprocess.STDOUT, cwd=self._work_directory)
 
-    def _is_accessible(self):
-        return self.query("SELECT 1", fail_ok=True) is not None
+    def stop(self, kill=False, timeout=15, postgres=False):
+        if postgres:
+            return subprocess.call(['pg_ctl', '-D', self._data_dir, 'stop', '-mi', '-w'])
+        super(PatroniController, self).stop(kill, timeout)
+        if isinstance(self._context.dcs_ctl, KubernetesController):
+            self._context.dcs_ctl.delete_pod(self._name[8:])
+        if self.watchdog:
+            self.watchdog.stop()
 
-    def _make_patroni_test_config(self, name, dcs, tags):
+    def _is_accessible(self):
+        cursor = self.query("SELECT 1", fail_ok=True)
+        if cursor is not None:
+            cursor.execute("SET synchronous_commit TO 'local'")
+            return True
+
+    def _make_patroni_test_config(self, name, custom_config):
         patroni_config_name = self.PATRONI_CONFIG.format(name)
         patroni_config_path = os.path.join(self._output_dir, patroni_config_name)
 
         with open(patroni_config_name) as f:
             config = yaml.safe_load(f)
-            config.pop('etcd')
+            config.pop('etcd', None)
 
         host = config['postgresql']['listen'].split(':')[0]
 
         config['postgresql']['listen'] = config['postgresql']['connect_address'] = '{0}:{1}'.format(host, self.__PORT)
 
+        config['name'] = name
+        config['postgresql']['data_dir'] = self._data_dir
+        config['postgresql']['use_unix_socket'] = True
+        config['postgresql']['parameters'].update({
+            'logging_collector': 'on', 'log_destination': 'csvlog', 'log_directory': self._output_dir,
+            'log_filename': name + '.log', 'log_statement': 'all', 'log_min_messages': 'debug1',
+            'unix_socket_directories': self._data_dir})
+
+        if 'bootstrap' in config:
+            config['bootstrap']['post_bootstrap'] = 'psql -w -c "SELECT 1"'
+            if 'initdb' in config['bootstrap']:
+                config['bootstrap']['initdb'].extend([{'auth': 'md5'}, {'auth-host': 'md5'}])
+
+        if custom_config is not None:
+            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)
+
         user = config['postgresql'].get('authentication', config['postgresql']).get('superuser', {})
         self._connkwargs = {k: user[n] for n, k in [('username', 'user'), ('password', 'password')] if n in user}
         self._connkwargs.update({'host': host, 'port': self.__PORT, 'database': 'postgres'})
 
-        config['name'] = name
-        config['postgresql']['data_dir'] = self._data_dir
-        config['postgresql']['parameters'].update({
-            'logging_collector': 'on', 'log_destination': 'csvlog', 'log_directory': self._output_dir,
-            'log_filename': name + '.log', 'log_statement': 'all', 'log_min_messages': 'debug1'})
-
-        if 'bootstrap' in config and 'initdb' in config['bootstrap']:
-            config['bootstrap']['initdb'].extend([{'auth': 'md5'}, {'auth-host': 'md5'}])
-
-        if tags:
-            config['tags'] = tags
-
-        with open(patroni_config_path, 'w') as f:
-            yaml.safe_dump(config, f, default_flow_style=False)
+        self._replication = config['postgresql'].get('authentication', config['postgresql']).get('replication', {})
+        self._replication.update({'host': host, 'port': self.__PORT, 'database': 'postgres'})
 
         return patroni_config_path
 
@@ -177,46 +235,158 @@ class PatroniController(AbstractController):
             time.sleep(1)
         return False
 
+    def get_watchdog(self):
+        return self.watchdog
+
+    def _get_pid(self):
+        try:
+            pidfile = os.path.join(self._data_dir, 'postmaster.pid')
+            if not os.path.exists(pidfile):
+                return None
+            return int(open(pidfile).readline().strip())
+        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'):
+        subprocess.call([PatroniPoolController.BACKUP_SCRIPT, '--walmethod=none',
+                         '--datadir=' + os.path.join(self._output_dir, dest),
+                         '--dbname=' + self.backup_source])
+
+
+class ProcessHang(object):
+
+    """A background thread implementing a cancelable process hang via SIGSTOP."""
+
+    def __init__(self, pid, timeout):
+        self._cancelled = threading.Event()
+        self._thread = threading.Thread(target=self.run)
+        self.pid = pid
+        self.timeout = timeout
+
+    def start(self):
+        self._thread.start()
+
+    def run(self):
+        os.kill(self.pid, signal.SIGSTOP)
+        try:
+            self._cancelled.wait(self.timeout)
+        finally:
+            os.kill(self.pid, signal.SIGCONT)
+
+    def close(self):
+        self._cancelled.set()
+        self._thread.join()
+
 
 class AbstractDcsController(AbstractController):
 
-    _CLUSTER_NODE = '/service/batman'
+    _CLUSTER_NODE = '/service/{0}'
+
+    def __init__(self, context, mktemp=True):
+        work_directory = mktemp and tempfile.mkdtemp() or None
+        super(AbstractDcsController, self).__init__(context, self.name(), work_directory, context.pctl.output_dir)
 
     def _is_accessible(self):
         return self._is_running()
 
-    def stop_and_remove_work_directory(self, timeout=15):
+    def stop(self, kill=False, timeout=15):
         """ terminate process and wipe out the temp work directory, but only if we actually started it"""
-        self.stop(timeout=timeout)
+        super(AbstractDcsController, self).stop(kill=kill, timeout=timeout)
         if self._work_directory:
             shutil.rmtree(self._work_directory)
 
-    def path(self, key=None):
-        return self._CLUSTER_NODE + (key and '/' + key or '')
+    def path(self, key=None, scope='batman'):
+        return self._CLUSTER_NODE.format(scope) + (key and '/' + key or '')
 
     @abc.abstractmethod
-    def query(self, key):
+    def query(self, key, scope='batman'):
         """ query for a value of a given key """
 
-    @abc.abstractmethod
-    def set(self, key, value):
-        """ set a value to a given key """
-
     @abc.abstractmethod
     def cleanup_service_tree(self):
         """ clean all contents stored in the tree used for the tests """
 
+    @classmethod
+    def get_subclasses(cls):
+        for subclass in cls.__subclasses__():
+            for subsubclass in subclass.get_subclasses():
+                yield subsubclass
+            yield subclass
+
+    @classmethod
+    def name(cls):
+        return cls.__name__[:-10].lower()
+
 
 class ConsulController(AbstractDcsController):
 
-    def __init__(self, output_dir):
-        super(ConsulController, self).__init__('consul', tempfile.mkdtemp(), output_dir)
+    def __init__(self, context):
+        super(ConsulController, self).__init__(context)
         os.environ['PATRONI_CONSUL_HOST'] = 'localhost:8500'
+        os.environ['PATRONI_CONSUL_REGISTER_SERVICE'] = 'on'
         self._client = consul.Consul()
+        self._config_file = None
 
     def _start(self):
-        return subprocess.Popen(['consul', 'agent', '-server', '-bootstrap', '-advertise=127.0.0.1',
-                                 '-data-dir', self._work_directory], stdout=self._log, stderr=subprocess.STDOUT)
+        self._config_file = self._work_directory + '.json'
+        with open(self._config_file, 'wb') as f:
+            f.write(b'{"session_ttl_min":"5s","server":true,"bootstrap":true,"advertise_addr":"127.0.0.1"}')
+        return subprocess.Popen(['consul', 'agent', '-config-file', self._config_file, '-data-dir',
+                                 self._work_directory], stdout=self._log, stderr=subprocess.STDOUT)
+
+    def stop(self, kill=False, timeout=15):
+        super(ConsulController, self).stop(kill=kill, timeout=timeout)
+        if self._config_file:
+            os.unlink(self._config_file)
 
     def _is_running(self):
         try:
@@ -224,45 +394,42 @@ class ConsulController(AbstractDcsController):
         except Exception:
             return False
 
-    def path(self, key=None):
-        return super(ConsulController, self).path(key)[1:]
+    def path(self, key=None, scope='batman'):
+        return super(ConsulController, self).path(key, scope)[1:]
 
-    def query(self, key):
-        _, value = self._client.kv.get(self.path(key))
+    def query(self, key, scope='batman'):
+        _, value = self._client.kv.get(self.path(key, scope))
         return value and value['Value'].decode('utf-8')
 
-    def set(self, key, value):
-        self._client.kv.put(self.path(key), value)
-
     def cleanup_service_tree(self):
-        self._client.kv.delete(self.path(), recurse=True)
+        self._client.kv.delete(self.path(scope=''), recurse=True)
+
+    def start(self, max_wait_limit=15):
+        super(ConsulController, self).start(max_wait_limit)
 
 
 class EtcdController(AbstractDcsController):
 
     """ handles all etcd related tasks, used for the tests setup and cleanup """
 
-    def __init__(self, output_dir):
-        super(EtcdController, self).__init__('etcd', tempfile.mkdtemp(), output_dir)
-        os.environ['PATRONI_ETCD_HOST'] = 'localhost:4001'
-        self._client = etcd.Client()
+    def __init__(self, context):
+        super(EtcdController, self).__init__(context)
+        os.environ['PATRONI_ETCD_HOST'] = 'localhost:2379'
+        self._client = etcd.Client(port=2379)
 
     def _start(self):
         return subprocess.Popen(["etcd", "--debug", "--data-dir", self._work_directory],
                                 stdout=self._log, stderr=subprocess.STDOUT)
 
-    def query(self, key):
+    def query(self, key, scope='batman'):
         try:
-            return self._client.get(self.path(key)).value
+            return self._client.get(self.path(key, scope)).value
         except etcd.EtcdKeyNotFound:
             return None
 
-    def set(self, key, value):
-        self._client.set(self.path(key), value)
-
     def cleanup_service_tree(self):
         try:
-            self._client.delete(self.path(), recursive=True)
+            self._client.delete(self.path(scope=''), recursive=True)
         except (etcd.EtcdKeyNotFound, etcd.EtcdConnectionFailed):
             return
         except Exception as e:
@@ -276,12 +443,82 @@ class EtcdController(AbstractDcsController):
             return False
 
 
+class KubernetesController(AbstractDcsController):
+
+    def __init__(self, context):
+        super(KubernetesController, self).__init__(context)
+        self._namespace = 'default'
+        self._labels = {"application": "patroni"}
+        self._label_selector = ','.join('{0}={1}'.format(k, v) for k, v in self._labels.items())
+        os.environ['PATRONI_KUBERNETES_LABELS'] = json.dumps(self._labels)
+        os.environ['PATRONI_KUBERNETES_USE_ENDPOINTS'] = 'true'
+
+        from kubernetes import client as k8s_client, config as k8s_config
+        k8s_config.load_kube_config(context='local')
+        self._client = k8s_client
+        self._api = self._client.CoreV1Api()
+
+    def _start(self):
+        pass
+
+    def create_pod(self, name, scope):
+        labels = self._labels.copy()
+        labels['cluster-name'] = scope
+        metadata = self._client.V1ObjectMeta(namespace=self._namespace, name=name, labels=labels)
+        spec = self._client.V1PodSpec(containers=[self._client.V1Container(name=name, image='empty')])
+        body = self._client.V1Pod(metadata=metadata, spec=spec)
+        self._api.create_namespaced_pod(self._namespace, body)
+
+    def delete_pod(self, name):
+        try:
+            self._api.delete_namespaced_pod(name, self._namespace, self._client.V1DeleteOptions())
+        except:
+            pass
+        while True:
+            try:
+                self._api.read_namespaced_pod(name, self._namespace)
+            except:
+                break
+
+    def query(self, key, scope='batman'):
+        if key.startswith('members/'):
+            pod = self._api.read_namespaced_pod(key[8:], self._namespace)
+            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':
+                    return e.metadata.annotations[key]
+                else:
+                    return json.dumps(e.metadata.annotations)
+            except:
+                return None
+
+    def cleanup_service_tree(self):
+        try:
+            self._api.delete_collection_namespaced_pod(self._namespace, label_selector=self._label_selector)
+        except:
+            pass
+        try:
+            self._api.delete_collection_namespaced_endpoints(self._namespace, label_selector=self._label_selector)
+        except:
+            pass
+
+        while True:
+            result = self._api.list_namespaced_pod(self._namespace, label_selector=self._label_selector)
+            if len(result.items) < 1:
+                break
+
+    def _is_running(self):
+        return True
+
+
 class ZooKeeperController(AbstractDcsController):
 
     """ handles all zookeeper related tasks, used for the tests setup and cleanup """
 
-    def __init__(self, output_dir, export_env=True):
-        super(ZooKeeperController, self).__init__('zookeeper', None, output_dir)
+    def __init__(self, context, export_env=True):
+        super(ZooKeeperController, self).__init__(context, False)
         if export_env:
             os.environ['PATRONI_ZOOKEEPER_HOSTS'] = "'localhost:2181'"
         self._client = kazoo.client.KazooClient()
@@ -289,18 +526,15 @@ class ZooKeeperController(AbstractDcsController):
     def _start(self):
         pass  # TODO: implement later
 
-    def query(self, key):
+    def query(self, key, scope='batman'):
         try:
-            return self._client.get(self.path(key))[0].decode('utf-8')
+            return self._client.get(self.path(key, scope))[0].decode('utf-8')
         except kazoo.exceptions.NoNodeError:
             return None
 
-    def set(self, key, value):
-        self._client.set(self.path(key), value.encode('utf-8'))
-
     def cleanup_service_tree(self):
         try:
-            self._client.delete(self.path(), recursive=True)
+            self._client.delete(self.path(scope=''), recursive=True)
         except (kazoo.exceptions.NoNodeError):
             return
         except Exception as e:
@@ -318,22 +552,23 @@ class ZooKeeperController(AbstractDcsController):
 
 class ExhibitorController(ZooKeeperController):
 
-    def __init__(self, output_dir):
-        super(ExhibitorController, self).__init__(output_dir, False)
+    def __init__(self, context):
+        super(ExhibitorController, self).__init__(context, False)
         os.environ.update({'PATRONI_EXHIBITOR_HOSTS': 'localhost', 'PATRONI_EXHIBITOR_PORT': '8181'})
 
 
 class PatroniPoolController(object):
 
-    KNOWN_DCS = {'consul': ConsulController, 'etcd': EtcdController,
-                 'zookeeper': ZooKeeperController, 'exhibitor': ExhibitorController}
+    BACKUP_SCRIPT = 'features/backup_create.sh'
 
-    def __init__(self):
+    def __init__(self, context):
+        self._context = context
         self._dcs = None
         self._output_dir = None
         self._patroni_path = None
         self._processes = {}
         self.create_and_set_output_directory('')
+        self.known_dcs = {subclass.name(): subclass for subclass in AbstractDcsController.get_subclasses()}
 
     @property
     def patroni_path(self):
@@ -350,21 +585,25 @@ class PatroniPoolController(object):
     def output_dir(self):
         return self._output_dir
 
-    def start(self, pg_name, max_wait_limit=20, tags=None):
-        if pg_name not in self._processes:
-            self._processes[pg_name] = PatroniController(self.dcs, pg_name, self.patroni_path, self._output_dir, tags)
-        self._processes[pg_name].start(max_wait_limit)
+    def start(self, name, max_wait_limit=20, custom_config=None):
+        if name not in self._processes:
+            self._processes[name] = PatroniController(self._context, name, self.patroni_path,
+                                                      self._output_dir, custom_config)
+        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']:
+        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']:
             raise AttributeError("PatroniPoolController instance has no attribute '{0}'".format(func))
 
-        def wrapper(pg_name, *args, **kwargs):
-            return getattr(self._processes[pg_name], func)(*args, **kwargs)
+        def wrapper(name, *args, **kwargs):
+            return getattr(self._processes[name], func)(*args, **kwargs)
         return wrapper
 
     def stop_all(self):
         for ctl in self._processes.values():
+            ctl.cancel_background()
             ctl.stop()
         self._processes.clear()
 
@@ -375,28 +614,201 @@ class PatroniPoolController(object):
         os.makedirs(feature_dir)
         self._output_dir = feature_dir
 
+    def clone(self, from_name, cluster_name, to_name):
+        f = self._processes[from_name]
+        custom_config = {
+            'scope': cluster_name,
+            'bootstrap': {
+                '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'))
+                },
+                'authentication': {
+                    'superuser': {'password': 'zalando1'},
+                    'replication': {'password': 'rep-pass1'}
+                }
+            }
+        }
+        self.start(to_name, custom_config=custom_config)
+
+    def bootstrap_from_backup(self, name, cluster_name):
+        custom_config = {
+            'scope': cluster_name,
+            'bootstrap': {
+                'method': 'backup_restore',
+                'backup_restore': {
+                    'command': 'features/backup_restore.sh --sourcedir=' + os.path.join(self._output_dir, 'basebackup'),
+                    'recovery_conf': {
+                        'recovery_target_action': 'promote',
+                        'recovery_target_timeline': 'latest',
+                        'restore_command': 'cp {0}/wal_archive/%f %p'.format(self._output_dir)
+                    }
+                }
+            },
+            'postgresql': {
+                'authentication': {
+                    'superuser': {'password': 'zalando2'},
+                    'replication': {'password': 'rep-pass2'}
+                }
+            }
+        }
+        self.start(name, custom_config=custom_config)
+
     @property
     def dcs(self):
         if self._dcs is None:
             self._dcs = os.environ.pop('DCS', 'etcd')
-            assert self._dcs in self.KNOWN_DCS, 'Unsupported dcs: ' + self._dcs
+            assert self._dcs in self.known_dcs, 'Unsupported dcs: ' + self._dcs
         return self._dcs
 
 
+class WatchdogMonitor(object):
+    """Testing harness for emulating a watchdog device as a named pipe. Because we can't easily emulate ioctl's we
+    require a custom driver on Patroni side. The device takes no action, only notes if it was pinged and/or triggered.
+    """
+    def __init__(self, name, work_directory, output_dir):
+        self.fifo_path = os.path.join(work_directory, 'data', 'watchdog.{0}.fifo'.format(name))
+        self.fifo_file = None
+        self._stop_requested = False  # Relying on bool setting being atomic
+        self._thread = None
+        self.last_ping = None
+        self.was_pinged = False
+        self.was_closed = False
+        self._was_triggered = False
+        self.timeout = 60
+        self._log_file = open(os.path.join(output_dir, 'watchdog.{0}.log'.format(name)), 'w')
+        self._log("watchdog {0} initialized".format(name))
+
+    def _log(self, msg):
+        tstamp = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S,%f")
+        self._log_file.write("{0}: {1}\n".format(tstamp, msg))
+
+    def start(self):
+        assert self._thread is None
+        self._stop_requested = False
+        self._log("starting fifo {0}".format(self.fifo_path))
+        fifo_dir = os.path.dirname(self.fifo_path)
+        if os.path.exists(self.fifo_path):
+            os.unlink(self.fifo_path)
+        elif not os.path.exists(fifo_dir):
+            os.mkdir(fifo_dir)
+        os.mkfifo(self.fifo_path)
+        self.last_ping = time.time()
+
+        self._thread = threading.Thread(target=self.run)
+        self._thread.start()
+
+    def run(self):
+        try:
+            while not self._stop_requested:
+                self._log("opening")
+                self.fifo_file = os.open(self.fifo_path, os.O_RDONLY)
+                try:
+                    self._log("Fifo {0} connected".format(self.fifo_path))
+                    self.was_closed = False
+                    while not self._stop_requested:
+                        c = os.read(self.fifo_file, 1)
+
+                        if c == b'X':
+                            self._log("Stop requested")
+                            return
+                        elif c == b'':
+                            self._log("Pipe closed")
+                            break
+                        elif c == b'C':
+                            command = b''
+                            c = os.read(self.fifo_file, 1)
+                            while c != b'\n' and c != b'':
+                                command += c
+                                c = os.read(self.fifo_file, 1)
+                            command = command.decode('utf8')
+
+                            if command.startswith('timeout='):
+                                self.timeout = int(command.split('=')[1])
+                                self._log("timeout={0}".format(self.timeout))
+                        elif c in [b'V', b'1']:
+                            cur_time = time.time()
+                            if cur_time - self.last_ping > self.timeout:
+                                self._log("Triggered")
+                                self._was_triggered = True
+                            if c == b'V':
+                                self._log("magic close")
+                                self.was_closed = True
+                            elif c == b'1':
+                                self.was_pinged = True
+                                self._log("ping after {0} seconds".format(cur_time - (self.last_ping or cur_time)))
+                                self.last_ping = cur_time
+                        else:
+                            self._log('Unknown command {0} received from fifo'.format(c))
+                finally:
+                    self.was_closed = True
+                    self._log("closing")
+                    os.close(self.fifo_file)
+        except Exception as e:
+            self._log("Error {0}".format(e))
+        finally:
+            self._log("stopping")
+            self._log_file.flush()
+            if os.path.exists(self.fifo_path):
+                os.unlink(self.fifo_path)
+
+    def stop(self):
+        self._log("Monitor stop")
+        self._stop_requested = True
+        try:
+            if os.path.exists(self.fifo_path):
+                fd = os.open(self.fifo_path, os.O_WRONLY)
+                os.write(fd, b'X')
+                os.close(fd)
+        except Exception as e:
+            self._log("err while closing: {0}".format(str(e)))
+        if self._thread:
+            self._thread.join()
+            self._thread = None
+
+    def reset(self):
+        self._log("reset")
+        self.was_pinged = self.was_closed = self._was_triggered = False
+
+    @property
+    def was_triggered(self):
+        delta = time.time() - self.last_ping
+        triggered = self._was_triggered or not self.was_closed and delta > self.timeout
+        self._log("triggered={0}, {1}s left".format(triggered, self.timeout - delta))
+        return triggered
+
+
 # actions to execute on start/stop of the tests and before running invidual features
 def before_all(context):
-    context.pctl = PatroniPoolController()
-    context.dcs_ctl = context.pctl.KNOWN_DCS[context.pctl.dcs](context.pctl.output_dir)
+    os.environ.update({'PATRONI_RESTAPI_USERNAME': 'username', 'PATRONI_RESTAPI_PASSWORD': 'password'})
+    context.ci = 'TRAVIS_BUILD_NUMBER' in os.environ or 'BUILD_NUMBER' in os.environ
+    context.timeout_multiplier = 2 if context.ci else 1
+    context.pctl = PatroniPoolController(context)
+    context.dcs_ctl = context.pctl.known_dcs[context.pctl.dcs](context)
     context.dcs_ctl.start()
     try:
         context.dcs_ctl.cleanup_service_tree()
     except AssertionError:  # after_all handlers won't be executed in before_all
-        context.dcs_ctl.stop_and_remove_work_directory()
+        context.dcs_ctl.stop()
         raise
 
 
 def after_all(context):
-    context.dcs_ctl.stop_and_remove_work_directory()
+    context.dcs_ctl.stop()
     subprocess.call(['coverage', 'combine'])
     subprocess.call(['coverage', 'report'])
 

features/patroni_api.feature

@@ -13,17 +13,17 @@ Scenario: check API requests on a stand-alone server
 	When I run patronictl.py reinit batman postgres0 --force
 	Then I receive a response returncode 0
 	And I receive a response output "Failed: reinitialize for member postgres0, status code=503, (I am the leader, can not reinitialize)"
-	When I run patronictl.py failover batman --master postgres0 --force
+	When I run patronictl.py switchover batman --master postgres0 --force
 	Then I receive a response returncode 1
-	And I receive a response output "Error: No candidates found to failover to"
-	When I issue a POST request to http://127.0.0.1:8008/failover with {"leader": "postgres0"}
-	Then I receive a response code 500
-	And I receive a response text failover is not possible: cluster does not have members except leader
+	And I receive a response output "Error: No candidates found to switchover to"
+	When I issue a POST request to http://127.0.0.1:8008/switchover with {"leader": "postgres0"}
+	Then I receive a response code 412
+	And I receive a response text switchover is not possible: cluster does not have members except leader
 	When I issue an empty POST request to http://127.0.0.1:8008/failover
 	Then I receive a response code 400
 	When I issue a POST request to http://127.0.0.1:8008/failover with {"foo": "bar"}
 	Then I receive a response code 400
-	And I receive a response text "No values given for required parameters leader and candidate"
+	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
@@ -34,16 +34,16 @@ Scenario: check local configuration reload
 	Then I receive a response code 202
 
 Scenario: check dynamic configuration change via DCS
-	Given I issue a PATCH request to http://127.0.0.1:8008/config with {"ttl": 20, "loop_wait": 2, "postgresql": {"parameters": {"max_connections": 101}}}
-	Then I receive a response code 200
-	And I receive a response loop_wait 2
+	Given I run patronictl.py edit-config -s 'ttl=10' -s 'loop_wait=2' -p 'max_connections=101' --force batman
+	Then I receive a response returncode 0
+	And I receive a response output "+loop_wait: 2"
 	And Response on GET http://127.0.0.1:8008/patroni contains pending_restart after 11 seconds
 	When I issue a GET request to http://127.0.0.1:8008/config
 	Then I receive a response code 200
 	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'}
 
 Scenario: check API requests for the primary-replica pair in the pause mode
 	Given I run patronictl.py pause batman
@@ -64,36 +64,52 @@ Scenario: check API requests for the primary-replica pair in the pause mode
 	When I sleep for 10 seconds
 	Then postgres1 role is the secondary after 15 seconds
 
-Scenario: check the failover via the API in the pause mode
-	Given I run patronictl.py failover batman --master postgres0 --candidate postgres1 --force
-	Then I receive a response returncode 0
+Scenario: check the switchover via the API in the pause mode
+	Given I issue a POST request to http://127.0.0.1:8008/switchover with {"leader": "postgres0", "candidate": "postgres1"}
+	Then I receive a response code 200
 	And postgres1 is a leader after 5 seconds
 	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
+	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 failover
-	Given I issue a scheduled failover from postgres1 to postgres0 in 1 seconds
+Scenario: check the scheduled switchover
+	Given I issue a scheduled switchover from postgres1 to postgres0 in 3 seconds
 	Then I receive a response returncode 1
-	And I receive a response output "Can't schedule failover in the paused state"
+	And I receive a response output "Can't schedule switchover in the paused state"
 	When I run patronictl.py resume batman
 	Then I receive a response returncode 0
-	Given I issue a scheduled failover from postgres1 to postgres0 in 1 seconds
+	Given I issue a scheduled switchover from postgres1 to postgres0 in 3 seconds
 	Then I receive a response returncode 0
 	And postgres0 is a leader after 20 seconds
 	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
+	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
 
 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 1 seconds with {"role": "replica"}
+	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 2 seconds
+		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 1 seconds with {"restart_pending": "True"}
+	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 +1,34 @@
+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 I sleep for 2 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 2 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
+    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 I sleep for 2 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 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 20 seconds

features/steps/basic_replication.py

@@ -11,7 +11,7 @@ def start_patroni(context, name):
 
 @step('I shut down {name:w}')
 def stop_patroni(context, name):
-    return context.pctl.stop(name)
+    return context.pctl.stop(name, timeout=60)
 
 
 @step('I kill {name:w}')
@@ -19,6 +19,11 @@ def kill_patroni(context, name):
     return context.pctl.stop(name, kill=True)
 
 
+@step('I kill postmaster on {name:w}')
+def stop_postgres(context, name):
+    return context.pctl.stop(name, postgres=True)
+
+
 @step('I add the table {table_name:w} to {pg_name:w}')
 def add_table(context, table_name, pg_name):
     # parse the configuration file and get the port
@@ -30,6 +35,7 @@ def add_table(context, table_name, pg_name):
 
 @then('Table {table_name:w} is present on {pg_name:w} after {max_replication_delay:d} seconds')
 def table_is_present_on(context, table_name, pg_name, max_replication_delay):
+    max_replication_delay *= context.timeout_multiplier
     for _ in range(int(max_replication_delay)):
         if context.pctl.query(pg_name, "SELECT 1 FROM {0}".format(table_name), fail_ok=True) is not None:
             break
@@ -41,6 +47,7 @@ def table_is_present_on(context, table_name, pg_name, max_replication_delay):
 
 @then('{pg_name:w} role is the {pg_role:w} after {max_promotion_timeout:d} seconds')
 def check_role(context, pg_name, pg_role, max_promotion_timeout):
+    max_promotion_timeout *= context.timeout_multiplier
     assert context.pctl.check_role_has_changed_to(pg_name, pg_role, timeout=int(max_promotion_timeout)),\
         "{0} role didn't change to {1} after {2} seconds".format(pg_name, pg_role, max_promotion_timeout)
 

features/steps/cascading_replication.py

@@ -1,9 +1,12 @@
+import json
+import time
+
 from behave import step, then
 
 
 @step('I configure and start {name:w} with a tag {tag_name:w} {tag_value:w}')
 def start_patroni_with_a_name_value_tag(context, name, tag_name, tag_value):
-    return context.pctl.start(name, tags={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')
@@ -15,3 +18,18 @@ def check_label(context, content, name):
 @step('I create label with "{content:w}" in {name:w} data directory')
 def write_label(context, content, name):
     context.pctl.write_label(name, content)
+
+
+@step('"{name}" key in DCS has {key:w}={value:w} after {time_limit:d} seconds')
+def check_member(context, name, key, value, time_limit):
+    time_limit *= context.timeout_multiplier
+    max_time = time.time() + int(time_limit)
+    while time.time() < max_time:
+        try:
+            response = json.loads(context.dcs_ctl.query(name))
+            if response.get(key) == value:
+                return
+        except Exception:
+            pass
+        time.sleep(1)
+    assert False, "{0} does not have {1}={2} in dcs after {3} seconds".format(name, key, value, time_limit)

features/steps/custom_bootstrap.py

@@ -0,0 +1,27 @@
+import time
+
+from behave import step, then
+
+
+@step('I start {name:w} in a cluster {cluster_name:w} as a clone of {name2:w}')
+def start_cluster_clone(context, name, cluster_name, name2):
+    context.pctl.clone(name2, cluster_name, name)
+
+
+@step('I start {name:w} in a cluster {cluster_name:w} from backup')
+def start_cluster_from_backup(context, name, cluster_name):
+    context.pctl.bootstrap_from_backup(name, cluster_name)
+
+
+@then('{name:w} is a leader of {cluster_name:w} after {time_limit:d} seconds')
+def is_a_leader(context, name, cluster_name, time_limit):
+    time_limit *= context.timeout_multiplier
+    max_time = time.time() + int(time_limit)
+    while (context.dcs_ctl.query("leader", scope=cluster_name) != name):
+        time.sleep(1)
+        assert time.time() < max_time, "{0} is not a leader in dcs after {1} seconds".format(name, time_limit)
+
+
+@step('I do a backup of {name:w}')
+def do_backup(context, name):
+    context.pctl.backup(name)

features/steps/patroni_api.py

@@ -1,6 +1,7 @@
+import base64
 import json
+import os
 import parse
-import pytz
 import requests
 import shlex
 import subprocess
@@ -8,8 +9,11 @@ import time
 import yaml
 
 from behave import register_type, step, then
+from dateutil import tz
 from datetime import datetime, timedelta
 
+tzutc = tz.tzutc()
+
 
 @parse.with_pattern(r'https?://(?:\w|\.|:|/)+')
 def parse_url(text):
@@ -27,6 +31,7 @@ register_type(url=parse_url)
 @step('{name:w} is a leader after {time_limit:d} seconds')
 @then('{name:w} is a leader after {time_limit:d} seconds')
 def is_a_leader(context, name, time_limit):
+    time_limit *= context.timeout_multiplier
     max_time = time.time() + int(time_limit)
     while (context.dcs_ctl.query("leader") != name):
         time.sleep(1)
@@ -74,11 +79,13 @@ 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'}
     try:
         if request_method == 'PATCH':
-            r = requests.patch(url, json=data)
+            r = requests.patch(url, headers=headers, json=data)
         else:
-            r = requests.post(url, json=data)
+            r = requests.post(url, headers=headers, json=data)
     except requests.exceptions.RequestException:
         context.status_code = None
         context.response = None
@@ -90,7 +97,10 @@ def do_request(context, request_method, url, data):
 def do_run(context, cmd):
     cmd = ['coverage', 'run', '--source=patroni', '-p'] + shlex.split(cmd)
     try:
-        response = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
+        # XXX: Dirty hack! We need to take name/passwd from the config!
+        env = os.environ.copy()
+        env.update({'PATRONI_RESTAPI_USERNAME': 'username', 'PATRONI_RESTAPI_PASSWORD': 'password'})
+        response = subprocess.check_output(cmd, stderr=subprocess.STDOUT, env=env)
         context.status_code = 0
     except subprocess.CalledProcessError as e:
         response = e.output
@@ -104,7 +114,8 @@ def check_response(context, component, data):
         assert context.status_code == int(data),\
             "status code {0} != {1}, response: {2}".format(context.status_code, data, context.response)
     elif component == 'returncode':
-        assert context.status_code == int(data), "return code {0} != {1}".format(context.status_code, data)
+        assert context.status_code == int(data), "return code {0} != {1}, {2}".format(context.status_code,
+                                                                                      data, context.response)
     elif component == 'text':
         assert context.response == data.strip('"'), "response {0} does not contain {1}".format(context.response, data)
     elif component == 'output':
@@ -114,17 +125,17 @@ def check_response(context, component, data):
         assert str(context.response[component]) == str(data), "{0} does not contain {1}".format(component, data)
 
 
-@step('I issue a scheduled failover from {from_host:w} to {to_host:w} in {in_seconds:d} seconds')
-def scheduled_failover(context, from_host, to_host, in_seconds):
+@step('I issue a scheduled switchover from {from_host:w} to {to_host:w} in {in_seconds:d} seconds')
+def scheduled_switchover(context, from_host, to_host, in_seconds):
     context.execute_steps(u"""
-        Given I run patronictl.py failover batman --master {0} --candidate {1} --scheduled "{2}" --force
-    """.format(from_host, to_host, datetime.now(pytz.utc) + timedelta(seconds=int(in_seconds))))
+        Given I run patronictl.py switchover batman --master {0} --candidate {1} --scheduled "{2}" --force
+    """.format(from_host, to_host, datetime.now(tzutc) + timedelta(seconds=int(in_seconds))))
 
 
 @step('I issue a scheduled restart at {url:url} in {in_seconds:d} seconds with {data}')
 def scheduled_restart(context, url, in_seconds, data):
     data = data and json.loads(data) or {}
-    data.update(schedule='{0}'.format((datetime.now(pytz.utc) + timedelta(seconds=int(in_seconds))).isoformat()))
+    data.update(schedule='{0}'.format((datetime.now(tzutc) + timedelta(seconds=int(in_seconds))).isoformat()))
     context.execute_steps(u"""Given I issue a POST request to {0}/restart with {1}""".format(url, json.dumps(data)))
 
 
@@ -135,6 +146,7 @@ def add_tag_to_config(context, tag, value, pg_name):
 
 @then('Response on GET {url} contains {value} after {timeout:d} seconds')
 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:

features/steps/standby_cluster.py

@@ -0,0 +1,67 @@
+import os
+import time
+
+from behave import step
+
+
+select_replication_query = """
+SELECT * FROM pg_catalog.pg_stat_replication
+WHERE application_name = '{0}'
+"""
+
+
+@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
+    })
+
+
+@step('I start {name:w} in a standby cluster {cluster_name:w} as a clone of {name2:w}')
+def start_patroni_stanby_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": {
+                "standby_cluster": {
+                    "host": "localhost",
+                    "port": port,
+                    "primary_slot_name": "pm_1",
+                }
+            }
+        }
+    })
+    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:
+            return True
+
+        time.sleep(1)
+
+    return False

features/steps/watchdog.py

@@ -0,0 +1,74 @@
+from behave import step, then
+import time
+
+
+def polling_loop(timeout, interval=1):
+    """Returns an iterator that returns values until timeout has passed. Timeout is measured from start of iteration."""
+    start_time = time.time()
+    iteration = 0
+    end_time = start_time + timeout
+    while time.time() < end_time:
+        yield iteration
+        iteration += 1
+        time.sleep(interval)
+
+
+@step('I start {name:w} with watchdog')
+def start_patroni_with_watchdog(context, name):
+    return context.pctl.start(name, custom_config={'watchdog': True})
+
+
+@step('{name:w} watchdog has been pinged after {timeout:d} seconds')
+def watchdog_was_pinged(context, name, timeout):
+    for _ in polling_loop(timeout):
+        if context.pctl.get_watchdog(name).was_pinged:
+            return True
+    return False
+
+
+@then('{name:w} watchdog has been closed')
+def watchdog_was_closed(context, name):
+    assert context.pctl.get_watchdog(name).was_closed
+
+
+@step('I reset {name:w} watchdog state')
+def watchdog_reset_pinged(context, name):
+    context.pctl.get_watchdog(name).reset()
+
+
+@then('{name:w} watchdog is triggered after {timeout:d} seconds')
+def watchdog_was_triggered(context, name, timeout):
+    for _ in polling_loop(timeout):
+        if context.pctl.get_watchdog(name).was_triggered:
+            return True
+    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)

features/watchdog.feature

@@ -0,0 +1,31 @@
+Feature: watchdog
+  Verify that watchdog gets pinged and triggered under appropriate circumstances.
+
+  Scenario: watchdog is opened and pinged
+    Given I start postgres0 with watchdog
+    Then postgres0 is a leader after 10 seconds
+    And postgres0 role is the primary after 10 seconds
+    And postgres0 watchdog has been pinged after 10 seconds
+
+  Scenario: watchdog is disabled during pause
+    Given I run patronictl.py pause batman
+    Then I receive a response returncode 0
+    When I sleep for 2 seconds
+    Then postgres0 watchdog has been closed
+
+  Scenario: watchdog is opened and pinged after resume
+    Given I reset postgres0 watchdog state
+    And I run patronictl.py resume batman
+    Then I receive a response returncode 0
+    And postgres0 watchdog has been pinged after 10 seconds
+
+  Scenario: watchdog is disabled when shutting down
+    Given I shut down postgres0
+    Then postgres0 watchdog has been closed
+
+  Scenario: watchdog is triggered if patroni stops responding
+    Given I reset postgres0 watchdog state
+    And I start postgres0 with watchdog
+    Then postgres0 role is the primary after 10 seconds
+    When postgres0 hangs for 30 seconds
+    Then postgres0 watchdog is triggered after 30 seconds

haproxy.cfg

@@ -1,21 +1,25 @@
 global
-	maxconn 100
+    maxconn 100
 
 defaults
-	log	global
-	mode	tcp
-	retries 2
-	timeout client 30m
-	timeout connect 4s
-	timeout server 30m
-	timeout check 5s
+    log global
+    mode tcp
+    retries 2
+    timeout client 30m
+    timeout connect 4s
+    timeout server 30m
+    timeout check 5s
 
-frontend ft_postgresql
-	bind *:5000
-	default_backend bk_db
-
-backend bk_db
-	option httpchk
+listen stats
+    mode http
+    bind *:7000
+    stats enable
+    stats uri /
 
+listen batman
+    bind *:5000
+    option httpchk
+    http-check expect status 200
+    default-server inter 3s fall 3 rise 2 on-marked-down shutdown-sessions
     server postgresql_127.0.0.1_5432 127.0.0.1:5432 maxconn 100 check port 8008
     server postgresql_127.0.0.1_5433 127.0.0.1:5433 maxconn 100 check port 8009

kubernetes/Dockerfile

@@ -0,0 +1,34 @@
+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-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 \
+    && 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 python3-pip python3-wheel \
+    && apt-get autoremove -y \
+    && apt-get clean -y \
+    && rm -rf /var/lib/apt/lists/* /root/.cache
+
+ADD entrypoint.sh /
+
+EXPOSE 5432 8008
+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/entrypoint.sh

@@ -0,0 +1,39 @@
+#!/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:
+    postgresql:
+      use_pg_rewind: true
+  initdb:
+  - auth-host: md5
+  - auth-local: trust
+  - encoding: UTF8
+  - locale: en_US.UTF-8
+  - data-checksums
+  pg_hba:
+  - host all all 0.0.0.0/0 md5
+  - host replication ${PATRONI_REPLICATION_USERNAME} ${PATRONI_KUBERNETES_POD_IP}/16 md5
+restapi:
+  connect_address: '${PATRONI_KUBERNETES_POD_IP}:8008'
+postgresql:
+  connect_address: '${PATRONI_KUBERNETES_POD_IP}:5432'
+  authentication:
+    superuser:
+      password: '${PATRONI_SUPERUSER_PASSWORD}'
+    replication:
+      password: '${PATRONI_REPLICATION_PASSWORD}'
+__EOF__
+
+unset PATRONI_SUPERUSER_PASSWORD PATRONI_REPLICATION_PASSWORD
+export KUBERNETES_NAMESPACE=$PATRONI_KUBERNETES_NAMESPACE
+export POD_NAME=$PATRONI_NAME
+
+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

@@ -0,0 +1,188 @@
+apiVersion: apps/v1beta1
+kind: StatefulSet
+metadata:
+  name: &cluster_name patronidemo
+  labels:
+    application: patroni
+    cluster-name: *cluster_name
+spec:
+  replicas: 3
+  serviceName: *cluster_name
+  template:
+    metadata:
+      labels:
+        application: patroni
+        cluster-name: *cluster_name
+    spec:
+      serviceAccountName: patronidemo
+      containers:
+      - name: *cluster_name
+        image: patroni  # docker build -t patroni .
+        imagePullPolicy: IfNotPresent
+        ports:
+        - containerPort: 8008
+          protocol: TCP
+        - containerPort: 5432
+          protocol: TCP
+        volumeMounts:
+        - mountPath: /home/postgres/pgdata
+          name: pgdata
+        env:
+        - name: PATRONI_KUBERNETES_POD_IP
+          valueFrom:
+            fieldRef:
+              fieldPath: status.podIP
+        - name: PATRONI_KUBERNETES_NAMESPACE
+          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
+          value: postgres
+        - name: PATRONI_SUPERUSER_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              name: *cluster_name
+              key: superuser-password
+        - name: PATRONI_REPLICATION_USERNAME
+          value: standby
+        - name: PATRONI_REPLICATION_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              name: *cluster_name
+              key: replication-password
+        - name: PATRONI_SCOPE
+          value: *cluster_name
+        - name: PATRONI_NAME
+          valueFrom:
+            fieldRef:
+              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'
+      terminationGracePeriodSeconds: 0
+      volumes:
+      - name: pgdata
+        emptyDir: {}
+#  volumeClaimTemplates:
+#  - metadata:
+#      labels:
+#        application: spilo
+#        spilo-cluster: *cluster_name
+#      annotations:
+#        volume.alpha.kubernetes.io/storage-class: anything
+#      name: pgdata
+#    spec:
+#      accessModes:
+#      - ReadWriteOnce
+#      resources:
+#        requests:
+#          storage: 5Gi
+
+---
+apiVersion: v1
+kind: Endpoints
+metadata:
+  name: &cluster_name patronidemo
+  labels:
+    application: patroni
+    cluster-name: *cluster_name
+subsets: []
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: &cluster_name patronidemo
+  labels:
+    application: patroni
+    cluster-name: *cluster_name
+spec:
+  type: ClusterIP
+  ports:
+  - port: 5432
+    targetPort: 5432
+
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: &cluster_name patronidemo
+  labels:
+    application: patroni
+    cluster-name: *cluster_name
+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 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: patronidemo
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: patronidemo
+subjects:
+- kind: ServiceAccount
+  name: patronidemo

patroni/__init__.py

@@ -1,28 +1,32 @@
 import logging
+import os
 import signal
 import sys
 import time
 
-from patroni.api import RestApiServer
-from patroni.config import Config
-from patroni.dcs import get_dcs
-from patroni.exceptions import DCSError
-from patroni.ha import Ha
-from patroni.postgresql import Postgresql
-from patroni.utils import reap_children, sigchld_handler
-from patroni.version import __version__
-
 logger = logging.getLogger(__name__)
 
 
 class Patroni(object):
 
     def __init__(self):
+        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.watchdog import Watchdog
+
         self.setup_signal_handlers()
 
         self.version = __version__
+        self.logger = PatroniLogger()
         self.config = Config()
+        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'])
@@ -34,31 +38,40 @@ class Patroni(object):
         self.scheduled_restart = {}
 
     def load_dynamic_configuration(self):
+        from patroni.exceptions import DCSError
         while True:
             try:
                 cluster = self.dcs.get_cluster()
-                if cluster and cluster.config:
+                if cluster and cluster.config and cluster.config.data:
                     if self.config.set_dynamic_configuration(cluster.config):
                         self.dcs.reload_config(self.config)
+                        self.watchdog.reload_config(self.config)
                 elif not self.config.dynamic_configuration and 'bootstrap' in self.config:
                     if self.config.set_dynamic_configuration(self.config['bootstrap']['dcs']):
                         self.dcs.reload_config(self.config)
                 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()
-                if tag not in ('clonefrom', 'nofailover', 'noloadbalance') or value}
+                if tag not in ('clonefrom', 'nofailover', 'noloadbalance', 'nosync') or value}
 
     @property
     def nofailover(self):
         return bool(self.tags.get('nofailover', False))
 
+    @property
+    def nosync(self):
+        return bool(self.tags.get('nosync', False))
+
     def reload_config(self):
         try:
             self.tags = self.get_tags()
+            self.logger.reload_config(self.config.get('log', {}))
             self.dcs.reload_config(self.config)
+            self.watchdog.reload_config(self.config)
             self.api.reload_config(self.config['restapi'])
             self.postgresql.reload_config(self.config['postgresql'])
         except Exception:
@@ -90,7 +103,7 @@ class Patroni(object):
             time.sleep(0.001)
             # Warn user that Patroni is not keeping up
             logger.warning("Loop time exceeded, rescheduling immediately.")
-        elif self.dcs.watch(nap_time):
+        elif self.ha.watch(nap_time):
             self.next_run = time.time()
 
     def run(self):
@@ -105,37 +118,97 @@ class Patroni(object):
 
             logger.info(self.ha.run_cycle())
 
-            cluster = self.dcs.cluster
-            if cluster and cluster.config and self.config.set_dynamic_configuration(cluster.config):
+            if self.dcs.cluster and self.dcs.cluster.config and self.dcs.cluster.config.data \
+                    and self.config.set_dynamic_configuration(self.dcs.cluster.config):
                 self.reload_config()
 
-            if not self.postgresql.data_directory_empty():
+            if self.postgresql.role != 'uninitialized':
                 self.config.save_cache()
 
-            reap_children()
             self.schedule_next_run()
 
     def setup_signal_handlers(self):
         self._received_sighup = False
         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)
-        signal.signal(signal.SIGCHLD, sigchld_handler)
+
+    def shutdown(self):
+        try:
+            self.api.shutdown()
+        except Exception:
+            logger.exception('Exception during RestApi.shutdown')
+        self.ha.shutdown()
 
 
-def main():
-    logging.basicConfig(format='%(asctime)s %(levelname)s: %(message)s', level=logging.INFO)
-    logging.getLogger('requests').setLevel(logging.WARNING)
-
+def patroni_main():
     patroni = Patroni()
     try:
         patroni.run()
     except KeyboardInterrupt:
         pass
     finally:
-        patroni.api.shutdown()
-        if patroni.ha.is_paused():
-            logger.info('Leader key is not deleted and Postgresql is not stopped due paused state')
-        else:
-            patroni.postgresql.stop(checkpoint=False)
-            patroni.dcs.delete_leader()
+        patroni.shutdown()
+        logging.shutdown()
+
+
+def pg_ctl_start(args):
+    import subprocess
+    if os.name != 'nt':
+        os.setsid()
+    postmaster = subprocess.Popen(args)
+    print(postmaster.pid)
+
+
+def call_self(args, **kwargs):
+    """This function executes Patroni once again with provided arguments.
+
+    :args: list of arguments to call Patroni with.
+    :returns: `Popen` object"""
+
+    exe = [sys.executable]
+    if not getattr(sys, 'frozen', False):  # Binary distribution?
+        exe.append(sys.argv[0])
+
+    import subprocess
+    return subprocess.Popen(exe + args, **kwargs)
+
+
+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:])
+        return patroni_main()
+
+    pid = 0
+
+    # Looks like we are in a docker, so we will act like init
+    def sigchld_handler(signo, stack_frame):
+        try:
+            while True:
+                ret = os.waitpid(-1, os.WNOHANG)
+                if ret == (0, 0):
+                    break
+                elif ret[0] != pid:
+                    logger.info('Reaped pid=%s, exit status=%s', *ret)
+        except OSError:
+            pass
+
+    def passtochild(signo, stack_frame):
+        if pid:
+            os.kill(pid, signo)
+
+    signal.signal(signal.SIGCHLD, sigchld_handler)
+    if os.name != 'nt':
+        signal.signal(signal.SIGHUP, passtochild)
+        signal.signal(signal.SIGQUIT, passtochild)
+    signal.signal(signal.SIGINT, passtochild)
+    signal.signal(signal.SIGUSR1, passtochild)
+    signal.signal(signal.SIGUSR2, passtochild)
+    signal.signal(signal.SIGABRT, passtochild)
+    signal.signal(signal.SIGTERM, passtochild)
+
+    patroni = call_self(sys.argv[1:])
+    pid = patroni.pid
+    patroni.wait()

patroni/api.py

@@ -1,15 +1,16 @@
 import base64
-import fcntl
 import json
 import logging
 import psycopg2
 import time
+import traceback
 import dateutil.parser
 import datetime
-import pytz
+import os
 
-from patroni.exceptions import PostgresConnectionException
-from patroni.utils import deep_compare, patch_config, Retry, RetryFailedError, is_valid_pg_version
+from patroni.postgresql import PostgresConnectionException, PostgresException, Postgresql
+from patroni.utils import deep_compare, parse_bool, patch_config, Retry, \
+    RetryFailedError, parse_int, split_host_port, tzutc
 from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from six.moves.socketserver import ThreadingMixIn
 from threading import Thread
@@ -25,9 +26,9 @@ def check_auth(func):
     def do_PUT_foo():
         pass
     """
-    def wrapper(handler):
+    def wrapper(handler, *args, **kwargs):
         if handler.check_auth_header():
-            return func(handler)
+            return func(handler, *args, **kwargs)
     return wrapper
 
 
@@ -57,7 +58,9 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     def _write_status_response(self, status_code, response):
         patroni = self.server.patroni
-        response.update({'tags': patroni.tags} if patroni.tags else {})
+        tags = patroni.ha.get_effective_tags()
+        if tags:
+            response['tags'] = tags
         if patroni.postgresql.sysid:
             response['database_system_identifier'] = patroni.postgresql.sysid
         if patroni.postgresql.pending_restart:
@@ -67,6 +70,10 @@ class RestApiHandler(BaseHTTPRequestHandler):
             response['scheduled_restart'] = patroni.scheduled_restart.copy()
             del response['scheduled_restart']['postmaster_start_time']
             response['scheduled_restart']['schedule'] = (response['scheduled_restart']['schedule']).isoformat()
+        if not patroni.ha.watchdog.is_healthy:
+            response['watchdog_failed'] = True
+        if patroni.ha.is_paused():
+            response['pause'] = True
         self._write_json_response(status_code, response)
 
     def do_GET(self, write_status_code_only=False):
@@ -77,24 +84,27 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
         patroni = self.server.patroni
         cluster = patroni.dcs.cluster
-        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 response['role'] in path:  # response['role'] != 'master'
-                status_code = 503 if patroni.noloadbalance else 200
+
+        replica_status_code = 200 if not patroni.noloadbalance and response.get('role') == 'replica' 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:
+            # Round-robing across all masters in pause mode if DCS is not accessible
+            if not cluster and patroni.ha.is_paused():
+                status_code = 200 if response['role'] == 'master' else 503
             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
-        else:
-            status_code = 503
+                status_code = 200 if patroni.ha.is_leader() else 503
+        elif 'replica' in path:
+            status_code = replica_status_code
+        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]
@@ -140,6 +150,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 value = json.dumps(data, separators=(',', ':'))
                 if not self.server.patroni.dcs.set_config_value(value, cluster.config.index):
                     return self.send_error(409)
+            self.server.patroni.ha.wakeup()
             self._write_json_response(200, data)
 
     @check_auth
@@ -178,7 +189,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
             if scheduled_at.tzinfo is None:
                 error = 'Timezone information is mandatory for the scheduled {0}'.format(action)
                 status_code = 400
-            elif scheduled_at < datetime.datetime.now(pytz.utc):
+            elif scheduled_at < datetime.datetime.now(tzutc):
                 error = 'Cannot schedule {0} in the past'.format(action)
                 status_code = 422
             else:
@@ -217,9 +228,17 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     data = "PostgreSQL role should be either master or replica"
                     break
             elif k == 'postgres_version':
-                if not is_valid_pg_version(request[k]):
+                try:
+                    Postgresql.postgres_version_to_int(request[k])
+                except PostgresException as e:
                     status_code = 400
-                    data = "PostgreSQL version should be in the first.major.minor format"
+                    data = e.value
+                    break
+            elif k == 'timeout':
+                request[k] = parse_int(request[k], 's')
+                if request[k] is None or request[k] <= 0:
+                    status_code = 400
+                    data = "Timeout should be a positive number of seconds"
                     break
             elif k != 'restart_pending':
                 status_code = 400
@@ -234,7 +253,6 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     logger.exception('Exception during restart')
                     status_code = 400
             else:
-                request['postmaster_start_time'] = self.server.patroni.ha.state_handler.postmaster_start_time()
                 if self.server.patroni.ha.schedule_future_restart(request):
                     data = "Restart scheduled"
                     status_code = 202
@@ -255,7 +273,14 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     @check_auth
     def do_POST_reinitialize(self):
-        data = self.server.patroni.ha.reinitialize()
+        request = self._read_json_content(body_is_optional=True)
+
+        if request:
+            logger.debug('received reinitialize request: %s', request)
+
+        force = isinstance(request, dict) and parse_bool(request.get('force')) or False
+
+        data = self.server.patroni.ha.reinitialize(force)
         if data is None:
             status_code = 200
             data = 'reinitialize started'
@@ -263,43 +288,50 @@ 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):
+    def is_failover_possible(self, cluster, leader, candidate, action):
         if leader and (not cluster.leader or cluster.leader.name != leader):
             return 'leader name does not match'
         if candidate:
+            if action == 'switchover' and cluster.is_synchronous_mode() and cluster.sync.sync_standby != candidate:
+                return 'candidate name does not match with sync_standby'
             members = [m for m in cluster.members if m.name == candidate]
             if not members:
                 return 'candidate does not exists'
+        elif cluster.is_synchronous_mode():
+            members = [m for m in cluster.members if m.name == cluster.sync.sync_standby]
+            if not members:
+                return action + ' is not possible: can not find sync_standby'
         else:
             members = [m for m in cluster.members if m.name != cluster.leader.name and m.api_url]
             if not members:
-                return 'failover is not possible: cluster does not have members except leader'
-        for _, reachable, _, _, tags in self.server.patroni.ha.fetch_nodes_statuses(members):
-            if reachable and not tags.get('nofailover', False):
+                return action + ' is not possible: cluster does not have members except leader'
+        for st in self.server.patroni.ha.fetch_nodes_statuses(members):
+            if st.failover_limitation() is None:
                 return None
-        return 'failover is not possible: no good candidates have been found'
+        return action + ' is not possible: no good candidates have been found'
 
     @check_auth
-    def do_POST_failover(self):
+    def do_POST_failover(self, action='failover'):
         request = self._read_json_content()
-        status_code = 500
+        (status_code, data) = (400, '')
         if not request:
             return
 
@@ -308,39 +340,47 @@ class RestApiHandler(BaseHTTPRequestHandler):
         scheduled_at = request.get('scheduled_at')
         cluster = self.server.patroni.dcs.get_cluster()
 
-        if scheduled_at and cluster.is_paused():
-            self._write_response(status_code, "Can't schedule failover in the paused state")
+        logger.info("received %s request with leader=%s candidate=%s scheduled_at=%s",
+                    action, leader, candidate, scheduled_at)
 
-        logger.info("received failover request with leader=%s candidate=%s scheduled_at=%s",
-                    leader, candidate, scheduled_at)
+        if action == 'failover' and not candidate:
+            data = 'Failover could be performed only to a specific candidate'
+        elif action == 'switchover' and not leader:
+            data = 'Switchover could be performed only from a specific leader'
 
-        data = ''
-        if leader or candidate:
-            if scheduled_at:
-                (_, data, scheduled_at) = self.parse_schedule(scheduled_at, "failover")
-                if _:
-                    status_code = _
-                elif self.server.patroni.dcs.manual_failover(leader, candidate, scheduled_at=scheduled_at):
-                    self.server.patroni.dcs.event.set()
-                    data = 'Failover scheduled'
+        if not data and scheduled_at:
+            if not leader:
+                data = 'Scheduled {0} is possible only from a specific leader'.format(action)
+            if not data and cluster.is_paused():
+                data = "Can't schedule {0} in the paused state".format(action)
+            if not data:
+                (status_code, data, scheduled_at) = self.parse_schedule(scheduled_at, action)
+
+        if not data and cluster.is_paused() and not candidate:
+            data = action.title() + ' is possible only to a specific candidate in a paused state'
+
+        if not data and not scheduled_at:
+            data = self.is_failover_possible(cluster, leader, candidate, action)
+            if data:
+                status_code = 412
+
+        if not data:
+            if self.server.patroni.dcs.manual_failover(leader, candidate, scheduled_at=scheduled_at):
+                self.server.patroni.ha.wakeup()
+                if scheduled_at:
+                    data = action.title() + ' scheduled'
                     status_code = 202
                 else:
-                    data = 'failed to write failover key into DCS'
-                    status_code = 503
+                    status_code, data = self.poll_failover_result(cluster.leader and cluster.leader.name,
+                                                                  candidate, action)
             else:
-                data = self.is_failover_possible(cluster, leader, candidate)
-                if not data:
-                    if self.server.patroni.dcs.manual_failover(leader, candidate):
-                        self.server.patroni.dcs.event.set()
-                        status_code, data = self.poll_failover_result(cluster.leader and cluster.leader.name, candidate)
-                    else:
-                        data = 'failed to write failover key into DCS'
-                        status_code = 503
-        else:
-            status_code = 400
-            data = 'No values given for required parameters leader and candidate'
+                data = 'failed to write {0} key into DCS'.format(action)
+                status_code = 503
         self._write_response(status_code, data)
 
+    def do_POST_switchover(self):
+        self.do_POST_failover(action='switchover')
+
     def parse_request(self):
         """Override parse_request method to enrich basic functionality of `BaseHTTPRequestHandler` class
 
@@ -367,36 +407,51 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     def get_postgresql_status(self, retry=False):
         try:
-            row = self.query("""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'),
-                                       pg_is_in_recovery(),
-                                       CASE WHEN pg_is_in_recovery()
-                                            THEN 0
-                                            ELSE pg_xlog_location_diff(pg_current_xlog_location(), '0/0')::bigint
-                                       END,
-                                       pg_xlog_location_diff(pg_last_xlog_receive_location(), '0/0')::bigint,
-                                       pg_xlog_location_diff(pg_last_xlog_replay_location(), '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_xlog_replay_paused(),
-                                       (SELECT json_agg(row_to_json(ri)) FROM replication_info ri)""", retry=retry)[0]
+            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_catalog.pg_stat_replication) 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(), "
+                    "(SELECT pg_catalog.array_to_json(pg_catalog.array_agg("
+                    "pg_catalog.row_to_json(ri))) FROM replication_info ri)")
+
+            row = self.query(stmt.format(self.server.patroni.postgresql.wal_name,
+                                         self.server.patroni.postgresql.lsn_name), retry=retry)[0]
 
             result = {
                 'state': self.server.patroni.postgresql.state,
                 'postmaster_start_time': row[0],
-                'role': 'replica' if row[1] else 'master',
+                '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],
                     'replayed_timestamp': row[5],
-                    'paused': row[6]} if row[1] else {
+                    'paused': row[6]} if row[1] == 0 else {
                     'location': row[2]
                 })
             }
 
+            if row[1] > 0:
+                result['timeline'] = row[1]
+            else:
+                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)
+
             if row[7]:
                 result['replication'] = row[7]
 
@@ -416,6 +471,7 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
 
     def __init__(self, patroni, config):
         self.patroni = patroni
+        self.__listen = None
         self.__initialize(config)
         self.__set_config_parameters(config)
         self.daemon = True
@@ -433,8 +489,10 @@ 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
@@ -450,18 +508,25 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
     def __get_ssl_options(config):
         return {option: config[option] for option in ['certfile', 'keyfile'] if option in config}
 
-    def __set_connection_string(self, connect_address):
-        self.connection_string = '{0}://{1}/patroni'.format(self.__protocol, connect_address or self.__listen)
-
     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'))
+        self.connection_string = '{0}://{1}/patroni'.format(self.__protocol,
+                                                            config.get('connect_address') or self.__listen)
 
     def __initialize(self, config):
-        self.__ssl_options = self.__get_ssl_options(config)
+        try:
+            host, port = split_host_port(config['listen'], None)
+        except Exception:
+            raise ValueError('Invalid "restapi" config: expected <HOST>:<PORT> for "listen", but got "{0}"'
+                             .format(config['listen']))
+
+        if self.__listen is not None:  # changing config in runtime
+            self.shutdown()
+
         self.__listen = config['listen']
-        host, port = config['listen'].split(':')
-        HTTPServer.__init__(self, (host, int(port)), RestApiHandler)
+        self.__ssl_options = self.__get_ssl_options(config)
+
+        HTTPServer.__init__(self, (host, port), RestApiHandler)
         Thread.__init__(self, target=self.serve_forever)
         self._set_fd_cloexec(self.socket)
 
@@ -473,11 +538,19 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
             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'))
+        return True
 
     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)
+        if 'listen' not in config:  # changing config in runtime
+            raise ValueError('Can not find "restapi.listen" config')
+
+        elif (self.__listen != config['listen'] or self.__ssl_options != self.__get_ssl_options(config)) \
+                and self.__initialize(config):
             self.start()
+        self.__set_config_parameters(config)
+
+    @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

@@ -1,25 +1,78 @@
 import logging
-from threading import RLock, Thread
+from threading import Event, Lock, RLock, Thread
 
 logger = logging.getLogger(__name__)
 
 
+class CriticalTask(object):
+    """Represents a critical task in a background process that we either need to cancel or get the result of.
+
+    Fields of this object may be accessed only when holding a lock on it. To perform the critical task the background
+    thread must, while holding lock on this object, check `is_cancelled` flag, run the task and mark the task as
+    complete using `complete()`.
+
+    The main thread must hold async lock to prevent the task from completing, hold lock on critical task object,
+    call cancel. If the task has completed `cancel()` will return False and `result` field will contain the result of
+    the task. When cancel returns True it is guaranteed that the background task will notice the `is_cancelled` flag.
+    """
+    def __init__(self):
+        self._lock = Lock()
+        self.is_cancelled = False
+        self.result = None
+
+    def reset(self):
+        """Must be called every time the background task is finished.
+
+        Must be called from async thread. Caller must hold lock on async executor when calling."""
+        self.is_cancelled = False
+        self.result = None
+
+    def cancel(self):
+        """Tries to cancel the task, returns True if the task has already run.
+
+        Caller must hold lock on async executor and the task when calling."""
+        if self.result is not None:
+            return False
+        self.is_cancelled = True
+        return True
+
+    def complete(self, result):
+        """Mark task as completed along with a result.
+
+        Must be called from async thread. Caller must hold lock on task when calling."""
+        self.result = result
+
+    def __enter__(self):
+        self._lock.acquire()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._lock.release()
+
+
 class AsyncExecutor(object):
 
-    def __init__(self):
+    def __init__(self, state_handler, ha_wakeup):
+        self.state_handler = state_handler
+        self._ha_wakeup = ha_wakeup
         self._thread_lock = RLock()
         self._scheduled_action = None
         self._scheduled_action_lock = RLock()
+        self._is_cancelled = False
+        self._finish_event = Event()
+        self.critical_task = CriticalTask()
 
     @property
     def busy(self):
         return self.scheduled_action is not None
 
-    def schedule(self, action, immediately=False):
+    def schedule(self, action):
         with self._scheduled_action_lock:
             if self._scheduled_action is not None:
                 return self._scheduled_action
             self._scheduled_action = action
+            self._is_cancelled = False
+            self._finish_event.set()
         return None
 
     @property
@@ -32,17 +85,45 @@ class AsyncExecutor(object):
             self._scheduled_action = None
 
     def run(self, func, args=()):
+        wakeup = False
         try:
-            return func(*args) if args else func()
-        except:
+            with self:
+                if self._is_cancelled:
+                    return
+                self._finish_event.clear()
+
+            self.state_handler.reset_is_cancelled()
+            # if the func returned something (not None) - wake up main HA loop
+            wakeup = func(*args) if args else func()
+            return wakeup
+        except Exception:
             logger.exception('Exception during execution of long running task %s', self.scheduled_action)
         finally:
             with self:
                 self.reset_scheduled_action()
+                self._finish_event.set()
+                with self.critical_task:
+                    self.critical_task.reset()
+            if wakeup is not None:
+                self._ha_wakeup()
 
     def run_async(self, func, args=()):
         Thread(target=self.run, args=(func, args)).start()
 
+    def cancel(self):
+        with self:
+            with self._scheduled_action_lock:
+                if self._scheduled_action is None:
+                    return
+                logger.warning('Cancelling long running task %s', self._scheduled_action)
+            self._is_cancelled = True
+
+        self.state_handler.cancel()
+        self._finish_event.wait()
+
+        with self:
+            self.reset_scheduled_action()
+
     def __enter__(self):
         self._thread_lock.acquire()
 

patroni/callback_executor.py

@@ -0,0 +1,37 @@
+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

@@ -1,6 +1,7 @@
 import json
 import logging
 import os
+import shutil
 import sys
 import tempfile
 import yaml
@@ -9,7 +10,8 @@ from collections import defaultdict
 from copy import deepcopy
 from patroni.dcs import ClusterConfig
 from patroni.postgresql import Postgresql
-from patroni.utils import deep_compare, parse_int, patch_config
+from patroni.utils import deep_compare, parse_bool, parse_int, patch_config
+from requests.structures import CaseInsensitiveDict
 
 logger = logging.getLogger(__name__)
 
@@ -41,10 +43,26 @@ class Config(object):
     __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 Postgresql.CMDLINE_OPTIONS.items()})
+        },
+        'watchdog': {
+            'mode': 'automatic',
         }
     }
 
@@ -81,6 +99,9 @@ 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:
@@ -104,7 +125,7 @@ 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)
@@ -148,6 +169,8 @@ class Config(object):
                     self._local_configuration = configuration
                     self.__effective_configuration = new_configuration
                     return True
+                else:
+                    logger.info('No configuration items changed, nothing to reload.')
             except Exception:
                 logger.exception('Exception when reloading local configuration from %s', self.config_file)
                 if dry_run:
@@ -171,8 +194,15 @@ 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
-                config[name] = int(value)
+                if name in ('synchronous_mode', 'synchronous_mode_strict'):
+                    config[name] = value
+                else:
+                    config[name] = int(value)
         return config
 
     @staticmethod
@@ -187,6 +217,15 @@ class Config(object):
             if value:
                 ret[param] = value
 
+        def _fix_log_env(name, oldname):
+            value = _popenv(oldname)
+            name = Config.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)
@@ -195,6 +234,22 @@ class Config(object):
 
         _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile'])
         _set_section_values('postgresql', ['listen', 'connect_address', 'data_dir', 'pgpass', 'bin_dir'])
+        _set_section_values('log', ['level', 'format', 'dateformat', 'dir', 'file_size', 'file_num', 'loggers'])
+
+        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):
             ret = {}
@@ -230,15 +285,21 @@ class Config(object):
 
         for param in list(os.environ.keys()):
             if param.startswith(Config.PATRONI_ENV_PREFIX):
-                name, suffix = (param[8:].rsplit('_', 1) + [''])[:2]
+                name, suffix = (param[8:].split('_', 1) + [''])[:2]
                 if name and suffix:
-                    # PATRONI_(ETCD|CONSUL|ZOOKEEPER|EXHIBITOR|...)_(HOSTS?|PORT)
-                    if suffix in ('HOST', 'HOSTS', 'PORT') and '_' not in name:
+                    # PATRONI_(ETCD|CONSUL|ZOOKEEPER|EXHIBITOR|...)_(HOSTS?|PORT|..)
+                    if suffix in ('HOST', 'HOSTS', 'PORT', 'SRV', 'URL', 'PROXY', 'CACERT', 'CERT', 'KEY', 'VERIFY',
+                                  'TOKEN', 'CHECKS', 'DC', 'REGISTER_SERVICE', 'SERVICE_CHECK_INTERVAL', '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 == 'HOSTS':
+                        elif suffix in ('HOSTS', 'PORTS', 'CHECKS'):
                             value = value and _parse_list(value)
+                        elif suffix == 'LABELS':
+                            value = _parse_dict(value)
+                        elif suffix == 'REGISTER_SERVICE':
+                            value = parse_bool(value)
                         if value:
                             ret[name.lower()][suffix.lower()] = value
                     # PATRONI_<username>_PASSWORD=<password>, PATRONI_<username>_OPTIONS=<option1,option2,...>
@@ -265,14 +326,12 @@ class Config(object):
                         config['postgresql'][name].update(self._process_postgresql_parameters(value, True))
                     elif name != 'use_slots':  # replication slots must be enabled/disabled globally
                         config['postgresql'][name] = deepcopy(value)
-            elif name not in config:
+            elif name not in config or name in ['watchdog']:
                 config[name] = deepcopy(value) if value else {}
 
         # restapi server expects to get restapi.auth = 'username:password'
         if 'authentication' in config['restapi']:
-            restapi = config['restapi']
-            auth = restapi['authentication']
-            restapi['auth'] = '{0}:{1}'.format(auth['username'], auth['password'])
+            config['restapi']['auth'] = '{username}:{password}'.format(**config['restapi']['authentication'])
 
         # special treatment for old config
 
@@ -294,8 +353,15 @@ class Config(object):
         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',
-                          '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/dcs/__init__.py

@@ -3,17 +3,40 @@ import dateutil
 import importlib
 import inspect
 import json
+import logging
 import os
 import pkgutil
+import re
 import six
 import sys
 
-from collections import namedtuple
+from collections import defaultdict, namedtuple
+from copy import deepcopy
 from patroni.exceptions import PatroniException
+from patroni.utils import parse_bool
 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:
@@ -51,18 +74,22 @@ def dcs_modules():
 def get_dcs(config):
     available_implementations = set()
     for module_name in dcs_modules():
-        module = importlib.import_module(module_name)
-        for name in filter(lambda name: not name.startswith('__'), dir(module)):  # iterate through module content
-            value = getattr(module, name)
-            name = name.lower()
-            # try to find implementation of AbstractDCS interface, class name must match with module_name
-            if inspect.isclass(value) and issubclass(value, AbstractDCS) and __package__ + '.' + name == module_name:
-                available_implementations.add(name)
-                if name in config:  # which has configuration section in the config file
-                    # propagate some parameters
-                    config[name].update({p: config[p] for p in ('namespace', 'name', 'scope',
-                                         'loop_wait', 'ttl', 'retry_timeout') if p in config})
-                    return value(config[name])
+        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
+                        # 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:
+            if not config.get('patronictl'):
+                logger.info('Failed to import %s', module_name)
     raise PatroniException("""Can not find suitable configuration of distributed configuration store
 Available implementations: """ + ', '.join(available_implementations))
 
@@ -100,12 +127,29 @@ 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 = 'postgresql://{host}:{port}'.format(
+                host=conn_kwargs.get('host'),
+                port=conn_kwargs.get('port'),
+            )
+            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 = {
@@ -142,6 +186,34 @@ class Member(namedtuple('Member', 'index,name,session,data')):
     def clonefrom(self):
         return self.tags.get('clonefrom', False) and bool(self.conn_url)
 
+    @property
+    def state(self):
+        return self.data.get('state', 'unknown')
+
+    @property
+    def is_running(self):
+        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')):
 
@@ -162,40 +234,48 @@ class Leader(namedtuple('Leader', 'index,session,member')):
     def conn_url(self):
         return self.member.conn_url
 
+    @property
+    def timeline(self):
+        return self.member.data.get('timeline')
+
 
 class Failover(namedtuple('Failover', 'index,leader,candidate,scheduled_at')):
 
     """
     >>> 'Failover' in str(Failover.from_node(1, '{"leader": "cluster_leader"}'))
     True
+    >>> 'Failover' in str(Failover.from_node(1, {"leader": "cluster_leader"}))
+    True
     >>> 'Failover' in str(Failover.from_node(1, '{"leader": "cluster_leader", "member": "cluster_candidate"}'))
     True
     >>> Failover.from_node(1, 'null') is None
-    True
+    False
     >>> n = '{"leader": "cluster_leader", "member": "cluster_candidate", "scheduled_at": "2016-01-14T10:09:57.1394Z"}'
     >>> 'tzinfo=' in str(Failover.from_node(1, n))
     True
     >>> Failover.from_node(1, None) is None
-    True
+    False
     >>> Failover.from_node(1, '{}') is None
-    True
+    False
     >>> 'abc' in Failover.from_node(1, 'abc:def')
     True
     """
     @staticmethod
     def from_node(index, value):
-        if not value:
-            return None
-
-        try:
-            data = json.loads(value)
-            if not data:
-                return None
-        except ValueError:
-            t = [a.strip() for a in value.split(':')]
-            leader = t[0]
-            candidate = t[1] if len(t) > 1 else None
-            return Failover(index, leader, candidate, None) if leader or candidate else None
+        if isinstance(value, dict):
+            data = value
+        elif value:
+            try:
+                data = json.loads(value)
+                if not isinstance(data, dict):
+                    data = {}
+            except ValueError:
+                t = [a.strip() for a in value.split(':')]
+                leader = t[0]
+                candidate = t[1] if len(t) > 1 else None
+                return Failover(index, leader, candidate, None) if leader or candidate else None
+        else:
+            data = {}
 
         if data.get('scheduled_at'):
             data['scheduled_at'] = dateutil.parser.parse(data['scheduled_at'])
@@ -212,17 +292,102 @@ 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 Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operation,members,failover')):
+class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
+    """Immutable object (namedtuple) which represents last observed synhcronous replication state
+
+    :param index: modification index of a synchronization key in a Configuration Store
+    :param leader: reference to member that was leader
+    :param sync_standby: standby that was last synchronized to leader
+    """
+
+    @staticmethod
+    def from_node(index, value):
+        """
+        >>> SyncState.from_node(1, None).leader is None
+        True
+        >>> SyncState.from_node(1, '{}').leader is None
+        True
+        >>> SyncState.from_node(1, '{').leader is None
+        True
+        >>> SyncState.from_node(1, '[]').leader is None
+        True
+        >>> SyncState.from_node(1, '{"leader": "leader"}').leader == "leader"
+        True
+        >>> SyncState.from_node(1, {"leader": "leader"}).leader == "leader"
+        True
+        """
+        if isinstance(value, dict):
+            data = value
+        elif value:
+            try:
+                data = json.loads(value)
+                if not isinstance(data, dict):
+                    data = {}
+            except (TypeError, ValueError):
+                data = {}
+        else:
+            data = {}
+        return SyncState(index, data.get('leader'), data.get('sync_standby'))
+
+    def matches(self, name):
+        """
+        Returns if a node name matches one of the nodes in the sync state
+
+        >>> s = SyncState(1, 'foo', 'bar')
+        >>> s.matches('foo')
+        True
+        >>> s.matches('bar')
+        True
+        >>> s.matches('baz')
+        False
+        >>> s.matches(None)
+        False
+        >>> SyncState(1, None, None).matches('foo')
+        False
+        """
+        return name is not None and name in (self.leader, self.sync_standby)
+
+
+class TimelineHistory(namedtuple('TimelineHistory', 'index,value,lines')):
+    """Object representing timeline history file"""
+
+    @staticmethod
+    def from_node(index, value):
+        """
+        >>> h = TimelineHistory.from_node(1, 2)
+        >>> h.lines
+        []
+        """
+        try:
+            lines = json.loads(value)
+        except (TypeError, ValueError):
+            lines = None
+        if not isinstance(lines, list):
+            lines = []
+        return TimelineHistory(index, value, lines)
+
+
+class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operation,members,failover,sync,history')):
 
     """Immutable object (namedtuple) which represents PostgreSQL cluster.
     Consists of the following fields:
@@ -232,7 +397,10 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
     :param last_leader_operation: int or long object containing position of last known leader operation.
         This value is stored in `/optime/leader` key
     :param members: list of Member object, all PostgreSQL cluster members including leader
-    :param failover: reference to `Failover` object"""
+    :param failover: reference to `Failover` object
+    :param sync: reference to `SyncState` object, last observed synchronous replication state.
+    :param history: reference to `TimelineHistory` object
+    """
 
     def is_unlocked(self):
         return not (self.leader and self.leader.name)
@@ -243,12 +411,98 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
     def get_member(self, member_name, fallback_to_leader=True):
         return ([m for m in self.members if m.name == member_name] or [self.leader if fallback_to_leader else None])[0]
 
-    def get_clone_member(self):
-        candidates = [m for m in self.members if m.clonefrom and (not self.leader or m.name != self.leader.name)]
+    def get_clone_member(self, exclude):
+        exclude = [exclude] + [self.leader.name] if self.leader else []
+        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 self.check_mode('synchronous_mode')
+
+    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
+        if role in ('master', 'standby_leader'):
+            slot_members = [m.name for m in self.members if 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 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)
@@ -258,9 +512,11 @@ class AbstractDCS(object):
     _CONFIG = 'config'
     _LEADER = 'leader'
     _FAILOVER = 'failover'
+    _HISTORY = 'history'
     _MEMBERS = 'members/'
     _OPTIME = 'optime'
     _LEADER_OPTIME = _OPTIME + '/' + _LEADER
+    _SYNC = 'sync'
 
     def __init__(self, config):
         """
@@ -268,12 +524,13 @@ class AbstractDCS(object):
             i.e.: `zookeeper` for zookeeper, `etcd` for etcd, etc...
         """
         self._name = config['name']
-        self._namespace = '/{0}'.format(config.get('namespace', '/service/').strip('/'))
-        self._base_path = '/'.join([self._namespace, 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_thread_lock = Lock()
+        self._last_leader_operation = ''
         self.event = Event()
 
     def client_path(self, path):
@@ -303,10 +560,18 @@ class AbstractDCS(object):
     def failover_path(self):
         return self.client_path(self._FAILOVER)
 
+    @property
+    def history_path(self):
+        return self.client_path(self._HISTORY)
+
     @property
     def leader_optime_path(self):
         return self.client_path(self._LEADER_OPTIME)
 
+    @property
+    def sync_path(self):
+        return self.client_path(self._SYNC)
+
     @abc.abstractmethod
     def set_ttl(self, ttl):
         """Set the new ttl value for leader key"""
@@ -341,7 +606,7 @@ class AbstractDCS(object):
         with self._cluster_thread_lock:
             try:
                 self._load_cluster()
-            except:
+            except Exception:
                 self._cluster = None
                 raise
             return self._cluster
@@ -356,12 +621,17 @@ class AbstractDCS(object):
             self._cluster = None
 
     @abc.abstractmethod
-    def write_leader_optime(self, last_operation):
+    def _write_leader_optime(self, last_operation):
         """write current xlog location into `/optime/leader` key in DCS
-        :param last_operation: absolute xlog location in bytes"""
+        :param last_operation: absolute xlog location in bytes
+        :returns: `!True` on success."""
+
+    def write_leader_optime(self, last_operation):
+        if self._last_leader_operation != last_operation and self._write_leader_optime(last_operation):
+            self._last_leader_operation = last_operation
 
     @abc.abstractmethod
-    def update_leader(self):
+    def _update_leader(self):
         """Update leader key (or session) ttl
 
         :returns: `!True` if leader key (or session) has been updated successfully.
@@ -370,6 +640,18 @@ 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, access_is_restricted=False):
+        """Update leader key (or session) ttl and optime/leader
+
+        :param last_operation: absolute xlog location in bytes
+        :returns: `!True` if leader key (or session) has been updated successfully.
+            If not, `!False` must be returned and current instance would be demoted."""
+
+        ret = self._update_leader()
+        if ret and last_operation:
+            self.write_leader_optime(last_operation)
+        return ret
+
     @abc.abstractmethod
     def attempt_to_acquire_leader(self, permanent=False):
         """Attempt to acquire leader lock
@@ -395,7 +677,6 @@ class AbstractDCS(object):
 
         if scheduled_at:
             failover_value['scheduled_at'] = scheduled_at.isoformat()
-
         return self.set_failover_value(json.dumps(failover_value, separators=(',', ':')), index)
 
     @abc.abstractmethod
@@ -408,7 +689,7 @@ class AbstractDCS(object):
         This method should create or update key with the name = '/members/' + `~self._name`
         and value = data in a given DCS.
 
-        :param data: json serialized information about instance (including connection strings)
+        :param data: information about instance (including connection strings)
         :param ttl: ttl for member key, optional parameter. If it is None `~self.member_ttl will be used`
         :param permanent: if set to `!True`, the member key will never expire.
          Used in patronictl for the external master.
@@ -445,10 +726,32 @@ class AbstractDCS(object):
     def delete_cluster(self):
         """Delete cluster from DCS"""
 
-    def watch(self, timeout):
+    @staticmethod
+    def sync_state(leader, sync_standby):
+        """Build sync_state dict"""
+        return {'leader': leader, 'sync_standby': sync_standby}
+
+    def write_sync_state(self, leader, sync_standby, index=None):
+        sync_value = self.sync_state(leader, sync_standby)
+        return self.set_sync_state_value(json.dumps(sync_value, separators=(',', ':')), index)
+
+    @abc.abstractmethod
+    def set_history_value(self, value):
+        """"""
+
+    @abc.abstractmethod
+    def set_sync_state_value(self, value, index=None):
+        """"""
+
+    @abc.abstractmethod
+    def delete_sync_state(self, index=None):
+        """"""
+
+    def watch(self, leader_index, timeout):
         """If the current node is a master it should just sleep.
         Any other node should watch for changes of leader key with a given timeout
 
+        :param leader_index: index of a leader key
         :param timeout: timeout in seconds
         :returns: `!True` if you would like to reschedule the next run of ha cycle"""
 

patroni/dcs/consul.py

@@ -1,14 +1,20 @@
 from __future__ import absolute_import
+import json
 import logging
 import os
+import re
+import socket
+import ssl
 import time
-import six
+import urllib3
 
-from consul import ConsulException, NotFound, base, std
-from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member
+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 sleep
-from requests.exceptions import RequestException
+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, quote
+from six.moves.http_client import HTTPException
 
 logger = logging.getLogger(__name__)
 
@@ -17,70 +23,201 @@ class ConsulError(DCSError):
     pass
 
 
-class HTTPClient(std.HTTPClient):
+class ConsulInternalError(ConsulException):
+    """An internal Consul server error occurred"""
 
-    def __init__(self, *args, **kwargs):
-        super(HTTPClient, self).__init__(*args, **kwargs)
 
-    def patch_default_timeout(self, timeout):
-        # Set a default timeout for the `request.session.request` method, that is used
-        # internally  by the methods request.session.get, request.session.post and
-        # others. We monkey-patch here to avoid reimplementing each individual method from
-        # `std.HTTPClient`. By default, the timeout is not set. It means that a new
-        # session may hang almost indefinitely waiting for the server to respond,
-        # which is not what we want in Patroni.
+class InvalidSessionTTL(ConsulException):
+    """Session TTL is too small or too big"""
 
-        request_func = getattr(self.session.request, '__func__' if six.PY3 else 'im_func')
-        defaults_attr_name = '__defaults__' if six.PY3 else 'func_defaults'
-        defaults = list(getattr(request_func, defaults_attr_name))
-        code = request_func.__code__ if six.PY3 else request_func.func_code
-        defaults[code.co_varnames[code.co_argcount - len(defaults):code.co_argcount].index('timeout')] = timeout
-        setattr(request_func, defaults_attr_name, tuple(defaults))  # monkeypatching
 
-    def get(self, callback, path, params=None):
-        # The get function is overridden to handle a special case of it being called
-        # with an index and wait parameters. That form indicates that a user needs to
-        # wait for the given key to change its value, with a wait timeout supplied. We
-        # don't want our monkey-patched timeout to be less than the value of the wait
-        # parameter, therefore, we set it to either the value of wait or a default of 5 minutes.
+class InvalidSession(ConsulException):
+    """invalid session"""
 
-        if isinstance(params, dict) and 'index' in params:
-            timeout = (float(params['wait'][:-1]) if 'wait' in params else 300) + 1
-        else:
-            timeout = None
-        return callback(self.response(self.session.get(self.uri(path, params), verify=self.verify, timeout=timeout)))
+
+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)
+        kwargs = {}
+        if cert:
+            if isinstance(cert, tuple):
+                # Key and cert are separate
+                kwargs['cert_file'] = cert[0]
+                kwargs['key_file'] = cert[1]
+            else:
+                # combined certificate
+                kwargs['cert_file'] = cert
+        if ca_cert:
+            kwargs['ca_certs'] = ca_cert
+        if verify or ca_cert:
+            kwargs['cert_reqs'] = ssl.CERT_REQUIRED
+        self.http = urllib3.PoolManager(num_pools=10, **kwargs)
+        self._ttl = None
+
+    def set_read_timeout(self, timeout):
+        self._read_timeout = timeout/3.0
+
+    @property
+    def ttl(self):
+        return self._ttl
+
+    def set_ttl(self, ttl):
+        ret = self._ttl != ttl
+        self._ttl = ttl
+        return ret
+
+    @staticmethod
+    def response(response):
+        data = response.data.decode('utf-8')
+        if response.status == 500:
+            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)
+
+    def uri(self, path, params=None):
+        return '{0}{1}{2}'.format(self.base_uri, path, params and '?' + urlencode(params) or '')
+
+    def __getattr__(self, method):
+        if method not in ('get', 'post', 'put', 'delete'):
+            raise AttributeError("HTTPClient instance has no attribute '{0}'".format(method))
+
+        def wrapper(callback, path, params=None, data=''):
+            # python-consul doesn't allow to specify ttl smaller then 10 seconds
+            # because session_ttl_min defaults to 10s, so we have to do this ugly dirty hack...
+            if method == 'put' and path == '/v1/session/create':
+                ttl = '"ttl": "{0}s"'.format(self._ttl)
+                if not data or data == '{}':
+                    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
+            else:
+                kwargs['timeout'] = self._read_timeout
+            token = params.pop('token', self.token) if isinstance(params, dict) else self.token
+            if token:
+                kwargs['headers'] = {'X-Consul-Token': token}
+            return callback(self.response(self.http.request(method.upper(), self.uri(path, params), **kwargs)))
+        return wrapper
 
 
 class ConsulClient(base.Consul):
 
-    @staticmethod
-    def connect(host, port, scheme, verify=True):
-        return HTTPClient(host, port, scheme, verify)
+    def __init__(self, *args, **kwargs):
+        self._cert = kwargs.pop('cert', None)
+        self._ca_cert = kwargs.pop('ca_cert', None)
+        self._token = kwargs.get('token')
+        super(ConsulClient, self).__init__(*args, **kwargs)
+
+    def connect(self, *args, **kwargs):
+        kwargs.update(dict(zip(['host', 'port', 'scheme', 'verify'], args)))
+        if self._cert:
+            kwargs['cert'] = self._cert
+        if self._ca_cert:
+            kwargs['ca_cert'] = self._ca_cert
+        if self._token:
+            kwargs['token'] = self._token
+        return HTTPClient(**kwargs)
 
 
 def catch_consul_errors(func):
     def wrapper(*args, **kwargs):
         try:
             return func(*args, **kwargs)
-        except (ConsulException, RequestException):
+        except (RetryFailedError, ConsulException, HTTPException, HTTPError, socket.error, socket.timeout):
             return False
     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):
         super(Consul, self).__init__(config)
-        self._ttl = None
-        self._session = None
-        self._my_member_data = None
-        self.set_ttl(config.get('ttl') or 30)
-        host, port = config.get('host', '127.0.0.1:8500').split(':')
-        self._client = ConsulClient(host=host, port=port)
-        self._client.http.patch_default_timeout(config['retry_timeout']/2.0)
         self._scope = config['scope']
-        self.create_session()
+        self._session = None
         self.__do_not_watch = False
+        self._retry = Retry(deadline=config['retry_timeout'], max_delay=1, max_tries=-1,
+                            retry_exceptions=(ConsulInternalError, HTTPException,
+                                              HTTPError, socket.error, socket.timeout))
+
+        kwargs = {}
+        if 'url' in config:
+            r = urlparse(config['url'])
+            config.update({'scheme': r.scheme, 'host': r.hostname, 'port': r.port or 8500})
+        elif 'host' in config:
+            host, port = split_host_port(config.get('host', '127.0.0.1:8500'), 8500)
+            config['host'] = host
+            if 'port' not in config:
+                config['port'] = int(port)
+
+        if config.get('cacert'):
+            config['ca_cert'] = config.pop('cacert')
+
+        if config.get('key') and config.get('cert'):
+            config['cert'] = (config['cert'], config['key'])
+
+        config_keys = ('host', 'port', 'token', 'scheme', 'cert', 'ca_cert', 'dc')
+        kwargs = {p: config.get(p) for p in config_keys if config.get(p)}
+
+        verify = config.get('verify')
+        if not isinstance(verify, bool):
+            verify = parse_bool(verify)
+        if isinstance(verify, bool):
+            kwargs['verify'] = verify
+
+        self._client = ConsulClient(**kwargs)
+        self.set_retry_timeout(config['retry_timeout'])
+        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()
+
+    def retry(self, *args, **kwargs):
+        return self._retry.copy()(*args, **kwargs)
 
     def create_session(self):
         while not self._session:
@@ -88,34 +225,56 @@ class Consul(AbstractDCS):
                 self.refresh_session()
             except ConsulError:
                 logger.info('waiting on consul')
-                sleep(5)
+                time.sleep(5)
 
     def set_ttl(self, ttl):
-        ttl = ttl/2.0  # My experiments have shown that session expires after 2*ttl time
-        if self._ttl != ttl:
+        if self._client.http.set_ttl(ttl/2.0):  # Consul multiplies the TTL by 2x
             self._session = None
             self.__do_not_watch = True
-        self._ttl = ttl
 
     def set_retry_timeout(self, retry_timeout):
-        self._client.http.patch_default_timeout(retry_timeout/2.0)
+        self._retry.deadline = retry_timeout
+        self._client.http.set_read_timeout(retry_timeout)
 
-    def refresh_session(self):
+    def adjust_ttl(self):
+        try:
+            settings = self._client.agent.self()
+            min_ttl = (settings['Config']['SessionTTLMin'] or 10000000000)/1000000000.0
+            logger.warning('Changing Session TTL from %s to %s', self._client.http.ttl, min_ttl)
+            self._client.http.set_ttl(min_ttl)
+        except Exception:
+            logger.exception('adjust_ttl')
+
+    def _do_refresh_session(self):
         """:returns: `!True` if it had to create new session"""
+        if self._session and self._last_session_refresh + self._loop_wait > time.time():
+            return False
+
         if self._session:
             try:
-                return self._client.session.renew(self._session) is None
+                self._client.session.renew(self._session)
             except NotFound:
                 self._session = None
-        if not self._session:
-            name = self._scope + '-' + self._name
+        ret = not self._session
+        if ret:
             try:
-                self._session = self._client.session.create(name=name, lock_delay=0, behavior='delete', ttl=self._ttl)
-            except (ConsulException, RequestException):
+                self._session = self._client.session.create(name=self._scope + '-' + self._name,
+                                                            checks=self.__session_checks,
+                                                            lock_delay=0.001, behavior='delete')
+            except InvalidSessionTTL:
                 logger.exception('session.create')
-        if not self._session:
-            raise ConsulError('Failed to renew/create session')
-        return True
+                self.adjust_ttl()
+                raise
+
+        self._last_session_refresh = time.time()
+        return ret
+
+    def refresh_session(self):
+        try:
+            return self.retry(self._do_refresh_session)
+        except (ConsulException, RetryFailedError):
+            logger.exception('refresh_session')
+        raise ConsulError('Failed to renew/create session')
 
     def client_path(self, path):
         return super(Consul, self).client_path(path)[1:]
@@ -127,7 +286,7 @@ class Consul(AbstractDCS):
     def _load_cluster(self):
         try:
             path = self.client_path('/')
-            _, results = self._client.kv.get(path, recurse=True)
+            _, results = self.retry(self._client.kv.get, path, recurse=True)
 
             if results is None:
                 raise NotFound
@@ -135,7 +294,7 @@ 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[os.path.relpath(node['Key'], path).replace('\\', '/')] = node
 
             # get initialize flag
             initialize = nodes.get(self._INITIALIZE)
@@ -145,6 +304,10 @@ class Consul(AbstractDCS):
             config = nodes.get(self._CONFIG)
             config = config and ClusterConfig.from_node(config['ModifyIndex'], config['Value'])
 
+            # get timeline history
+            history = nodes.get(self._HISTORY)
+            history = history and TimelineHistory.from_node(history['ModifyIndex'], history['Value'])
+
             # get last leader operation
             last_leader_operation = nodes.get(self._LEADER_OPTIME)
             last_leader_operation = 0 if last_leader_operation is None else int(last_leader_operation['Value'])
@@ -154,7 +317,8 @@ class Consul(AbstractDCS):
 
             # get leader
             leader = nodes.get(self._LEADER)
-            if leader and leader['Value'] == self._name and self._session != leader.get('Session', 'x'):
+            if not self._ctl and leader and leader['Value'] == self._name \
+                    and self._session != leader.get('Session', 'x'):
                 logger.info('I am leader but not owner of the session. Removing leader node')
                 self._client.kv.delete(self.leader_path, cas=leader['ModifyIndex'])
                 leader = None
@@ -169,42 +333,115 @@ class Consul(AbstractDCS):
             if failover:
                 failover = Failover.from_node(failover['ModifyIndex'], failover['Value'])
 
-            self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover)
+            # get synchronization state
+            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)
         except NotFound:
-            self._cluster = Cluster(None, None, None, None, [], None)
-        except:
+            self._cluster = 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, **kwargs):
+    @catch_consul_errors
+    def touch_member(self, data, ttl=None, permanent=False):
         cluster = self.cluster
-        member = cluster and ([m for m in cluster.members if m.name == self._name] or [None])[0]
-        create_member = 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
+        member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
+        create_member = not permanent and self.refresh_session()
 
-        if not create_member and member and data == self._my_member_data:
+        if member and (create_member or member.session != self._session):
+            self._client.kv.delete(self.member_path)
+            create_member = True
+
+        if not create_member and member and deep_compare(data, member.data):
             return True
 
         try:
-            args = {} if kwargs.get('permanent', False) else {'acquire': self._session}
-            self._client.kv.put(self.member_path, data, **args)
-            self._my_member_data = data
+            args = {} if permanent else {'acquire': self._session}
+            self._client.kv.put(self.member_path, json.dumps(data, separators=(',', ':')), **args)
+            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 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):
-        args = {} if permanent else {'acquire': self._session}
-        ret = self._client.kv.put(self.leader_path, self._name, **args)
+        if not self._session and not permanent:
+            self.refresh_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):
@@ -219,25 +456,32 @@ class Consul(AbstractDCS):
         return self._client.kv.put(self.config_path, value, cas=index)
 
     @catch_consul_errors
-    def write_leader_optime(self, last_operation):
+    def _write_leader_optime(self, last_operation):
         return self._client.kv.put(self.leader_optime_path, last_operation)
 
-    @staticmethod
-    def update_leader():
-        return True
+    @catch_consul_errors
+    def _update_leader(self):
+        if self._session:
+            self.retry(self._client.session.renew, self._session)
+            self._last_session_refresh = time.time()
+        return bool(self._session)
 
     @catch_consul_errors
     def initialize(self, create_new=True, sysid=''):
         kwargs = {'cas': 0} if create_new else {}
-        return self._client.kv.put(self.initialize_path, sysid, **kwargs)
+        return self.retry(self._client.kv.put, self.initialize_path, sysid, **kwargs)
 
     @catch_consul_errors
     def cancel_initialization(self):
-        return self._client.kv.delete(self.initialize_path)
+        return self.retry(self._client.kv.delete, self.initialize_path)
 
     @catch_consul_errors
     def delete_cluster(self):
-        return self._client.kv.delete(self.client_path(''), recurse=True)
+        return self.retry(self._client.kv.delete, self.client_path(''), recurse=True)
+
+    @catch_consul_errors
+    def set_history_value(self, value):
+        return self._client.kv.put(self.history_path, value)
 
     @catch_consul_errors
     def delete_leader(self):
@@ -245,24 +489,32 @@ class Consul(AbstractDCS):
         if cluster and isinstance(cluster.leader, Leader) and cluster.leader.name == self._name:
             return self._client.kv.delete(self.leader_path, cas=cluster.leader.index)
 
-    def watch(self, timeout):
+    @catch_consul_errors
+    def set_sync_state_value(self, value, index=None):
+        return self.retry(self._client.kv.put, self.sync_path, value, cas=index)
+
+    @catch_consul_errors
+    def delete_sync_state(self, index=None):
+        return self.retry(self._client.kv.delete, self.sync_path, cas=index)
+
+    def watch(self, leader_index, timeout):
         if self.__do_not_watch:
             self.__do_not_watch = False
             return True
 
-        cluster = self.cluster
-        if cluster and cluster.leader and cluster.leader.name != self._name and cluster.leader.index:
+        if leader_index:
             end_time = time.time() + timeout
             while timeout >= 1:
                 try:
-                    idx, _ = self._client.kv.get(self.leader_path, index=cluster.leader.index, wait=str(timeout) + 's')
-                    return str(idx) != str(cluster.leader.index)
-                except (ConsulException, RequestException):
-                    logging.exception('watch')
+                    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):
+                    logger.exception('watch')
 
                 timeout = end_time - time.time()
 
         try:
-            return super(Consul, self).watch(timeout)
+            return super(Consul, self).watch(None, timeout)
         finally:
+            self._last_session_refresh = 0
             self.event.clear()

patroni/dcs/etcd.py

@@ -1,35 +1,95 @@
 from __future__ import absolute_import
 import etcd
+import json
 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
+from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
 from patroni.exceptions import DCSError
-from patroni.utils import Retry, RetryFailedError, sleep
+from patroni.utils import Retry, RetryFailedError, split_host_port
 from urllib3.exceptions import HTTPError, ReadTimeoutError
 from requests.exceptions import RequestException
+from six.moves.queue import Queue
 from six.moves.http_client import HTTPException
+from six.moves.urllib_parse import urlparse
+from threading import Thread
 
 logger = logging.getLogger(__name__)
 
 
+def uri(protocol, host, port, endpoint=''):
+    return '{0}://{1}:{2}{3}'.format(protocol, host, port, endpoint)
+
+
 class EtcdError(DCSError):
     pass
 
 
+class DnsCachingResolver(Thread):
+
+    def __init__(self, cache_time=600.0, cache_fail_time=30.0):
+        super(DnsCachingResolver, self).__init__()
+        self._cache = {}
+        self._cache_time = cache_time
+        self._cache_fail_time = cache_fail_time
+        self._resolve_queue = Queue()
+        self.daemon = True
+        self.start()
+
+    def run(self):
+        while True:
+            (host, port), attempt = self._resolve_queue.get()
+            response = self._do_resolve(host, port)
+            if response:
+                self._cache[(host, port)] = (time.time(), response)
+            else:
+                if attempt < 10:
+                    self.resolve_async(host, port, attempt + 1)
+                    time.sleep(1)
+
+    def resolve(self, host, port):
+        current_time = time.time()
+        cached_time, response = self._cache.get((host, port), (0, []))
+        time_passed = current_time - cached_time
+        if time_passed > self._cache_time or (not response and time_passed > self._cache_fail_time):
+            new_response = self._do_resolve(host, port)
+            if new_response:
+                self._cache[(host, port)] = (current_time, new_response)
+                response = new_response
+        return response
+
+    def resolve_async(self, host, port, attempt=0):
+        self._resolve_queue.put(((host, port), attempt))
+
+    @staticmethod
+    def _do_resolve(host, port):
+        try:
+            return socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM, socket.IPPROTO_TCP)
+        except socket.gaierror:
+            logger.warning('failed to resolve host %s', host)
+            return []
+
+
 class Client(etcd.Client):
 
-    def __init__(self, config):
-        super(Client, self).__init__(read_timeout=config['retry_timeout'])
+    def __init__(self, config, dns_resolver, cache_ttl=300):
+        self._dns_resolver = dns_resolver
+        self.set_machines_cache_ttl(cache_ttl)
+        self._machines_cache_updated = 0
+        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)
         self._config = config
         self._load_machines_cache()
-        self._allow_reconnect = True
+        self._allow_reconnect = not self._use_proxies
 
     def _build_request_parameters(self):
         kwargs = {'headers': self._get_headers(), 'redirect': self.allow_redirect}
@@ -48,6 +108,9 @@ class Client(etcd.Client):
         kwargs['timeout'] = self.read_timeout/float(kwargs['retries'] + 1)/etcd_nodes
         return kwargs
 
+    def set_machines_cache_ttl(self, cache_ttl):
+        self._machines_cache_ttl = cache_ttl
+
     @property
     def machines(self):
         """Original `machines` method(property) of `etcd.Client` class raise exception
@@ -68,6 +131,10 @@ class Client(etcd.Client):
                 machines = [n.strip() for n in self._handle_server_response(response).data.decode('utf-8').split(',')]
                 logger.debug("Retrieved list of machines: %s", machines)
                 random.shuffle(machines)
+                for url in machines:
+                    r = urlparse(url)
+                    port = r.port or (443 if r.scheme == 'https' else 80)
+                    self._dns_resolver.resolve_async(r.hostname, port)
                 return machines
             except Exception as e:
                 # We can't get the list of machines, if one server is in the
@@ -119,6 +186,11 @@ 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()
 
         kwargs.update(self._build_request_parameters())
 
@@ -138,8 +210,11 @@ class Client(etcd.Client):
                 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
+        except etcd.EtcdConnectionFailed as e:
+            if isinstance(e, etcd.EtcdWatchTimedOut) and self._machines_cache:
+                self._base_uri = self._next_server()
+            else:
+                self._update_machines_cache = True
             if not response:
                 raise
         return self._handle_server_response(response)
@@ -147,40 +222,51 @@ class Client(etcd.Client):
     @staticmethod
     def get_srv_record(host):
         try:
-            return [(str(r.target).rstrip('.'), r.port) for r in resolver.query('_etcd-server._tcp.' + host, 'SRV')]
+            return [(r.target.to_text(True), r.port) for r in resolver.query(host, 'SRV')]
         except DNSException:
-            logger.exception('Can not resolve SRV for %s', host)
-        return []
+            return []
 
-    def _get_machines_cache_from_srv(self, discovery_srv):
+    def _get_machines_cache_from_srv(self, srv):
         """Fetch list of etcd-cluster member by resolving _etcd-server._tcp. SRV record.
         This record should contain list of host and peer ports which could be used to run
         'GET http://{host}:{port}/members' request (peer protocol)"""
 
         ret = []
-        for host, port in self.get_srv_record(discovery_srv):
-            url = '{0}://{1}:{2}/members'.format(self._protocol, host, port)
-            try:
-                response = requests.get(url, timeout=self.read_timeout)
-                if response.ok:
-                    for member in response.json():
-                        ret.extend(member['clientURLs'])
-                    break
-            except RequestException:
-                logger.exception('GET %s', url)
+        for r in ['-client-ssl', '-client', '-ssl', '', '-server-ssl', '-server']:
+            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)
+                if endpoint:
+                    try:
+                        response = requests.get(url, timeout=self.read_timeout, verify=False)
+                        if response.ok:
+                            for member in response.json():
+                                ret.extend(member['clientURLs'])
+                            break
+                    except RequestException:
+                        logger.exception('GET %s', url)
+                else:
+                    ret.append(url)
+            if ret:
+                self._protocol = protocol
+                break
+        else:
+            logger.warning('Can not resolve SRV for %s', srv)
         return list(set(ret))
 
-    def _get_machines_cache_from_dns(self, addr):
+    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"""
-
-        ret = []
-        host, port = addr.split(':')
-        try:
-            for r in set(socket.getaddrinfo(host, port, socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP)):
-                ret.append('{0}://{1}:{2}'.format(self._protocol, r[4][0], r[4][1]))
-        except socket.error:
-            logger.exception('Can not resolve %s', host)
-        return list(set(ret)) if ret else ['{0}://{1}:{2}'.format(self._protocol, host, port)]
+        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))
+            if ret:
+                return list(set(ret))
+        return [uri(self.protocol, host, port)]
 
     def _load_machines_cache(self):
         """This method should fill up `_machines_cache` from scratch.
@@ -190,42 +276,36 @@ class Client(etcd.Client):
 
         self._update_machines_cache = True
 
-        if 'discovery_srv' not in self._config and 'host' not in self._config:
-            raise Exception('Neither discovery_srv nor host are defined in etcd section of config')
+        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')
 
-        self._machines_cache = []
+        if self._use_proxies:
+            self._machines_cache = [uri(self.protocol, self._config['host'], self._config['port'])]
+        else:
+            self._machines_cache = []
 
-        if 'discovery_srv' in self._config:
-            self._machines_cache = self._get_machines_cache_from_srv(self._config['discovery_srv'])
+            if 'srv' in self._config:
+                self._machines_cache = self._get_machines_cache_from_srv(self._config['srv'])
 
-        if not self._machines_cache and 'host' in self._config:
-            self._machines_cache = self._get_machines_cache_from_dns(self._config['host'])
+            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'])
 
         # Can not bootstrap list of etcd-cluster members, giving up
         if not self._machines_cache:
             raise etcd.EtcdException
 
         # After filling up initial list of machines_cache we should ask etcd-cluster about actual list
-        self._base_uri = self._machines_cache.pop(0)
+        self._base_uri = self._next_server()
         self._machines_cache = self.machines
 
         if self._base_uri in self._machines_cache:
             self._machines_cache.remove(self._base_uri)
 
         self._update_machines_cache = False
-
-
-def catch_etcd_errors(func):
-    def wrapper(*args, **kwargs):
-        try:
-            return func(*args, **kwargs) is not None
-        except (RetryFailedError, etcd.EtcdException):
-            return False
-        except:
-            logger.exception("")
-            raise EtcdError("unexpected error")
-
-    return wrapper
+        self._machines_cache_updated = time.time()
 
 
 class Etcd(AbstractDCS):
@@ -239,25 +319,123 @@ class Etcd(AbstractDCS):
                                               etcd.EtcdEventIndexCleared))
         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)
 
+    def _handle_exception(self, e, name='', do_sleep=False, raise_ex=None):
+        if not self._has_failed:
+            logger.exception(name)
+        else:
+            logger.error(e)
+            if do_sleep:
+                time.sleep(1)
+        self._has_failed = True
+        if isinstance(raise_ex, Exception):
+            raise raise_ex
+
+    def catch_etcd_errors(func):
+        def wrapper(self, *args, **kwargs):
+            try:
+                retval = func(self, *args, **kwargs) is not None
+                self._has_failed = False
+                return retval
+            except (RetryFailedError, etcd.EtcdException) as e:
+                self._handle_exception(e)
+                return False
+            except Exception as e:
+                self._handle_exception(e, raise_ex=EtcdError('unexpected error'))
+
+        return wrapper
+
     @staticmethod
     def get_etcd_client(config):
+        if 'proxy' in config:
+            config['use_proxies'] = True
+            config['url'] = config['proxy']
+
+        if 'url' in config:
+            r = urlparse(config['url'])
+            config.update({'protocol': r.scheme, 'host': r.hostname, 'port': r.port or 2379,
+                           'username': r.username, 'password': r.password})
+        elif 'hosts' in config:
+            hosts = config.pop('hosts')
+            default_port = config.pop('port', 2379)
+            protocol = config.get('protocol', 'http')
+
+            if isinstance(hosts, six.string_types):
+                hosts = hosts.split(',')
+
+            config['hosts'] = []
+            for value in hosts:
+                if isinstance(value, six.string_types):
+                    config['hosts'].append(uri(protocol, *split_host_port(value, default_port)))
+        elif 'host' in config:
+            host, port = split_host_port(config['host'], 2379)
+            config['host'] = host
+            if 'port' not in config:
+                config['port'] = int(port)
+
+        if config.get('cacert'):
+            config['ca_cert'] = config.pop('cacert')
+
+        if config.get('key') and config.get('cert'):
+            config['cert'] = (config['cert'], config['key'])
+
+        for p in ('discovery_srv', 'srv_domain'):
+            if p in config:
+                config['srv'] = config.pop(p)
+
+        dns_resolver = DnsCachingResolver()
+
+        def create_connection_patched(address, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+                                      source_address=None, socket_options=None):
+            host, port = address
+            if host.startswith('['):
+                host = host.strip('[]')
+            err = None
+            for af, socktype, proto, _, sa in dns_resolver.resolve(host, port):
+                sock = None
+                try:
+                    sock = socket.socket(af, socktype, proto)
+                    if socket_options:
+                        for opt in socket_options:
+                            sock.setsockopt(*opt)
+                    if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
+                        sock.settimeout(timeout)
+                    if source_address:
+                        sock.bind(source_address)
+                    sock.connect(sa)
+                    return sock
+
+                except socket.error as e:
+                    err = e
+                    if sock is not None:
+                        sock.close()
+                        sock = None
+
+            if err is not None:
+                raise err
+
+            raise socket.error("getaddrinfo returns an empty list")
+
+        urllib3.util.connection.create_connection = create_connection_patched
+
         client = None
         while not client:
             try:
-                client = Client(config)
+                client = Client(config, dns_resolver)
             except etcd.EtcdException:
                 logger.info('waiting on etcd')
-                sleep(5)
+                time.sleep(5)
         return client
 
     def set_ttl(self, ttl):
         ttl = int(ttl)
         self.__do_not_watch = self._ttl != ttl
         self._ttl = ttl
+        self._client.set_machines_cache_ttl(ttl*10)
 
     def set_retry_timeout(self, retry_timeout):
         self._retry.deadline = retry_timeout
@@ -270,7 +448,7 @@ class Etcd(AbstractDCS):
     def _load_cluster(self):
         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 = {os.path.relpath(node.key, result.key).replace('\\', '/'): node for node in result.leaves}
 
             # get initialize flag
             initialize = nodes.get(self._INITIALIZE)
@@ -280,6 +458,10 @@ class Etcd(AbstractDCS):
             config = nodes.get(self._CONFIG)
             config = config and ClusterConfig.from_node(config.modifiedIndex, config.value)
 
+            # get timeline history
+            history = nodes.get(self._HISTORY)
+            history = history and TimelineHistory.from_node(history.modifiedIndex, history.value)
+
             # get last leader operation
             last_leader_operation = nodes.get(self._LEADER_OPTIME)
             last_leader_operation = 0 if last_leader_operation is None else int(last_leader_operation.value)
@@ -300,16 +482,21 @@ class Etcd(AbstractDCS):
             if failover:
                 failover = Failover.from_node(failover.modifiedIndex, failover.value)
 
-            self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover)
+            # get synchronization state
+            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)
         except etcd.EtcdKeyNotFound:
-            self._cluster = Cluster(None, None, None, None, [], None)
-        except:
-            logger.exception('get_cluster')
-            raise EtcdError('Etcd is not responding properly')
+            self._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
 
     @catch_etcd_errors
     def touch_member(self, data, ttl=None, permanent=False):
-        return self.retry(self._client.set, self.member_path, data, None if permanent else ttl or self._ttl)
+        data = json.dumps(data, separators=(',', ':'))
+        return self._client.set(self.member_path, data, None if permanent else ttl or self._ttl)
 
     @catch_etcd_errors
     def take_leader(self):
@@ -337,11 +524,11 @@ class Etcd(AbstractDCS):
         return self._client.write(self.config_path, value, prevIndex=index or 0)
 
     @catch_etcd_errors
-    def write_leader_optime(self, last_operation):
+    def _write_leader_optime(self, last_operation):
         return self._client.set(self.leader_optime_path, last_operation)
 
     @catch_etcd_errors
-    def update_leader(self):
+    def _update_leader(self):
         return self.retry(self._client.test_and_set, self.leader_path, self._name, self._name, self._ttl)
 
     @catch_etcd_errors
@@ -360,31 +547,46 @@ class Etcd(AbstractDCS):
     def delete_cluster(self):
         return self.retry(self._client.delete, self.client_path(''), recursive=True)
 
-    def watch(self, timeout):
+    @catch_etcd_errors
+    def set_history_value(self, value):
+        return self._client.write(self.history_path, value)
+
+    @catch_etcd_errors
+    def set_sync_state_value(self, value, index=None):
+        return self.retry(self._client.write, self.sync_path, value, prevIndex=index or 0)
+
+    @catch_etcd_errors
+    def delete_sync_state(self, index=None):
+        return self.retry(self._client.delete, self.sync_path, prevIndex=index or 0)
+
+    def watch(self, leader_index, timeout):
         if self.__do_not_watch:
             self.__do_not_watch = False
             return True
 
-        cluster = self.cluster
-        # watch on leader key changes if it is defined and current node is not lock owner
-        if cluster and cluster.leader and cluster.leader.name != self._name and cluster.leader.index:
+        if leader_index:
             end_time = time.time() + timeout
 
             while timeout >= 1:  # when timeout is too small urllib3 doesn't have enough time to connect
                 try:
-                    self._client.watch(self.leader_path, index=cluster.leader.index, timeout=timeout + 0.5)
+                    self._client.watch(self.leader_path, index=leader_index, timeout=timeout + 0.5)
+                    self._has_failed = False
                     # Synchronous work of all cluster members with etcd is less expensive
                     # than reestablishing http connection every time from every replica.
                     return True
                 except etcd.EtcdWatchTimedOut:
                     self._client.http.clear()
+                    self._has_failed = False
                     return False
-                except etcd.EtcdException:
-                    logging.exception('watch')
+                except (etcd.EtcdEventIndexCleared, etcd.EtcdWatcherCleared):  # Watch failed
+                    self._has_failed = False
+                    return True  # leave the loop, because watch with the same parameters will fail anyway
+                except etcd.EtcdException as e:
+                    self._handle_exception(e, 'watch', True)
 
                 timeout = end_time - time.time()
 
         try:
-            return super(Etcd, self).watch(timeout)
+            return super(Etcd, self).watch(None, timeout)
         finally:
             self.event.clear()

patroni/dcs/exhibitor.py

@@ -4,7 +4,6 @@ import requests
 import time
 
 from patroni.dcs.zookeeper import ZooKeeper
-from patroni.utils import sleep
 from requests.exceptions import RequestException
 
 logger = logging.getLogger(__name__)
@@ -24,7 +23,7 @@ class ExhibitorEnsembleProvider(object):
         self._next_poll = None
         while not self.poll():
             logger.info('waiting on exhibitor')
-            sleep(5)
+            time.sleep(5)
 
     def poll(self):
         if self._next_poll and self._next_poll > time.time():

patroni/dcs/kubernetes.py

@@ -0,0 +1,415 @@
+from __future__ import absolute_import
+import datetime
+import functools
+import json
+import logging
+import socket
+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.exceptions import HTTPError
+from six.moves.http_client import HTTPException
+
+logger = logging.getLogger(__name__)
+
+
+class KubernetesError(DCSError):
+    pass
+
+
+class KubernetesRetriableException(k8s_client.rest.ApiException):
+
+    def __init__(self, orig):
+        super(KubernetesRetriableException, self).__init__(orig.status, orig.reason)
+        self.body = orig.body
+        self.headers = orig.headers
+
+
+class CoreV1ApiProxy(object):
+
+    def __init__(self, use_endpoints=False):
+        self._api = k8s_client.CoreV1Api()
+        self._request_timeout = None
+        self._use_endpoints = use_endpoints
+
+    def set_timeout(self, timeout):
+        self._request_timeout = (1, timeout / 3.0)
+
+    def __getattr__(self, func):
+        if func.endswith('_kind'):
+            func = func[:-4] + ('endpoints' if self._use_endpoints else 'config_map')
+
+        def wrapper(*args, **kwargs):
+            if '_request_timeout' not in kwargs:
+                kwargs['_request_timeout'] = self._request_timeout
+            try:
+                return getattr(self._api, func)(*args, **kwargs)
+            except k8s_client.rest.ApiException as e:
+                if e.status in (502, 503, 504):  # XXX
+                    raise KubernetesRetriableException(e)
+                raise
+        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 Kubernetes(AbstractDCS):
+
+    def __init__(self, config):
+        self._labels = config['labels']
+        self._labels[config.get('scope_label', 'cluster-name')] = config['scope']
+        self._label_selector = ','.join('{0}={1}'.format(k, v) for k, v in self._labels.items())
+        self._namespace = config.get('namespace') or 'default'
+        self._role_label = config.get('role_label', 'role')
+        config['namespace'] = ''
+        super(Kubernetes, self).__init__(config)
+        self._retry = Retry(deadline=config['retry_timeout'], max_delay=1, max_tries=-1,
+                            retry_exceptions=(KubernetesRetriableException, HTTPException,
+                                              HTTPError, socket.error, socket.timeout))
+        self._ttl = None
+        try:
+            k8s_config.load_incluster_config()
+        except k8s_config.ConfigException:
+            k8s_config.load_kube_config(context=config.get('context', 'local'))
+
+        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'])]
+            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 = 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.__do_not_watch = False
+
+    def retry(self, *args, **kwargs):
+        return self._retry.copy()(*args, **kwargs)
+
+    def client_path(self, path):
+        return super(Kubernetes, self).client_path(path)[1:].replace('/', '-')
+
+    @property
+    def leader_path(self):
+        return self._base_path[1:] if self.__subsets else super(Kubernetes, self).leader_path
+
+    def set_ttl(self, ttl):
+        ttl = int(ttl)
+        self.__do_not_watch = self._ttl != ttl
+        self._ttl = ttl
+
+    def set_retry_timeout(self, retry_timeout):
+        self._retry.deadline = retry_timeout
+        self._api.set_timeout(retry_timeout)
+
+    @staticmethod
+    def member(pod):
+        annotations = pod.metadata.annotations or {}
+        member = Member.from_node(pod.metadata.resource_version, pod.metadata.name, None, annotations.get('status', ''))
+        member.data['pod_labels'] = pod.metadata.labels
+        return member
+
+    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]
+
+            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}
+
+            config = nodes.get(self.config_path)
+            metadata = config and config.metadata
+            annotations = metadata and metadata.annotations or {}
+
+            # get initialize flag
+            initialize = annotations.get(self._INITIALIZE)
+
+            # get global dynamic configuration
+            config = ClusterConfig.from_node(metadata and metadata.resource_version,
+                                             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,
+                                                annotations.get(self._HISTORY) or '[]')
+
+            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 and leader.subsets else []
+            annotations = metadata and metadata.annotations or {}
+
+            # get last leader operation
+            last_leader_operation = annotations.get(self._OPTIME)
+            last_leader_operation = 0 if last_leader_operation is None else int(last_leader_operation)
+
+            # get leader
+            leader_record = {n: annotations.get(n) for n in (self._LEADER, 'acquireTime',
+                             'ttl', 'renewTime', 'transitions') if n in annotations}
+            if (leader_record or self._leader_observed_record) and leader_record != self._leader_observed_record:
+                self._leader_observed_record = leader_record
+                self._leader_observed_time = time.time()
+
+            leader = leader_record.get(self._LEADER)
+            try:
+                ttl = int(leader_record.get('ttl')) or self._ttl
+            except (TypeError, ValueError):
+                ttl = self._ttl
+
+            if not metadata or not self._leader_observed_time or self._leader_observed_time + ttl < time.time():
+                leader = None
+
+            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)
+
+            # 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)
+
+            # 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)
+        except Exception:
+            logger.exception('get_cluster')
+            raise KubernetesError('Kubernetes API is not responding properly')
+
+    @staticmethod
+    def compare_ports(p1, p2):
+        return p1.name == p2.name and p1.port == p2.port and (p1.protocol or 'TCP') == (p2.protocol or 'TCP')
+
+    @staticmethod
+    def subsets_changed(last_observed_subsets, subsets):
+        """
+        >>> Kubernetes.subsets_changed([], [])
+        False
+        >>> Kubernetes.subsets_changed([], [k8s_client.V1EndpointSubset()])
+        True
+        >>> s1 = [k8s_client.V1EndpointSubset(addresses=[k8s_client.V1EndpointAddress(ip='1.2.3.4')])]
+        >>> s2 = [k8s_client.V1EndpointSubset(addresses=[k8s_client.V1EndpointAddress(ip='1.2.3.5')])]
+        >>> Kubernetes.subsets_changed(s1, s2)
+        True
+        >>> a = [k8s_client.V1EndpointAddress(ip='1.2.3.4')]
+        >>> s1 = [k8s_client.V1EndpointSubset(addresses=a, ports=[k8s_client.V1EndpointPort(protocol='TCP', port=1)])]
+        >>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[k8s_client.V1EndpointPort(port=5432)])]
+        >>> Kubernetes.subsets_changed(s1, s2)
+        True
+        >>> p1 = k8s_client.V1EndpointPort(name='port1', port=1)
+        >>> p2 = k8s_client.V1EndpointPort(name='port2', port=2)
+        >>> p3 = k8s_client.V1EndpointPort(name='port3', port=3)
+        >>> s1 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p1, p2])]
+        >>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p2, p3])]
+        >>> Kubernetes.subsets_changed(s1, s2)
+        True
+        >>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p2, p1])]
+        >>> Kubernetes.subsets_changed(s1, s2)
+        False
+        """
+        if len(last_observed_subsets) != len(subsets):
+            return True
+        if subsets == []:
+            return False
+        if len(last_observed_subsets[0].addresses or []) != 1 or \
+                last_observed_subsets[0].addresses[0].ip != subsets[0].addresses[0].ip or \
+                len(last_observed_subsets[0].ports) != len(subsets[0].ports):
+            return True
+        if len(subsets[0].ports) == 1:
+            return not Kubernetes.compare_ports(last_observed_subsets[0].ports[0], subsets[0].ports[0])
+        observed_ports = {p.name: p for p in last_observed_subsets[0].ports}
+        for p in subsets[0].ports:
+            if p.name not in observed_ports or not Kubernetes.compare_ports(p, observed_ports.pop(p.name)):
+                return True
+        return False
+
+    @catch_kubernetes_errors
+    def patch_or_create(self, name, annotations, resource_version=None, patch=False, retry=True, subsets=None):
+        metadata = {'namespace': self._namespace, 'name': name, 'labels': self._labels, 'annotations': annotations}
+        if patch or resource_version:
+            if resource_version is not None:
+                metadata['resource_version'] = resource_version
+            func = functools.partial(self._api.patch_namespaced_kind, name)
+        else:
+            func = functools.partial(self._api.create_namespaced_kind)
+            # skip annotations with null values
+            metadata['annotations'] = {k: v for k, v in metadata['annotations'].items() if v is not None}
+
+        metadata = k8s_client.V1ObjectMeta(**metadata)
+        if subsets is not None and self.__subsets:
+            endpoints = {'metadata': metadata}
+            if self.subsets_changed(self._leader_observed_subsets, subsets):
+                endpoints['subsets'] = subsets
+            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)
+
+    def _write_leader_optime(self, last_operation):
+        """Unused"""
+
+    def _update_leader(self):
+        """Unused"""
+
+    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,
+                       'transitions': self._leader_observed_record.get('transitions') or '0'}
+        if last_operation:
+            annotations[self._OPTIME] = last_operation
+
+        subsets = self.__subsets
+        if subsets is not None and access_is_restricted:
+            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
+
+    def attempt_to_acquire_leader(self, permanent=False):
+        now = datetime.datetime.now(tzutc).isoformat()
+        annotations = {self._LEADER: self._name, 'ttl': str(sys.maxsize if permanent else self._ttl),
+                       'renewTime': now, 'acquireTime': now, 'transitions': '0'}
+        if self._leader_observed_record:
+            try:
+                transitions = int(self._leader_observed_record.get('transitions'))
+            except (TypeError, ValueError):
+                transitions = 0
+
+            if self._leader_observed_record.get(self._LEADER) != self._name:
+                transitions += 1
+            else:
+                annotations['acquireTime'] = self._leader_observed_record.get('acquireTime') or now
+            annotations['transitions'] = str(transitions)
+        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:
+            logger.info('Could not take out TTL lock')
+        return ret
+
+    def take_leader(self):
+        return self.attempt_to_acquire_leader()
+
+    def set_failover_value(self, value, index=None):
+        """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}
+        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)
+
+    @catch_kubernetes_errors
+    def touch_member(self, data, ttl=None, permanent=False):
+        cluster = self.cluster
+        if cluster and cluster.leader and cluster.leader.name == self._name:
+            role = 'master'
+        elif data['state'] == 'running' and data['role'] != 'master':
+            role = data['role']
+        else:
+            role = None
+
+        member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
+        pod_labels = member and member.data.pop('pod_labels', None)
+        ret = pod_labels is not None and pod_labels.get(self._role_label) == role and deep_compare(data, member.data)
+
+        if not ret:
+            metadata = {'namespace': self._namespace, 'name': self._name, 'labels': {self._role_label: role},
+                        '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)
+        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)
+
+    def delete_leader(self):
+        if self.cluster and isinstance(self.cluster.leader, Leader) and self.cluster.leader.name == self._name:
+            self.patch_or_create(self.leader_path, {self._LEADER: None}, self._leader_resource_version, True, False, [])
+            self.reset_cluster()
+
+    def cancel_initialization(self):
+        self.patch_or_create(self.config_path, {self._INITIALIZE: None}, self.cluster.config.index, True)
+
+    @catch_kubernetes_errors
+    def delete_cluster(self):
+        self.retry(self._api.delete_collection_namespaced_kind, self._namespace, label_selector=self._label_selector)
+
+    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)
+
+    def set_sync_state_value(self, value, index=None):
+        """Unused"""
+
+    def write_sync_state(self, leader, sync_standby, index=None):
+        return self.patch_or_create(self.sync_path, self.sync_state(leader, sync_standby), index, False)
+
+    def delete_sync_state(self, index=None):
+        return self.write_sync_state(None, None, index)
+
+    def watch(self, leader_index, timeout):
+        if self.__do_not_watch:
+            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:
+                    logger.exception('watch')
+
+                timeout = end_time - time.time()
+
+        try:
+            return super(Kubernetes, self).watch(None, timeout)
+        finally:
+            self.event.clear()

patroni/dcs/zookeeper.py

@@ -1,10 +1,14 @@
+import json
 import logging
+import select
+import time
 
-from kazoo.client import KazooClient, KazooState
+from kazoo.client import KazooClient, KazooState, KazooRetry
 from kazoo.exceptions import NoNodeError, NodeExistsError
 from kazoo.handlers.threading import SequentialThreadingHandler
-from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member
+from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
 from patroni.exceptions import DCSError
+from patroni.utils import deep_compare
 
 logger = logging.getLogger(__name__)
 
@@ -34,12 +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):
 
@@ -51,13 +64,12 @@ class ZooKeeper(AbstractDCS):
             hosts = ','.join(hosts)
 
         self._client = KazooClient(hosts, handler=PatroniSequentialThreadingHandler(config['retry_timeout']),
-                                   timeout=config['ttl'], connection_retry={'max_delay': 1, 'max_tries': -1},
-                                   command_retry={'deadline': config['retry_timeout'], 'max_delay': 1, 'max_tries': -1})
+                                   timeout=config['ttl'], connection_retry=KazooRetry(max_delay=1, max_tries=-1,
+                                   sleep_func=time.sleep), command_retry=KazooRetry(deadline=config['retry_timeout'],
+                                   max_delay=1, max_tries=-1, sleep_func=time.sleep))
         self._client.add_listener(self.session_listener)
 
-        self._my_member_data = None
         self._fetch_cluster = True
-        self._last_leader_operation = 0
 
         self._orig_kazoo_connect = self._client._connection._connect
         self._client._connection._connect = self._kazoo_connect
@@ -65,7 +77,6 @@ class ZooKeeper(AbstractDCS):
         self._client.start()
 
     def _kazoo_connect(self, host, port):
-
         """Kazoo is using Ping's to determine health of connection to zookeeper. If there is no
         response on Ping after Ping interval (1/2 from read_timeout) it will consider current
         connection dead and try to connect to another node. Without this "magic" it was taking
@@ -116,7 +127,8 @@ class ZooKeeper(AbstractDCS):
             return True
 
     def set_retry_timeout(self, retry_timeout):
-        self._client._retry.deadline = retry_timeout
+        retry = self._client.retry if isinstance(self._client.retry, KazooRetry) else self._client._retry
+        retry.deadline = retry_timeout
 
     def get_node(self, key, watch=None):
         try:
@@ -135,10 +147,11 @@ class ZooKeeper(AbstractDCS):
         except NoNodeError:
             return []
 
-    def load_members(self):
+    def load_members(self, sync_standby):
         members = []
         for member in self.get_children(self.members_path, self.cluster_watcher):
-            data = self.get_node(self.members_path + member)
+            watch = member == sync_standby and self.cluster_watcher or None
+            data = self.get_node(self.members_path + member, watch)
             if data is not None:
                 members.append(self.member(member, *data))
         return members
@@ -157,14 +170,28 @@ class ZooKeeper(AbstractDCS):
         config = self.get_node(self.config_path, watch=self.cluster_watcher) if self._CONFIG in nodes else None
         config = config and ClusterConfig.from_node(config[1].version, config[0], config[1].mzxid)
 
+        # get timeline history
+        history = self.get_node(self.history_path, watch=self.cluster_watcher) if self._HISTORY in nodes else None
+        history = history and TimelineHistory.from_node(history[1].mzxid, history[0])
+
+        # get last leader operation
+        last_leader_operation = self._OPTIME in nodes and self._fetch_cluster and self.get_node(self.leader_optime_path)
+        last_leader_operation = last_leader_operation and int(last_leader_operation[0]) or 0
+
+        # get synchronization state
+        sync = self.get_node(self.sync_path, watch=self.cluster_watcher) if self._SYNC in nodes else None
+        sync = SyncState.from_node(sync and sync[1].version, sync and sync[0])
+
         # get list of members
-        members = self.load_members() if self._MEMBERS[:-1] in nodes else []
+        sync_standby = sync.leader == self._name and sync.sync_standby or None
+        members = self.load_members(sync_standby) if self._MEMBERS[:-1] in nodes else []
 
         # get leader
         leader = self.get_node(self.leader_path) if self._LEADER in nodes else None
         if leader:
             client_id = self._client.client_id
-            if leader[0] == self._name and client_id is not None and client_id[0] != leader[1].ephemeralOwner:
+            if not self._ctl and leader[0] == self._name and client_id is not None \
+                    and client_id[0] != leader[1].ephemeralOwner:
                 logger.info('I am leader but not owner of the session. Removing leader node')
                 self._client.delete(self.leader_path)
                 leader = None
@@ -179,10 +206,7 @@ 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])
 
-        # get last leader operation
-        optime = self.get_node(self.leader_optime_path) if self._OPTIME in nodes and self._fetch_cluster else None
-        self._last_leader_operation = 0 if optime is None else int(optime[0])
-        self._cluster = Cluster(initialize, config, leader, self._last_leader_operation, members, failover)
+        self._cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
 
     def _load_cluster(self):
         if self._fetch_cluster or self._cluster is None:
@@ -193,73 +217,82 @@ class ZooKeeper(AbstractDCS):
                 self.cluster_watcher(None)
                 raise ZooKeeperError('ZooKeeper in not responding properly')
 
-    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:
-            return False
+        except Exception:
+            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_value(self, 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, self.failover_path, 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(self.failover_path, value))
-        except:
-            logging.exception('set_failover_value')
-            return False
+            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:
+            logger.exception('Failed to update %s', key)
+        return False
+
+    def set_failover_value(self, value, index=None):
+        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):
         cluster = self.cluster
-        member = cluster and ([m for m in cluster.members if m.name == self._name] or [None])[0]
-        data = data.encode('utf-8')
+        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]:
             try:
                 self._client.delete_async(self.member_path).get(timeout=1)
             except NoNodeError:
                 pass
-            except:
+            except Exception:
                 return False
             member = None
 
         if member:
-            if data == self._my_member_data:
+            if deep_compare(data, member.data):
                 return True
         else:
             try:
-                self._client.create_async(self.member_path, data, makepath=True, ephemeral=not permanent).get(timeout=1)
-                self._my_member_data = data
+                self._client.create_async(self.member_path, encoded_data, makepath=True,
+                                          ephemeral=not permanent).get(timeout=1)
                 return True
             except Exception as e:
                 if not isinstance(e, NodeExistsError):
                     logger.exception('touch_member')
                     return False
         try:
-            self._client.set_async(self.member_path, data).get(timeout=1)
-            self._my_member_data = data
+            self._client.set_async(self.member_path, encoded_data).get(timeout=1)
             return True
-        except:
+        except Exception:
             logger.exception('touch_member')
 
         return False
@@ -267,27 +300,14 @@ class ZooKeeper(AbstractDCS):
     def take_leader(self):
         return self.attempt_to_acquire_leader()
 
-    def write_leader_optime(self, last_operation):
-        last_operation = last_operation.encode('utf-8')
-        if last_operation != self._last_leader_operation:
-            try:
-                self._client.set_async(self.leader_optime_path, last_operation).get(timeout=1)
-                self._last_leader_operation = last_operation
-            except NoNodeError:
-                try:
-                    self._client.create_async(self.leader_optime_path, last_operation, makepath=True).get(timeout=1)
-                    self._last_leader_operation = last_operation
-                except:
-                    logger.exception('Failed to create %s', self.leader_optime_path)
-            except:
-                logger.exception('Failed to update %s', self.leader_optime_path)
+    def _write_leader_optime(self, last_operation):
+        return self._set_or_create(self.leader_optime_path, last_operation)
 
-    def update_leader(self):
+    def _update_leader(self):
         return True
 
     def delete_leader(self):
         self._client.restart()
-        self._my_member_data = None
         return True
 
     def _cancel_initialization(self):
@@ -298,7 +318,7 @@ class ZooKeeper(AbstractDCS):
     def cancel_initialization(self):
         try:
             self._client.retry(self._cancel_initialization)
-        except:
+        except Exception:
             logger.exception("Unable to delete initialize key")
 
     def delete_cluster(self):
@@ -307,7 +327,16 @@ class ZooKeeper(AbstractDCS):
         except NoNodeError:
             return True
 
-    def watch(self, timeout):
-        if super(ZooKeeper, self).watch(timeout):
+    def set_history_value(self, value):
+        return self._set_or_create(self.history_path, value)
+
+    def set_sync_state_value(self, value, index=None):
+        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)
+
+    def watch(self, leader_index, timeout):
+        if super(ZooKeeper, self).watch(leader_index, timeout):
             self._fetch_cluster = True
         return self._fetch_cluster

patroni/exceptions.py

@@ -23,3 +23,7 @@ class DCSError(PatroniException):
 
 class PostgresConnectionException(PostgresException):
     pass
+
+
+class WatchdogError(PatroniException):
+    pass

patroni/log.py

@@ -0,0 +1,66 @@
+import logging
+import os
+
+from copy import deepcopy
+from logging.handlers import RotatingFileHandler
+from patroni.utils import deep_compare
+
+
+class PatroniLogger(object):
+
+    DEFAULT_LEVEL = 'INFO'
+    DEFAULT_FORMAT = '%(asctime)s %(levelname)s: %(message)s'
+
+    def __init__(self):
+        self.root_logger = logging.getLogger()
+        self.config = None
+        self.handler = None
+        self.reload_config({'level': 'DEBUG'})
+
+    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):
+            self.root_logger.setLevel(config.get('level', PatroniLogger.DEFAULT_LEVEL))
+
+            add_handler = None
+            if 'dir' in config:
+                if not isinstance(self.handler, RotatingFileHandler):
+                    add_handler = RotatingFileHandler(os.path.join(config['dir'], __name__))
+                handler = add_handler or self.handler
+                handler.maxBytes = int(config.get('file_size', 25000000))
+                handler.backupCount = int(config.get('file_num', 4))
+            else:
+                if self.handler is None or isinstance(self.handler, RotatingFileHandler):
+                    add_handler = logging.StreamHandler()
+                handler = add_handler or self.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 add_handler:
+                handler.setFormatter(logging.Formatter(logformat, dateformat))
+
+            if add_handler:
+                self.root_logger.addHandler(add_handler)
+
+                if self.handler is not None:
+                    self.root_logger.removeHandler(self.handler)
+                    self.handler.close()
+
+                self.handler = add_handler
+
+            self.config = config.copy()
+            self.update_loggers()

patroni/postmaster.py

@@ -0,0 +1,171 @@
+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 if os.name != 'nt' else signal.SIGABRT,
+}
+
+
+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 ('PATH', 'LD_LIBRARY_PATH', 'LC_ALL', 'LANG', 'SYSTEMROOT') if p in os.environ}
+        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))
+        proc = call_self(['pg_ctl_start'] + cmdline, close_fds=(os.name != 'nt'),
+                         stdout=subprocess.PIPE, env=env)
+        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/scripts/aws.py

@@ -6,63 +6,64 @@ from requests.exceptions import RequestException
 import sys
 import boto.ec2
 
+from patroni.utils import Retry, RetryFailedError
+
 logger = logging.getLogger(__name__)
 
 
 class AWSConnection(object):
+
     def __init__(self, cluster_name):
         self.available = False
         self.cluster_name = cluster_name if cluster_name is not None else 'unknown'
+        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=0.1)
+            r = requests.get('http://169.254.169.254/latest/dynamic/instance-identity/document', timeout=2.1)
         except RequestException:
-            logger.info("cannot query AWS meta-data")
+            logger.error('cannot query AWS meta-data')
             return
+
         if r.ok:
             try:
                 content = r.json()
                 self.instance_id = content['instanceId']
                 self.region = content['region']
-            except Exception as e:
-                logger.info('unable to fetch instance id and region from AWS meta-data: {}'.format(e))
+            except Exception:
+                logger.exception('unable to fetch instance id and region from AWS meta-data')
                 return
             self.available = True
 
+    def retry(self, *args, **kwargs):
+        return self._retry.copy()(*args, **kwargs)
+
     def aws_available(self):
         return self.available
 
-    def _tag_ebs(self, role):
+    def _tag_ebs(self, conn, role):
         """ set tags, carrying the cluster name, instance role and instance id for the EBS storage """
-        if not self.available:
-            return False
-
         tags = {'Name': 'spilo_' + self.cluster_name, 'Role': role, 'Instance': self.instance_id}
-        try:
-            conn = boto.ec2.connect_to_region(self.region)
-            volumes = conn.get_all_volumes(filters={'attachment.instance-id': self.instance_id})
-            conn.create_tags([v.id for v in volumes], tags)
-        except Exception as e:
-            logger.info('could not set tags for EBS storage devices attached: {}'.format(e))
-            return False
-        return True
+        volumes = conn.get_all_volumes(filters={'attachment.instance-id': self.instance_id})
+        conn.create_tags([v.id for v in volumes], tags)
 
-    def _tag_ec2(self, role):
+    def _tag_ec2(self, conn, role):
         """ tag the current EC2 instance with a cluster role """
-        if not self.available:
-            return False
         tags = {'Role': role}
-        try:
-            conn = boto.ec2.connect_to_region(self.region)
-            conn.create_tags([self.instance_id], tags)
-        except Exception as e:
-            logger.info("could not set tags for EC2 instance %s: %s", self.instance_id, e)
-            return False
-        return True
+        conn.create_tags([self.instance_id], tags)
 
     def on_role_change(self, new_role):
-        ret = self._tag_ec2(new_role)
-        return self._tag_ebs(new_role) and ret
+        if not self.available:
+            return False
+        try:
+            conn = self.retry(boto.ec2.connect_to_region, self.region)
+            self.retry(self._tag_ec2, conn, new_role)
+            self.retry(self._tag_ebs, conn, new_role)
+        except RetryFailedError:
+            logger.warning("Unable to communicate to AWS "
+                           "when setting tags for the EC2 instance {0} "
+                           "and attached EBS volumes".format(self.instance_id))
+            return False
+        return True
 
 
 def main():
@@ -72,5 +73,6 @@ def main():
     else:
         sys.exit("Usage: {0} action role name".format(sys.argv[0]))
 
+
 if __name__ == '__main__':
     main()

patroni/scripts/wale_restore.py

@@ -23,77 +23,180 @@
 # currently also requires that you configure the restore_command to use wal_e, example:
 #       recovery_conf:
 #               restore_command: envdir /etc/wal-e.d/env wal-e wal-fetch "%f" "%p" -p 1
-
-from collections import namedtuple
+import argparse
+import csv
 import logging
 import os
 import psycopg2
 import subprocess
 import sys
-import argparse
+import time
 
-
-if sys.hexversion >= 0x0300000:
-    long = int
+from collections import namedtuple
 
 logger = logging.getLogger(__name__)
 
+RETRY_SLEEP_INTERVAL = 1
+si_prefixes = ['K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y']
+
+
+# Meaningful names to the exit codes used by WALERestore
+ExitCode = type('Enum', (), {
+    'SUCCESS': 0,  #: Succeeded
+    'RETRY_LATER': 1,  #: External issue, retry later
+    'FAIL': 2  #: Don't try again unless configuration changes
+})
+
+
+# We need to know the current PG version in order to figure out the correct WAL directory name
+def get_major_version(data_dir):
+    version_file = os.path.join(data_dir, 'PG_VERSION')
+    if os.path.isfile(version_file):  # version file exists
+        try:
+            with open(version_file) as f:
+                return float(f.read())
+        except Exception:
+            logger.exception('Failed to read PG_VERSION from %s', data_dir)
+    return 0.0
+
+
+def repr_size(n_bytes):
+    """
+    >>> repr_size(1000)
+    '1000 Bytes'
+    >>> repr_size(8257332324597)
+    '7.5 TiB'
+    """
+    if n_bytes < 1024:
+        return '{0} Bytes'.format(n_bytes)
+    i = -1
+    while n_bytes > 1023:
+        n_bytes /= 1024.0
+        i += 1
+    return '{0} {1}iB'.format(round(n_bytes, 1), si_prefixes[i])
+
+
+def size_as_bytes(size_, prefix):
+    """
+    >>> size_as_bytes(7.5, 'T')
+    8246337208320
+    """
+    prefix = prefix.upper()
+
+    assert prefix in si_prefixes
+
+    exponent = si_prefixes.index(prefix) + 1
+
+    return int(size_ * (1024.0 ** exponent))
+
+
+WALEConfig = namedtuple(
+    'WALEConfig',
+    [
+        'env_dir',
+        'threshold_mb',
+        'threshold_pct',
+        'cmd',
+    ]
+)
+
 
 class WALERestore(object):
-
-    def __init__(self, scope, datadir, connstring, env_dir, threshold_mb, threshold_pct, use_iam, no_master):
+    def __init__(self, scope, datadir, connstring, env_dir, threshold_mb,
+                 threshold_pct, use_iam, no_master, retries):
         self.scope = scope
         self.master_connection = connstring
         self.data_dir = datadir
-        self.wal_e = namedtuple('wale', 'dir,threshold_mb,threshold_pct,iam_string,cmd')
-        self.wal_e.dir = env_dir
-        self.wal_e.threshold_mb = threshold_mb
-        self.wal_e.threshold_pct = threshold_pct
-        self.wal_e.iam_string = ' --aws-instance-profile ' if use_iam == 1 else ''
         self.no_master = no_master
-        self.wal_e.cmd = 'envdir {0} wal-e {1} '.format(self.wal_e.dir, self.wal_e.iam_string)
-        self.init_error = (not os.path.exists(self.wal_e.dir))
+
+        wale_cmd = [
+            'envdir',
+            env_dir,
+            'wal-e',
+        ]
+
+        if use_iam == 1:
+            wale_cmd += ['--aws-instance-profile']
+
+        self.wal_e = WALEConfig(
+            env_dir=env_dir,
+            threshold_mb=threshold_mb,
+            threshold_pct=threshold_pct,
+            cmd=wale_cmd,
+        )
+
+        self.init_error = (not os.path.exists(self.wal_e.env_dir))
+        self.retries = retries
 
     def run(self):
-        """ creates a new replica using WAL-E """
-        if not self.init_error and self.should_use_s3_to_create_replica():
-            return self.create_replica_with_s3()
-        return 2
+        """
+        Creates a new replica using WAL-E
+
+        Returns
+        -------
+        ExitCode
+            0 = Success
+            1 = Error, try again
+            2 = Error, don't try again
+
+        """
+        if self.init_error:
+            logger.error('init error: %r did not exist at initialization time',
+                         self.wal_e.env_dir)
+            return ExitCode.FAIL
+
+        try:
+            should_use_s3 = self.should_use_s3_to_create_replica()
+            if should_use_s3 is None:  # Need to retry
+                return ExitCode.RETRY_LATER
+            elif should_use_s3:
+                return self.create_replica_with_s3()
+            elif not should_use_s3:
+                return ExitCode.FAIL
+        except Exception:
+            logger.exception("Unhandled exception when running WAL-E restore")
+        return ExitCode.FAIL
 
     def should_use_s3_to_create_replica(self):
         """ determine whether it makes sense to use S3 and not pg_basebackup """
 
         threshold_megabytes = self.wal_e.threshold_mb
-        threshold_backup_size_percentage = self.wal_e.threshold_pct
+        threshold_percent = self.wal_e.threshold_pct
 
         try:
-            latest_backup = subprocess.check_output(self.wal_e.cmd.split() + ['backup-list', '--detail', 'LATEST'])
-            # name    last_modified   expanded_size_bytes wal_segment_backup_start    wal_segment_offset_backup_start
-            #                                                   wal_segment_backup_stop wal_segment_offset_backup_stop
-            # base_00000001000000000000007F_00000040  2015-05-18T10:13:25.000Z
-            # 20310671    00000001000000000000007F    00000040
-            # 00000001000000000000007F    00000240
-            backup_strings = latest_backup.decode('utf-8').splitlines() if latest_backup else ()
-            if len(backup_strings) != 2:
+            cmd = self.wal_e.cmd + ['backup-list', '--detail', 'LATEST']
+
+            logger.debug('calling %r', cmd)
+            wale_output = subprocess.check_output(cmd)
+
+            reader = csv.DictReader(wale_output.decode('utf-8').splitlines(),
+                                    dialect='excel-tab')
+            rows = list(reader)
+            if not len(rows):
+                logger.warning('wal-e did not find any backups')
                 return False
 
-            names = backup_strings[0].split()
-            vals = backup_strings[1].split()
-            if (len(names) != len(vals)) or (len(names) != 7):
+            # This check might not add much, it was performed in the previous
+            # version of this code. since the old version rolled CSV parsing the
+            # check may have been part of the CSV parsing.
+            if len(rows) > 1:
+                logger.warning(
+                    'wal-e returned more than one row of backups: %r',
+                    rows)
                 return False
 
-            backup_info = dict(zip(names, vals))
-        except subprocess.CalledProcessError as e:
-            logger.error("could not query wal-e latest backup: {}".format(e))
-            return False
+            backup_info = rows[0]
+        except subprocess.CalledProcessError:
+            logger.exception("could not query wal-e latest backup")
+            return None
 
         try:
-            backup_size = backup_info['expanded_size_bytes']
+            backup_size = int(backup_info['expanded_size_bytes'])
             backup_start_segment = backup_info['wal_segment_backup_start']
             backup_start_offset = backup_info['wal_segment_offset_backup_start']
-        except Exception as e:
-            logger.error("unable to get some of WALE backup parameters: {}".format(e))
-            return False
+        except KeyError:
+            logger.exception("unable to get some of WALE backup parameters")
+            return None
 
         # WAL filename is XXXXXXXXYYYYYYYY000000ZZ, where X - timeline, Y - LSN logical log file,
         # ZZ - 2 high digits of LSN offset. The rest of the offset is the provided decimal offset,
@@ -101,41 +204,130 @@ class WALERestore(object):
 
         lsn_segment = backup_start_segment[8:16]
         # first 2 characters of the result are 0x and the last one is L
-        lsn_offset = hex((long(backup_start_segment[16:32], 16) << 24) + long(backup_start_offset))[2:-1]
+        lsn_offset = hex((int(backup_start_segment[16:32], 16) << 24) + int(backup_start_offset))[2:-1]
 
         # construct the LSN from the segment and offset
         backup_start_lsn = '{0}/{1}'.format(lsn_segment, lsn_offset)
 
-        diff_in_bytes = long(backup_size)
-        if not self.no_master:
-            try:
-                # get the difference in bytes between the current WAL location and the backup start offset
-                with psycopg2.connect(self.master_connection) as con:
-                    con.autocommit = True
-                    with con.cursor() as cur:
-                        cur.execute("SELECT pg_xlog_location_diff(pg_current_xlog_location(), %s)", (backup_start_lsn,))
-                        diff_in_bytes = long(cur.fetchone()[0])
-            except psycopg2.Error as e:
-                logger.error('could not determine difference with the master location: %s', e)
-                return False
-        else:
-            # always try to use WAL-E if base backup is available
-            diff_in_bytes = 0
+        diff_in_bytes = backup_size
+        attempts_no = 0
+        while True:
+            if self.master_connection:
+                try:
+                    # get the difference in bytes between the current WAL location and the backup start offset
+                    with psycopg2.connect(self.master_connection) as con:
+                        if con.server_version >= 100000:
+                            wal_name = 'wal'
+                            lsn_name = 'lsn'
+                        else:
+                            wal_name = 'xlog'
+                            lsn_name = 'location'
+                        con.autocommit = True
+                        with con.cursor() as cur:
+                            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])
+                except psycopg2.Error:
+                    logger.exception('could not determine difference with the master location')
+                    if attempts_no < self.retries:  # retry in case of a temporarily connection issue
+                        attempts_no = attempts_no + 1
+                        time.sleep(RETRY_SLEEP_INTERVAL)
+                        continue
+                    else:
+                        if not self.no_master:
+                            return False  # do no more retries on the outer level
+                        logger.info("continue with base backup from S3 since master is not available")
+                        diff_in_bytes = 0
+                        break
+            else:
+                # always try to use WAL-E if master connection string is not available
+                diff_in_bytes = 0
+            break
 
         # if the size of the accumulated WAL segments is more than a certan percentage of the backup size
         # or exceeds the pre-determined size - pg_basebackup is chosen instead.
-        return (diff_in_bytes < long(threshold_megabytes) * 1048576) and\
-            (diff_in_bytes < long(backup_size) * float(threshold_backup_size_percentage) / 100)
+        is_size_thresh_ok = diff_in_bytes < int(threshold_megabytes) * 1048576
+        threshold_pct_bytes = backup_size * threshold_percent / 100.0
+        is_percentage_thresh_ok = float(diff_in_bytes) < int(threshold_pct_bytes)
+        are_thresholds_ok = is_size_thresh_ok and is_percentage_thresh_ok
+
+        class Size(object):
+            def __init__(self, n_bytes, prefix=None):
+                self.n_bytes = n_bytes
+                self.prefix = prefix
+
+            def __repr__(self):
+                if self.prefix is not None:
+                    n_bytes = size_as_bytes(self.n_bytes, self.prefix)
+                else:
+                    n_bytes = self.n_bytes
+                return repr_size(n_bytes)
+
+        class HumanContext(object):
+            def __init__(self, items):
+                self.items = items
+
+            def __repr__(self):
+                return ', '.join('{}={!r}'.format(key, value)
+                                 for key, value in self.items)
+
+        human_context = repr(HumanContext([
+            ('threshold_size', Size(threshold_megabytes, 'M')),
+            ('threshold_percent', threshold_percent),
+            ('threshold_percent_size', Size(threshold_pct_bytes)),
+            ('backup_size', Size(backup_size)),
+            ('backup_diff', Size(diff_in_bytes)),
+            ('is_size_thresh_ok', is_size_thresh_ok),
+            ('is_percentage_thresh_ok', is_percentage_thresh_ok),
+        ]))
+
+        if not are_thresholds_ok:
+            logger.info('wal-e backup size diff is over threshold, falling back '
+                        'to other means of restore: %s', human_context)
+        else:
+            logger.info('Thresholds are OK, using wal-e basebackup: %s', human_context)
+        return are_thresholds_ok
+
+    def fix_subdirectory_path_if_broken(self, dirname):
+        # in case it is a symlink pointing to a non-existing location, remove it and create the actual directory
+        path = os.path.join(self.data_dir, dirname)
+        if not os.path.exists(path):
+            if os.path.islink(path):  # broken xlog symlink, to remove
+                try:
+                    os.remove(path)
+                except OSError:
+                    logger.exception("could not remove broken %s symlink pointing to %s",
+                                     dirname, os.readlink(path))
+                    return False
+            try:
+                os.mkdir(path)
+            except OSError:
+                logger.exception("coud not create missing %s directory path", dirname)
+                return False
+        return True
 
     def create_replica_with_s3(self):
         # if we're set up, restore the replica using fetch latest
         try:
-            ret = subprocess.call(self.wal_e.cmd.split() + ['backup-fetch', '{}'.format(self.data_dir), 'LATEST'])
+            cmd = self.wal_e.cmd + ['backup-fetch',
+                                    '{}'.format(self.data_dir),
+                                    'LATEST']
+            logger.debug('calling: %r', cmd)
+            exit_code = subprocess.call(cmd)
         except Exception as e:
             logger.error('Error when fetching backup with WAL-E: {0}'.format(e))
-            return 1
+            return ExitCode.RETRY_LATER
 
-        return ret
+        if (exit_code == 0 and not
+           self.fix_subdirectory_path_if_broken('pg_xlog' if get_major_version(self.data_dir) < 10 else 'pg_wal')):
+            return ExitCode.FAIL
+        return exit_code
 
 
 def main():
@@ -153,17 +345,27 @@ def main():
     parser.add_argument('--no_master', type=int, default=0)
     args = parser.parse_args()
 
-    # retry cloning in a loop
+    exit_code = None
+    assert args.retries >= 0
+
+    # Retry cloning in a loop. We do separate retries for the master
+    # connection attempt inside should_use_s3_to_create_replica,
+    # because we need to differentiate between the last attempt and
+    # the rest and make a decision when the last attempt fails on
+    # whether to use WAL-E or not depending on the no_master flag.
     for _ in range(0, args.retries + 1):
         restore = WALERestore(scope=args.scope, datadir=args.datadir, connstring=args.connstring,
                               env_dir=args.envdir, threshold_mb=args.threshold_megabytes,
                               threshold_pct=args.threshold_backup_size_percentage, use_iam=args.use_iam,
-                              no_master=args.no_master)
-        ret = restore.run()
-        if ret == 0:
+                              no_master=args.no_master, retries=args.retries)
+        exit_code = restore.run()
+        if not exit_code == ExitCode.RETRY_LATER:  # only WAL-E failures lead to the retry
+            logger.debug('exit_code is %r, not retrying', exit_code)
             break
+        time.sleep(RETRY_SLEEP_INTERVAL)
+
+    return exit_code
 
-    sys.exit(ret)
 
 if __name__ == '__main__':
-    main()
+    sys.exit(main())

patroni/utils.py

@@ -1,16 +1,10 @@
-import os
 import random
-import sys
 import time
-import re
 
+from dateutil import tz
 from patroni.exceptions import PatroniException
 
-if sys.hexversion >= 0x0300000:
-    long = int
-
-__interrupted_sleep = False
-__reap_children = False
+tzutc = tz.tzutc()
 
 
 def deep_compare(obj1, obj2):
@@ -100,17 +94,17 @@ def strtol(value, strict=True):
     True
     """
     value = str(value).strip()
-    l = len(value)
+    ln = len(value)
     i = 0
     # skip sign:
-    if i < l and value[i] in ('-', '+'):
+    if i < ln and value[i] in ('-', '+'):
         i += 1
 
     # we always expect to get digit in the beginning
-    if i < l and value[i].isdigit():
+    if i < ln and value[i].isdigit():
         if value[i] == '0':
             i += 1
-            if i < l and value[i] in ('x', 'X'):  # '0' followed by 'x': HEX
+            if i < ln and value[i] in ('x', 'X'):  # '0' followed by 'x': HEX
                 base = 16
                 i += 1
             else:  # just starts with '0': OCT
@@ -119,10 +113,10 @@ def strtol(value, strict=True):
             base = 10
 
         ret = None
-        while i <= l:
+        while i <= ln:
             try:  # try to find maximally long number
                 i += 1  # by giving to `int` longer and longer strings
-                ret = long(value[:i], base)
+                ret = int(value[:i], base)
             except ValueError:  # until we will not get an exception or end of the string
                 i -= 1
                 break
@@ -195,40 +189,8 @@ def compare_values(vartype, unit, old_value, new_value):
     return old_value is not None and new_value is not None and old_value == new_value
 
 
-def sigchld_handler(signo, stack_frame):
-    global __interrupted_sleep, __reap_children
-    __reap_children = __interrupted_sleep = True
-
-
-def sleep(interval):
-    global __interrupted_sleep
-    current_time = time.time()
-    end_time = current_time + interval
-    while current_time < end_time:
-        __interrupted_sleep = False
-        time.sleep(end_time - current_time)
-        if not __interrupted_sleep:  # we will ignore only sigchld
-            break
-        current_time = time.time()
-    __interrupted_sleep = False
-
-
-def reap_children():
-    global __reap_children
-    if __reap_children:
-        try:
-            while True:
-                ret = os.waitpid(-1, os.WNOHANG)
-                if ret == (0, 0):
-                    break
-        except OSError:
-            pass
-        finally:
-            __reap_children = False
-
-
-def is_valid_pg_version(version):
-    return re.match(r'[1-9][0-9]?(\.(0|([1-9][0-9]?))){2}$', version)
+def _sleep(interval):
+    time.sleep(interval)
 
 
 class RetryFailedError(PatroniException):
@@ -241,7 +203,7 @@ class Retry(object):
     """Helper for retrying a method in the face of retry-able exceptions"""
 
     def __init__(self, max_tries=1, delay=0.1, backoff=2, max_jitter=0.8, max_delay=3600,
-                 sleep_func=sleep, deadline=None, retry_exceptions=PatroniException):
+                 sleep_func=_sleep, deadline=None, retry_exceptions=PatroniException):
         """Create a :class:`Retry` instance for retrying function calls
 
         :param max_tries: How many times to retry the command. -1 means infinite tries.
@@ -302,3 +264,20 @@ class Retry(object):
                 else:
                     self.sleep_func(sleeptime)
                 self._cur_delay = min(self._cur_delay * self.backoff, self.max_delay)
+
+
+def polling_loop(timeout, interval=1):
+    """Returns an iterator that returns values until timeout has passed. Timeout is measured from start of iteration."""
+    start_time = time.time()
+    iteration = 0
+    end_time = start_time + timeout
+    while time.time() < end_time:
+        yield iteration
+        iteration += 1
+        time.sleep(interval)
+
+
+def split_host_port(value, default_port):
+    t = value.rsplit(':', 1)
+    t.append(default_port)
+    return t[0], int(t[1])

patroni/version.py

@@ -1 +1 @@
-__version__ = '1.1'
+__version__ = '1.5.4'

patroni/watchdog/__init__.py

@@ -0,0 +1,2 @@
+from patroni.watchdog.base import WatchdogError, Watchdog
+__all__ = ['WatchdogError', 'Watchdog']

patroni/watchdog/base.py

@@ -0,0 +1,313 @@
+import abc
+import logging
+import platform
+import six
+import sys
+from threading import RLock
+
+from patroni.exceptions import WatchdogError
+
+__all__ = ['WatchdogError', 'Watchdog']
+
+logger = logging.getLogger(__name__)
+
+MODE_REQUIRED = 'required'    # Will not run if a watchdog is not available
+MODE_AUTOMATIC = 'automatic'  # Will use a watchdog if one is available
+MODE_OFF = 'off'              # Will not try to use a watchdog
+
+
+def parse_mode(mode):
+    if mode is False:
+        return MODE_OFF
+    mode = mode.lower()
+    if mode in ['require', 'required']:
+        return MODE_REQUIRED
+    elif mode in ['auto', 'automatic']:
+        return MODE_AUTOMATIC
+    else:
+        if mode not in ['off', 'disable', 'disabled']:
+            logger.warning("Watchdog mode {0} not recognized, disabling watchdog".format(mode))
+        return MODE_OFF
+
+
+def synchronized(func):
+    def wrapped(self, *args, **kwargs):
+        with self._lock:
+            return func(self, *args, **kwargs)
+    return wrapped
+
+
+class WatchdogConfig(object):
+    """Helper to contain a snapshot of configuration"""
+    def __init__(self, config):
+        self.mode = parse_mode(config['watchdog'].get('mode', 'automatic'))
+        self.ttl = config['ttl']
+        self.loop_wait = config['loop_wait']
+        self.safety_margin = config['watchdog'].get('safety_margin', 5)
+        self.driver = config['watchdog'].get('driver', 'default')
+        self.driver_config = dict((k, v) for k, v in config['watchdog'].items()
+                                  if k not in ['mode', 'safety_margin', 'driver'])
+
+    def __eq__(self, other):
+        return isinstance(other, WatchdogConfig) and \
+            all(getattr(self, attr) == getattr(other, attr) for attr in
+                ['mode', 'ttl', 'loop_wait', 'safety_margin', 'driver', 'driver_config'])
+
+    def __ne__(self, other):
+        return not self == other
+
+    def get_impl(self):
+        if self.driver == 'testing':
+            from patroni.watchdog.linux import TestingWatchdogDevice
+            return TestingWatchdogDevice.from_config(self.driver_config)
+        elif platform.system() == 'Linux' and self.driver == 'default':
+            from patroni.watchdog.linux import LinuxWatchdogDevice
+            return LinuxWatchdogDevice.from_config(self.driver_config)
+        else:
+            return NullWatchdog()
+
+    @property
+    def timeout(self):
+        if self.safety_margin == -1:
+            return int(self.ttl // 2)
+        else:
+            return self.ttl - self.safety_margin
+
+    @property
+    def timing_slack(self):
+        return self.timeout - self.loop_wait
+
+
+class Watchdog(object):
+    """Facade to dynamically manage watchdog implementations and handle config changes.
+
+    When activation fails underlying implementation will be switched to a Null implementation. To avoid log spam
+    activation will only be retried when watchdog configuration is changed."""
+    def __init__(self, config):
+        self.active_config = self.config = WatchdogConfig(config)
+        self._lock = RLock()
+        self.active = False
+
+        if self.config.mode == MODE_OFF:
+            self.impl = NullWatchdog()
+        else:
+            self.impl = self.config.get_impl()
+            if self.config.mode == MODE_REQUIRED and self.impl.is_null:
+                logger.error("Configuration requires a watchdog, but watchdog is not supported on this platform.")
+                sys.exit(1)
+
+    @synchronized
+    def reload_config(self, config):
+        self.config = WatchdogConfig(config)
+        # Turning a watchdog off can always be done immediately
+        if self.config.mode == MODE_OFF:
+            if self.active:
+                self._disable()
+            self.active_config = self.config
+            self.impl = NullWatchdog()
+        # If watchdog is not active we can apply config immediately to show any warnings early. Otherwise we need to
+        # delay until next time a keepalive is sent so timeout matches up with leader key update.
+        if not self.active:
+            if self.config.driver != self.active_config.driver or \
+               self.config.driver_config != self.active_config.driver_config:
+                self.impl = self.config.get_impl()
+            self.active_config = self.config
+
+    @synchronized
+    def activate(self):
+        """Activates the watchdog device with suitable timeouts. While watchdog is active keepalive needs
+        to be called every time loop_wait expires.
+
+        :returns False if a safe watchdog could not be configured, but is required.
+        """
+        self.active = True
+        return self._activate()
+
+    def _activate(self):
+        self.active_config = self.config
+
+        if self.config.timing_slack < 0:
+            logger.warning('Watchdog not supported because leader TTL {0} is less than 2x loop_wait {1}'
+                           .format(self.config.ttl, self.config.loop_wait))
+            self.impl = NullWatchdog()
+
+        try:
+            self.impl.open()
+            actual_timeout = self._set_timeout()
+        except WatchdogError as e:
+            logger.warning("Could not activate %s: %s", self.impl.describe(), e)
+            self.impl = NullWatchdog()
+
+        if self.impl.is_running and not self.impl.can_be_disabled:
+            logger.warning("Watchdog implementation can't be disabled."
+                           " Watchdog will trigger after Patroni loses leader key.")
+
+        if not self.impl.is_running or actual_timeout > self.config.timeout:
+            if self.config.mode == MODE_REQUIRED:
+                if self.impl.is_null:
+                    logger.error("Configuration requires watchdog, but watchdog could not be configured.")
+                else:
+                    logger.error("Configuration requires watchdog, but a safe watchdog timeout {0} could"
+                                 " not be configured. Watchdog timeout is {1}.".format(
+                                     self.config.timeout, actual_timeout))
+                return False
+            else:
+                if not self.impl.is_null:
+                    logger.warning("Watchdog timeout {0} seconds does not ensure safe termination within {1} seconds"
+                                   .format(actual_timeout, self.config.timeout))
+
+        if self.is_running:
+            logger.info("{0} activated with {1} second timeout, timing slack {2} seconds"
+                        .format(self.impl.describe(), actual_timeout, self.config.timing_slack))
+        else:
+            if self.config.mode == MODE_REQUIRED:
+                logger.error("Configuration requires watchdog, but watchdog could not be activated")
+                return False
+
+        return True
+
+    def _set_timeout(self):
+        if self.impl.has_set_timeout():
+            self.impl.set_timeout(self.config.timeout)
+
+        # Safety checks for watchdog implementations that don't support configurable timeouts
+        actual_timeout = self.impl.get_timeout()
+        if self.impl.is_running and actual_timeout < self.config.loop_wait:
+            logger.error('loop_wait of {0} seconds is too long for watchdog {1} second timeout'
+                         .format(self.config.loop_wait, actual_timeout))
+            if self.impl.can_be_disabled:
+                logger.info('Disabling watchdog due to unsafe timeout.')
+                self.impl.close()
+                self.impl = NullWatchdog()
+                return None
+        return actual_timeout
+
+    @synchronized
+    def disable(self):
+        self._disable()
+        self.active = False
+
+    def _disable(self):
+        try:
+            if self.impl.is_running and not self.impl.can_be_disabled:
+                # Give sysadmin some extra time to clean stuff up.
+                self.impl.keepalive()
+                logger.warning("Watchdog implementation can't be disabled. System will reboot after "
+                               "{0} seconds when watchdog times out.".format(self.impl.get_timeout()))
+            self.impl.close()
+        except WatchdogError as e:
+            logger.error("Error while disabling watchdog: %s", e)
+
+    @synchronized
+    def keepalive(self):
+        try:
+            if self.active:
+                self.impl.keepalive()
+            # In case there are any pending configuration changes apply them now.
+            if self.active and self.config != self.active_config:
+                if self.config.mode != MODE_OFF and self.active_config.mode == MODE_OFF:
+                    self.impl = self.config.get_impl()
+                    self._activate()
+                if self.config.driver != self.active_config.driver \
+                   or self.config.driver_config != self.active_config.driver_config:
+                    self._disable()
+                    self.impl = self.config.get_impl()
+                    self._activate()
+                if self.config.timeout != self.active_config.timeout:
+                    self.impl.set_timeout(self.config.timeout)
+        except WatchdogError as e:
+            logger.error("Error while sending keepalive: %s", e)
+
+    @property
+    @synchronized
+    def is_running(self):
+        return self.impl.is_running
+
+    @property
+    @synchronized
+    def is_healthy(self):
+        if self.config.mode != MODE_REQUIRED:
+            return True
+        return self.config.timing_slack >= 0 and self.impl.is_healthy
+
+
+@six.add_metaclass(abc.ABCMeta)
+class WatchdogBase(object):
+    """A watchdog object when opened requires periodic calls to keepalive.
+    When keepalive is not called within a timeout the system will be terminated."""
+    is_null = False
+
+    @property
+    def is_running(self):
+        """Returns True when watchdog is activated and capable of performing it's task."""
+        return False
+
+    @property
+    def is_healthy(self):
+        """Returns False when calling open() is known to fail."""
+        return False
+
+    @property
+    def can_be_disabled(self):
+        """Returns True when watchdog will be disabled by calling close(). Some watchdog devices
+        will keep running no matter what once activated. May raise WatchdogError if called without
+        calling open() first."""
+        return True
+
+    @abc.abstractmethod
+    def open(self):
+        """Open watchdog device.
+
+        When watchdog is opened keepalive must be called. Returns nothing on success
+        or raises WatchdogError if the device could not be opened."""
+
+    @abc.abstractmethod
+    def close(self):
+        """Gracefully close watchdog device."""
+
+    @abc.abstractmethod
+    def keepalive(self):
+        """Resets the watchdog timer.
+
+        Watchdog must be open when keepalive is called."""
+
+    @abc.abstractmethod
+    def get_timeout(self):
+        """Returns the current keepalive timeout in effect."""
+
+    @staticmethod
+    def has_set_timeout():
+        """Returns True if setting a timeout is supported."""
+        return False
+
+    def set_timeout(self, timeout):
+        """Set the watchdog timer timeout.
+
+        :param timeout: watchdog timeout in seconds"""
+        raise WatchdogError("Setting timeout is not supported on {0}".format(self.describe()))
+
+    def describe(self):
+        """Human readable name for this device"""
+        return self.__class__.__name__
+
+    @classmethod
+    def from_config(cls, config):
+        return cls()
+
+
+class NullWatchdog(WatchdogBase):
+    """Null implementation when watchdog is not supported."""
+    is_null = True
+
+    def open(self):
+        return
+
+    def close(self):
+        return
+
+    def keepalive(self):
+        return
+
+    def get_timeout(self):
+        # A big enough number to not matter
+        return 1000000000

patroni/watchdog/linux.py

@@ -0,0 +1,234 @@
+import collections
+import ctypes
+import fcntl
+import os
+import platform
+from patroni.watchdog.base import WatchdogBase, WatchdogError
+
+# Pythonification of linux/ioctl.h
+IOC_NONE = 0
+IOC_WRITE = 1
+IOC_READ = 2
+
+IOC_NRBITS = 8
+IOC_TYPEBITS = 8
+IOC_SIZEBITS = 14
+IOC_DIRBITS = 2
+
+# Non-generic platform special cases
+machine = platform.machine()
+if machine in ['mips', 'sparc', 'powerpc', 'ppc64']:
+    IOC_SIZEBITS = 13
+    IOC_DIRBITS = 3
+    IOC_NONE, IOC_WRITE, IOC_READ = 1, 2, 4
+elif machine == 'parisc':
+    IOC_WRITE, IOC_READ = 2, 1
+
+IOC_NRSHIFT = 0
+IOC_TYPESHIFT = IOC_NRSHIFT + IOC_NRBITS
+IOC_SIZESHIFT = IOC_TYPESHIFT + IOC_TYPEBITS
+IOC_DIRSHIFT = IOC_SIZESHIFT + IOC_SIZEBITS
+
+
+def IOW(type_, nr, size):
+    return IOC(IOC_WRITE, type_, nr, size)
+
+
+def IOR(type_, nr, size):
+    return IOC(IOC_READ, type_, nr, size)
+
+
+def IOWR(type_, nr, size):
+    return IOC(IOC_READ | IOC_WRITE, type_, nr, size)
+
+
+def IOC(dir_, type_, nr, size):
+    return (dir_ << IOC_DIRSHIFT) \
+        | (ord(type_) << IOC_TYPESHIFT) \
+        | (nr << IOC_NRSHIFT) \
+        | (size << IOC_SIZESHIFT)
+
+
+# Pythonification of linux/watchdog.h
+
+WATCHDOG_IOCTL_BASE = 'W'
+
+
+class watchdog_info(ctypes.Structure):
+    _fields_ = [
+        ('options', ctypes.c_uint32),           # Options the card/driver supports
+        ('firmware_version', ctypes.c_uint32),  # Firmware version of the card
+        ('identity', ctypes.c_uint8 * 32),      # Identity of the board
+    ]
+
+
+struct_watchdog_info_size = ctypes.sizeof(watchdog_info)
+int_size = ctypes.sizeof(ctypes.c_int)
+
+WDIOC_GETSUPPORT = IOR(WATCHDOG_IOCTL_BASE, 0, struct_watchdog_info_size)
+WDIOC_GETSTATUS = IOR(WATCHDOG_IOCTL_BASE, 1, int_size)
+WDIOC_GETBOOTSTATUS = IOR(WATCHDOG_IOCTL_BASE, 2, int_size)
+WDIOC_GETTEMP = IOR(WATCHDOG_IOCTL_BASE, 3, int_size)
+WDIOC_SETOPTIONS = IOR(WATCHDOG_IOCTL_BASE, 4, int_size)
+WDIOC_KEEPALIVE = IOR(WATCHDOG_IOCTL_BASE, 5, int_size)
+WDIOC_SETTIMEOUT = IOWR(WATCHDOG_IOCTL_BASE, 6, int_size)
+WDIOC_GETTIMEOUT = IOR(WATCHDOG_IOCTL_BASE, 7, int_size)
+WDIOC_SETPRETIMEOUT = IOWR(WATCHDOG_IOCTL_BASE, 8, int_size)
+WDIOC_GETPRETIMEOUT = IOR(WATCHDOG_IOCTL_BASE, 9, int_size)
+WDIOC_GETTIMELEFT = IOR(WATCHDOG_IOCTL_BASE, 10, int_size)
+
+
+WDIOF_UNKNOWN = -1  # Unknown flag error
+WDIOS_UNKNOWN = -1  # Unknown status error
+
+WDIOF = {
+    "OVERHEAT": 0x0001,       # Reset due to CPU overheat
+    "FANFAULT": 0x0002,       # Fan failed
+    "EXTERN1": 0x0004,        # External relay 1
+    "EXTERN2": 0x0008,        # External relay 2
+    "POWERUNDER": 0x0010,     # Power bad/power fault
+    "CARDRESET": 0x0020,      # Card previously reset the CPU
+    "POWEROVER": 0x0040,      # Power over voltage
+    "SETTIMEOUT": 0x0080,     # Set timeout (in seconds)
+    "MAGICCLOSE": 0x0100,     # Supports magic close char
+    "PRETIMEOUT": 0x0200,     # Pretimeout (in seconds), get/set
+    "ALARMONLY": 0x0400,      # Watchdog triggers a management or other external alarm not a reboot
+    "KEEPALIVEPING": 0x8000,  # Keep alive ping reply
+}
+
+WDIOS = {
+    "DISABLECARD": 0x0001,    # Turn off the watchdog timer
+    "ENABLECARD": 0x0002,     # Turn on the watchdog timer
+    "TEMPPANIC": 0x0004,      # Kernel panic on temperature trip
+}
+
+# Implementation
+
+
+class WatchdogInfo(collections.namedtuple('WatchdogInfo', 'options,version,identity')):
+    """Watchdog descriptor from the kernel"""
+    def __getattr__(self, name):
+        """Convenience has_XYZ attributes for checking WDIOF bits in options"""
+        if name.startswith('has_') and name[4:] in WDIOF:
+            return bool(self.options & WDIOF[name[4:]])
+
+        raise AttributeError("WatchdogInfo instance has no attribute '{0}'".format(name))
+
+
+class LinuxWatchdogDevice(WatchdogBase):
+    DEFAULT_DEVICE = '/dev/watchdog'
+
+    def __init__(self, device):
+        self.device = device
+        self._support_cache = None
+        self._fd = None
+
+    @classmethod
+    def from_config(cls, config):
+        device = config.get('device', cls.DEFAULT_DEVICE)
+        return cls(device)
+
+    @property
+    def is_running(self):
+        return self._fd is not None
+
+    @property
+    def is_healthy(self):
+        return os.path.exists(self.device) and os.access(self.device, os.W_OK)
+
+    def open(self):
+        try:
+            self._fd = os.open(self.device, os.O_WRONLY)
+        except OSError as e:
+            raise WatchdogError("Can't open watchdog device: {0}".format(e))
+
+    def close(self):
+        if self.is_running:
+            try:
+                os.write(self._fd, b'V')
+                os.close(self._fd)
+                self._fd = None
+            except OSError as e:
+                raise WatchdogError("Error while closing {0}: {1}".format(self.describe(), e))
+
+    @property
+    def can_be_disabled(self):
+        return self.get_support().has_MAGICCLOSE
+
+    def _ioctl(self, func, arg):
+        """Runs the specified ioctl on the underlying fd.
+
+        Raises WatchdogError if the device is closed.
+        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)
+
+    def get_support(self):
+        if self._support_cache is None:
+            info = watchdog_info()
+            try:
+                self._ioctl(WDIOC_GETSUPPORT, info)
+            except (WatchdogError, OSError, IOError) as e:
+                raise WatchdogError("Could not get information about watchdog device: {}".format(e))
+            self._support_cache = WatchdogInfo(info.options,
+                                               info.firmware_version,
+                                               bytearray(info.identity).decode(errors='ignore').rstrip('\x00'))
+        return self._support_cache
+
+    def describe(self):
+        dev_str = " at {0}".format(self.device) if self.device != self.DEFAULT_DEVICE else ""
+        ver_str = ""
+        identity = "Linux watchdog device"
+        if self._fd:
+            try:
+                _, version, identity = self.get_support()
+                ver_str = " (firmware {0})".format(version) if version else ""
+            except WatchdogError:
+                pass
+
+        return identity + ver_str + dev_str
+
+    def keepalive(self):
+        try:
+            os.write(self._fd, b'1')
+        except OSError as e:
+            raise WatchdogError("Could not send watchdog keepalive: {0}".format(e))
+
+    def has_set_timeout(self):
+        """Returns True if setting a timeout is supported."""
+        return self.get_support().has_SETTIMEOUT
+
+    def set_timeout(self, timeout):
+        timeout = int(timeout)
+        if not 0 < timeout < 0xFFFF:
+            raise WatchdogError("Invalid timeout {0}. Supported values are between 1 and 65535".format(timeout))
+        try:
+            self._ioctl(WDIOC_SETTIMEOUT, ctypes.c_int(timeout))
+        except (WatchdogError, OSError, IOError) as e:
+            raise WatchdogError("Could not set timeout on watchdog device: {}".format(e))
+
+    def get_timeout(self):
+        timeout = ctypes.c_int()
+        try:
+            self._ioctl(WDIOC_GETTIMEOUT, timeout)
+        except (WatchdogError, OSError, IOError) as e:
+            raise WatchdogError("Could not get timeout on watchdog device: {}".format(e))
+        return timeout.value
+
+
+class TestingWatchdogDevice(LinuxWatchdogDevice):
+    """Converts timeout ioctls to regular writes that can be intercepted from a named pipe."""
+    timeout = 60
+
+    def get_support(self):
+        return WatchdogInfo(WDIOF['MAGICCLOSE'] | WDIOF['SETTIMEOUT'], 0, "Watchdog test harness")
+
+    def set_timeout(self, timeout):
+        buf = "Ctimeout={0}\n".format(timeout).encode('utf8')
+        while len(buf):
+            buf = buf[os.write(self._fd, buf):]
+        self.timeout = timeout
+
+    def get_timeout(self):
+        return self.timeout

postgres0.yml

@@ -11,8 +11,13 @@ 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:
-  host: 127.0.0.1:4001
+  host: 127.0.0.1:2379
 
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
@@ -22,6 +27,12 @@ bootstrap:
     loop_wait: 10
     retry_timeout: 10
     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
@@ -29,8 +40,8 @@ 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
@@ -48,6 +59,9 @@ bootstrap:
   - host all all 0.0.0.0/0 md5
 #  - hostssl all all 0.0.0.0/0 md5
 
+  # Additional script to be launched after initial cluster creation (will be passed the connection URL as parameter)
+# post_init: /usr/local/bin/setup_cluster.sh
+
   # Some additional users users which needs to be created after initializing new cluster
   users:
     admin:
@@ -61,6 +75,7 @@ postgresql:
   connect_address: 127.0.0.1:5432
   data_dir: data/postgresql0
 #  bin_dir:
+#  config_dir:
   pgpass: /tmp/pgpass0
   authentication:
     replication:
@@ -71,7 +86,14 @@ postgresql:
       password: zalando
   parameters:
     unix_socket_directories: '.'
+
+#watchdog:
+#  mode: automatic # Allowed values: off, automatic, required
+#  device: /dev/watchdog
+#  safety_margin: 5
+
 tags:
     nofailover: false
     noloadbalance: false
     clonefrom: false
+    nosync: false

postgres1.yml

@@ -11,8 +11,13 @@ 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:
-  host: 127.0.0.1:4001
+  host: 127.0.0.1:2379
 
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
@@ -29,8 +34,8 @@ 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
@@ -48,6 +53,9 @@ bootstrap:
   - host all all 0.0.0.0/0 md5
 #  - hostssl all all 0.0.0.0/0 md5
 
+  # Additional script to be launched after initial cluster creation (will be passed the connection URL as parameter)
+# post_init: /usr/local/bin/setup_cluster.sh
+
   # Some additional users users which needs to be created after initializing new cluster
   users:
     admin:
@@ -61,6 +69,7 @@ postgresql:
   connect_address: 127.0.0.1:5433
   data_dir: data/postgresql1
 #  bin_dir:
+#  config_dir:
   pgpass: /tmp/pgpass1
   authentication:
     replication:
@@ -71,6 +80,9 @@ postgresql:
       password: zalando
   parameters:
     unix_socket_directories: '.'
+  basebackup:
+      - verbose
+      - max-rate: 100M
 tags:
     nofailover: false
     noloadbalance: false

postgres2.yml

@@ -11,8 +11,13 @@ 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:
-  host: 127.0.0.1:4001
+  host: 127.0.0.1:2379
 
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
@@ -29,8 +34,8 @@ 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
@@ -61,6 +66,7 @@ postgresql:
   connect_address: 127.0.0.1:5434
   data_dir: data/postgresql2
 #  bin_dir:
+#  config_dir:
   pgpass: /tmp/pgpass2
   authentication:
     replication:

requirements.txt

@@ -1,12 +1,16 @@
+urllib3>=1.19.1,!=1.21
 boto
-psycopg2>=2.6.1
+psycopg2>=2.5.4
 PyYAML
 requests
 six >= 1.7
-kazoo==2.2.1
-python-etcd==0.4.3
-python-consul==0.6.0
+kazoo>=1.3.1
+python-etcd>=0.4.3,<0.5
+python-consul>=0.7.0
 click>=4.1
 prettytable>=0.7
 tzlocal
-python-dateutil
+python-dateutil
+psutil
+cdiff
+kubernetes>=2.0.0,<=7.0.0,!=4.0.*,!=5.0.*

setup.py

@@ -24,6 +24,7 @@ def read_version(package):
         exec(fd.read(), data)
     return data['__version__']
 
+
 NAME = 'patroni'
 MAIN_PACKAGE = NAME
 SCRIPTS = 'scripts'
@@ -31,9 +32,10 @@ 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'
 
 COVERAGE_XML = True
 COVERAGE_HTML = False
@@ -42,16 +44,22 @@ 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',
 ]
 
@@ -86,7 +94,7 @@ class PyTest(TestCommand):
     def run_tests(self):
         try:
             import pytest
-        except:
+        except Exception:
             raise RuntimeError('py.test is not installed, run: pip install pytest')
         params = {'args': self.test_args}
         if self.cov:
@@ -99,6 +107,8 @@ class PyTest(TestCommand):
         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']
+        if not os.getenv('SYSTEMROOT'):
+            os.environ['SYSTEMROOT'] = '/'
         errno = pytest.main(**params)
         sys.exit(errno)
 
@@ -114,13 +124,23 @@ def read(fname):
 
 def setup_package():
     # Assemble additional setup commands
-    cmdclass = {}
-    cmdclass['test'] = PyTest
+    cmdclass = {'test': PyTest}
 
     # Some helper variables
     version = os.getenv('GO_PIPELINE_LABEL', VERSION)
 
-    install_reqs = get_install_requirements('requirements.txt')
+    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'):
+        extra = False
+        for e, v in extras_require.items():
+            if r.startswith(v[0]):
+                extras_require[e] = [r]
+                extra = True
+        if not extra:
+            install_requires.append(r)
 
     command_options = {'test': {'test_suite': ('setup.py', 'tests')}}
     if JUNIT_XML:
@@ -144,10 +164,10 @@ def setup_package():
         test_suite='tests',
         packages=find_packages(exclude=['tests', 'tests.*']),
         package_data={MAIN_PACKAGE: ["*.json"]},
-        install_requires=install_reqs,
-        setup_requires=['flake8'],
+        install_requires=install_requires,
+        extras_require=extras_require,
         cmdclass=cmdclass,
-        tests_require=['mock>=2.0.0', 'pytest-cov', 'pytest'],
+        tests_require=['flake8', 'mock>=2.0.0', 'pytest-cov', 'pytest'],
         command_options=command_options,
         entry_points={'console_scripts': CONSOLE_SCRIPTS},
     )

tests/test_api.py

@@ -1,19 +1,20 @@
 import datetime
 import json
 import psycopg2
-import pytz
 import unittest
 
-from mock import Mock, patch
+from mock import Mock, PropertyMock, patch
 from patroni.api import RestApiHandler, RestApiServer
 from patroni.dcs import ClusterConfig, Member
+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
 
 
-future_restart_time = datetime.datetime.now(pytz.utc) + datetime.timedelta(days=5)
-postmaster_start_time = datetime.datetime.now(pytz.utc)
+future_restart_time = datetime.datetime.now(tzutc) + datetime.timedelta(days=5)
+postmaster_start_time = datetime.datetime.now(tzutc)
 
 
 class MockPostgresql(object):
@@ -25,6 +26,8 @@ class MockPostgresql(object):
     sysid = 'dummysysid'
     scope = 'dummy'
     pending_restart = True
+    wal_name = 'wal'
+    lsn_name = 'lsn'
 
     @staticmethod
     def connection():
@@ -34,13 +37,26 @@ class MockPostgresql(object):
     def postmaster_start_time():
         return str(postmaster_start_time)
 
+    @staticmethod
+    def replica_cached_timeline(_):
+        return 2
+
+
+class MockWatchdog(object):
+    is_healthy = False
+
 
 class MockHa(object):
 
     state_handler = MockPostgresql()
+    watchdog = MockWatchdog()
 
     @staticmethod
-    def reinitialize():
+    def is_leader():
+        return False
+
+    @staticmethod
+    def reinitialize(_):
         return 'reinitialize'
 
     @staticmethod
@@ -57,12 +73,32 @@ class MockHa(object):
 
     @staticmethod
     def fetch_nodes_statuses(members):
-        return [[None, True, None, None, {}]]
+        return [_MemberStatus(None, True, None, 0, None, {}, False)]
 
     @staticmethod
     def schedule_future_restart(data):
         return True
 
+    @staticmethod
+    def is_lagging(wal):
+        return False
+
+    @staticmethod
+    def get_effective_tags():
+        return {'nosync': True}
+
+    @staticmethod
+    def wakeup():
+        pass
+
+    @staticmethod
+    def is_paused():
+        return True
+
+    @staticmethod
+    def is_standby_cluster():
+        return False
+
 
 class MockPatroni(object):
 
@@ -72,7 +108,7 @@ class MockPatroni(object):
     dcs = Mock()
     tags = {}
     version = '0.00'
-    noloadbalance = Mock(return_value=False)
+    noloadbalance = PropertyMock(return_value=False)
     scheduled_restart = {'schedule': future_restart_time,
                          'postmaster_start_time': postgresql.postmaster_start_time()}
 
@@ -89,19 +125,20 @@ class MockRequest(object):
     def makefile(self, *args, **kwargs):
         return IO(self.request)
 
+    def sendall(self, *args, **kwargs):
+        pass
+
 
 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'}
         super(MockRestApiServer, self).__init__(MockPatroni(), config)
-        config['certfile'] = 'dumb'
-        self.reload_config(config)
         Handler(MockRequest(request), ('0.0.0.0', 8080), self)
 
 
@@ -117,7 +154,14 @@ class TestRestApiHandler(unittest.TestCase):
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
             MockRestApiServer(RestApiHandler, 'GET /replica')
         MockRestApiServer(RestApiHandler, 'GET /master')
-        MockPatroni.dcs.cluster.leader.name = MockPostgresql.name
+        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.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'})):
@@ -125,10 +169,15 @@ class TestRestApiHandler(unittest.TestCase):
         with patch.object(MockHa, 'restart_scheduled', Mock(return_value=True)):
             MockRestApiServer(RestApiHandler, 'GET /master')
         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'))
 
+    @patch.object(MockPostgresql, 'state', PropertyMock(return_value='stopped'))
     def test_do_GET_patroni(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))
 
@@ -225,6 +274,10 @@ class TestRestApiHandler(unittest.TestCase):
 
         mock_dcs.get_cluster.return_value.is_paused.return_value = True
         MockRestApiServer(RestApiHandler, make_request(schedule='2016-08-42 12:45TZ+1', role='master'))
+        # Valid timeout
+        MockRestApiServer(RestApiHandler, make_request(timeout='60s'))
+        # Invalid timeout
+        MockRestApiServer(RestApiHandler, make_request(timeout='42towels'))
 
     def test_do_DELETE_restart(self):
         for retval in (True, False):
@@ -236,7 +289,7 @@ class TestRestApiHandler(unittest.TestCase):
     def test_do_POST_reinitialize(self, mock_dcs):
         cluster = mock_dcs.get_cluster.return_value
         cluster.is_paused.return_value = False
-        request = 'POST /reinitialize HTTP/1.0' + self._authorization
+        request = 'POST /reinitialize HTTP/1.0' + self._authorization + '\nContent-Length: 15\n\n{"force": true}'
         MockRestApiServer(RestApiHandler, request)
         with patch.object(MockHa, 'reinitialize', Mock(return_value=None)):
             MockRestApiServer(RestApiHandler, request)
@@ -250,11 +303,13 @@ class TestRestApiHandler(unittest.TestCase):
 
     @patch('time.sleep', Mock())
     @patch.object(MockPatroni, 'dcs')
-    def test_do_POST_failover(self, dcs):
+    def test_do_POST_switchover(self, dcs):
         dcs.loop_wait = 10
         cluster = dcs.get_cluster.return_value
+        cluster.is_synchronous_mode.return_value = False
+        cluster.is_paused.return_value = False
 
-        post = 'POST /failover HTTP/1.0' + self._authorization + '\nContent-Length: '
+        post = 'POST /switchover HTTP/1.0' + self._authorization + '\nContent-Length: '
 
         MockRestApiServer(RestApiHandler, post + '7\n\n{"1":2}')
 
@@ -264,14 +319,22 @@ class TestRestApiHandler(unittest.TestCase):
         cluster.leader.name = 'postgresql1'
         MockRestApiServer(RestApiHandler, request)
 
-        MockRestApiServer(RestApiHandler, post + '25\n\n{"leader": "postgresql1"}')
+        request = post + '25\n\n{"leader": "postgresql1"}'
+
+        cluster.is_paused.return_value = True
+        MockRestApiServer(RestApiHandler, request)
+
+        cluster.is_paused.return_value = False
+        for cluster.is_synchronous_mode.return_value in (True, False):
+            MockRestApiServer(RestApiHandler, request)
 
         cluster.leader.name = 'postgresql2'
         request = post + '53\n\n{"leader": "postgresql1", "candidate": "postgresql2"}'
         MockRestApiServer(RestApiHandler, request)
 
         cluster.leader.name = 'postgresql1'
-        MockRestApiServer(RestApiHandler, request)
+        for cluster.is_synchronous_mode.return_value in (True, False):
+            MockRestApiServer(RestApiHandler, request)
 
         cluster.members = [Member(0, 'postgresql0', 30, {'api_url': 'http'}),
                            Member(0, 'postgresql2', 30, {'api_url': 'http'})]
@@ -285,6 +348,7 @@ 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)
 
@@ -319,3 +383,24 @@ class TestRestApiHandler(unittest.TestCase):
 
         # Invalid date
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, request + '2010-02-29T18:13:30.568224+01:00"}'))
+
+    @patch.object(MockPatroni, 'dcs', Mock())
+    def test_do_POST_failover(self):
+        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.wrap_socket', Mock(return_value=0))
+class TestRestApiServer(unittest.TestCase):
+
+    def test_reload_config(self):
+        bad_config = {'listen': 'foo'}
+        self.assertRaises(ValueError, MockRestApiServer, None, '', bad_config)
+        srv = MockRestApiServer(lambda a1, a2, a3: None, '')
+        self.assertRaises(ValueError, srv.reload_config, bad_config)
+        self.assertRaises(ValueError, srv.reload_config, {})
+        srv.reload_config({'listen': '127.0.0.2:8008'})
+
+    def test_handle_error(self):
+        self.assertIsNone(MockRestApiServer.handle_error(None, ('127.0.0.1', 55555)))

tests/test_async_executor.py

@@ -1,14 +1,14 @@
 import unittest
 
 from mock import Mock, patch
-from patroni.async_executor import AsyncExecutor
+from patroni.async_executor import AsyncExecutor, CriticalTask
 from threading import Thread
 
 
 class TestAsyncExecutor(unittest.TestCase):
 
     def setUp(self):
-        self.a = AsyncExecutor()
+        self.a = AsyncExecutor(Mock(), Mock())
 
     @patch.object(Thread, 'start', Mock())
     def test_run_async(self):
@@ -16,3 +16,17 @@ class TestAsyncExecutor(unittest.TestCase):
 
     def test_run(self):
         self.a.run(Mock(side_effect=Exception()))
+
+    def test_cancel(self):
+        self.a.cancel()
+        self.a.schedule('foo')
+        self.a.cancel()
+        self.a.run(Mock())
+
+
+class TestCriticalTask(unittest.TestCase):
+
+    def test_completed_task(self):
+        ct = CriticalTask()
+        ct.complete(1)
+        self.assertFalse(ct.cancel())

tests/test_aws.py

@@ -1,5 +1,4 @@
 import boto.ec2
-import requests
 import sys
 import unittest
 
@@ -11,82 +10,60 @@ from requests.exceptions import RequestException
 
 class MockEc2Connection(object):
 
-    def __init__(self, error=False):
-        self.error = error
-
-    def get_all_volumes(self, filters):
-        if self.error:
-            raise Exception("get_all_volumes")
+    @staticmethod
+    def get_all_volumes(*args, **kwargs):
         oid = namedtuple('Volume', 'id')
         return [oid(id='a'), oid(id='b')]
 
-    def create_tags(self, objects, tags):
-        if self.error or len(objects) == 0:
-            raise Exception("create_tags")
+    @staticmethod
+    def create_tags(objects, *args, **kwargs):
+        if len(objects) == 0:
+            raise boto.exception.BotoServerError(503, 'Service Unavailable', 'Request limit exceeded')
         return True
 
 
 class MockResponse(object):
+    ok = True
 
     def __init__(self, content):
         self.content = content
-        self.ok = True
 
     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):
 
-    def boto_ec2_connect_to_region(self, region):
-        return MockEc2Connection(self.error)
-
-    def requests_get(self, url, **kwargs):
-        if self.error:
-            raise RequestException("foo")
-        result = namedtuple('Request', 'ok content')
-        result.ok = True
-        if url.split('/')[-1] == 'document' and not self.json_error:
-            result = {"instanceId": "012345", "region": "eu-west-1"}
-        else:
-            result = 'foo'
-        return MockResponse(result)
-
+    @patch('requests.get', requests_get)
     def setUp(self):
-        self.error = False
-        self.json_error = False
-        requests.get = self.requests_get
-        boto.ec2.connect_to_region = self.boto_ec2_connect_to_region
         self.conn = AWSConnection('test')
 
-    def test_aws_available(self):
-        self.assertTrue(self.conn.aws_available())
-
     def test_on_role_change(self):
-        self.assertTrue(self.conn._tag_ebs('master'))
-        self.assertTrue(self.conn._tag_ec2('master'))
         self.assertTrue(self.conn.on_role_change('master'))
+        with patch.object(MockEc2Connection, 'get_all_volumes', Mock(return_value=[])):
+            self.conn._retry.max_tries = 1
+            self.assertFalse(self.conn.on_role_change('master'))
 
+    @patch('requests.get', Mock(side_effect=RequestException('foo')))
     def test_non_aws(self):
-        self.error = True
         conn = AWSConnection('test')
-        self.assertFalse(conn.aws_available())
-        self.assertFalse(conn._tag_ebs('master'))
-        self.assertFalse(conn._tag_ec2('master'))
+        self.assertFalse(conn.on_role_change("master"))
 
+    @patch('requests.get', Mock(return_value=MockResponse('foo')))
     def test_aws_bizare_response(self):
-        self.json_error = True
         conn = AWSConnection('test')
         self.assertFalse(conn.aws_available())
 
-    def test_aws_tag_ebs_error(self):
-        self.error = True
-        self.assertFalse(self.conn._tag_ebs("master"))
-
-    def test_aws_tag_ec2_error(self):
-        self.error = True
-        self.assertFalse(self.conn._tag_ec2("master"))
-
+    @patch('requests.get', requests_get)
     @patch('sys.exit', Mock())
     def test_main(self):
         self.assertIsNone(_main())

tests/test_callback_executor.py

@@ -0,0 +1,24 @@
+import unittest
+
+from mock import Mock, patch
+from patroni.callback_executor import CallbackExecutor
+
+
+class TestCallbackExecutor(unittest.TestCase):
+
+    @patch('subprocess.Popen')
+    def test_callback_executor(self, mock_popen):
+        mock_popen.return_value.wait.side_effect = Exception
+        mock_popen.return_value.poll.return_value = None
+
+        ce = CallbackExecutor()
+        self.assertIsNone(ce.call([]))
+        ce.join()
+
+        self.assertIsNone(ce.call([]))
+
+        mock_popen.side_effect = Exception
+        ce = CallbackExecutor()
+        ce._callback_event.wait = Mock(side_effect=[None, Exception])
+        self.assertIsNone(ce.call([]))
+        ce.join()

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
@@ -20,15 +20,18 @@ class TestConfig(unittest.TestCase):
     def test_no_config(self):
         self.assertRaises(SystemExit, Config)
 
-    @patch.object(Config, '_build_effective_configuration', Mock(side_effect=Exception))
     def test_set_dynamic_configuration(self):
-        self.assertIsNone(self.config.set_dynamic_configuration({'foo': 'bar'}))
+        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, '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',
@@ -38,9 +41,20 @@ class TestConfig(unittest.TestCase):
             'PATRONI_POSTGRESQL_LISTEN': '0.0.0.0:5432',
             'PATRONI_POSTGRESQL_CONNECT_ADDRESS': '127.0.0.1:5432',
             'PATRONI_POSTGRESQL_DATA_DIR': 'data/postgres0',
+            'PATRONI_POSTGRESQL_CONFIG_DIR': 'data/postgres0',
             'PATRONI_POSTGRESQL_PGPASS': '/tmp/pgpass0',
             'PATRONI_ETCD_HOST': '127.0.0.1:2379',
+            'PATRONI_ETCD_URL': 'https://127.0.0.1:2379',
+            'PATRONI_ETCD_PROXY': 'http://127.0.0.1:2379',
+            'PATRONI_ETCD_SRV': 'test',
+            'PATRONI_ETCD_CACERT': '/cacert',
+            'PATRONI_ETCD_CERT': '/cert',
+            'PATRONI_ETCD_KEY': '/key',
             'PATRONI_CONSUL_HOST': '127.0.0.1:8500',
+            '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'",
             'PATRONI_EXHIBITOR_HOSTS': 'host1,host2',
             'PATRONI_EXHIBITOR_PORT': '8181',
@@ -59,12 +73,13 @@ class TestConfig(unittest.TestCase):
                 self.assertRaises(Exception, config.reload_local_configuration, True)
             self.assertTrue(config.reload_local_configuration(True))
             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'}})
@@ -72,3 +87,15 @@ 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

@@ -1,8 +1,10 @@
 import consul
 import unittest
 
+from consul import ConsulException, NotFound
 from mock import Mock, patch
-from patroni.dcs.consul import AbstractDCS, Cluster, Consul, ConsulError, ConsulException, HTTPClient, NotFound
+from patroni.dcs.consul import AbstractDCS, Cluster, Consul, ConsulInternalError, \
+                                ConsulError, HTTPClient, InvalidSessionTTL, InvalidSession
 from test_etcd import SleepException
 
 
@@ -30,17 +32,39 @@ def kv_get(self, key, **kwargs):
                   'Value': ('postgres://replicator:[email protected]:5433/postgres' +
                             '?application_name=http://127.0.0.1:8009/patroni').encode('utf-8')},
                  {'CreateIndex': 1085, 'Flags': 0, 'Key': key + 'optime/leader', 'LockIndex': 0,
-                  'ModifyIndex': 6429, 'Value': b'4496294792'}])
+                  'ModifyIndex': 6429, 'Value': b'4496294792'},
+                 {'CreateIndex': 1085, 'Flags': 0, 'Key': key + 'sync', 'LockIndex': 0,
+                  'ModifyIndex': 6429, 'Value': b'{"leader": "leader", "sync_standby": null}'}])
     raise ConsulException
 
 
 class TestHTTPClient(unittest.TestCase):
 
-    def test_get(self):
+    def setUp(self):
         self.client = HTTPClient('127.0.0.1', '8500', 'http', False)
-        self.client.session.get = Mock()
+        self.client.http.request = Mock()
+
+    def test_get(self):
         self.client.get(Mock(), '')
-        self.client.get(Mock(), '', {'wait': '1s', 'index': 1})
+        self.client.get(Mock(), '', {'wait': '1s', 'index': 1, 'token': 'foo'})
+        self.client.http.request.return_value.status = 500
+        self.client.http.request.return_value.data = b'Foo'
+        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:
+            self.client.bla(Mock(), '')
+            self.assertFail()
+        except Exception as e:
+            self.assertTrue(isinstance(e, AttributeError))
+
+    def test_put(self):
+        self.client.put(Mock(), '/v1/session/create')
+        self.client.put(Mock(), '/v1/session/create', params=[], data='{"foo": "bar"}')
 
 
 @patch.object(consul.Consul.KV, 'get', kv_get)
@@ -51,7 +75,13 @@ class TestConsul(unittest.TestCase):
     @patch.object(consul.Consul.KV, 'get', kv_get)
     @patch.object(consul.Consul.KV, 'delete', Mock())
     def setUp(self):
-        self.c = Consul({'ttl': 30, 'scope': 'test', 'name': 'postgresql1', 'host': 'localhost:1', 'retry_timeout': 10})
+        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',
+                '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()
 
@@ -62,10 +92,13 @@ class TestConsul(unittest.TestCase):
         self.assertRaises(SleepException, self.c.create_session)
 
     @patch.object(consul.Consul.Session, 'renew', Mock(side_effect=NotFound))
-    @patch.object(consul.Consul.Session, 'create', Mock(side_effect=ConsulException))
+    @patch.object(consul.Consul.Session, 'create', Mock(side_effect=[InvalidSessionTTL, ConsulException]))
+    @patch.object(consul.Consul.Agent, 'self', Mock(return_value={'Config': {'SessionTTLMin': 0}}))
+    @patch.object(HTTPClient, 'set_ttl', Mock(side_effect=ValueError))
     def test_referesh_session(self):
         self.c._session = '1'
-        self.c._name = ''
+        self.assertFalse(self.c.refresh_session())
+        self.c._last_session_refresh = 0
         self.assertRaises(ConsulError, self.c.refresh_session)
 
     @patch.object(consul.Consul.KV, 'delete', Mock())
@@ -79,18 +112,21 @@ 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')
-        self.c.touch_member('balbla')
-        self.c.touch_member('balbla')
         self.c.refresh_session = Mock(return_value=False)
-        self.c.touch_member('balbla')
+        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()
         self.c.take_leader()
 
     @patch.object(consul.Consul.KV, 'put', Mock(return_value=True))
@@ -103,10 +139,11 @@ class TestConsul(unittest.TestCase):
 
     @patch.object(consul.Consul.KV, 'put', Mock(side_effect=ConsulException))
     def test_write_leader_optime(self):
-        self.c.write_leader_optime('')
+        self.c.write_leader_optime('1')
 
+    @patch.object(consul.Consul.Session, 'renew', Mock())
     def test_update_leader(self):
-        self.c.update_leader()
+        self.c.update_leader(None)
 
     @patch.object(consul.Consul.KV, 'delete', Mock(return_value=True))
     def test_delete_leader(self):
@@ -126,15 +163,37 @@ class TestConsul(unittest.TestCase):
 
     @patch.object(AbstractDCS, 'watch', Mock())
     def test_watch(self):
+        self.c.watch(None, 1)
         self.c._name = ''
-        self.c.watch(1)
+        self.c.watch(6429, 1)
         with patch.object(consul.Consul.KV, 'get', Mock(side_effect=ConsulException)):
-            self.c.watch(1)
-
-    @patch.object(consul.Consul.Session, 'destroy', Mock(side_effect=ConsulException))
-    def test_set_ttl(self):
-        self.c.set_ttl(20)
-        self.assertTrue(self.c.watch(1))
+            self.c.watch(6429, 1)
 
     def test_set_retry_timeout(self):
         self.c.set_retry_timeout(10)
+
+    @patch.object(consul.Consul.KV, 'delete', Mock(return_value=True))
+    @patch.object(consul.Consul.KV, 'put', Mock(return_value=True))
+    def test_sync_state(self):
+        self.assertTrue(self.c.set_sync_state_value('{}'))
+        self.assertTrue(self.c.delete_sync_state())
+
+    @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))

tests/test_ctl.py

@@ -5,14 +5,17 @@ import sys
 import unittest
 
 from click.testing import CliRunner
+from datetime import datetime, timedelta
 from mock import patch, Mock
-from patroni.ctl import ctl, members, store_config, load_config, output_members, request_patroni, get_dcs, parse_dcs, \
-    wait_for_leader, get_all_members, get_any_member, get_cursor, query_member, configure, PatroniCtlException
-from patroni.dcs.etcd import Client
+from patroni.ctl import ctl, store_config, load_config, output_members, request_patroni, 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
+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, \
-    get_cluster_initialized_with_only_leader, get_cluster_not_initialized_without_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'
@@ -30,8 +33,8 @@ def test_rw_config():
 
 
 @patch('patroni.ctl.load_config',
-       Mock(return_value={'postgresql': {'data_dir': '.', 'parameters': {}, 'retry_timeout': 5},
-                          'restapi': {'auth': 'u:p', 'listen': ''}, 'etcd': {'host': 'localhost:4001'}}))
+       Mock(return_value={'scope': 'alpha', 'postgresql': {'data_dir': '.', 'parameters': {}, 'retry_timeout': 5},
+                          'restapi': {'auth': 'u:p', 'listen': ''}, 'etcd': {'host': 'localhost:2379'}}))
 class TestCtl(unittest.TestCase):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
@@ -54,8 +57,8 @@ class TestCtl(unittest.TestCase):
 
     def test_parse_dcs(self):
         assert parse_dcs(None) is None
-        assert parse_dcs('localhost') == {'etcd': {'host': 'localhost:4001'}}
-        assert parse_dcs('') == {'etcd': {'host': 'localhost:4001'}}
+        assert parse_dcs('localhost') == {'etcd': {'host': 'localhost:2379'}}
+        assert parse_dcs('') == {'etcd': {'host': 'localhost:2379'}}
         assert parse_dcs('localhost:8500') == {'consul': {'host': 'localhost:8500'}}
         assert parse_dcs('zookeeper://localhost') == {'zookeeper': {'hosts': ['localhost:2181']}}
         assert parse_dcs('exhibitor://dummy') == {'exhibitor': {'hosts': ['dummy'], 'port': 8181}}
@@ -63,79 +66,92 @@ class TestCtl(unittest.TestCase):
         self.assertRaises(PatroniCtlException, parse_dcs, 'invalid://test')
 
     def test_output_members(self):
-        cluster = get_cluster_initialized_with_leader()
+        scheduled_at = datetime.now(tzutc) + timedelta(seconds=600)
+        cluster = get_cluster_initialized_with_leader(Failover(1, 'foo', 'bar', scheduled_at))
         self.assertIsNone(output_members(cluster, name='abc', fmt='pretty'))
         self.assertIsNone(output_members(cluster, name='abc', fmt='json'))
+        self.assertIsNone(output_members(cluster, name='abc', fmt='yaml'))
         self.assertIsNone(output_members(cluster, name='abc', fmt='tsv'))
 
+    @patch('patroni.ctl.get_dcs')
+    @patch('patroni.ctl.request_patroni', 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
+        mock_get_dcs.return_value.set_failover_value = Mock()
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
+        assert 'leader' in result.output
+
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n2300-01-01T12:23:00\ny')
+        assert result.exit_code == 0
+
+        with patch('patroni.dcs.Cluster.is_paused', Mock(return_value=True)):
+            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
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], 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
+
+        # Reality is not part of this cluster
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nReality\n\ny')
+        assert result.exit_code == 1
+
+        result = self.runner.invoke(ctl, ['switchover', 'dummy', '--force'])
+        assert 'Member' in result.output
+
+        result = self.runner.invoke(ctl, ['switchover', 'dummy', '--force', '--scheduled', '2015-01-01T12:00:00+01:00'])
+        assert result.exit_code == 0
+
+        # Invalid timestamp
+        result = self.runner.invoke(ctl, ['switchover', 'dummy', '--force', '--scheduled', 'invalid'])
+        assert result.exit_code != 0
+
+        # Invalid timestamp
+        result = self.runner.invoke(ctl, ['switchover', 'dummy', '--force', '--scheduled', '2115-02-30T12:00:00+01:00'])
+        assert result.exit_code != 0
+
+        # Specifying wrong leader
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='dummy')
+        assert result.exit_code == 1
+
+        with patch('patroni.ctl.request_patroni', 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
+            result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
+            assert 'Switchover failed' in result.output
+
+            mocked.return_value.status_code = 501
+            mocked.return_value.text = 'Server does not support this operation'
+            result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
+            assert 'Switchover failed' in result.output
+
+        # No members available
+        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_only_leader
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
+        assert result.exit_code == 1
+
+        # No master available
+        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_without_leader
+        result = self.runner.invoke(ctl, ['switchover', 'dummy'], input='leader\nother\n\ny')
+        assert result.exit_code == 1
+
     @patch('patroni.ctl.get_dcs')
     @patch('patroni.ctl.request_patroni', 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
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n\ny')
-        assert 'leader' in result.output
-
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n2100-01-01T12:23:00\ny')
-        assert result.exit_code == 0
-
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n2030-01-01T12:23:00\ny')
-        assert result.exit_code == 0
-
-        with patch('patroni.dcs.Cluster.is_paused', Mock(return_value=True)):
-            result = self.runner.invoke(ctl,
-                                        ['failover', 'dummy', '--force', '--scheduled', '2015-01-01T12:00:00+01:00'])
-            assert result.exit_code == 1
-
-        # Aborting failover,as we anser NO to the confirmation
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n\nN')
-        assert result.exit_code == 1
-
-        # Target and source are equal
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nleader\n\ny')
-        assert result.exit_code == 1
-
-        # Reality is not part of this cluster
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nReality\n\ny')
-        assert result.exit_code == 1
-
-        result = self.runner.invoke(ctl, ['failover', 'dummy', '--force'])
-        assert 'Member' in result.output
-
-        result = self.runner.invoke(ctl, ['failover', 'dummy', '--force', '--scheduled', '2015-01-01T12:00:00+01:00'])
-        assert result.exit_code == 0
-
-        # Invalid timestamp
-        result = self.runner.invoke(ctl, ['failover', 'dummy', '--force', '--scheduled', 'invalid'])
-        assert result.exit_code != 0
-
-        # Invalid timestamp
-        result = self.runner.invoke(ctl, ['failover', 'dummy', '--force', '--scheduled', '2115-02-30T12:00:00+01:00'])
-        assert result.exit_code != 0
-
-        # Specifying wrong leader
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='dummy')
-        assert result.exit_code == 1
-
-        with patch('patroni.ctl.request_patroni', Mock(side_effect=Exception)):
-            # Non-responding patroni
-            result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n\ny')
-            assert 'falling back to DCS' in result.output
-
-        with patch('patroni.ctl.request_patroni') as mocked:
-            mocked.return_value.status_code = 500
-            result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n\ny')
-            assert 'Failover failed' in result.output
-
-        # No members available
-        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_only_leader
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n\ny')
-        assert result.exit_code == 1
-
-        # No master available
-        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_without_leader
-        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='leader\nother\n\ny')
-        assert result.exit_code == 1
+        mock_get_dcs.return_value.set_failover_value = Mock()
+        result = self.runner.invoke(ctl, ['failover', 'dummy'], input='\n')
+        assert 'Failover could be performed only to a specific candidate' in result.output
 
     def test_get_dcs(self):
         self.assertRaises(PatroniCtlException, get_dcs, {'dummy': {}}, 'dummy')
@@ -176,24 +192,24 @@ 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()', {})
+                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):
@@ -209,6 +225,22 @@ class TestCtl(unittest.TestCase):
         result = self.runner.invoke(ctl, ['dsn', 'alpha', '--member', 'dummy'])
         assert result.exit_code == 1
 
+    @patch('requests.post')
+    @patch('patroni.ctl.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, ['reload', 'alpha'], input='y')
+        assert 'Failed: reload for member' in result.output
+
+        mock_post.return_value.status_code = 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_code = 202
+        result = self.runner.invoke(ctl, ['reload', 'alpha'], input='y')
+        assert 'Reload request received for member' in result.output
+
     @patch('requests.post', requests_get)
     @patch('patroni.ctl.get_dcs')
     def test_restart_reinit(self, mock_get_dcs):
@@ -221,7 +253,7 @@ class TestCtl(unittest.TestCase):
         assert result.exit_code == 1
 
         # successful reinit
-        result = self.runner.invoke(ctl, ['reinit', 'alpha', 'other'], input='y')
+        result = self.runner.invoke(ctl, ['reinit', 'alpha', 'other'], input='y\ny')
         assert result.exit_code == 0
 
         # Aborted restart
@@ -237,9 +269,12 @@ class TestCtl(unittest.TestCase):
 
         # Wrong pg version
         result = self.runner.invoke(ctl, ['restart', 'alpha', '--any', '--pg-version', '9.1'], input='y')
-        assert 'Error: PostgreSQL version' in result.output
+        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',
@@ -260,7 +295,7 @@ class TestCtl(unittest.TestCase):
         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', '42.0.0',
+            result = self.runner.invoke(ctl, ['restart', 'alpha', '--pg-version', '42.0',
                                         '--scheduled', '2300-10-01T14:30'], input='y')
             assert result.exit_code == 0
 
@@ -308,17 +343,15 @@ class TestCtl(unittest.TestCase):
         result = self.runner.invoke(ctl, ['remove', 'alpha'], input='alpha\nYes I am aware\nleader')
         assert result.exit_code == 0
 
-    @patch('patroni.dcs.AbstractDCS.watch', Mock(return_value=None))
-    @patch('patroni.dcs.AbstractDCS.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
-    def test_wait_for_leader(self):
-        self.assertRaises(PatroniCtlException, wait_for_leader, self.e, 0)
-
-        cluster = wait_for_leader(self.e, timeout=2)
-        assert cluster.leader.member.name == 'leader'
-
     @patch('requests.post', Mock(side_effect=requests.exceptions.ConnectionError('foo')))
-    def test_request_patroni(self):
+    @patch('click.get_current_context')
+    def test_request_patroni(self, mock_context):
         member = get_cluster_initialized_with_leader().leader.member
+
+        mock_context.return_value.obj = {'ctl': {'cacert': 'cert.pem'}}
+        self.assertRaises(requests.exceptions.ConnectionError, request_patroni, member, 'post', 'dummy', {})
+
+        mock_context.return_value.obj = {'ctl': {'insecure': True}}
         self.assertRaises(requests.exceptions.ConnectionError, request_patroni, member, 'post', 'dummy', {})
 
     def test_ctl(self):
@@ -331,27 +364,29 @@ 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):
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
-        result = self.runner.invoke(members, ['alpha'])
+        result = self.runner.invoke(ctl, ['list'])
         assert '127.0.0.1' in result.output
         assert result.exit_code == 0
+        with patch('patroni.ctl.load_config', Mock(return_value={})):
+            self.runner.invoke(ctl, ['list'])
 
     def test_configure(self):
         result = self.runner.invoke(configure, ['--dcs', 'abc', '-c', 'dummy', '-n', 'bla'])
@@ -364,6 +399,7 @@ class TestCtl(unittest.TestCase):
         mock_get_dcs.return_value.initialize = Mock(return_value=True)
         mock_get_dcs.return_value.touch_member = Mock(return_value=True)
         mock_get_dcs.return_value.attempt_to_acquire_leader = Mock(return_value=True)
+        mock_get_dcs.return_value.delete_cluster = Mock()
 
         with patch.object(self.e, 'initialize', return_value=False):
             result = self.runner.invoke(ctl, ['scaffold', 'alpha'])
@@ -383,9 +419,10 @@ class TestCtl(unittest.TestCase):
     @patch('patroni.ctl.get_dcs')
     def test_list_extended(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
-        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
+        cluster = get_cluster_initialized_with_leader(sync=('leader', 'other'))
+        mock_get_dcs.return_value.get_cluster = Mock(return_value=cluster)
 
-        result = self.runner.invoke(ctl, ['list', 'dummy', '--extended'])
+        result = self.runner.invoke(ctl, ['list', 'dummy', '--extended', '--timestamp'])
         assert '2100' in result.output
         assert 'Scheduled restart' in result.output
 
@@ -405,14 +442,11 @@ class TestCtl(unittest.TestCase):
             assert 'Failed: flush scheduled restart' in result.output
 
     @patch('patroni.ctl.get_dcs')
+    @patch('patroni.ctl.polling_loop', Mock(return_value=[1]))
     def test_pause_cluster(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('requests.patch', Mock(return_value=MockResponse(200))):
-            result = self.runner.invoke(ctl, ['pause', 'dummy'])
-            assert 'Success' in result.output
-
         with patch('requests.patch', Mock(return_value=MockResponse(500))):
             result = self.runner.invoke(ctl, ['pause', 'dummy'])
             assert 'Failed' in result.output
@@ -422,6 +456,17 @@ class TestCtl(unittest.TestCase):
             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'])
+
     @patch('patroni.ctl.get_dcs')
     def test_resume_cluster(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
@@ -440,3 +485,92 @@ class TestCtl(unittest.TestCase):
                     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
+
+    def test_apply_config_changes(self):
+        config = {"postgresql": {"parameters": {"work_mem": "4MB"}, "use_pg_rewind": True}, "ttl": 30}
+
+        before_editing = format_config_for_editing(config)
+
+        # Spaces are allowed and stripped, numbers and booleans are interpreted
+        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.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.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.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.assertEqual(changed_config, {"ttl": 30})
+
+        self.assertRaises(PatroniCtlException, apply_config_changes, before_editing, config, ['a'])
+
+    @patch('sys.stdout.isatty', return_value=False)
+    @patch('cdiff.markup_to_pager')
+    def test_show_diff(self, mock_markup_to_pager, mock_isatty):
+        show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
+        mock_markup_to_pager.assert_not_called()
+
+        mock_isatty.return_value = True
+        show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
+        mock_markup_to_pager.assert_called_once()
+
+        # Test that unicode handling doesn't fail with an exception
+        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('patroni.ctl.get_dcs')
+    def test_show_config(self, mock_get_dcs):
+        mock_get_dcs.return_value = self.e
+        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
+        self.runner.invoke(ctl, ['show-config', 'dummy'])
+
+    @patch('patroni.ctl.get_dcs')
+    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
+        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)
+        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:
+            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}
+            result = self.runner.invoke(ctl, ['version', 'dummy'])
+            assert '1.2.3' in result.output
+        with patch('requests.get', Mock(side_effect=Exception)):
+            result = self.runner.invoke(ctl, ['version', 'dummy'])
+            assert 'failed to get version' in result.output
+
+    def test_format_pg_version(self):
+        self.assertEqual(format_pg_version(100001), '10.1')
+        self.assertEqual(format_pg_version(90605), '9.6.5')

tests/test_etcd.py

@@ -1,12 +1,13 @@
 import etcd
 import json
+import urllib3.util.connection
 import requests
 import socket
 import unittest
 
 from dns.exception import DNSException
 from mock import Mock, patch
-from patroni.dcs.etcd import AbstractDCS, Client, Cluster, Etcd, EtcdError
+from patroni.dcs.etcd import AbstractDCS, Client, Cluster, Etcd, EtcdError, DnsCachingResolver
 from patroni.exceptions import DCSError
 from urllib3.exceptions import ReadTimeoutError
 
@@ -17,7 +18,6 @@ class MockResponse(object):
         self.status_code = status_code
         self.content = '{}'
         self.ok = True
-        self.text = ''
 
     def json(self):
         return json.loads(self.content)
@@ -26,6 +26,10 @@ class MockResponse(object):
     def data(self):
         return self.content.encode('utf-8')
 
+    @property
+    def text(self):
+        return self.content
+
     @property
     def status(self):
         return self.status_code
@@ -42,11 +46,17 @@ def requests_get(url, **kwargs):
     if url.startswith('http://local'):
         raise requests.exceptions.RequestException()
     elif ':8011/patroni' in url:
-        response.content = '{"role": "replica", "xlog": {"replayed_location": 0}, "tags": {}}'
+        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
@@ -58,8 +68,10 @@ def etcd_watch(self, key, index=None, timeout=None, recursive=None):
         raise etcd.EtcdWatchTimedOut
     elif timeout == 5.0:
         return etcd.EtcdResult('delete', {})
-    elif timeout == 10.0:
+    elif 5 < timeout <= 10.0:
         raise etcd.EtcdException
+    elif timeout == 20.0:
+        raise etcd.EtcdEventIndexCleared
 
 
 def etcd_write(self, key, value, **kwargs):
@@ -78,7 +90,7 @@ 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},
@@ -91,6 +103,8 @@ def etcd_read(self, key, **kwargs):
                     {"key": "/service/batman5/optime/leader", "value": "2164261704",
                      "modifiedIndex": 20729, "createdIndex": 20729}],
                  "modifiedIndex": 20437, "createdIndex": 20437},
+                {"key": "/service/batman5/sync", "value": '{"leader": "leader"}',
+                 "modifiedIndex": 1582, "createdIndex": 1582},
                 {"key": "/service/batman5/members", "dir": True, "nodes": [
                     {"key": "/service/batman5/members/postgresql1",
                      "value": "postgres://replicator:[email protected]:5434/postgres" +
@@ -112,23 +126,23 @@ class SleepException(Exception):
     pass
 
 
-class MockSRV(object):
-    port = 2380
-    target = '127.0.0.1'
-
-
 def dns_query(name, _):
+    if '-server' not in name or '-ssl' in name:
+        return []
     if name == '_etcd-server._tcp.blabla':
         return []
     elif name == '_etcd-server._tcp.exception':
         raise DNSException()
-    return [MockSRV()]
+    srv = Mock()
+    srv.port = 2380
+    srv.target.to_text.return_value = 'localhost' if name == '_etcd-server._tcp.foobar' else '127.0.0.1'
+    return [srv]
 
 
 def socket_getaddrinfo(*args):
-    if args[0] == 'ok':
-        return [(2, 1, 6, '', ('127.0.0.1', 2379)), (2, 1, 6, '', ('127.0.0.1', 2379))]
-    raise socket.error
+    if args[0] in ('ok', 'localhost', '127.0.0.1'):
+        return [(socket.AF_INET, 1, 6, '', ('127.0.0.1', 0)), (socket.AF_INET6, 1, 6, '', ('::1', 0))]
+    raise socket.gaierror
 
 
 def http_request(method, url, **kwargs):
@@ -143,17 +157,28 @@ def http_request(method, url, **kwargs):
     raise socket.error
 
 
+class TestDnsCachingResolver(unittest.TestCase):
+
+    @patch('time.sleep', Mock(side_effect=SleepException))
+    @patch('socket.getaddrinfo', Mock(side_effect=socket.gaierror))
+    def test_run(self):
+        r = DnsCachingResolver()
+        self.assertIsNone(r.resolve_async('', 0))
+        r.join()
+
+
 @patch('dns.resolver.query', dns_query)
 @patch('socket.getaddrinfo', socket_getaddrinfo)
 @patch('requests.get', requests_get)
 class TestClient(unittest.TestCase):
 
     @patch('dns.resolver.query', dns_query)
+    @patch('socket.getaddrinfo', socket_getaddrinfo)
     @patch('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'])
-            self.client = Client({'discovery_srv': 'test', 'retry_timeout': 3})
+            self.client = Client({'srv': 'test', 'retry_timeout': 3}, DnsCachingResolver())
             self.client.http.request = http_request
             self.client.http.request_encode_body = http_request
 
@@ -179,6 +204,10 @@ class TestClient(unittest.TestCase):
         self.client._base_uri = 'http://localhost:4001'
         self.client._machines_cache = ['http://localhost:2379']
         self.client.api_execute('/', 'POST', timeout=0)
+        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.EtcdException, self.client.api_execute, '/', '')
         self.client._update_machines_cache = True
@@ -186,31 +215,43 @@ class TestClient(unittest.TestCase):
             self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'GET')
 
     def test_get_srv_record(self):
-        self.assertEquals(self.client.get_srv_record('blabla'), [])
-        self.assertEquals(self.client.get_srv_record('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')
         self.client.get_srv_record = Mock(return_value=[('localhost', 2380)])
         self.client._get_machines_cache_from_srv('blabla')
 
     def test__get_machines_cache_from_dns(self):
-        self.client._get_machines_cache_from_dns('error:2379')
+        self.client._get_machines_cache_from_dns('error', 2379)
 
     @patch.object(Client, 'machines')
     def test__load_machines_cache(self, mock_machines):
         mock_machines.__get__ = Mock(return_value=['http://localhost:2379'])
         self.client._config = {}
         self.assertRaises(Exception, self.client._load_machines_cache)
-        self.client._config = {'discovery_srv': 'blabla'}
+        self.client._config = {'srv': 'blabla'}
         self.assertRaises(etcd.EtcdException, self.client._load_machines_cache)
 
+    @patch.object(socket.socket, 'connect')
+    def test_create_connection_patched(self, mock_connect):
+        self.assertRaises(socket.error, urllib3.util.connection.create_connection, ('fail', 2379))
+        urllib3.util.connection.create_connection(('[localhost]', 2379))
+        mock_connect.side_effect = socket.error
+        self.assertRaises(socket.error, urllib3.util.connection.create_connection, ('[localhost]', 2379),
+                          timeout=1, source_address=('localhost', 53333),
+                          socket_options=[(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)])
+
 
 @patch('requests.get', requests_get)
+@patch('socket.getaddrinfo', socket_getaddrinfo)
 @patch.object(etcd.Client, 'write', etcd_write)
 @patch.object(etcd.Client, 'read', etcd_read)
 @patch.object(etcd.Client, 'delete', Mock(side_effect=etcd.EtcdException))
 class TestEtcd(unittest.TestCase):
 
+    @patch('socket.getaddrinfo', socket_getaddrinfo)
     def setUp(self):
         with patch.object(Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
@@ -218,7 +259,7 @@ 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):
@@ -226,10 +267,18 @@ class TestEtcd(unittest.TestCase):
             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})
+                                  {'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})
 
     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)
@@ -253,7 +302,7 @@ class TestEtcd(unittest.TestCase):
         self.etcd.write_leader_optime('0')
 
     def test_update_leader(self):
-        self.assertTrue(self.etcd.update_leader())
+        self.assertTrue(self.etcd.update_leader(None))
 
     def test_initialize(self):
         self.assertFalse(self.etcd.initialize())
@@ -267,14 +316,16 @@ class TestEtcd(unittest.TestCase):
     def test_delete_cluster(self):
         self.assertFalse(self.etcd.delete_cluster())
 
+    @patch('time.sleep', Mock(side_effect=SleepException))
     @patch.object(etcd.Client, 'watch', etcd_watch)
     def test_watch(self):
-        self.etcd.watch(0)
+        self.etcd.watch(None, 0)
         self.etcd.get_cluster()
-        self.etcd.watch(1.5)
-        self.etcd.watch(4.5)
+        self.etcd.watch(20729, 1.5)
+        self.etcd.watch(20729, 4.5)
         with patch.object(AbstractDCS, 'watch', Mock()):
-            self.etcd.watch(9.5)
+            self.assertTrue(self.etcd.watch(20729, 19.5))
+            self.assertRaises(SleepException, self.etcd.watch, 20729, 9.5)
 
     def test_other_exceptions(self):
         self.etcd.retry = Mock(side_effect=AttributeError('foo'))
@@ -282,4 +333,11 @@ class TestEtcd(unittest.TestCase):
 
     def test_set_ttl(self):
         self.etcd.set_ttl(20)
-        self.assertTrue(self.etcd.watch(1))
+        self.assertTrue(self.etcd.watch(None, 1))
+
+    def test_sync_state(self):
+        self.assertFalse(self.etcd.write_sync_state('leader', None))
+        self.assertFalse(self.etcd.delete_sync_state())
+
+    def test_set_history_value(self):
+        self.assertFalse(self.etcd.set_history_value('{}'))

tests/test_kubernetes.py

@@ -0,0 +1,114 @@
+import unittest
+
+from mock import Mock, patch
+from patroni.dcs.kubernetes import Kubernetes, KubernetesError, k8s_client, k8s_watch, RetryFailedError
+
+
+def mock_list_namespaced_config_map(self, *args, **kwargs):
+    metadata = {'resource_version': '1', 'labels': {'f': 'b'}, 'name': 'test-config',
+                'annotations': {'initialize': '123', 'config': '{}'}}
+    items = [k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata))]
+    metadata.update({'name': 'test-leader', 'annotations': {'optime': '1234', 'leader': 'p-0', 'ttl': '30s'}})
+    items.append(k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata)))
+    metadata.update({'name': 'test-failover', 'annotations': {'leader': 'p-0'}})
+    items.append(k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata)))
+    metadata.update({'name': 'test-sync', 'annotations': {'leader': 'p-0'}})
+    items.append(k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata)))
+    metadata = k8s_client.V1ObjectMeta(resource_version='1')
+    return k8s_client.V1ConfigMapList(metadata=metadata, items=items)
+
+
+def mock_list_namespaced_pod(self, *args, **kwargs):
+    metadata = k8s_client.V1ObjectMeta(resource_version='1', name='p-0', annotations={'status': '{}'})
+    items = [k8s_client.V1Pod(metadata=metadata)]
+    return k8s_client.V1PodList(items=items)
+
+
+@patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', Mock())
+@patch.object(k8s_client.CoreV1Api, 'create_namespaced_config_map', Mock())
+class TestKubernetes(unittest.TestCase):
+
+    @patch('kubernetes.config.load_kube_config', Mock())
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod)
+    def setUp(self):
+        self.k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'retry_timeout': 10, 'labels': {'f': 'b'}})
+        with patch('time.time', Mock(return_value=1)):
+            self.k.get_cluster()
+
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod)
+    def test_get_cluster(self):
+        self.k.get_cluster()
+        with patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', Mock(side_effect=Exception)):
+            self.assertRaises(KubernetesError, self.k.get_cluster)
+
+    @patch('kubernetes.config.load_kube_config', Mock())
+    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', Mock())
+    def test_update_leader(self):
+        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'retry_timeout': 10,
+                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
+        self.assertIsNotNone(k.update_leader('123'))
+
+    @patch('kubernetes.config.load_kube_config', Mock())
+    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', Mock())
+    def test_update_leader_with_restricted_access(self):
+        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'retry_timeout': 10,
+                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
+        self.assertIsNotNone(k.update_leader('123', True))
+
+    def test_take_leader(self):
+        self.k.take_leader()
+        self.k._leader_observed_record['leader'] = 'test'
+        self.k.patch_or_create = Mock(return_value=False)
+        self.k.take_leader()
+
+    def test_manual_failover(self):
+        with patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', Mock(side_effect=RetryFailedError(''))):
+            self.k.manual_failover('foo', 'bar')
+
+    def test_set_config_value(self):
+        self.k.set_config_value('{}')
+
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', Mock(return_value=True))
+    def test_touch_member(self):
+        self.k.touch_member({})
+        self.k._name = 'p-1'
+        self.k.touch_member({'state': 'running', 'role': 'replica'})
+        self.k.touch_member({'state': 'stopped', 'role': 'master'})
+
+    def test_initialize(self):
+        self.k.initialize()
+
+    def test_delete_leader(self):
+        self.k.delete_leader()
+
+    def test_cancel_initialization(self):
+        self.k.cancel_initialization()
+
+    @patch.object(k8s_client.CoreV1Api, 'delete_collection_namespaced_config_map',
+                  Mock(side_effect=k8s_client.rest.ApiException(403, '')))
+    def test_delete_cluster(self):
+        self.k.delete_cluster()
+
+    @patch('kubernetes.config.load_kube_config', Mock())
+    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints',
+                  Mock(side_effect=[k8s_client.rest.ApiException(502, ''), k8s_client.rest.ApiException(500, '')]))
+    def test_delete_sync_state(self):
+        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'retry_timeout': 10,
+                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
+        self.assertFalse(k.delete_sync_state())
+
+    def test_watch(self):
+        self.k.set_ttl(10)
+        self.k.watch(None, 0)
+        self.k.watch(None, 0)
+        with patch.object(k8s_watch.Watch, 'stream',
+                          Mock(side_effect=[Exception, [], KeyboardInterrupt,
+                                            [{'raw_object': {'metadata': {'resourceVersion': '2'}}}]])):
+            self.assertFalse(self.k.watch('1', 2))
+            self.assertRaises(KeyboardInterrupt, self.k.watch, '1', 2)
+            self.assertTrue(self.k.watch('1', 2))
+
+    def test_set_history_value(self):
+        self.k.set_history_value('{}')

tests/test_log.py

@@ -0,0 +1,38 @@
+import os
+import sys
+import unittest
+import yaml
+
+from mock import Mock, patch
+from patroni.config import Config
+from patroni.log import PatroniLogger
+
+
+class TestPatroniLogger(unittest.TestCase):
+
+    @patch('logging.FileHandler._open', Mock())
+    def setUp(self):
+        self.config = {
+            'log': {
+                'dir': 'foo',
+                'file_size': 4096,
+                'file_num': 5,
+                'loggers': {
+                    'foo.bar': 'INFO'
+                }
+            },
+            'restapi': {}, 'postgresql': {'data_dir': 'foo'}
+        }
+        sys.argv = ['patroni.py']
+        os.environ[Config.PATRONI_CONFIG_VARIABLE] = yaml.dump(self.config, default_flow_style=False)
+        self.logger = PatroniLogger()
+        config = Config()
+        self.logger.reload_config(config['log'])
+
+    def test_rotating_handler(self):
+        self.assertEqual(self.logger.handler.maxBytes, self.config['log']['file_size'])
+        self.assertEqual(self.logger.handler.backupCount, self.config['log']['file_num'])
+
+    def test_reload_config(self):
+        self.config['log'].pop('dir')
+        self.logger.reload_config(self.config['log'])

tests/test_patroni.py

@@ -1,17 +1,18 @@
 import etcd
+import signal
 import sys
 import time
 import unittest
 
-from mock import Mock, patch
+from mock import Mock, PropertyMock, patch
 from patroni.api import RestApiServer
 from patroni.async_executor import AsyncExecutor
 from patroni.dcs.etcd import Client
 from patroni.exceptions import DCSError
-from patroni import Patroni, main as _main
+from patroni import Patroni, main as _main, patroni_main
 from six.moves import BaseHTTPServer
 from test_etcd import SleepException, etcd_read, etcd_write
-from test_postgresql import Postgresql, psycopg2_connect
+from test_postgresql import Postgresql, psycopg2_connect, MockPostmaster
 
 
 class MockFrozenImporter(object):
@@ -25,7 +26,8 @@ class MockFrozenImporter(object):
 @patch.object(Postgresql, 'write_pg_hba', Mock())
 @patch.object(Postgresql, '_write_postgresql_conf', Mock())
 @patch.object(Postgresql, 'write_recovery_conf', Mock())
-@patch.object(Postgresql, 'is_running', Mock(return_value=True))
+@patch.object(Postgresql, 'is_running', Mock(return_value=MockPostmaster()))
+@patch.object(Postgresql, 'call_nowait', Mock())
 @patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
 @patch.object(AsyncExecutor, 'run', Mock())
 @patch.object(etcd.Client, 'write', etcd_write)
@@ -53,20 +55,59 @@ class TestPatroni(unittest.TestCase):
     @patch('time.sleep', Mock(side_effect=SleepException))
     @patch.object(etcd.Client, 'delete', Mock())
     @patch.object(Client, 'machines')
-    def test_patroni_main(self, mock_machines):
+    def test_patroni_patroni_main(self, mock_machines):
         with patch('subprocess.call', Mock(return_value=1)):
             sys.argv = ['patroni.py', 'postgres0.yml']
 
             mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
             with patch.object(Patroni, 'run', Mock(side_effect=SleepException)):
-                self.assertRaises(SleepException, _main)
+                self.assertRaises(SleepException, patroni_main)
             with patch.object(Patroni, 'run', Mock(side_effect=KeyboardInterrupt())):
                 with patch('patroni.ha.Ha.is_paused', Mock(return_value=True)):
-                    _main()
+                    patroni_main()
+
+    @patch('os.getpid')
+    @patch('subprocess.Popen', )
+    @patch('patroni.patroni_main', Mock())
+    def test_patroni_main(self, mock_popen, mock_getpid):
+        mock_getpid.return_value = 2
+        _main()
+
+        with patch('sys.frozen', Mock(return_value=True), create=True), patch('os.setsid', Mock()):
+            sys.argv = ['/patroni', 'pg_ctl_start', 'postgres', '-D', '/data', '--max_connections=100']
+            _main()
+
+        mock_getpid.return_value = 1
+
+        def mock_signal(signo, handler):
+            handler(signo, None)
+
+        with patch('signal.signal', mock_signal):
+            with patch('os.waitpid', Mock(side_effect=[(1, 0), (0, 0)])):
+                _main()
+            with patch('os.waitpid', Mock(side_effect=OSError)):
+                _main()
+
+        ref = {'passtochild': lambda signo, stack_frame: 0}
+
+        def mock_sighup(signo, handler):
+            if signo == signal.SIGHUP:
+                ref['passtochild'] = handler
+
+        def mock_wait():
+            ref['passtochild'](0, None)
+
+        mock_popen.return_value.wait = mock_wait
+        with patch('signal.signal', mock_sighup), patch('os.kill', Mock()):
+            self.assertIsNone(_main())
 
     @patch('patroni.config.Config.save_cache', Mock())
     @patch('patroni.config.Config.reload_local_configuration', Mock(return_value=True))
+    @patch('patroni.ha.Ha.is_leader', Mock(return_value=True))
+    @patch.object(Postgresql, 'state', PropertyMock(return_value='running'))
+    @patch.object(Postgresql, 'data_directory_empty', Mock(return_value=False))
     def test_run(self):
+        self.p.postgresql.set_role('replica')
         self.p.sighup_handler()
         self.p.ha.dcs.watch = Mock(side_effect=SleepException)
         self.p.api.start = Mock()
@@ -105,3 +146,13 @@ class TestPatroni(unittest.TestCase):
         self.p.reload_config()
         self.p.get_tags = Mock(side_effect=Exception)
         self.p.reload_config()
+
+    def test_nosync(self):
+        self.p.tags['nosync'] = True
+        self.assertTrue(self.p.nosync)
+        self.p.tags['nosync'] = None
+        self.assertFalse(self.p.nosync)
+
+    def test_shutdown(self):
+        self.p.api.shutdown = Mock(side_effect=Exception)
+        self.p.shutdown()

tests/test_postmaster.py

@@ -0,0 +1,102 @@
+import psutil
+import unittest
+
+from mock import Mock, patch, mock_open
+from patroni.postmaster import PostmasterProcess
+from six.moves import builtins
+
+
+class TestPostmasterProcess(unittest.TestCase):
+    @patch('psutil.Process.__init__', Mock())
+    def test_init(self):
+        proc = PostmasterProcess(-123)
+        self.assertTrue(proc.is_single_user)
+
+    @patch('psutil.Process.create_time')
+    @patch('psutil.Process.__init__')
+    @patch('patroni.postmaster.PostmasterProcess._read_postmaster_pidfile')
+    def test_from_pidfile(self, mock_read, mock_init, mock_create_time):
+        mock_init.side_effect = psutil.NoSuchProcess(123)
+        mock_read.return_value = {}
+        self.assertIsNone(PostmasterProcess.from_pidfile(''))
+        mock_read.return_value = {"pid": "foo"}
+        self.assertIsNone(PostmasterProcess.from_pidfile(''))
+        mock_read.return_value = {"pid": "123"}
+        self.assertIsNone(PostmasterProcess.from_pidfile(''))
+
+        mock_init.side_effect = None
+        with patch.object(psutil.Process, 'pid', 123), \
+                patch.object(psutil.Process, 'ppid', return_value=124), \
+                patch('os.getpid', return_value=125) as mock_ospid, \
+                patch('os.getppid', return_value=126):
+
+            self.assertIsNotNone(PostmasterProcess.from_pidfile(''))
+
+            mock_create_time.return_value = 100000
+            mock_read.return_value = {"pid": "123", "start_time": "200000"}
+            self.assertIsNone(PostmasterProcess.from_pidfile(''))
+
+            mock_read.return_value = {"pid": "123", "start_time": "foobar"}
+            self.assertIsNotNone(PostmasterProcess.from_pidfile(''))
+
+            mock_ospid.return_value = 123
+            mock_read.return_value = {"pid": "123", "start_time": "100000"}
+            self.assertIsNone(PostmasterProcess.from_pidfile(''))
+
+    @patch('psutil.Process.__init__')
+    def test_from_pid(self, mock_init):
+        mock_init.side_effect = psutil.NoSuchProcess(123)
+        self.assertEqual(PostmasterProcess.from_pid(123), None)
+        mock_init.side_effect = None
+        self.assertNotEquals(PostmasterProcess.from_pid(123), None)
+
+    @patch('psutil.Process.__init__', Mock())
+    @patch('psutil.Process.send_signal')
+    @patch('psutil.Process.pid', Mock(return_value=123))
+    def test_signal_stop(self, mock_send_signal):
+        proc = PostmasterProcess(-123)
+        self.assertEqual(proc.signal_stop('immediate'), False)
+
+        mock_send_signal.side_effect = [None, psutil.NoSuchProcess(123), psutil.AccessDenied()]
+        proc = PostmasterProcess(123)
+        self.assertEqual(proc.signal_stop('immediate'), None)
+        self.assertEqual(proc.signal_stop('immediate'), True)
+        self.assertEqual(proc.signal_stop('immediate'), False)
+
+    @patch('psutil.Process.__init__', Mock())
+    @patch('psutil.wait_procs')
+    def test_wait_for_user_backends_to_close(self, mock_wait):
+        c1 = Mock()
+        c1.cmdline = Mock(return_value=["postgres: startup process   "])
+        c2 = Mock()
+        c2.cmdline = Mock(return_value=["postgres: postgres postgres [local] idle"])
+        c3 = Mock()
+        c3.cmdline = Mock(side_effect=psutil.NoSuchProcess(123))
+        with patch('psutil.Process.children', Mock(return_value=[c1, c2, c3])):
+            proc = PostmasterProcess(123)
+            self.assertIsNone(proc.wait_for_user_backends_to_close())
+            mock_wait.assert_called_with([c2])
+
+        with patch('psutil.Process.children', Mock(side_effect=psutil.NoSuchProcess(123))):
+            proc = PostmasterProcess(123)
+            self.assertIsNone(proc.wait_for_user_backends_to_close())
+
+    @patch('subprocess.Popen')
+    @patch.object(PostmasterProcess, 'from_pid')
+    @patch.object(PostmasterProcess, '_from_pidfile')
+    def test_start(self, mock_frompidfile, mock_frompid, mock_popen):
+        mock_frompidfile.return_value._is_postmaster_process.return_value = False
+        mock_frompid.return_value = "proc 123"
+        mock_popen.return_value.stdout.readline.return_value = '123'
+        self.assertEqual(PostmasterProcess.start('true', '/tmp', '/tmp/test.conf', []), "proc 123")
+        mock_frompid.assert_called_with(123)
+
+        mock_frompidfile.side_effect = psutil.NoSuchProcess(123)
+        self.assertEqual(PostmasterProcess.start('true', '/tmp', '/tmp/test.conf', []), "proc 123")
+
+    @patch('psutil.Process.__init__', Mock(side_effect=psutil.NoSuchProcess(123)))
+    def test_read_postmaster_pidfile(self):
+        with patch.object(builtins, 'open', Mock(side_effect=IOError)):
+            self.assertIsNone(PostmasterProcess.from_pidfile(''))
+        with patch.object(builtins, 'open', mock_open(read_data='123\n')):
+            self.assertIsNone(PostmasterProcess.from_pidfile(''))