Release 2.0.1 (#1722)

* Bump version
* Update release notes

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,48 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Environment**
+- Patroni version:
+- PostgreSQL version:
+- DCS (and its version):
+
+**Patroni configuration file**
+```
+Please copy&paste your Patroni configuration file here
+```
+
+**patronictl show-config**
+```
+Please copy&paste the output of "patronictl show-config" command here
+```
+
+**Have you checked Patroni logs?**
+Please provide a snippet of Patroni log files here
+
+**Have you checked PostgreSQL logs?**
+Please provide a snippet here
+
+**Have you tried to use GitHub issue search?**
+Maybe there is already a similar issue solved.
+
+
+**Additional context**
+Add any other context about the problem here.

.travis.yml

@@ -7,20 +7,23 @@ addons:
       - expect-dev # for unbuffer
 env:
   global:
-  - ETCDVERSION=3.0.17 ZKVERSION=3.4.14 CONSULVERSION=0.7.4
-  - PYVERSIONS="2.7 3.5 3.6"
-  - EXCLUDE_BEHAVE="3.5"
+  - ETCDVERSION=3.3.13 ZKVERSION=3.4.14 CONSULVERSION=0.7.4
+  - PYVERSIONS="2.7 3.6"
   - BOTO_CONFIG=/doesnotexist
 matrix:
   include:
   - python: "3.5"
-    env: TEST_SUITE="python setup.py"
+    env: PYVERSIONS="2.7 3.5 3.6" TEST_SUITE="python setup.py"
   - python: "3.6"
     env: DCS="etcd" TEST_SUITE="behave"
+  - python: "3.6"
+    env: DCS="etcd3" 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="raft" TEST_SUITE="behave"
   - python: "3.6"
     env: DCS="kubernetes" TEST_SUITE="behave"
 branches:
@@ -34,10 +37,8 @@ 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
+      fpv=$(basename $(readlink $HOME/virtualenv/python${pv}))
+      mv $HOME/virtualenv/${fpv} $HOME/mycache/${fpv}
   done
 install:
   - |
@@ -58,6 +59,7 @@ install:
         function get_etcd() {
             EC=~/mycache/etcd_${ETCDVERSION}
             if [[ ! -x $EC ]]; then
+                rm -rf ~/mycache/etcd_*
                 curl -L https://github.com/coreos/etcd/releases/download/v${ETCDVERSION}/etcd-v${ETCDVERSION}-linux-amd64.tar.gz \
                     | tar xz -C . --strip=1 --wildcards --no-anchored etcd
                 [[ ${PIPESTATUS[0]} == 0 ]] || return 1
@@ -66,6 +68,10 @@ install:
             ln -s $EC etcd
         }
 
+        function get_etcd3() {
+            get_etcd
+        }
+
         function get_kubernetes() {
             wget -O localkube "https://storage.googleapis.com/minikube/k8sReleases/v1.7.0/localkube-linux-amd64"
             chmod +x localkube
@@ -102,6 +108,10 @@ install:
             done&
         }
 
+        function get_raft() {
+            return 0
+        }
+
         attempt_num=1
         until get_${DCS}; do
             [[ $attempt_num -ge 3 ]] && exit 1
@@ -111,41 +121,38 @@ install:
     fi
 
     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' 'psycopg2-binary behave codacy-coverage coverage coveralls flake8 mock pytest-cov pytest setuptools'; do
-                pip install $p --upgrade
-            done
+        fpv=$(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' 'psycopg2-binary behave codacy-coverage coverage coveralls flake8 mock pytest-cov pytest setuptools'; do
+            pip install $p --upgrade
+        done
     done
 script:
   - |
     for pv in $PYVERSIONS; do
-        if [[ $TEST_SUITE == "behave" && $pv == $EXCLUDE_BEHAVE ]]; then
-            continue
-        fi
-
         source ~/virtualenv/python${pv}/bin/activate
 
-        if [[ $TEST_SUITE != "behave" ]]; then
-            echo Running unit tests using python${pv}
-            unbuffer $TEST_SUITE test
-            $TEST_SUITE flake8
-        elif [[ $pv != $EXCLUDE_BEHAVE ]]; then
-            echo Running acceptance tests using python${pv}
+        if [[ $TEST_SUITE = "behave" ]]; then
+            echo Running integration tests using python${pv}
             if ! PATH=.:/usr/lib/postgresql/9.6/bin:$PATH unbuffer $TEST_SUITE; then
                 # output all log files when tests are failing
                 grep . features/output/*_failed/*postgres?.*
                 exit 1
             fi
+        else
+            echo Running unit tests using python${pv}
+            unbuffer $TEST_SUITE test
+            $TEST_SUITE flake8
         fi
+        mv .coverage /tmp/.coverage.$pv
     done
+    mv /tmp/.coverage.* .
+    python -m coverage combine
 
     set +e
 after_success:

Dockerfile

@@ -14,7 +14,7 @@ ARG PGDATA
 ARG LC_ALL
 ARG LANG
 
-ENV ETCDVERSION=2.3.8 CONFDVERSION=0.16.0
+ENV ETCDVERSION=3.3.13 CONFDVERSION=0.16.0
 
 RUN set -ex \
     && export DEBIAN_FRONTEND=noninteractive \

README.rst

@@ -96,7 +96,7 @@ Patroni can be installed with pip:
 
 where dependencies can be either empty, or consist of one or more of the following:
 
-etcd
+etcd or etcd3
     `python-etcd` module in order to use Etcd as DCS
 consul
     `python-consul` module in order to use Consul as DCS
@@ -106,6 +106,8 @@ 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
+raft
+    `pysyncobj` module in order to use python Raft implementation as DCS
 aws
     `boto` in order to use AWS callbacks
 

docker-compose.yml

@@ -6,57 +6,31 @@ networks:
     demo:
 
 services:
-    etcd1:
+    etcd1: &etcd
         image: patroni
         networks: [ demo ]
-        env_file: docker/etcd.env
+        environment:
+            ETCD_LISTEN_PEER_URLS: http://0.0.0.0:2380
+            ETCD_LISTEN_CLIENT_URLS: http://0.0.0.0:2379
+            ETCD_INITIAL_CLUSTER: etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
+            ETCD_INITIAL_CLUSTER_STATE: new
+            ETCD_INITIAL_CLUSTER_TOKEN: tutorial
         container_name: demo-etcd1
         hostname: etcd1
         command: etcd -name etcd1 -initial-advertise-peer-urls http://etcd1:2380
 
     etcd2:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/etcd.env
+        <<: *etcd
         container_name: demo-etcd2
         hostname: etcd2
         command: etcd -name etcd2 -initial-advertise-peer-urls http://etcd2:2380
 
     etcd3:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/etcd.env
+        <<: *etcd
         container_name: demo-etcd3
         hostname: etcd3
         command: etcd -name etcd3 -initial-advertise-peer-urls http://etcd3:2380
 
-    patroni1:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni1
-        container_name: demo-patroni1
-        environment:
-            PATRONI_NAME: patroni1
-
-    patroni2:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni2
-        container_name: demo-patroni2
-        environment:
-            PATRONI_NAME: patroni2
-
-    patroni3:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni3
-        container_name: demo-patroni3
-        environment:
-            PATRONI_NAME: patroni3
-
     haproxy:
         image: patroni
         networks: [ demo ]
@@ -67,3 +41,37 @@ services:
             - "5000:5000"
             - "5001:5001"
         command: haproxy
+        environment: &haproxy_env
+            ETCDCTL_ENDPOINTS: http://etcd1:2379,http://etcd2:2379,http://etcd3:2379
+            PATRONI_ETCD3_HOSTS: "'etcd1:2379','etcd2:2379','etcd3:2379'"
+            PATRONI_SCOPE: demo
+
+    patroni1:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni1
+        container_name: demo-patroni1
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni1
+
+    patroni2:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni2
+        container_name: demo-patroni2
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni2
+
+    patroni3:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni3
+        container_name: demo-patroni3
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni3

docker/entrypoint.sh

@@ -25,7 +25,7 @@ case "$1" in
             while ! etcdctl cluster-health 2> /dev/null; do
                 sleep 1
             done
-            exec dumb-init $CONFD etcd -node $(echo $ETCDCTL_ENDPOINTS | sed 's/,/ -node /g')
+            exec dumb-init $CONFD etcdv3 -node $(echo $ETCDCTL_ENDPOINTS | sed 's/,/ -node /g')
         fi
         ;;
     etcd)
@@ -37,7 +37,7 @@ case "$1" in
 esac
 
 ## We start an etcd
-if [ -z "$PATRONI_ETCD_HOSTS" ] && [ -z "$PATRONI_ZOOKEEPER_HOSTS" ]; then
+if [ -z "$PATRONI_ETCD3_HOSTS" ] && [ -z "$PATRONI_ZOOKEEPER_HOSTS" ]; then
     export PATRONI_ETCD_URL="http://127.0.0.1:2379"
     etcd --data-dir /tmp/etcd.data -advertise-client-urls=$PATRONI_ETCD_URL -listen-client-urls=http://0.0.0.0:2379 > /var/log/etcd.log 2> /var/log/etcd.err &
 fi

docker/etcd.env

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

docker/patroni.env

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

docs/ENVIRONMENT.rst

@@ -66,9 +66,27 @@ Etcd
 -  **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.
 
+Etcdv3
+------
+Environment names for Etcdv3 are similar as for Etcd, you just need to use ``ETCD3`` instead of ``ETCD`` in the variable name. Example: ``PATRONI_ETCD3_HOST``, ``PATRONI_ETCD3_CACERT``, and so on.
+
+.. warning::
+    Keys created with protocol version 2 are not visible with protocol version 3 and the other way around, therefore it is not possible to switch from Etcd to Etcdv3 just by updating Patroni configuration.
+
+
 ZooKeeper
 ---------
--  **PATRONI\_ZOOKEEPER\_HOSTS**: comma separated list of ZooKeeper cluster members: "'host1:port1','host2:port2','etc...'". It is important to quote every single entity!
+-  **PATRONI\_ZOOKEEPER\_HOSTS**: Comma separated list of ZooKeeper cluster members: "'host1:port1','host2:port2','etc...'". It is important to quote every single entity!
+-  **PATRONI\_ZOOKEEPER\_USE\_SSL**: (optional) Whether SSL is used or not. Defaults to ``false``. If set to ``false``, all SSL specific parameters are ignored.
+-  **PATRONI\_ZOOKEEPER\_CACERT**: (optional) The CA certificate. If present it will enable validation.
+-  **PATRONI\_ZOOKEEPER\_CERT**: (optional) File with the client certificate.
+-  **PATRONI\_ZOOKEEPER\_KEY**: (optional) File with the client key.
+-  **PATRONI\_ZOOKEEPER\_KEY\_PASSWORD**: (optional) The client key password.
+-  **PATRONI\_ZOOKEEPER\_VERIFY**: (optional) Whether to verify certificate or not. Defaults to ``true``.
+
+.. note::
+    It is required to install ``kazoo>=2.6.0`` to support SSL.
+
 
 Exhibitor
 ---------
@@ -79,6 +97,7 @@ Exhibitor
 
 Kubernetes
 ----------
+-  **PATRONI\_KUBERNETES\_BYPASS\_API\_SERVICE**: (optional) When communicating with the Kubernetes API, Patroni is usually relying on the `kubernetes` service, the address of which is exposed in the pods via the `KUBERNETES_SERVICE_HOST` environment variable. If `PATRONI_KUBERNETES_BYPASS_API_SERVICE` is set to ``true``, Patroni will resolve the list of API nodes behind the service and connect directly to them.
 -  **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`.
@@ -87,6 +106,15 @@ Kubernetes
 -  **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.
 
+Raft
+----
+
+-  **PATRONI\_RAFT\_SELF\_ADDR**: ``ip:port`` to listen on for Raft connections. The ``self_addr`` must be accessible from other nodes of the cluster. If not set, the node will not participate in consensus.
+-  **PATRONI\_RAFT\_BIND\_ADDR**: (optional) ``ip:port`` to listen on for Raft connections. If not specified the ``self_addr`` will be used.
+-  **PATRONI\_RAFT\_PARTNER\_ADDRS**: list of other Patroni nodes in the cluster in format ``"'ip1:port1','ip2:port2'"``. It is important to quote every single entity!
+-  **PATRONI\_RAFT\_DATA\_DIR**: directory where to store Raft log and snapshot. If not specified the current working directory is used.
+-  **PATRONI\_RAFT\_PASSWORD**: (optional) Encrypt Raft traffic with a specified password, requires ``cryptography`` python module.
+
 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.
@@ -99,23 +127,32 @@ PostgreSQL
 -  **PATRONI\_REPLICATION\_PASSWORD**: replication password; the user will be created during initialization.
 -  **PATRONI\_REPLICATION\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
 -  **PATRONI\_REPLICATION\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_REPLICATION\_SSLPASSWORD**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``PATRONI_REPLICATION_SSLKEY``.
 -  **PATRONI\_REPLICATION\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
 -  **PATRONI\_REPLICATION\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
 -  **PATRONI\_REPLICATION\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REPLICATION\_GSSENCMODE**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+-  **PATRONI\_REPLICATION\_CHANNEL\_BINDING**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
 -  **PATRONI\_SUPERUSER\_USERNAME**: name for the superuser, set during initialization (initdb) and later used by Patroni to connect to the postgres. Also this user is used by pg_rewind.
 -  **PATRONI\_SUPERUSER\_PASSWORD**: password for the superuser, set during initialization (initdb).
 -  **PATRONI\_SUPERUSER\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
 -  **PATRONI\_SUPERUSER\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_SUPERUSER\_SSLPASSWORD**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``PATRONI_SUPERUSER_SSLKEY``.
 -  **PATRONI\_SUPERUSER\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
 -  **PATRONI\_SUPERUSER\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
 -  **PATRONI\_SUPERUSER\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_SUPERUSER\_GSSENCMODE**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+-  **PATRONI\_SUPERUSER\_CHANNEL\_BINDING**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
 -  **PATRONI\_REWIND\_USERNAME**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
 -  **PATRONI\_REWIND\_PASSWORD**: password for the user for ``pg_rewind``; the user will be created during initialization.
 -  **PATRONI\_REWIND\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
 -  **PATRONI\_REWIND\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_REWIND\_SSLPASSWORD**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``PATRONI_REWIND_SSLKEY``.
 -  **PATRONI\_REWIND\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
 -  **PATRONI\_REWIND\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
 -  **PATRONI\_REWIND\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REWIND\_GSSENCMODE**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+-  **PATRONI\_REWIND\_CHANNEL\_BINDING**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
 
 REST API
 --------
@@ -126,11 +163,13 @@ REST API
 -  **PATRONI\_RESTAPI\_CERTFILE**: Specifies the file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
 -  **PATRONI\_RESTAPI\_KEYFILE**: Specifies the file with the secret key in the PEM format.
 -  **PATRONI\_RESTAPI\_CAFILE**: Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
--  **PATRONI\_RESTAPI\_VERIFY\_CLIENT**: ``none`` (default), ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. When ``required`` is used, then client authentication succeeds, if the certificate signature verification succeeds. For ``optional`` the client cert will only be checked for ``PUT``, ``POST``, ``PATCH``, and ``DELETE`` requests. 
+-  **PATRONI\_RESTAPI\_VERIFY\_CLIENT**: ``none`` (default), ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. When ``required`` is used, then client authentication succeeds, if the certificate signature verification succeeds. For ``optional`` the client cert will only be checked for ``PUT``, ``POST``, ``PATCH``, and ``DELETE`` requests.
+-  **PATRONI\_RESTAPI\_HTTP\_EXTRA\_HEADERS**: (optional) HTTP headers let the REST API server pass additional information with an HTTP response.
+-  **PATRONI\_RESTAPI\_HTTPS\_EXTRA\_HEADERS**: (optional) HTTPS headers let the REST API server pass additional information with an HTTP response when TLS is enabled. This will also pass additional information set in ``http_extra_headers``.
 
 CTL
 ---
--  **PATRONICTL\_CONFIG\_FILE**: location of the configuration file. 
+-  **PATRONICTL\_CONFIG\_FILE**: location of the configuration file.
 -  **PATRONI\_CTL\_INSECURE**: Allow connections to REST API without verifying SSL certs.
 -  **PATRONI\_CTL\_CACERT**: Specifies the file with the CA_BUNDLE file or directory with certificates of trusted CAs to use while verifying REST API SSL certs. If not provided patronictl will use the value provided for REST API "cafile" parameter.
 -  **PATRONI\_CTL\_CERTFILE**: Specifies the file with the client certificate in the PEM format. If not provided patronictl will use the value provided for REST API "certfile" parameter.

docs/README.rst

@@ -72,7 +72,7 @@ Patroni can be installed with pip:
 
 where dependencies can be either empty, or consist of one or more of the following:
 
-etcd
+etcd or etcd3
     `python-etcd` module in order to use Etcd as DCS
 consul
     `python-consul` module in order to use Consul as DCS
@@ -82,6 +82,8 @@ 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
+raft
+    `pysyncobj` module in order to use python Raft implementation as DCS
 aws
     `boto` in order to use AWS callbacks
 
@@ -97,6 +99,13 @@ independently of Patroni.
 
 .. _running_configuring:
 
+Planning the Number of PostgreSQL Nodes
+---------------------------------------
+
+Patroni/PostgreSQL nodes are decoupled from DCS nodes (except when Patroni implements RAFT on its own) and therefore
+there is no requirement on the minimal number of nodes. Running a cluster consisting of one master and one standby is 
+perfectly fine. You can add more standby nodes later.
+
 Running and Configuring
 -----------------------
 

docs/SETTINGS.rst

@@ -103,8 +103,23 @@ Most of the parameters are optional, but you have to specify one of the **host**
 -  **consistency**: (optional) Select consul consistency mode. Possible values are ``default``, ``consistent``, or ``stale`` (more details in `consul API reference <https://www.consul.io/api/features/consistency.html/>`__)
 -  **checks**: (optional) list of Consul health checks used for the session. By default an empty list is used.
 -  **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\_tags**: (optional) additional static tags to add to the Consul service apart from the role (``master``/``replica``/``standby-leader``).  By default an empty list is used.
 -  **service\_check\_interval**: (optional) how often to perform health check against registered url.
 
+The ``token`` needs to have the following ACL permissions:
+
+::
+
+    service_prefix "${scope}" {
+        policy = "write"
+    }
+    key_prefix "${namespace}/${scope}" {
+        policy = "write"
+    }
+    session_prefix "" {
+        policy = "write"
+    }
+
 Etcd
 ----
 Most of the parameters are optional, but you have to specify one of the **host**, **hosts**, **url**, **proxy** or **srv**
@@ -122,9 +137,27 @@ Most of the parameters are optional, but you have to specify one of the **host**
 -  **cert**: (optional) file with the client certificate.
 -  **key**: (optional) file with the client key. Can be empty if the key is part of **cert**.
 
+Etcdv3
+------
+If you want that Patroni works with Etcd cluster via protocol version 3, you need to use the ``etcd3`` section in the Patroni configuration file. All configuration parameters are the same as for ``etcd``.
+
+.. warning::
+    Keys created with protocol version 2 are not visible with protocol version 3 and the other way around, therefore it is not possible to switch from ``etcd`` to ``etcd3`` just by updating Patroni config file.
+
+
 ZooKeeper
 ----------
--  **hosts**: list of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+-  **hosts**: List of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+-  **use_ssl**: (optional) Whether SSL is used or not. Defaults to ``false``. If set to ``false``, all SSL specific parameters are ignored.
+-  **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.
+-  **key_password**: (optional) The client key password.
+-  **verify**: (optional) Whether to verify certificate or not. Defaults to ``true``.
+
+.. note::
+    It is required to install ``kazoo>=2.6.0`` to support SSL.
+
 
 Exhibitor
 ---------
@@ -136,6 +169,7 @@ Exhibitor
 
 Kubernetes
 ----------
+-  **bypass\_api\_service**: (optional) When communicating with the Kubernetes API, Patroni is usually relying on the `kubernetes` service, the address of which is exposed in the pods via the `KUBERNETES_SERVICE_HOST` environment variable. If `bypass_api_service` is set to ``true``, Patroni will resolve the list of API nodes behind the service and connect directly to them.
 -  **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`.
@@ -144,6 +178,40 @@ Kubernetes
 -  **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.
 
+
+.. _raft_settings:
+
+Raft
+----
+-  **self\_addr**: ``ip:port`` to listen on for Raft connections. The ``self_addr`` must be accessible from other nodes of the cluster. If not set, the node will not participate in consensus.
+-  **bind\_addr**: (optional) ``ip:port`` to listen on for Raft connections. If not specified the ``self_addr`` will be used.
+-  **partner\_addrs**: list of other Patroni nodes in the cluster in format: ['ip1:port', 'ip2:port', 'etc...']
+-  **data\_dir**: directory where to store Raft log and snapshot. If not specified the current working directory is used.
+-  **password**: (optional) Encrypt Raft traffic with a specified password, requires ``cryptography`` python module.
+
+  Short FAQ about Raft implementation
+
+  - Q: How to list all the nodes providing consensus?
+
+    A: ``syncobj_admin -conn host:port`` -status where the host:port is the address of one of the cluster nodes
+
+  - Q: Node that was a part of consensus and has gone and I can't reuse the same IP for other node. How to remove this node from the consensus?
+
+    A: ``syncobj_admin -conn host:port -remove host2:port2`` where the ``host2:port2`` is the address of the node you want to remove from consensus.
+
+  - Q: Where to get the ``syncobj_admin`` utility?
+
+    A: It is installed together with ``pysyncobj`` module (python RAFT implementation), which is Patroni dependancy.
+
+  - Q: it is possible to run Patroni node without adding in to the consensus?
+
+    A: Yes, just comment out or remove ``raft.self_addr`` from Patroni configuration.
+
+  - Q: It is possible to run Patroni and PostgreSQL only on two nodes?
+
+    A: Yes, on the third node you can run ``patroni_raft_controller`` (without Patroni and PostgreSQL). In such setup one can temporary loose one node without affecting the primary.
+
+
 .. _postgresql_settings:
 
 PostgreSQL
@@ -155,25 +223,34 @@ PostgreSQL
             -  **password**: password for the superuser, set during initialization (initdb).
             -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
             -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+            -  **sslpassword**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``sslkey``.
             -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
             -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
             -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **gssencmode**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+            -  **channel_binding**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
         -  **replication**:
             -  **username**: replication username; the user will be created during initialization. Replicas will use this user to access master via streaming replication
             -  **password**: replication password; the user will be created during initialization.
             -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
             -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+            -  **sslpassword**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``sslkey``.
             -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
             -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
             -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **gssencmode**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+            -  **channel_binding**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
         -  **rewind**:
             -  **username**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
             -  **password**: password for the user for ``pg_rewind``; the user will be created during initialization.
             -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
             -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+            -  **sslpassword**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``sslkey``.
             -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
             -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
             -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **gssencmode**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+            -  **channel_binding**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
     -  **callbacks**: callback scripts to run on certain actions. Patroni will pass the action, role and cluster name. (See scripts/aws.py as an example of how to write them.)
             -  **on\_reload**: run this script when configuration reload is triggered.
             -  **on\_restart**: run this script when the postgres restarts (without changing role).
@@ -204,12 +281,13 @@ PostgreSQL
     -  **remove\_data\_directory\_on\_rewind\_failure**: If this option is enabled, Patroni will remove the PostgreSQL data directory and recreate the replica. Otherwise it will try to follow the new leader. Default value is **false**.
     -  **remove\_data\_directory\_on\_diverged\_timelines**: Patroni will remove the PostgreSQL data directory and recreate the replica if it notices that timelines are diverging and the former master can not start streaming from the new master. This option is useful when ``pg_rewind`` can not be used. Default value is **false**.
     -  **replica\_method**: for each create_replica_methods other than basebackup, you would add a configuration section of the same name. At a minimum, this should include "command" with a full path to the actual script to be executed. Other configuration parameters will be passed along to the script in the form "parameter=value".
+    -  **pre\_promote**: a fencing script that executes during a failover after acquiring the leader lock but before promoting the replica. If the script exits with a non-zero code, Patroni does not promote the replica and removes the leader key from DCS.
 
 REST API
 --------
 -  **restapi**:
         -  **connect\_address**: IP address (or hostname) and port, to access the Patroni's :ref:`REST API <rest_api>`. All the members of the cluster must be able to connect to this address, so unless the Patroni setup is intended for a demo inside the localhost, this address must be a non "localhost" or loopback address (ie: "localhost" or "127.0.0.1"). It can serve as an endpoint for HTTP health checks (read below about the "listen" REST API parameter), and also for user queries (either directly or via the REST API), as well as for the health checks done by the cluster members during leader elections (for example, to determine whether the master is still running, or if there is a node which has a WAL position that is ahead of the one doing the query; etc.) The connect_address is put in the member key in DCS, making it possible to translate the member name into the address to connect to its REST API.
-        
+
         -  **listen**: IP address (or hostname) and port that Patroni will listen to for the REST API - to provide also the same health checks and cluster messaging between the participating nodes, as described above. to provide health-check information for HAProxy (or any other load balancer capable of doing a HTTP "OPTION" or "GET" checks).
 
         -  **authentication**: (optional)
@@ -219,6 +297,28 @@ REST API
         -  **keyfile**: (optional): Specifies the file with the secret key in the PEM format.
         -  **cafile**: (optional): Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
         -  **verify\_client**: (optional): ``none`` (default), ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. When ``required`` is used, then client authentication succeeds, if the certificate signature verification succeeds.  For ``optional`` the client cert will only be checked for ``PUT``, ``POST``, ``PATCH``, and ``DELETE`` requests.
+        -  **http\_extra\_headers**: (optional): HTTP headers let the REST API server pass additional information with an HTTP response.
+        -  **https\_extra\_headers**: (optional): HTTPS headers let the REST API server pass additional information with an HTTP response when TLS is enabled. This will also pass additional information set in ``http_extra_headers``.
+
+Here is an example of both **http_extra_headers** and **https_extra_headers**:
+
+.. code:: YAML
+
+        restapi:
+          listen: <listen>
+          connect_address: <connect_address>
+          authentication:
+            username: <username>
+            password: <password>
+          http_extra_headers:
+            'X-Frame-Options': 'SAMEORIGIN'
+            'X-XSS-Protection': '1; mode=block'
+            'X-Content-Type-Options': 'nosniff'
+          cafile: <ca file>
+          certfile: <cert>
+          keyfile: <key>
+          https_extra_headers:
+            'Strict-Transport-Security': 'max-age=31536000; includeSubDomains'
 
 .. _patronictl_settings:
 

docs/dynamic_configuration.rst

@@ -20,6 +20,8 @@ Patroni configuration is stored in the DCS (Distributed Configuration Store). Th
 	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 your external IP address when you are running inside ``docker``).
 
+The local configuration can be either a single YAML file or a directory. When it is a directory, all YAML files in that directory are loaded one by one in sorted order. In case a key is defined in multiple files, the occurrence in the last file takes precedence.
+
 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:
 
 - max_connections: 100
@@ -35,6 +37,7 @@ For the parameters below, PostgreSQL does not require equal values among the mas
 - max_wal_senders: 5
 - max_replication_slots: 5
 - wal_keep_segments: 8
+- wal_keep_size: 128MB
 
 These parameters are validated to ensure they are sane, or meet a minimum value.
 

docs/existing_data.rst

@@ -23,6 +23,21 @@ A Patroni cluster can be started with a data directory from a single-node Postgr
 3. Start Patroni (e.g. ``patroni /etc/patroni/patroni.yml``). It automatically detects that PostgreSQL daemon is already running but its configuration might be out-of-date.
 4. Ask Patroni to restart the node with ``patronictl restart cluster-name node-name``. This step is only required if PostgreSQL configuration is out-of-date.
 
+Major Upgrade of PostgreSQL Version
+===================================
+
+The only possible way to do a major upgrade currently is:
+
+1. Stop Patroni
+2. Upgrade PostgreSQL binaries and perform `pg_upgrade <https://www.postgresql.org/docs/current/pgupgrade.html>`_ on the master node
+3. Update patroni.yml
+4. Remove the initialize key from DCS or wipe complete cluster state from DCS. The second one could be achieved by running ``patronictl remove <cluster-name>``. It is necessary because pg_upgrade runs initdb which actually creates a new database with a new PostgreSQL system identifier.
+5. If you wiped the cluster state in the previous step, you may wish to copy patroni.dynamic.json from old data dir to the new one.  It will help you to retain some PostgreSQL parameters you had set before.
+6. Start Patroni on the master node.
+7. Upgrade PostgreSQL binaries, update patroni.yml and wipe the data_dir on standby nodes.
+8. Start Patroni on the standby nodes and wait for the replication to complete.
+
+Running pg_upgrade on standby nodes is not supported by PostgreSQL. If you know what you are doing, you can try the rsync procedure described in https://www.postgresql.org/docs/current/pgupgrade.html instead of wiping data_dir on standby nodes. The safest way is however to let Patroni replicate the data for you.
 
 FAQ
 ---

docs/index.rst

@@ -22,6 +22,7 @@ We call Patroni a "template" because it is far from being a one-size-fits-all or
    rest_api
    ENVIRONMENT
    SETTINGS
+   security
    replica_bootstrap
    replication_modes
    pause

docs/releases.rst

@@ -3,6 +3,276 @@
 Release notes
 =============
 
+Version 2.0.1
+-------------
+
+**New features**
+
+- Use ``more`` as pager in ``patronictl edit-config`` if ``less`` is not available (Pavel Golub)
+
+  On Windows it would be the ``more.com``. In addition to that, ``cdiff`` was changed to ``ydiff`` in ``requirements.txt``, but ``patronictl`` still supports both for compatibility.
+
+- Added support of ``raft`` ``bind_addr`` and ``password`` (Alexander Kukushkin)
+
+  ``raft.bind_addr`` might be useful when running behind NAT. ``raft.password`` enables traffic encryption (requires the ``cryptography`` module).
+
+- Added ``sslpassword`` connection parameter support (Kostiantyn Nemchenko)
+
+  The connection parameter was introduced in PostgreSQL 13.
+
+**Stability improvements**
+
+- Changed the behavior in pause (Alexander)
+
+  1. Patroni will not call the ``bootstrap`` method if the ``PGDATA`` directory is missing/empty.
+  2. Patroni will not exit on sysid mismatch in pause, only log a warning.
+  3. The node will not try to grab the leader key in pause mode if Postgres is running not in recovery (accepting writes) but the sysid doesn't match with the initialize key.
+
+- Apply ``master_start_timeout`` when executing crash recovery (Alexander)
+
+  If Postgres crashed on the leader node, Patroni does a crash-recovery by starting Postgres in single-user mode. During the crash-recovery the leader lock is being updated. If the crash-recovery didn't finish in ``master_start_timeout`` seconds, Patroni will stop it forcefully and release the leader lock.
+
+- Removed the ``secure`` extra from the ``urllib3`` requirements (Alexander)
+
+  The only reason for adding it there was the ``ipaddress`` dependency for python 2.7.
+
+**Bugfixes**
+
+- Fixed a bug in the ``Kubernetes.update_leader()`` (Alexander)
+
+  An unhandled exception was preventing demoting the primary when the update of the leader object failed.
+
+- Fixed hanging ``patronictl`` when RAFT is being used (Alexander)
+
+  When using ``patronictl`` with Patroni config, ``self_addr`` should be added to the ``partner_addrs``.
+
+- Fixed bug in ``get_guc_value()`` (Alexander)
+
+  Patroni was failing to get the value of ``restore_command`` on PostgreSQL 12, therefore fetching missing WALs for ``pg_rewind`` didn't work.
+
+
+Version 2.0.0
+-------------
+
+This version enhances compatibility with PostgreSQL 13, adds support of multiple synchronous standbys, has significant improvements in handling of ``pg_rewind``, adds support of Etcd v3 and Patroni on pure RAFT (without Etcd, Consul, or Zookeeper), and makes it possible to optionally call the ``pre_promote`` (fencing) script.
+
+**PostgreSQL 13 support**
+
+- Don't fire ``on_reload`` when promoting to ``standby_leader`` on PostgreSQL 13+ (Alexander Kukushkin)
+
+  When promoting to ``standby_leader`` we change ``primary_conninfo``, update the role and reload Postgres. Since ``on_role_change`` and ``on_reload`` effectively duplicate each other, Patroni will call only ``on_role_change``.
+
+- Added support for ``gssencmode`` and ``channel_binding`` connection parameters (Alexander)
+
+  PostgreSQL 12 introduced ``gssencmode`` and 13 ``channel_binding`` connection parameters and now they can be used if defined in the ``postgresql.authentication`` section.
+
+- Handle renaming of ``wal_keep_segments`` to ``wal_keep_size`` (Alexander)
+
+  In case of misconfiguration (``wal_keep_segments`` on 13 and ``wal_keep_size`` on older versions) Patroni will automatically adjust the configuration.
+
+- Use ``pg_rewind`` with ``--restore-target-wal`` on 13 if possible (Alexander)
+
+  On PostgreSQL 13 Patroni checks if ``restore_command`` is configured and tells ``pg_rewind`` to use it.
+
+
+**New features**
+
+- [BETA] Implemented support of Patroni on pure RAFT (Alexander)
+
+  This makes it possible to run Patroni without 3rd party dependencies, like Etcd, Consul, or Zookeeper. For HA you will have to run either three Patroni nodes or two nodes with Patroni and one node with ``patroni_raft_controller``. For more information please check the :ref:`documentation <raft_settings>`.
+
+- [BETA] Implemented support for Etcd v3 protocol via gPRC-gateway (Alexander)
+
+  Etcd 3.0 was released more than four years ago and Etcd 3.4 has v2 disabled by default. There are also chances that v2 will be completely removed from Etcd, therefore we implemented support of Etcd v3 in Patroni. In order to start using it you have to explicitly create the ``etcd3`` section is the Patroni configuration file.
+
+- Supporting multiple synchronous standbys (Krishna Sarabu)
+
+  It allows running a cluster with more than one synchronous replicas. The maximum number of synchronous replicas is controlled by the new parameter ``synchronous_node_count``. It is set to 1 by default and has no effect when the ``synchronous_mode`` is set to ``off``.
+
+- Added possibility to call the ``pre_promote`` script (Sergey Dudoladov)
+
+  Unlike callbacks, the ``pre_promote`` script is called synchronously after acquiring the leader lock, but before promoting Postgres. If the script fails or exits with a non-zero exitcode, the current node will release the leader lock.
+
+- Added support for configuration directories (Floris van Nee)
+
+  YAML files in the directory loaded and applied in alphabetical order.
+
+- Advanced validation of PostgreSQL parameters (Alexander)
+
+  In case the specific parameter is not supported by the current PostgreSQL version or when its value is incorrect, Patroni will remove the parameter completely or try to fix the value.
+
+- Wake up the main thread when the forced checkpoint after promote completed (Alexander)
+
+  Replicas are waiting for checkpoint indication via member key of the leader in DCS. The key is normally updated only once per HA loop. Without waking the main thread up, replicas will have to wait up to ``loop_wait`` seconds longer than necessary.
+
+- Use of ``pg_stat_wal_recevier`` view on 9.6+ (Alexander)
+
+  The view contains up-to-date values of ``primary_conninfo`` and ``primary_slot_name``, while the contents of ``recovery.conf`` could be stale.
+
+- Improved handing of IPv6 addresses in the Patroni config file (Mateusz Kowalski)
+
+  The IPv6 address is supposed to be enclosed into square brackets, but Patroni was expecting to get it plain. Now both formats are supported.
+
+- Added Consul ``service_tags`` configuration parameter (Robert Edström)
+
+  They are useful for dynamic service discovery, for example by load balancers.
+
+- Implemented SSL support for Zookeeper (Kostiantyn Nemchenko)
+
+  It requires ``kazoo>=2.6.0``.
+
+- Implemented ``no_params`` option for custom bootstrap method (Kostiantyn)
+
+  It allows calling ``wal-g``, ``pgBackRest`` and other backup tools without wrapping them into shell scripts.
+
+- Move WAL and tablespaces after a failed init (Feike Steenbergen)
+
+  When doing ``reinit``, Patroni was already removing not only ``PGDATA`` but also the symlinked WAL directory and tablespaces. Now the ``move_data_directory()`` method will do a similar job, i.e. rename WAL directory and tablespaces and update symlinks in PGDATA.
+
+
+**Improved in pg_rewind support**
+
+- Improved timeline divergence check (Alexander)
+
+  We don't need to rewind when the replayed location on the replica is not ahead of the switchpoint or the end of the checkpoint record on the former primary is the same as the switchpoint. In order to get the end of the checkpoint record we use ``pg_waldump`` and parse its output.
+
+- Try to fetch missing WAL if ``pg_rewind`` complains about it (Alexander)
+
+  It could happen that the WAL segment required for ``pg_rewind`` doesn't exist in the ``pg_wal`` directory anymore and therefore ``pg_rewind`` can't find the checkpoint location before the divergence point. Starting from PostgreSQL 13 ``pg_rewind`` could use ``restore_command`` for fetching missing WALs. For older PostgreSQL versions Patroni parses the errors of a failed rewind attempt and tries to fetch the missing WAL by calling the ``restore_command`` on its own.
+
+- Detect a new timeline in the standby cluster and trigger rewind/reinitialize if necessary (Alexander)
+
+  The ``standby_cluster`` is decoupled from the primary cluster and therefore doesn't immediately know about leader elections and timeline switches. In order to detect the fact, the ``standby_leader`` periodically checks for new history files in ``pg_wal``.
+
+- Shorten and beautify history log output (Alexander)
+
+  When Patroni is trying to figure out the necessity of ``pg_rewind``, it could write the content of the history file from the primary into the log. The history file is growing with every failover/switchover and eventually starts taking up too many lines, most of which are not so useful. Instead of showing the raw data, Patroni will show only 3 lines before the current replica timeline and 2 lines after.
+
+
+**Improvements on K8s**
+
+- Get rid of ``kubernetes`` python module (Alexander)
+
+  The official python kubernetes client contains a lot of auto-generated code and therefore very heavy. Patroni uses only a small fraction of K8s API endpoints and implementing support for them wasn't hard.
+
+- Make it possible to bypass the ``kubernetes`` service (Alexander)
+
+  When running on K8s, Patroni is usually communicating with the K8s API via the ``kubernetes`` service, the address of which is exposed in the ``KUBERNETES_SERVICE_HOST`` environment variable. Like any other service, the ``kubernetes`` service is handled by ``kube-proxy``, which in turn, depending on the configuration, is either relying on a userspace program or ``iptables`` for traffic routing. Skipping the intermediate component and connecting directly to the K8s master nodes allows us to implement a better retry strategy and mitigate risks of demoting Postgres when K8s master nodes are upgraded.
+
+- Sync HA loops of all pods of a Patroni cluster (Alexander)
+
+  Not doing so was increasing failure detection time from ``ttl`` to ``ttl + loop_wait``.
+
+- Populate ``references`` and ``nodename`` in the subsets addresses on K8s (Alexander)
+
+  Some load-balancers are relying on this information.
+
+- Fix possible race conditions in the ``update_leader()`` (Alexander)
+
+  The concurrent update of the leader configmap or endpoint happening outside of Patroni might cause the ``update_leader()`` call to fail. In this case Patroni rechecks that the current node is still owning the leader lock and repeats the update.
+
+- Explicitly disallow patching non-existent config (Alexander)
+
+  For DCS other than ``kubernetes`` the PATCH call is failing with an exception due to ``cluster.config`` being ``None``, but on Kubernetes it was happily creating the config annotation and preventing writing bootstrap configuration after the bootstrap finished.
+
+- Fix bug in ``pause`` (Alexander)
+
+  Replicas were removing ``primary_conninfo`` and restarting Postgres when the leader key was absent, but they should do nothing.
+
+
+**Improvements in REST API**
+
+- Defer TLS handshake until worker thread has started (Alexander, Ben Harris)
+
+  If the TLS handshake was done in the API thread and the client-side didn't send any data, the API thread was blocked (risking DoS).
+
+- Check ``basic-auth`` independently from client certificate in REST API (Alexander)
+
+  Previously only the client certificate was validated. Doing two checks independently is an absolutely valid use-case.
+
+- Write double ``CRLF`` after HTTP headers of the ``OPTIONS`` request (Sergey Burladyan)
+
+  HAProxy was happy with a single ``CRLF``, while Consul health-check complained about broken connection and unexpected EOF.
+
+- ``GET /cluster`` was showing stale members info for Zookeeper (Alexander)
+
+  The endpoint was using the Patroni internal cluster view. For Patroni itself it didn't cause any issues, but when exposed to the outside world we need to show up-to-date information, especially replication lag.
+
+- Fixed health-checks for standby cluster (Alexander)
+
+  The ``GET /standby-leader`` for a master and ``GET /master`` for a ``standby_leader`` were incorrectly responding with 200.
+
+- Implemented ``DELETE /switchover`` (Alexander)
+
+  The REST API call deletes the scheduled switchover.
+
+- Created ``/readiness`` and ``/liveness`` endpoints (Alexander)
+
+  They could be useful to eliminate "unhealthy" pods from subsets addresses when the K8s service is used with label selectors.
+
+- Enhanced ``GET /replica`` and ``GET /async`` REST API health-checks (Krishna, Alexander)
+
+  Checks now support optional keyword ``?lag=<max-lag>`` and will respond with 200 only if the lag is smaller than the supplied value. If relying on this feature please keep in mind that information about WAL position on the leader is updated only every ``loop_wait`` seconds!
+
+- Added support for user defined HTTP headers in the REST API response (Yogesh Sharma)
+
+  This feature might be useful if requests are made from a browser.
+
+
+**Improvements in patronictl**
+
+- Don't try to call non-existing leader in ``patronictl pause`` (Alexander)
+
+  While pausing a cluster without a leader on K8s, ``patronictl`` was showing warnings that member "None" could not be accessed.
+
+- Handle the case when member ``conn_url`` is missing (Alexander)
+
+  On K8s it is possible that the pod doesn't have the necessary annotations because Patroni is not yet running. It was making ``patronictl`` to fail.
+
+- Added ability to print ASCII cluster topology (Maxim Fedotov, Alexander)
+
+  It is very useful to get overview of the cluster with cascading replication.
+
+- Implement ``patronictl flush switchover`` (Alexander)
+
+  Before that ``patronictl flush`` only supported cancelling scheduled restarts.
+
+
+**Bugfixes**
+
+- Attribute error during bootstrap of the cluster with existing PGDATA (Krishna)
+
+  When trying to create/update the ``/history`` key, Patroni was accessing the ``ClusterConfig`` object which wasn't created in DCS yet.
+
+- Improved exception handling in Consul (Alexander)
+
+  Unhandled exception in the ``touch_member()`` method caused the whole Patroni process to crash.
+
+- Enforce ``synchronous_commit=local`` for the ``post_init`` script (Alexander)
+
+  Patroni was already doing that when creating users (``replication``, ``rewind``), but missing it in the case of ``post_init`` was an oversight. As a result, if the script wasn't doing it internally on it's own the bootstrap in ``synchronous_mode`` wasn't able to finish.
+
+- Increased ``maxsize`` in the Consul pool manager (ponvenkates)
+
+  With the default ``size=1`` some warnings were generated.
+
+- Patroni was wrongly reporting Postgres as running (Alexander)
+
+  The state wasn't updated when for example Postgres crashed due to an out-of-disk error.
+
+- Put ``*`` into ``pgpass`` instead of missing or empty values (Alexander)
+
+  If for example the ``standby_cluster.port`` is not specified, the ``pgpass`` file was incorrectly generated.
+
+- Skip physical replication slot creation on the leader node with special characters (Krishna)
+
+  Patroni appeared to be creating a dormant slot (when ``slots`` defined) for the leader node when the name contained special chars such as '-'  (for e.g. "abc-us-1").
+
+- Avoid removing non-existent ``pg_hba.conf`` in the custom bootstrap (Krishna)
+
+  Patroni was failing if ``pg_hba.conf`` happened to be located outside of the ``pgdata`` dir after custom bootstrap.
+
+
 Version 1.6.5
 -------------
 

docs/replica_bootstrap.rst

@@ -24,6 +24,7 @@ arguments to them, i.e. the name of the cluster and the path to the data directo
         <custom_bootstrap_method_name>:
             command: <path_to_custom_bootstrap_script> [param1 [, ...]]
             keep_existing_recovery_conf: False
+            no_params: False
             recovery_conf:
                 recovery_target_action: promote
                 recovery_target_timeline: latest
@@ -40,6 +41,8 @@ in the configuration files, Patroni supplies two cluster-specific ones:
 --datadir
     Path to the data directory of the cluster instance to be bootstrapped
 
+Passing these two additional flags can be disabled by setting a special ``no_params`` parameter to ``True``.
+
 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.

docs/replication_modes.rst

@@ -59,11 +59,14 @@ Synchronous mode can be switched on and off via Patroni REST interface. See :ref
 
 Note: Because of the way synchronous replication is implemented in PostgreSQL it is still possible to lose transactions even when using ``synchronous_mode_strict``. If the PostgreSQL backend is cancelled while waiting to acknowledge replication (as a result of packet cancellation due to client timeout or backend failure) transaction changes become visible for other backends. Such changes are not yet replicated and may be lost in case of standby promotion.
 
+Synchronous Replication Factor
+------------------------------
+The parameter ``synchronous_node_count`` is used by Patroni to manage number of synchronous standby databases. It is set to 1 by default. It has no effect when ``synchronous_mode`` is set to off. When enabled, Patroni manages precise number of synchronous standby databases based on parameter ``synchronous_node_count`` and adjusts the state in DCS & synchronous_standby_names as members join and leave.
 
 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:
+When in synchronous mode Patroni maintains synchronization state in the DCS, containing the latest primary and current synchronous standby databases. 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.
 
@@ -71,9 +74,9 @@ When in synchronous mode Patroni maintains synchronization state in the DCS, con
 
 - 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.
+Patroni will only assign one or more synchronous standby nodes based on ``synchronous_node_count`` parameter to ``synchronous_standby_names``.
 
-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.
+On each HA loop iteration Patroni re-evaluates synchronous standby nodes choice. If the current list of synchronous standby nodes are 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.

docs/rest_api.rst

@@ -19,6 +19,13 @@ For all health check ``GET`` requests Patroni returns a JSON document with the s
 
 - ``GET /replica``: replica health check endpoint. It returns HTTP status code **200** only when the Patroni node is in the state ``running``, the role is ``replica`` and ``noloadbalance`` tag is not set.
 
+- ``GET /replica?lag=<max-lag>``: replica check endpoint. In addition to checks from ``replica``, it also checks replication latency and returns status code **200** only when it is below specified value. The key cluster.last_leader_operation from DCS is used for Leader wal position and compute latency on replica for performance reasons. max-lag can be specified in bytes (integer) or in human readable values, for e.g. 16kB, 64MB, 1GB.
+
+  - ``GET /replica?lag=1048576``
+  - ``GET /replica?lag=1024kB``
+  - ``GET /replica?lag=10MB``
+  - ``GET /replica?lag=1GB``
+
 - ``GET /read-only``: like the above endpoint, but also includes the primary.
 
 - ``GET /standby-leader``: returns HTTP status code **200** only when the Patroni node is running as the leader in a :ref:`standby cluster <standby_cluster>`.
@@ -27,8 +34,45 @@ For all health check ``GET`` requests Patroni returns a JSON document with the s
 
 - ``GET /asynchronous`` or ``GET /async``: returns HTTP status code **200** only when the Patroni node is running as an asynchronous standby.
 
+- ``GET /asynchronous?lag=<max-lag>`` or ``GET /async?lag=<max-lag>``: asynchronous standby check endpoint. In addition to checks from ``asynchronous`` or ``async``, it also checks replication latency and returns status code **200** only when it is below specified value. The key cluster.last_leader_operation from DCS is used for Leader wal position and compute latency on replica for performance reasons. max-lag can be specified in bytes (integer) or in human readable values, for e.g. 16kB, 64MB, 1GB.
+
+  - ``GET /async?lag=1048576``
+  - ``GET /async?lag=1024kB``
+  - ``GET /async?lag=10MB``
+  - ``GET /async?lag=1GB``
+
 - ``GET /health``: returns HTTP status code **200** only when PostgreSQL is up and running.
 
+- ``GET /liveness``: always returns HTTP status code **200** what only indicates that Patroni is running. Could be used for ``livenessProbe``.
+
+- ``GET /readiness``: returns HTTP status code **200** when the Patroni node is running as the leader or when PostgreSQL is up and running. The endpoint could be used for ``readinessProbe`` when it is not possible to use Kubenetes endpoints for leader elections (OpenShift).
+
+Both, ``readiness`` and ``liveness`` endpoints are very light-weight and not executing any SQL. Probes should be configured in such a way that they start failing about time when the leader key is expiring. With the default value of ``ttl``, which is ``30s`` example probes would look like:
+
+.. code-block:: yaml
+
+    readinessProbe:
+      httpGet:
+        scheme: HTTP
+        path: /readiness
+        port: 8008
+      initialDelaySeconds: 3
+      periodSeconds: 10
+      timeoutSeconds: 5
+      successThreshold: 1
+      failureThreshold: 3
+    livenessProbe:
+      httpGet:
+        scheme: HTTP
+        path: /liveness
+        port: 8008
+      initialDelaySeconds: 3
+      periodSeconds: 10
+      timeoutSeconds: 5
+      successThreshold: 1
+      failureThreshold: 3
+
+
 Monitoring endpoint
 -------------------
 
@@ -149,7 +193,6 @@ Config endpoint
 	    "parameters": {
 	      "hot_standby": "on",
 	      "wal_log_hints": "on",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "max_wal_senders": 5,
 	      "max_replication_slots": 5,
@@ -177,7 +220,6 @@ Config endpoint
 	    "parameters": {
 	      "hot_standby": "on",
 	      "wal_log_hints": "on",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "max_wal_senders": 5,
 	      "max_replication_slots": 5,
@@ -229,7 +271,6 @@ If you want to remove (reset) some setting just patch it with ``null``:
 	    "parameters": {
 	      "hot_standby": "on",
 	      "unix_socket_directories": ".",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "wal_log_hints": "on",
 	      "max_wal_senders": 5,
@@ -245,7 +286,7 @@ The above call removes ``postgresql.parameters.max_connections`` from the dynami
 .. code-block:: bash
 
 	$ curl -s -XPUT -d \
-		'{"maximum_lag_on_failover":1048576,"retry_timeout":10,"postgresql":{"use_slots":true,"use_pg_rewind":true,"parameters":{"hot_standby":"on","wal_log_hints":"on","wal_keep_segments":8,"wal_level":"hot_standby","unix_socket_directories":".","max_wal_senders":5}},"loop_wait":3,"ttl":20}' \
+		'{"maximum_lag_on_failover":1048576,"retry_timeout":10,"postgresql":{"use_slots":true,"use_pg_rewind":true,"parameters":{"hot_standby":"on","wal_log_hints":"on","wal_level":"hot_standby","unix_socket_directories":".","max_wal_senders":5}},"loop_wait":3,"ttl":20}' \
 		http://localhost:8008/config | jq .
 	{
 	  "ttl": 20,
@@ -256,7 +297,6 @@ The above call removes ``postgresql.parameters.max_connections`` from the dynami
 	    "parameters": {
 	      "hot_standby": "on",
 	      "unix_socket_directories": ".",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "wal_log_hints": "on",
 	      "max_wal_senders": 5

docs/security.rst

@@ -0,0 +1,37 @@
+.. _security:
+
+=======================
+Security Considerations
+=======================
+
+A Patroni cluster has two interfaces to be protected from unauthorized access: the distributed configuration storage (DCS) and the Patroni REST API.
+
+Protecting DCS
+==============
+
+Patroni and patronictl both store and retrieve data to/from the DCS. 
+
+Despite DCS doesn't contain any sensitive information, it allows changing some of Patroni/Postgres configuration. Therefore the very first thing that should be protected is DCS itself.
+
+The details of protection depend on the type of DCS used. The authentication and encryption parameters (tokens/basic-auth/client certificates) for the supported types of DCS are covered in :ref:`SETTINGS <bootstrap_settings>` 
+
+The general recommendation is to enable TLS for all DCS communication.
+
+Protecting the REST API
+=======================
+
+Protecting the REST API is a more complicated task.
+
+The Patroni REST API is used by Patroni itself during the leader race, by the ``patronictl`` tool in order to perform failovers/switchovers/reinitialize/restarts/reloads, by HAProxy or any other kind of load balancer to perform HTTP health checks, and of course could also be used for monitoring. 
+
+From the point of view of security, REST API contains safe (``GET`` requests, only retrieve information) and unsafe (``PUT``, ``POST``, ``PATCH`` and ``DELETE`` requests, change the state of nodes) endpoints.
+
+The unsafe endpoints can be protected with HTTP basic-auth by setting the ``restapi.authentication.username`` and ``restapi.authentication.password`` parameters. There is no way to protect the safe endpoints without enabling TLS.
+
+When TLS for the REST API is enabled and a PKI is established, mutual authentication of the API server and API client is possible for all endpoints.
+
+The ``restapi`` section parameters enable TLS client authentication to the server. Depending on the value of the ``verify_client`` parameter, the API server requires a successful client certificate verification for both safe and unsafe API calls (``verify_client: required``), or only for unsafe API calls (``verify_client: optional``), or for no API calls (``verify_client: none``).
+
+The ``ctl`` section parameters enable TLS server authentication to the client (the ``patronictl`` tool which uses the same config as patroni). Set ``insecure: true`` to disable the server certificate verification by the client. See :ref:`SETTINGS <patronictl_settings>` for a detailed description of the TLS client parameters.
+
+Protecting the PostgreSQL database proper from unauthorized access is beyond the scope of this document and is covered in https://www.postgresql.org/docs/current/client-authentication.html

extras/startup-scripts/patroni.service

@@ -14,7 +14,8 @@ Group=postgres
 # Read in configuration file if it exists, otherwise proceed
 EnvironmentFile=-/etc/patroni_env.conf
 
-WorkingDirectory=~
+# the default is the user's home directory, and if you want to change it, you must provide an absolute path.
+# WorkingDirectory=/home/sameuser
 
 # Where to send early-startup messages from the server
 # This is normally controlled by the global default set by systemd

features/basic_replication.feature

@@ -28,6 +28,27 @@ Feature: basic replication
     When I issue a GET request to http://127.0.0.1:8009/async
     Then I receive a response code 200
 
+  Scenario: check multi sync replication
+    Given I issue a PATCH request to http://127.0.0.1:8008/config with {"synchronous_node_count": 2}
+    Then I receive a response code 200
+    And I sleep for 10 seconds
+    Then "sync" key in DCS has sync_standby=postgres1,postgres2 after 5 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/sync
+    Then I receive a response code 200
+    When I issue a PATCH request to http://127.0.0.1:8008/config with {"synchronous_node_count": 1}
+    Then I receive a response code 200
+    And I shut down postgres1
+    And I sleep for 10 seconds
+    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
+    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

features/environment.py

@@ -165,6 +165,11 @@ class PatroniController(AbstractController):
             config = yaml.safe_load(f)
             config.pop('etcd', None)
 
+        raft_port = os.environ.get('RAFT_PORT')
+        if raft_port:
+            os.environ['RAFT_PORT'] = str(int(raft_port) + 1)
+            config['raft'] = {'data_dir': self._output_dir, 'self_addr': 'localhost:' + os.environ['RAFT_PORT']}
+
         host = config['postgresql']['listen'].split(':')[0]
 
         config['postgresql']['listen'] = config['postgresql']['connect_address'] = '{0}:{1}'.format(host, self.__PORT)
@@ -373,21 +378,36 @@ class ConsulController(AbstractDcsController):
         super(ConsulController, self).start(max_wait_limit)
 
 
-class EtcdController(AbstractDcsController):
+class AbstractEtcdController(AbstractDcsController):
 
     """ handles all etcd related tasks, used for the tests setup and cleanup """
 
-    def __init__(self, context):
-        super(EtcdController, self).__init__(context)
-        os.environ['PATRONI_ETCD_HOST'] = 'localhost:2379'
-
-        import etcd
-        self._client = etcd.Client(port=2379)
+    def __init__(self, context, client_cls):
+        super(AbstractEtcdController, self).__init__(context)
+        self._client_cls = client_cls
 
     def _start(self):
         return subprocess.Popen(["etcd", "--debug", "--data-dir", self._work_directory],
                                 stdout=self._log, stderr=subprocess.STDOUT)
 
+    def _is_running(self):
+        from patroni.dcs.etcd import DnsCachingResolver
+        # if etcd is running, but we didn't start it
+        try:
+            self._client = self._client_cls({'host': 'localhost', 'port': 2379, 'retry_timeout': 30,
+                                             'patronictl': 1}, DnsCachingResolver())
+            return True
+        except Exception:
+            return False
+
+
+class EtcdController(AbstractEtcdController):
+
+    def __init__(self, context):
+        from patroni.dcs.etcd import EtcdClient
+        super(EtcdController, self).__init__(context, EtcdClient)
+        os.environ['PATRONI_ETCD_HOST'] = 'localhost:2379'
+
     def query(self, key, scope='batman'):
         import etcd
         try:
@@ -404,12 +424,25 @@ class EtcdController(AbstractDcsController):
         except Exception as e:
             assert False, "exception when cleaning up etcd contents: {0}".format(e)
 
-    def _is_running(self):
-        # if etcd is running, but we didn't start it
+
+class Etcd3Controller(AbstractEtcdController):
+
+    def __init__(self, context):
+        from patroni.dcs.etcd3 import Etcd3Client
+        super(Etcd3Controller, self).__init__(context, Etcd3Client)
+        os.environ['PATRONI_ETCD3_HOST'] = 'localhost:2379'
+
+    def query(self, key, scope='batman'):
+        import base64
+        response = self._client.range(self.path(key, scope))
+        for k in response.get('kvs', []):
+            return base64.b64decode(k['value']).decode('utf-8') if 'value' in k else None
+
+    def cleanup_service_tree(self):
         try:
-            return bool(self._client.machines)
-        except Exception:
-            return False
+            self._client.deleteprefix(self.path(scope=''))
+        except Exception as e:
+            assert False, "exception when cleaning up etcd contents: {0}".format(e)
 
 
 class KubernetesController(AbstractDcsController):
@@ -421,8 +454,9 @@ class KubernetesController(AbstractDcsController):
         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'
+        os.environ['PATRONI_KUBERNETES_BYPASS_API_SERVICE'] = 'true'
 
-        from kubernetes import client as k8s_client, config as k8s_config
+        from patroni.dcs.kubernetes import k8s_client, k8s_config
         k8s_config.load_kube_config(context='local')
         self._client = k8s_client
         self._api = self._client.CoreV1Api()
@@ -531,6 +565,48 @@ class ExhibitorController(ZooKeeperController):
         os.environ.update({'PATRONI_EXHIBITOR_HOSTS': 'localhost', 'PATRONI_EXHIBITOR_PORT': '8181'})
 
 
+class RaftController(AbstractDcsController):
+
+    CONTROLLER_ADDR = 'localhost:1234'
+
+    def __init__(self, context):
+        super(RaftController, self).__init__(context)
+        os.environ.update(PATRONI_RAFT_PARTNER_ADDRS="'" + self.CONTROLLER_ADDR + "'", RAFT_PORT='1234')
+        self._raft = None
+
+    def _start(self):
+        env = os.environ.copy()
+        del env['PATRONI_RAFT_PARTNER_ADDRS']
+        env['PATRONI_RAFT_SELF_ADDR'] = self.CONTROLLER_ADDR
+        env['PATRONI_RAFT_DATA_DIR'] = self._work_directory
+        return subprocess.Popen([sys.executable, '-m', 'coverage', 'run',
+                                '--source=patroni', '-p', 'patroni_raft_controller.py'],
+                                stdout=self._log, stderr=subprocess.STDOUT, env=env)
+
+    def query(self, key, scope='batman'):
+        ret = self._raft.get(self.path(key, scope))
+        return ret and ret['value']
+
+    def set(self, key, value):
+        self._raft.set(self.path(key), value)
+
+    def cleanup_service_tree(self):
+        from patroni.dcs.raft import KVStoreTTL
+        from pysyncobj import SyncObjConf
+
+        if self._raft:
+            self._raft.destroy()
+            self._raft._SyncObj__thread.join()
+            self.stop()
+            os.makedirs(self._work_directory)
+            self.start()
+
+        ready_event = threading.Event()
+        conf = SyncObjConf(appendEntriesUseBatch=False, dynamicMembershipChange=True, onReady=ready_event.set)
+        self._raft = KVStoreTTL(None, [self.CONTROLLER_ADDR], conf)
+        ready_event.wait()
+
+
 class PatroniPoolController(object):
 
     BACKUP_SCRIPT = [sys.executable, 'features/backup_create.py']

features/patroni_api.feature

@@ -61,9 +61,15 @@ Scenario: check the scheduled restart
 		And postgres0 role is the primary after 10 seconds
 
 Scenario: check API requests for the primary-replica pair in the pause mode
-	Given I run patronictl.py pause batman
+	Given I start postgres1
+	Then replication works from postgres0 to postgres1 after 20 seconds
+	When I run patronictl.py pause batman
+	Then I receive a response returncode 0
+	When I kill postmaster on postgres1
+	And I issue a GET request to http://127.0.0.1:8009/replica
+	Then I receive a response code 503
+	When I run patronictl.py restart batman postgres1 --force
 	Then I receive a response returncode 0
-	When I start postgres1
 	Then replication works from postgres0 to postgres1 after 20 seconds
 	When I issue a GET request to http://127.0.0.1:8009/replica
 	Then I receive a response code 200

features/standby_cluster.feature

@@ -25,6 +25,7 @@ Feature: standby cluster
     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
+    And I sleep for 3 seconds
     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/standby_leader
@@ -41,6 +42,7 @@ Feature: standby cluster
     Then postgres2 is replicating from postgres0 after 32 seconds
     When I issue a GET request to http://127.0.0.1:8010/master
     Then I receive a response code 503
+    And I sleep for 3 seconds
     When I issue a GET request to http://127.0.0.1:8010/standby_leader
     Then I receive a response code 200
     And I receive a response role standby_leader

features/steps/cascading_replication.py

@@ -21,7 +21,7 @@ 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')
+@step('"{name}" key in DCS has {key:w}={value} 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)

kubernetes/entrypoint.sh

@@ -33,7 +33,5 @@ postgresql:
 __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
+exec /usr/bin/python3 /usr/local/bin/patroni /home/postgres/patroni.yml

kubernetes/openshift-example/templates/template_patroni_ephemeral.yml

@@ -118,6 +118,8 @@ objects:
               fieldRef:
                 apiVersion: v1
                 fieldPath: metadata.namespace
+          - name: PATRONI_KUBERNETES_BYPASS_API_SERVICE
+            value: 'true'
           - name: PATRONI_KUBERNETES_LABELS
             value: '{application: ${APPLICATION_NAME}, cluster-name: ${PATRONI_CLUSTER_NAME}}'
           - name: PATRONI_SUPERUSER_USERNAME
@@ -152,6 +154,16 @@ objects:
           image: docker-registry.default.svc:5000/${NAMESPACE}/patroni:latest
           imagePullPolicy: IfNotPresent
           name: ${APPLICATION_NAME}
+          readinessProbe:
+            httpGet:
+              scheme: HTTP
+              path: /readiness
+              port: 8008
+            initialDelaySeconds: 3
+            periodSeconds: 10
+            timeoutSeconds: 5
+            successThreshold: 1
+            failureThreshold: 3
           ports:
           - containerPort: 8008
             protocol: TCP
@@ -240,6 +252,34 @@ objects:
   subjects:
   - kind: ServiceAccount
     name: ${SERVICE_ACCOUNT}
+# Following privileges are only required if deployed not in the "default"
+# namespace and you want Patroni to bypass kubernetes service
+# (PATRONI_KUBERNETES_BYPASS_API_SERVICE=true)
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRole
+  metadata:
+    name: patroni-k8s-ep-access
+  rules:
+  - apiGroups:
+    - ""
+    resources:
+    - endpoints
+    resourceNames:
+    - kubernetes
+    verbs:
+    - get
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRoleBinding
+  metadata:
+    name: ${NAMESPACE}-${SERVICE_ACCOUNT}-k8s-ep-access
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: ClusterRole
+    name: patroni-k8s-ep-access
+  subjects:
+  - kind: ServiceAccount
+    name: ${SERVICE_ACCOUNT}
+    namespace: ${NAMESPACE}
 parameters:
 - description: The name of the application for labelling all artifacts.
   displayName: Application Name

kubernetes/openshift-example/templates/template_patroni_persistent.yaml

@@ -5,11 +5,9 @@ metadata:
   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.
+    openshift.io/long-description: This template deploys a a patroni postgresql HA cluster with persistent storage.
     tags: postgresql
 objects:
 - apiVersion: v1
@@ -132,6 +130,8 @@ objects:
               fieldRef:
                 apiVersion: v1
                 fieldPath: metadata.namespace
+          - name: PATRONI_KUBERNETES_BYPASS_API_SERVICE
+            value: 'true'
           - name: PATRONI_KUBERNETES_LABELS
             value: '{application: ${APPLICATION_NAME}, cluster-name: ${PATRONI_CLUSTER_NAME}}'
           - name: PATRONI_SUPERUSER_USERNAME
@@ -166,6 +166,16 @@ objects:
           image: docker-registry.default.svc:5000/${NAMESPACE}/patroni:latest
           imagePullPolicy: IfNotPresent
           name: ${APPLICATION_NAME}
+          readinessProbe:
+            httpGet:
+              scheme: HTTP
+              path: /readiness
+              port: 8008
+            initialDelaySeconds: 3
+            periodSeconds: 10
+            timeoutSeconds: 5
+            successThreshold: 1
+            failureThreshold: 3
           ports:
           - containerPort: 8008
             protocol: TCP
@@ -266,6 +276,34 @@ objects:
   subjects:
   - kind: ServiceAccount
     name: ${SERVICE_ACCOUNT}
+# Following privileges are only required if deployed not in the "default"
+# namespace and you want Patroni to bypass kubernetes service
+# (PATRONI_KUBERNETES_BYPASS_API_SERVICE=true)
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRole
+  metadata:
+    name: patroni-k8s-ep-access
+  rules:
+  - apiGroups:
+    - ""
+    resources:
+    - endpoints
+    resourceNames:
+    - kubernetes
+    verbs:
+    - get
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRoleBinding
+  metadata:
+    name: ${NAMESPACE}-${SERVICE_ACCOUNT}-k8s-ep-access
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: ClusterRole
+    name: patroni-k8s-ep-access
+  subjects:
+  - kind: ServiceAccount
+    name: ${SERVICE_ACCOUNT}
+    namespace: ${NAMESPACE}
 parameters:
 - description: The name of the application for labelling all artifacts.
   displayName: Application Name
@@ -314,4 +352,4 @@ parameters:
 - description: The size of the persistent volume to create. 
   displayName: Persistent Volume Size
   name: PVC_SIZE
-  value: 5Gi
+  value: 5Gi

kubernetes/patroni_k8s.yaml

@@ -10,7 +10,7 @@ spec:
   clusterIP: None
 
 ---
-apiVersion: apps/v1beta1
+apiVersion: apps/v1
 kind: StatefulSet
 metadata:
   name: &cluster_name patronidemo
@@ -31,6 +31,16 @@ spec:
       - name: *cluster_name
         image: patroni  # docker build -t patroni .
         imagePullPolicy: IfNotPresent
+        readinessProbe:
+          httpGet:
+            scheme: HTTP
+            path: /readiness
+            port: 8008
+          initialDelaySeconds: 3
+          periodSeconds: 10
+          timeoutSeconds: 5
+          successThreshold: 1
+          failureThreshold: 3
         ports:
         - containerPort: 8008
           protocol: TCP
@@ -48,6 +58,8 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
+        - name: PATRONI_KUBERNETES_BYPASS_API_SERVICE
+          value: 'true'
         - name: PATRONI_KUBERNETES_USE_ENDPOINTS
           value: 'true'
         - name: PATRONI_KUBERNETES_LABELS
@@ -123,6 +135,25 @@ spec:
   - port: 5432
     targetPort: 5432
 
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: patronidemo-repl
+  labels:
+    application: patroni
+    cluster-name:  &cluster_name patronidemo
+    role: replica
+spec:
+  type: ClusterIP
+  selector:
+    application: patroni
+    cluster-name: *cluster_name
+    role: replica
+  ports:
+  - port: 5432
+    targetPort: 5432
+
 ---
 apiVersion: v1
 kind: Secret
@@ -210,3 +241,37 @@ roleRef:
 subjects:
 - kind: ServiceAccount
   name: patronidemo
+
+# Following privileges are only required if deployed not in the "default"
+# namespace and you want Patroni to bypass kubernetes service
+# (PATRONI_KUBERNETES_BYPASS_API_SERVICE=true)
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: patroni-k8s-ep-access
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - endpoints
+  resourceNames:
+  - kubernetes
+  verbs:
+  - get
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: patroni-k8s-ep-access
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: patroni-k8s-ep-access
+subjects:
+- kind: ServiceAccount
+  name: patronidemo
+# The namespace must be specified explicitly.
+# If deploying to the different namespace you have to change it.
+  namespace: default

patroni/__init__.py

@@ -4,7 +4,8 @@ import signal
 import sys
 import time
 
-from patroni.version import __version__
+from .daemon import AbstractPatroniDaemon, abstract_main
+from .version import __version__
 
 logger = logging.getLogger(__name__)
 
@@ -12,23 +13,19 @@ PATRONI_ENV_PREFIX = 'PATRONI_'
 KUBERNETES_ENV_PREFIX = 'KUBERNETES_'
 
 
-class Patroni(object):
+class Patroni(AbstractPatroniDaemon):
 
-    def __init__(self, conf):
+    def __init__(self, config):
         from patroni.api import RestApiServer
         from patroni.dcs import get_dcs
         from patroni.ha import Ha
-        from patroni.log import PatroniLogger
         from patroni.postgresql import Postgresql
         from patroni.request import PatroniRequest
         from patroni.watchdog import Watchdog
 
-        self.setup_signal_handlers()
+        super(Patroni, self).__init__(config)
 
         self.version = __version__
-        self.logger = PatroniLogger()
-        self.config = conf
-        self.logger.reload_config(self.config.get('log', {}))
         self.dcs = get_dcs(self.config)
         self.watchdog = Watchdog(self.config)
         self.load_dynamic_configuration()
@@ -71,14 +68,14 @@ class Patroni(object):
     def nosync(self):
         return bool(self.tags.get('nosync', False))
 
-    def reload_config(self, sighup=False):
+    def reload_config(self, sighup=False, local=False):
         try:
-            self.tags = self.get_tags()
-            self.logger.reload_config(self.config.get('log', {}))
-            self.watchdog.reload_config(self.config)
-            if sighup:
+            super(Patroni, self).reload_config(sighup, local)
+            if local:
+                self.tags = self.get_tags()
                 self.request.reload_config(self.config)
-            self.api.reload_config(self.config['restapi'])
+                self.api.reload_config(self.config['restapi'])
+            self.watchdog.reload_config(self.config)
             self.postgresql.reload_config(self.config['postgresql'], sighup)
             self.dcs.reload_config(self.config)
         except Exception:
@@ -88,15 +85,6 @@ class Patroni(object):
     def replicatefrom(self):
         return self.tags.get('replicatefrom')
 
-    def sighup_handler(self, *args):
-        self._received_sighup = True
-
-    def sigterm_handler(self, *args):
-        with self._sigterm_lock:
-            if not self._received_sigterm:
-                self._received_sigterm = True
-                sys.exit()
-
     @property
     def noloadbalance(self):
         return bool(self.tags.get('noloadbalance', False))
@@ -114,48 +102,24 @@ class Patroni(object):
         elif self.ha.watch(nap_time):
             self.next_run = time.time()
 
-    @property
-    def received_sigterm(self):
-        with self._sigterm_lock:
-            return self._received_sigterm
-
     def run(self):
         self.api.start()
-        self.logger.start()
         self.next_run = time.time()
+        super(Patroni, self).run()
 
-        while not self.received_sigterm:
-            if self._received_sighup:
-                self._received_sighup = False
-                if self.config.reload_local_configuration():
-                    self.reload_config(True)
-                else:
-                    self.postgresql.config.reload_config(self.config['postgresql'], True)
+    def _run_cycle(self):
+        logger.info(self.ha.run_cycle())
 
-            logger.info(self.ha.run_cycle())
+        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 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 self.postgresql.role != 'uninitialized':
+            self.config.save_cache()
 
-            if self.postgresql.role != 'uninitialized':
-                self.config.save_cache()
+        self.schedule_next_run()
 
-            self.schedule_next_run()
-
-    def setup_signal_handlers(self):
-        from threading import Lock
-
-        self._received_sighup = False
-        self._sigterm_lock = Lock()
-        self._received_sigterm = False
-        if os.name != 'nt':
-            signal.signal(signal.SIGHUP, self.sighup_handler)
-        signal.signal(signal.SIGTERM, self.sigterm_handler)
-
-    def shutdown(self):
-        with self._sigterm_lock:
-            self._received_sigterm = True
+    def _shutdown(self):
         try:
             self.api.shutdown()
         except Exception:
@@ -164,43 +128,14 @@ class Patroni(object):
             self.ha.shutdown()
         except Exception:
             logger.exception('Exception during Ha.shutdown')
-        self.logger.shutdown()
 
 
 def patroni_main():
-    import argparse
-
     from multiprocessing import freeze_support
-    from patroni.config import Config, ConfigParseError
     from patroni.validator import schema
 
     freeze_support()
-
-    parser = argparse.ArgumentParser()
-    parser.add_argument('--version', action='version', version='%(prog)s {0}'.format(__version__))
-    parser.add_argument('--validate-config', action='store_true', help='Run config validator and exit')
-    parser.add_argument('configfile', nargs='?', default='',
-                        help='Patroni may also read the configuration from the {0} environment variable'
-                        .format(Config.PATRONI_CONFIG_VARIABLE))
-    args = parser.parse_args()
-    try:
-        if args.validate_config:
-            conf = Config(args.configfile, validator=schema)
-            sys.exit()
-        else:
-            conf = Config(args.configfile)
-    except ConfigParseError as e:
-        if e.value:
-            print(e.value)
-        parser.print_help()
-        sys.exit(1)
-    patroni = Patroni(conf)
-    try:
-        patroni.run()
-    except KeyboardInterrupt:
-        pass
-    finally:
-        patroni.shutdown()
+    abstract_main(Patroni, schema)
 
 
 def fatal(string, *args):

patroni/api.py

@@ -9,20 +9,28 @@ import datetime
 import os
 import six
 import socket
+import sys
 
-from patroni.exceptions import PostgresConnectionException, PostgresException
-from patroni.postgresql.misc import postgres_version_to_int
-from patroni.utils import deep_compare, parse_bool, patch_config, Retry, \
-    RetryFailedError, parse_int, split_host_port, tzutc, uri, cluster_as_json
 from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from six.moves.socketserver import ThreadingMixIn
+from six.moves.urllib_parse import urlparse, parse_qs
 from threading import Thread
 
+from .exceptions import PostgresConnectionException, PostgresException
+from .postgresql.misc import postgres_version_to_int
+from .utils import deep_compare, enable_keepalive, parse_bool, patch_config, Retry, \
+    RetryFailedError, parse_int, split_host_port, tzutc, uri, cluster_as_json
+
 logger = logging.getLogger(__name__)
 
 
 class RestApiHandler(BaseHTTPRequestHandler):
 
+    def _write_status_code_only(self, status_code):
+        message = self.responses[status_code][0]
+        self.wfile.write('{0} {1} {2}\r\n\r\n'.format(self.protocol_version, status_code, message).encode('utf-8'))
+        self.log_request(status_code)
+
     def _write_response(self, status_code, body, content_type='text/html', headers=None):
         self.send_response(status_code)
         headers = headers or {}
@@ -30,6 +38,8 @@ class RestApiHandler(BaseHTTPRequestHandler):
             headers['Content-Type'] = content_type
         for name, value in headers.items():
             self.send_header(name, value)
+        for name, value in self.server.http_extra_headers.items():
+            self.send_header(name, value)
         self.end_headers()
         self.wfile.write(body.encode('utf-8'))
 
@@ -80,16 +90,20 @@ class RestApiHandler(BaseHTTPRequestHandler):
     def do_GET(self, write_status_code_only=False):
         """Default method for processing all GET requests which can not be routed to other methods"""
 
-        time_start = time.time()
-        request_type = 'OPTIONS' if write_status_code_only else 'GET'
-
         path = '/master' if self.path == '/' else self.path
         response = self.get_postgresql_status()
 
         patroni = self.server.patroni
         cluster = patroni.dcs.cluster
 
-        replica_status_code = 200 if not patroni.noloadbalance and \
+        leader_optime = cluster and cluster.last_leader_operation or 0
+        replayed_location = response.get('xlog', {}).get('replayed_location', 0)
+        max_replica_lag = parse_int(self.path_query.get('lag', [sys.maxsize])[0], 'B')
+        if max_replica_lag is None:
+            max_replica_lag = sys.maxsize
+        is_lagging = leader_optime and leader_optime > replayed_location + max_replica_lag
+
+        replica_status_code = 200 if not patroni.noloadbalance and not is_lagging and \
             response.get('role') == 'replica' and response.get('state') == 'running' else 503
 
         if not cluster and patroni.ha.is_paused():
@@ -119,25 +133,33 @@ class RestApiHandler(BaseHTTPRequestHandler):
             status_code = 200 if response.get('state') == 'running' else 503
         elif cluster:  # dcs is available
             is_synchronous = cluster.is_synchronous_mode() and cluster.sync \
-                    and cluster.sync.sync_standby == patroni.postgresql.name
+                    and patroni.postgresql.name in cluster.sync.members
             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]
-            self.wfile.write('{0} {1} {2}\r\n\r\n'.format(self.protocol_version, status_code, message).encode('utf-8'))
+            self._write_status_code_only(status_code)
         else:
             self._write_status_response(status_code, response)
 
-        time_end = time.time()
-        self.log_message('%s %s %s latency: %s ms', request_type, path,
-                         status_code, (time_end - time_start) * 1000)
-
     def do_OPTIONS(self):
         self.do_GET(write_status_code_only=True)
 
+    def do_GET_liveness(self):
+        self._write_status_code_only(200)
+
+    def do_GET_readiness(self):
+        patroni = self.server.patroni
+        if patroni.ha.is_leader():
+            status_code = 200
+        elif patroni.postgresql.state == 'running':
+            status_code = 200 if patroni.dcs.cluster else 503
+        else:
+            status_code = 503
+        self._write_status_code_only(status_code)
+
     def do_GET_patroni(self):
         response = self.get_postgresql_status(True)
         self._write_status_response(200, response)
@@ -176,6 +198,8 @@ class RestApiHandler(BaseHTTPRequestHandler):
         request = self._read_json_content()
         if request:
             cluster = self.server.patroni.dcs.get_cluster()
+            if not (cluster.config and cluster.config.modify_index):
+                return self.send_error(503)
             data = cluster.config.data.copy()
             if patch_config(data, request):
                 value = json.dumps(data, separators=(',', ':'))
@@ -345,13 +369,13 @@ class RestApiHandler(BaseHTTPRequestHandler):
         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:
+            if action == 'switchover' and cluster.is_synchronous_mode() and candidate not in cluster.sync.members:
                 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]
+            members = [m for m in cluster.members if m.name in cluster.sync.members]
             if not members:
                 return action + ' is not possible: can not find sync_standby'
         else:
@@ -428,6 +452,9 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
         ret = BaseHTTPRequestHandler.parse_request(self)
         if ret:
+            urlpath = urlparse(self.path)
+            self.path = urlpath.path
+            self.path_query = parse_qs(urlpath.query) or {}
             mname = self.path.lstrip('/').split('/')[0]
             mname = self.command + ('_' + mname if mname else '')
             if hasattr(self, 'do_' + mname):
@@ -491,8 +518,13 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 state = 'unknown'
             return {'state': state, 'role': postgresql.role}
 
+    def handle_one_request(self):
+        self.__start_time = time.time()
+        BaseHTTPRequestHandler.handle_one_request(self)
+
     def log_message(self, fmt, *args):
-        logger.debug("API thread: %s - - [%s] %s", self.client_address[0], self.log_date_time_string(), fmt % args)
+        latency = 1000.0 * (time.time() - self.__start_time)
+        logger.debug("API thread: %s - - %s latency: %0.3f ms", self.client_address[0], fmt % args, latency)
 
 
 class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
@@ -503,6 +535,7 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
         self.patroni = patroni
         self.__listen = None
         self.__ssl_options = None
+        self.http_extra_headers = {}
         self.reload_config(config)
         self.daemon = True
 
@@ -626,6 +659,7 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
     def get_request(self):
         sock = self.socket
         newsock, addr = socket.socket.accept(sock)
+        enable_keepalive(newsock, 10, 3)
         if hasattr(sock, 'context'):  # SSLSocket, we want to do the deferred handshake from a thread
             newsock = (sock, newsock)
         return newsock, addr
@@ -636,6 +670,9 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
 
         ssl_options = {n: config[n] for n in ('certfile', 'keyfile', 'cafile') if n in config}
 
+        self.http_extra_headers = config.get('http_extra_headers') or {}
+        self.http_extra_headers.update((config.get('https_extra_headers') or {}) if ssl_options.get('certfile') else {})
+
         if isinstance(config.get('verify_client'), six.string_types):
             ssl_options['verify_client'] = config['verify_client'].lower()
 

patroni/config.py

@@ -21,6 +21,7 @@ _AUTH_ALLOWED_PARAMETERS = (
     'sslmode',
     'sslcert',
     'sslkey',
+    'sslpassword',
     'sslrootcert',
     'sslcrl',
     'gssencmode',
@@ -64,6 +65,7 @@ class Config(object):
         'master_stop_timeout': 0,
         'synchronous_mode': False,
         'synchronous_mode_strict': False,
+        'synchronous_node_count': 1,
         'standby_cluster': {
             'create_replica_methods': '',
             'host': '',
@@ -76,7 +78,8 @@ class Config(object):
         'postgresql': {
             'bin_dir': '',
             'use_slots': True,
-            'parameters': CaseInsensitiveDict({p: v[0] for p, v in ConfigHandler.CMDLINE_OPTIONS.items()})
+            'parameters': CaseInsensitiveDict({p: v[0] for p, v in ConfigHandler.CMDLINE_OPTIONS.items()
+                                               if p not in ('wal_keep_segments', 'wal_keep_size')})
         },
         'watchdog': {
             'mode': 'automatic',
@@ -90,7 +93,7 @@ class Config(object):
         self.__environment_configuration = self._build_environment_configuration()
 
         # Patroni reads the configuration from the command-line argument if it exists, otherwise from the environment
-        self._config_file = configfile and os.path.isfile(configfile) and configfile
+        self._config_file = configfile and os.path.exists(configfile) and configfile
         if self._config_file:
             self._local_configuration = self._load_config_file()
         else:
@@ -118,12 +121,32 @@ class Config(object):
     def check_mode(self, mode):
         return bool(parse_bool(self._dynamic_configuration.get(mode)))
 
+    def _load_config_path(self, path):
+        """
+        If path is a file, loads the yml file pointed to by path.
+        If path is a directory, loads all yml files in that directory in alphabetical order
+        """
+        if os.path.isfile(path):
+            files = [path]
+        elif os.path.isdir(path):
+            files = [os.path.join(path, f) for f in sorted(os.listdir(path))
+                     if (f.endswith('.yml') or f.endswith('.yaml')) and os.path.isfile(os.path.join(path, f))]
+        else:
+            logger.error('config path %s is neither directory nor file', path)
+            raise ConfigParseError('invalid config path')
+
+        overall_config = {}
+        for fname in files:
+            with open(fname) as f:
+                config = yaml.safe_load(f)
+                patch_config(overall_config, config)
+        return overall_config
+
     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:
-            config = yaml.safe_load(f)
-            patch_config(config, self.__environment_configuration)
-            return config
+        config = self._load_config_path(self._config_file)
+        patch_config(config, self.__environment_configuration)
+        return config
 
     def _load_cache(self):
         if os.path.isfile(self._cache_file):
@@ -242,7 +265,8 @@ class Config(object):
                 if value:
                     ret[section][param] = value
 
-        _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile', 'cafile', 'verify_client'])
+        _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile', 'cafile', 'verify_client',
+                                        'http_extra_headers', 'https_extra_headers'])
         _set_section_values('ctl', ['insecure', 'cacert', 'certfile', 'keyfile'])
         _set_section_values('postgresql', ['listen', 'connect_address', 'config_dir', 'data_dir', 'pgpass', 'bin_dir'])
         _set_section_values('log', ['level', 'traceback_level', 'format', 'dateformat', 'max_queue_size',
@@ -293,6 +317,10 @@ class Config(object):
                 logger.exception('Exception when parsing list %s', value)
                 return None
 
+        _set_section_values('raft', ['data_dir', 'self_addr', 'partner_addrs', 'password', 'bind_addr'])
+        if 'raft' in ret and 'partner_addrs' in ret['raft']:
+            ret['raft']['partner_addrs'] = _parse_list(ret['raft']['partner_addrs'])
+
         for param in list(os.environ.keys()):
             if param.startswith(PATRONI_ENV_PREFIX):
                 # PATRONI_(ETCD|CONSUL|ZOOKEEPER|EXHIBITOR|...)_(HOSTS?|PORT|..)
@@ -300,7 +328,8 @@ class Config(object):
                 if suffix in ('HOST', 'HOSTS', 'PORT', 'USE_PROXIES', 'PROTOCOL', 'SRV', 'URL', 'PROXY',
                               'CACERT', 'CERT', 'KEY', 'VERIFY', 'TOKEN', 'CHECKS', 'DC', 'CONSISTENCY',
                               'REGISTER_SERVICE', 'SERVICE_CHECK_INTERVAL', 'NAMESPACE', 'CONTEXT',
-                              'USE_ENDPOINTS', 'SCOPE_LABEL', 'ROLE_LABEL', 'POD_IP', 'PORTS', 'LABELS') and name:
+                              'USE_ENDPOINTS', 'SCOPE_LABEL', 'ROLE_LABEL', 'POD_IP', 'PORTS', 'LABELS',
+                              'BYPASS_API_SERVICE', 'KEY_PASSWORD', 'USE_SSL') and name:
                     value = os.environ.pop(param)
                     if suffix == 'PORT':
                         value = value and parse_int(value)
@@ -308,12 +337,13 @@ class Config(object):
                         value = value and _parse_list(value)
                     elif suffix == 'LABELS':
                         value = _parse_dict(value)
-                    elif suffix in ('USE_PROXIES', 'REGISTER_SERVICE'):
+                    elif suffix in ('USE_PROXIES', 'REGISTER_SERVICE', 'BYPASS_API_SERVICE'):
                         value = parse_bool(value)
                     if value:
                         ret[name.lower()][suffix.lower()] = value
-        if 'etcd' in ret:
-            ret['etcd'].update(_get_auth('etcd'))
+        for dcs in ('etcd', 'etcd3'):
+            if dcs in ret:
+                ret[dcs].update(_get_auth(dcs))
 
         users = {}
         for param in list(os.environ.keys()):
@@ -381,6 +411,7 @@ class Config(object):
             'retry_timeout',
             'synchronous_mode',
             'synchronous_mode_strict',
+            'synchronous_node_count',
         )
 
         pg_config.update({p: config[p] for p in updated_fields if p in config})

patroni/ctl.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 '''
 Patroni Control
 '''
@@ -8,7 +7,6 @@ import codecs
 import datetime
 import dateutil.parser
 import dateutil.tz
-import cdiff
 import copy
 import difflib
 import io
@@ -33,8 +31,12 @@ from patroni.postgresql.misc import postgres_version_to_int
 from patroni.utils import cluster_as_json, patch_config, polling_loop
 from patroni.request import PatroniRequest
 from patroni.version import __version__
+from prettytable import ALL, FRAME, PrettyTable
 from six.moves.urllib_parse import urlparse
-from texttable import Texttable
+try:
+    from ydiff import markup_to_pager, PatchStream
+except ImportError:  # pragma: no cover
+    from cdiff import markup_to_pager, PatchStream
 
 CONFIG_DIR_PATH = click.get_app_dir('patroni')
 CONFIG_FILE_PATH = os.path.join(CONFIG_DIR_PATH, 'patronictl.yaml')
@@ -48,42 +50,32 @@ class PatroniCtlException(ClickException):
     pass
 
 
-class PatronictlPrettyTable(Texttable):
+class PatronictlPrettyTable(PrettyTable):
 
-    def __init__(self, header=None):
-        Texttable.__init__(self, 0)
+    def __init__(self, header, *args, **kwargs):
+        PrettyTable.__init__(self, *args, **kwargs)
         self.__table_header = header
         self.__hline_num = 0
-
-        if sys.platform != 'win32':
-            self._char_horiz = u'─'
-            self._char_vert = u'│'
-            self._hline_header = self._hline
-        self._char_header = self._char_horiz
+        self.__hline = None
 
     def _is_first_hline(self):
         return self.__hline_num == 0
 
-    def _is_last_hline(self):
-        return self.__hline_num > (len(self._rows) if self._has_hlines() else int(bool(self._header)))
+    def _set_hline(self, value):
+        self.__hline = value
 
-    def _hline(self):
-        if sys.platform == 'win32':
-            left = right = self._char_corner
-        elif self._is_first_hline():
-            left, self._char_corner, right = u'┌', u'┬', u'┐'
-        elif not self._is_last_hline():
-            left, self._char_corner, right = u'├', u'┼', u'┤'
-        else:
-            left, self._char_corner, right = u'└', u'┴', u'┘'
-
-        line = self._build_hline()
+    def _get_hline(self):
+        ret = self.__hline
 
+        # Inject nice table header
         if self._is_first_hline() and self.__table_header:
-            left += self.__table_header
+            header = self.__table_header[:len(ret) - 2]
+            ret = "".join([ret[0], header, ret[1 + len(header):]])
 
         self.__hline_num += 1
-        return left + line[len(left):-2] + right + '\n'
+        return ret
+
+    _hrule = property(_get_hline, _set_hline)
 
 
 def parse_dcs(dcs):
@@ -197,17 +189,14 @@ def print_output(columns, rows, alignment=None, fmt='pretty', header=None, delim
             for r in ([columns] if columns else []) + rows:
                 click.echo(delimiter.join(map(str, r)))
         else:
-            table = PatronictlPrettyTable(header)
-            if not any(any(isinstance(c, six.string_types) and '\n' in c for c in r) for r in rows):
-                table.set_deco(Texttable.VLINES | Texttable.BORDER | Texttable.HEADER)
-            if rows:
-                if columns:
-                    table.header(columns)
-                    table.set_cols_align([(alignment or {}).get(c, 'l') for c in columns])
-                table.add_rows(rows, header=False)
-            else:
-                table.add_rows([columns], header=False)
-            click.echo(table.draw())
+            hrules = ALL if any(any(isinstance(c, six.string_types) and '\n' in c for c in r) for r in rows) else FRAME
+            table = PatronictlPrettyTable(header, columns, hrules=hrules)
+            table.align = 'l'
+            for k, v in (alignment or {}).items():
+                table.align[k] = v
+            for r in rows:
+                table.add_row(r)
+            click.echo(table)
 
 
 def watching(w, watch, max_count=None, clear=True):
@@ -240,7 +229,7 @@ def watching(w, watch, max_count=None, clear=True):
 
 def get_all_members(cluster, role='master'):
     if role == 'master':
-        if cluster.leader is not None:
+        if cluster.leader is not None and cluster.leader.name:
             yield cluster.leader
         return
 
@@ -655,7 +644,7 @@ def _do_failover_or_switchover(obj, action, cluster_name, master, candidate, for
     dcs = get_dcs(obj, cluster_name)
     cluster = dcs.get_cluster()
 
-    if action == 'switchover' and cluster.leader is None:
+    if action == 'switchover' and (cluster.leader is None or not cluster.leader.name):
         raise PatroniCtlException('This cluster has no master')
 
     if master is None:
@@ -835,8 +824,7 @@ def output_members(cluster, name, extended=False, fmt='pretty'):
 
         rows.append([m.get(n.lower().replace(' ', '_'), '') for n in columns])
 
-    print_output(columns, rows, {'Member': 'l', 'Lag in MB': 'r', 'TL': 'r', 'Tags': 'l'},
-                 fmt, ' Cluster: {0} ({1}) '.format(name, initialize))
+    print_output(columns, rows, {'Lag in MB': 'r', 'TL': 'r'}, fmt, ' Cluster: {0} ({1}) '.format(name, initialize))
 
     if fmt not in ('pretty', 'topology'):  # Omit service info when using machine-readable formats
         return
@@ -1101,7 +1089,14 @@ def show_diff(before_editing, after_editing):
             side_by_side = False
             width = 80
             tab_width = 8
-        cdiff.markup_to_pager(cdiff.PatchStream(buf), opts)
+            wrap = True
+            if find_executable('less'):
+                pager = None
+            else:
+                pager = 'more.com' if sys.platform == 'win32' else 'more'
+            pager_options = None
+
+        markup_to_pager(PatchStream(buf), opts)
     else:
         for line in unified_diff:
             click.echo(line.rstrip('\n'))

patroni/daemon.py

@@ -0,0 +1,104 @@
+import abc
+import os
+import signal
+import six
+import sys
+
+from threading import Lock
+
+
+@six.add_metaclass(abc.ABCMeta)
+class AbstractPatroniDaemon(object):
+
+    def __init__(self, config):
+        from patroni.log import PatroniLogger
+
+        self.setup_signal_handlers()
+
+        self.logger = PatroniLogger()
+        self.config = config
+        AbstractPatroniDaemon.reload_config(self, local=True)
+
+    def sighup_handler(self, *args):
+        self._received_sighup = True
+
+    def sigterm_handler(self, *args):
+        with self._sigterm_lock:
+            if not self._received_sigterm:
+                self._received_sigterm = True
+                sys.exit()
+
+    def setup_signal_handlers(self):
+        self._received_sighup = False
+        self._sigterm_lock = Lock()
+        self._received_sigterm = False
+        if os.name != 'nt':
+            signal.signal(signal.SIGHUP, self.sighup_handler)
+        signal.signal(signal.SIGTERM, self.sigterm_handler)
+
+    @property
+    def received_sigterm(self):
+        with self._sigterm_lock:
+            return self._received_sigterm
+
+    def reload_config(self, sighup=False, local=False):
+        if local:
+            self.logger.reload_config(self.config.get('log', {}))
+
+    @abc.abstractmethod
+    def _run_cycle(self):
+        """_run_cycle"""
+
+    def run(self):
+        self.logger.start()
+        while not self.received_sigterm:
+            if self._received_sighup:
+                self._received_sighup = False
+                self.reload_config(True, self.config.reload_local_configuration())
+
+            self._run_cycle()
+
+    @abc.abstractmethod
+    def _shutdown(self):
+        """_shutdown"""
+
+    def shutdown(self):
+        with self._sigterm_lock:
+            self._received_sigterm = True
+        self._shutdown()
+        self.logger.shutdown()
+
+
+def abstract_main(cls, validator=None):
+    import argparse
+
+    from .config import Config, ConfigParseError
+    from .version import __version__
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--version', action='version', version='%(prog)s {0}'.format(__version__))
+    if validator:
+        parser.add_argument('--validate-config', action='store_true', help='Run config validator and exit')
+    parser.add_argument('configfile', nargs='?', default='',
+                        help='Patroni may also read the configuration from the {0} environment variable'
+                        .format(Config.PATRONI_CONFIG_VARIABLE))
+    args = parser.parse_args()
+    try:
+        if validator and args.validate_config:
+            Config(args.configfile, validator=validator)
+            sys.exit()
+
+        config = Config(args.configfile)
+    except ConfigParseError as e:
+        if e.value:
+            print(e.value)
+        parser.print_help()
+        sys.exit(1)
+
+    controller = cls(config)
+    try:
+        controller.run()
+    except KeyboardInterrupt:
+        pass
+    finally:
+        controller.shutdown()

patroni/dcs/__init__.py

@@ -13,7 +13,7 @@ import time
 
 from collections import defaultdict, namedtuple
 from copy import deepcopy
-from patroni.exceptions import PatroniException
+from patroni.exceptions import PatroniFatalException
 from patroni.utils import parse_bool, uri
 from random import randint
 from six.moves.urllib_parse import urlparse, urlunparse, parse_qsl
@@ -102,7 +102,7 @@ def get_dcs(config):
                                              and inspect.isclass(item) and issubclass(item, AbstractDCS))
         except ImportError:
             logger.info('Failed to import %s', module_name)
-    raise PatroniException("""Can not find suitable configuration of distributed configuration store
+    raise PatroniFatalException("""Can not find suitable configuration of distributed configuration store
 Available implementations: """ + ', '.join(sorted(set(available_implementations))))
 
 
@@ -351,7 +351,7 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
 
     :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
+    :param sync_standby: synchronous standby list (comma delimited) which are last synchronized to leader
     """
 
     @staticmethod
@@ -383,15 +383,22 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
             data = {}
         return SyncState(index, data.get('leader'), data.get('sync_standby'))
 
+    @property
+    def members(self):
+        """ Returns sync_standby in list """
+        return self.sync_standby and self.sync_standby.split(',') or []
+
     def matches(self, name):
         """
         Returns if a node name matches one of the nodes in the sync state
 
-        >>> s = SyncState(1, 'foo', 'bar')
+        >>> s = SyncState(1, 'foo', 'bar,zoo')
         >>> s.matches('foo')
         True
         >>> s.matches('bar')
         True
+        >>> s.matches('zoo')
+        True
         >>> s.matches('baz')
         False
         >>> s.matches(None)
@@ -399,7 +406,7 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
         >>> SyncState(1, None, None).matches('foo')
         False
         """
-        return name is not None and name in (self.leader, self.sync_standby)
+        return name is not None and name in [self.leader] + self.members
 
 
 class TimelineHistory(namedtuple('TimelineHistory', 'index,value,lines')):
@@ -500,7 +507,8 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
                     value['type'] = 'logical' if value.get('database') and value.get('plugin') else 'physical'
 
                 if value['type'] == 'physical':
-                    if name != my_name:  # Don't try to create permanent physical replication slot for yourself
+                    # Don't try to create permanent physical replication slot for yourself
+                    if name != slot_name_from_member_name(my_name):
                         slots[name] = value
                     continue
                 elif value['type'] == 'logical' and value.get('database') and value.get('plugin'):
@@ -786,8 +794,10 @@ class AbstractDCS(object):
 
     @staticmethod
     def sync_state(leader, sync_standby):
-        """Build sync_state dict"""
-        return {'leader': leader, 'sync_standby': sync_standby}
+        """Build sync_state dict
+           sync_standby dictionary key being kept for backward compatibility
+        """
+        return {'leader': leader, 'sync_standby': sync_standby and ','.join(sorted(sync_standby)) or None}
 
     def write_sync_state(self, leader, sync_standby, index=None):
         sync_value = self.sync_state(leader, sync_standby)

patroni/dcs/consul.py

@@ -219,6 +219,7 @@ class Consul(AbstractDCS):
         self.__session_checks = config.get('checks', [])
         self._register_service = config.get('register_service', False)
         if self._register_service:
+            self._service_tags = config.get('service_tags', [])
             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,
@@ -414,12 +415,14 @@ class Consul(AbstractDCS):
         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))
+        tags = self._service_tags[:]
+        tags.append(role)
         params = {
             'service_id': '{0}/{1}'.format(self._scope, self._name),
             'address': conn_parts.hostname,
             'port': conn_parts.port,
             'check': check,
-            'tags': [role]
+            'tags': tags
         }
 
         if state == 'stopped':

patroni/dcs/etcd.py

@@ -1,4 +1,5 @@
 from __future__ import absolute_import
+import abc
 import etcd
 import json
 import logging
@@ -82,7 +83,8 @@ class DnsCachingResolver(Thread):
             return []
 
 
-class Client(etcd.Client):
+@six.add_metaclass(abc.ABCMeta)
+class AbstractEtcdClientWithFailover(etcd.Client):
 
     def __init__(self, config, dns_resolver, cache_ttl=300):
         self._dns_resolver = dns_resolver
@@ -90,7 +92,7 @@ class Client(etcd.Client):
         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)
+        super(AbstractEtcdClientWithFailover, self).__init__(read_timeout=config['retry_timeout'], **args)
         # For some reason python3-etcd on debian and ubuntu are not based on the latest version
         # Workaround for the case when https://github.com/jplana/python-etcd/pull/196 is not applied
         self.http.connection_pool_kw.pop('ssl_version', None)
@@ -130,12 +132,16 @@ class Client(etcd.Client):
 
         return etcd_nodes, per_node_timeout, per_node_retries - 1
 
+    def reload_config(self, config):
+        self.username = config.get('username')
+        self.password = config.get('password')
+
     def _get_headers(self):
         basic_auth = ':'.join((self.username, self.password)) if self.username and self.password else None
         return urllib3.make_headers(basic_auth=basic_auth, user_agent=USER_AGENT)
 
-    def _build_request_parameters(self, etcd_nodes, timeout=None):
-        kwargs = {'headers': self._get_headers(), 'redirect': self.allow_redirect}
+    def _prepare_common_parameters(self, etcd_nodes, timeout=None):
+        kwargs = {'headers': self._get_headers(), 'redirect': self.allow_redirect, 'preload_content': False}
 
         if timeout is not None:
             kwargs.update(retries=0, timeout=timeout)
@@ -148,6 +154,14 @@ class Client(etcd.Client):
     def set_machines_cache_ttl(self, cache_ttl):
         self._machines_cache_ttl = cache_ttl
 
+    @abc.abstractmethod
+    def _prepare_get_members(self, etcd_nodes):
+        """returns: request parameters"""
+
+    @abc.abstractmethod
+    def _get_members(self, base_uri, **kwargs):
+        """returns: list of clientURLs"""
+
     @property
     def machines_cache(self):
         base_uri, cache = self._base_uri, self._machines_cache
@@ -166,13 +180,11 @@ class Client(etcd.Client):
         the original method was retrying 2 times with the `read_timeout` on each node."""
 
         machines_cache = self.machines_cache
-        kwargs = self._build_request_parameters(len(machines_cache))
+        kwargs = self._prepare_get_members(len(machines_cache))
 
         for base_uri in machines_cache:
             try:
-                response = self.http.request(self._MGET, base_uri + self.version_prefix + '/machines', **kwargs)
-                data = self._handle_server_response(response).data.decode('utf-8')
-                machines = [m.strip() for m in data.split(',') if m.strip()]
+                machines = list(self._get_members(base_uri, **kwargs))
                 logger.debug("Retrieved list of machines: %s", machines)
                 if machines:
                     random.shuffle(machines)
@@ -188,14 +200,15 @@ class Client(etcd.Client):
         self._read_timeout = timeout
 
     def _do_http_request(self, retry, machines_cache, request_executor, method, path, fields=None, **kwargs):
+        if fields is not None:
+            kwargs['fields'] = fields
         some_request_failed = False
         for i, base_uri in enumerate(machines_cache):
             if i > 0:
                 logger.info("Retrying on %s", base_uri)
             try:
-                response = request_executor(method, base_uri + path, fields=fields, **kwargs)
+                response = request_executor(method, base_uri + path, **kwargs)
                 response.data.decode('utf-8')
-                self._check_cluster_id(response)
                 if some_request_failed:
                     self.set_base_uri(base_uri)
                     self._refresh_machines_cache()
@@ -218,20 +231,12 @@ class Client(etcd.Client):
 
         raise etcd.EtcdConnectionFailed('No more machines in the cluster')
 
+    @abc.abstractmethod
+    def _prepare_request(self, kwargs, params=None, method=None):
+        """returns: request_executor"""
+
     def api_execute(self, path, method, params=None, timeout=None):
-        if not path.startswith('/'):
-            raise ValueError('Path does not start with /')
-
         retry = params.pop('retry', None) if isinstance(params, dict) else None
-        kwargs = {'fields': params, 'preload_content': False}
-
-        if method in [self._MGET, self._MDELETE]:
-            request_executor = self.http.request
-        elif method in [self._MPUT, self._MPOST]:
-            request_executor = self.http.request_encode_body
-            kwargs['encode_multipart'] = False
-        else:
-            raise etcd.EtcdException('HTTP method {0} not supported'.format(method))
 
         # Update machines_cache if previous attempt of update has failed
         if self._update_machines_cache:
@@ -241,7 +246,9 @@ class Client(etcd.Client):
 
         machines_cache = self.machines_cache
         etcd_nodes = len(machines_cache)
-        kwargs.update(self._build_request_parameters(etcd_nodes, timeout))
+
+        kwargs = self._prepare_common_parameters(etcd_nodes, timeout)
+        request_executor = self._prepare_request(kwargs, params, method)
 
         while True:
             try:
@@ -389,17 +396,47 @@ class Client(etcd.Client):
         self._base_uri = value
 
 
-class Etcd(AbstractDCS):
+class EtcdClient(AbstractEtcdClientWithFailover):
 
-    def __init__(self, config):
-        super(Etcd, self).__init__(config)
-        self._ttl = int(config.get('ttl') or 30)
+    ERROR_CLS = EtcdError
+
+    def __del__(self):
+        if self.http is not None:
+            try:
+                self.http.clear()
+            except (ReferenceError, TypeError):
+                pass
+
+    def _prepare_get_members(self, etcd_nodes):
+        return self._prepare_common_parameters(etcd_nodes)
+
+    def _get_members(self, base_uri, **kwargs):
+        response = self.http.request(self._MGET, base_uri + self.version_prefix + '/machines', **kwargs)
+        data = self._handle_server_response(response).data.decode('utf-8')
+        return [m.strip() for m in data.split(',') if m.strip()]
+
+    def _prepare_request(self, kwargs, params=None, method=None):
+        kwargs['fields'] = params
+        if method in (self._MPOST, self._MPUT):
+            kwargs['encode_multipart'] = False
+        return self.http.request
+
+
+class AbstractEtcd(AbstractDCS):
+
+    def __init__(self, config, client_cls, retry_errors_cls):
+        super(AbstractEtcd, self).__init__(config)
         self._retry = Retry(deadline=config['retry_timeout'], max_delay=1, max_tries=-1,
-                            retry_exceptions=(etcd.EtcdLeaderElectionInProgress, EtcdRaftInternal))
-        self._client = self.get_etcd_client(config)
+                            retry_exceptions=retry_errors_cls)
+        self._ttl = int(config.get('ttl') or 30)
+        self._client = self.get_etcd_client(config, client_cls)
         self.__do_not_watch = False
         self._has_failed = False
 
+    def reload_config(self, config):
+        super(AbstractEtcd, self).reload_config(config)
+        self._client.reload_config(config.get(self.__class__.__name__.lower(), {}))
+
     def retry(self, *args, **kwargs):
         retry = self._retry.copy()
         kwargs['retry'] = retry
@@ -416,22 +453,13 @@ class Etcd(AbstractDCS):
         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):
+    def set_socket_options(sock, socket_options):
+        if socket_options:
+            for opt in socket_options:
+                sock.setsockopt(*opt)
+
+    def get_etcd_client(self, config, client_cls):
         if 'proxy' in config:
             config['use_proxies'] = True
             config['url'] = config['proxy']
@@ -480,9 +508,7 @@ class Etcd(AbstractDCS):
                 sock = None
                 try:
                     sock = socket.socket(af, socktype, proto)
-                    if socket_options:
-                        for opt in socket_options:
-                            sock.setsockopt(*opt)
+                    self.set_socket_options(sock, socket_options)
                     if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
                         sock.settimeout(timeout)
                     if source_address:
@@ -506,7 +532,7 @@ class Etcd(AbstractDCS):
         client = None
         while not client:
             try:
-                client = Client(config, dns_resolver)
+                client = client_cls(config, dns_resolver)
                 if 'use_proxies' in config and not client.machines:
                     raise etcd.EtcdException
             except etcd.EtcdException:
@@ -516,9 +542,10 @@ class Etcd(AbstractDCS):
 
     def set_ttl(self, ttl):
         ttl = int(ttl)
-        self.__do_not_watch = self._ttl != ttl
+        ret = self._ttl != ttl
         self._ttl = ttl
         self._client.set_machines_cache_ttl(ttl*10)
+        return ret
 
     @property
     def ttl(self):
@@ -528,6 +555,31 @@ class Etcd(AbstractDCS):
         self._retry.deadline = retry_timeout
         self._client.set_read_timeout(retry_timeout)
 
+
+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=self._client.ERROR_CLS('unexpected error'))
+
+    return wrapper
+
+
+class Etcd(AbstractEtcd):
+
+    def __init__(self, config):
+        super(Etcd, self).__init__(config, EtcdClient, (etcd.EtcdLeaderElectionInProgress, EtcdRaftInternal))
+        self.__do_not_watch = False
+
+    def set_ttl(self, ttl):
+        self.__do_not_watch = super(Etcd, self).set_ttl(ttl)
+
     @staticmethod
     def member(node):
         return Member.from_node(node.modifiedIndex, os.path.basename(node.key), node.ttl, node.value)
@@ -658,8 +710,10 @@ class Etcd(AbstractDCS):
 
             while timeout >= 1:  # when timeout is too small urllib3 doesn't have enough time to connect
                 try:
-                    self._client.watch(self.leader_path, index=leader_index, timeout=timeout + 0.5)
+                    result = self._client.watch(self.leader_path, index=leader_index, timeout=timeout + 0.5)
                     self._has_failed = False
+                    if result.action == 'compareAndSwap':
+                        time.sleep(0.01)
                     # Synchronous work of all cluster members with etcd is less expensive
                     # than reestablishing http connection every time from every replica.
                     return True

patroni/dcs/etcd3.py

@@ -0,0 +1,795 @@
+from __future__ import absolute_import
+import base64
+import etcd
+import json
+import logging
+import os
+import six
+import socket
+import sys
+import time
+import urllib3
+
+from threading import Condition, Lock, Thread
+
+from . import ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
+from .etcd import AbstractEtcdClientWithFailover, AbstractEtcd, catch_etcd_errors
+from ..exceptions import DCSError, PatroniException
+from ..utils import deep_compare, enable_keepalive, iter_response_objects, RetryFailedError, USER_AGENT
+
+logger = logging.getLogger(__name__)
+
+
+class Etcd3Error(DCSError):
+    pass
+
+
+class UnsupportedEtcdVersion(PatroniException):
+    pass
+
+
+# google.golang.org/grpc/codes
+GRPCCode = type('Enum', (), {'OK': 0, 'Canceled': 1, 'Unknown': 2, 'InvalidArgument': 3, 'DeadlineExceeded': 4,
+                             'NotFound': 5, 'AlreadyExists': 6, 'PermissionDenied': 7, 'ResourceExhausted': 8,
+                             'FailedPrecondition': 9, 'Aborted': 10, 'OutOfRange': 11, 'Unimplemented': 12,
+                             'Internal': 13, 'Unavailable': 14, 'DataLoss': 15, 'Unauthenticated': 16})
+GRPCcodeToText = {v: k for k, v in GRPCCode.__dict__.items() if not k.startswith('__') and isinstance(v, int)}
+
+
+class Etcd3Exception(etcd.EtcdException):
+    pass
+
+
+class Etcd3ClientError(Etcd3Exception):
+
+    def __init__(self, code=None, error=None, status=None):
+        if not hasattr(self, 'error'):
+            self.error = error and error.strip()
+        self.codeText = GRPCcodeToText.get(code)
+        self.status = status
+
+    def __repr__(self):
+        return "<{0} error: '{1}', code: {2}>".format(self.__class__.__name__, self.error, self.code)
+
+    __str__ = __repr__
+
+    def as_dict(self):
+        return {'error': self.error, 'code': self.code, 'codeText': self.codeText, 'status': self.status}
+
+    @classmethod
+    def get_subclasses(cls):
+        for subclass in cls.__subclasses__():
+            for subsubclass in subclass.get_subclasses():
+                yield subsubclass
+            yield subclass
+
+
+class Unknown(Etcd3ClientError):
+    code = GRPCCode.Unknown
+
+
+class InvalidArgument(Etcd3ClientError):
+    code = GRPCCode.InvalidArgument
+
+
+class DeadlineExceeded(Etcd3ClientError):
+    code = GRPCCode.DeadlineExceeded
+    error = "context deadline exceeded"
+
+
+class NotFound(Etcd3ClientError):
+    code = GRPCCode.NotFound
+
+
+class FailedPrecondition(Etcd3ClientError):
+    code = GRPCCode.FailedPrecondition
+
+
+class Unavailable(Etcd3ClientError):
+    code = GRPCCode.Unavailable
+
+
+# https://github.com/etcd-io/etcd/blob/master/etcdserver/api/v3rpc/rpctypes/error.go
+class LeaseNotFound(NotFound):
+    error = "etcdserver: requested lease not found"
+
+
+class UserEmpty(InvalidArgument):
+    error = "etcdserver: user name is empty"
+
+
+class PermissionDenied(Etcd3ClientError):
+    code = GRPCCode.PermissionDenied
+    error = "etcdserver: permission denied"
+
+
+class AuthNotEnabled(FailedPrecondition):
+    error = "etcdserver: authentication is not enabled"
+
+
+class InvalidAuthToken(Etcd3ClientError):
+    code = GRPCCode.Unauthenticated
+    error = "etcdserver: invalid auth token"
+
+
+errStringToClientError = {s.error: s for s in Etcd3ClientError.get_subclasses() if hasattr(s, 'error')}
+errCodeToClientError = {s.code: s for s in Etcd3ClientError.__subclasses__()}
+
+
+def _raise_for_data(data, status_code=None):
+    try:
+        error = data.get('error') or data.get('Error')
+        if isinstance(error, dict):  # streaming response
+            status_code = error.get('http_code')
+            code = error['grpc_code']
+            error = error['message']
+        else:
+            code = data.get('code') or data.get('Code')
+    except Exception:
+        error = str(data)
+        code = GRPCCode.Unknown
+    err = errStringToClientError.get(error) or errCodeToClientError.get(code) or Unknown
+    raise err(code, error, status_code)
+
+
+def to_bytes(v):
+    return v if isinstance(v, bytes) else v.encode('utf-8')
+
+
+def prefix_range_end(v):
+    v = bytearray(to_bytes(v))
+    for i in range(len(v) - 1, -1, -1):
+        if v[i] < 0xff:
+            v[i] += 1
+            break
+    return bytes(v)
+
+
+def base64_encode(v):
+    return base64.b64encode(to_bytes(v)).decode('utf-8')
+
+
+def base64_decode(v):
+    return base64.b64decode(v).decode('utf-8')
+
+
+def build_range_request(key, range_end=None):
+    fields = {'key': base64_encode(key)}
+    if range_end:
+        fields['range_end'] = base64_encode(range_end)
+    return fields
+
+
+class Etcd3Client(AbstractEtcdClientWithFailover):
+
+    ERROR_CLS = Etcd3Error
+
+    def __init__(self, config, dns_resolver, cache_ttl=300):
+        self._token = None
+        self._cluster_version = None
+        self.version_prefix = '/v3beta'
+        super(Etcd3Client, self).__init__(config, dns_resolver, cache_ttl)
+
+        if six.PY2:  # pragma: no cover
+            # Old grpc-gateway sometimes sends double 'transfer-encoding: chunked' headers,
+            # what breaks the old (python2.7) httplib.HTTPConnection (it closes the socket).
+            def dedup_addheader(httpm, key, value):
+                prev = httpm.dict.get(key)
+                if prev is None:
+                    httpm.dict[key] = value
+                elif key != 'transfer-encoding' or prev != value:
+                    combined = ", ".join((prev, value))
+                    httpm.dict[key] = combined
+
+            import httplib
+            httplib.HTTPMessage.addheader = dedup_addheader
+
+        try:
+            self.authenticate()
+        except Exception as e:
+            logger.fatal('Etcd3 authentication failed: %r', e)
+            sys.exit(1)
+
+    def _get_headers(self):
+        headers = urllib3.make_headers(user_agent=USER_AGENT)
+        if self._token and self._cluster_version >= (3, 3, 0):
+            headers['authorization'] = self._token
+        return headers
+
+    def _prepare_request(self, kwargs, params=None, method=None):
+        if params is not None:
+            kwargs['body'] = json.dumps(params)
+            kwargs['headers']['Content-Type'] = 'application/json'
+        return self.http.urlopen
+
+    @staticmethod
+    def _handle_server_response(response):
+        data = response.data
+        try:
+            data = data.decode('utf-8')
+            data = json.loads(data)
+        except (TypeError, ValueError, UnicodeError) as e:
+            if response.status < 400:
+                raise etcd.EtcdException('Server response was not valid JSON: %r' % e)
+        if response.status < 400:
+            return data
+        _raise_for_data(data, response.status)
+
+    def _ensure_version_prefix(self, base_uri, **kwargs):
+        if self.version_prefix != '/v3':
+            response = self.http.urlopen(self._MGET, base_uri + '/version', **kwargs)
+            response = self._handle_server_response(response)
+
+            server_version_str = response['etcdserver']
+            server_version = tuple(int(x) for x in server_version_str.split('.'))
+            cluster_version_str = response['etcdcluster']
+            self._cluster_version = tuple(int(x) for x in cluster_version_str.split('.'))
+
+            if self._cluster_version < (3, 0) or server_version < (3, 0, 4):
+                raise UnsupportedEtcdVersion('Detected Etcd version {0} is lower than 3.0.4'.format(server_version_str))
+
+            if self._cluster_version < (3, 3):
+                if self.version_prefix != '/v3alpha':
+                    if self._cluster_version < (3, 1):
+                        logger.warning('Detected Etcd version %s is lower than 3.1.0, watches are not supported',
+                                       cluster_version_str)
+                    if self.username and self.password:
+                        logger.warning('Detected Etcd version %s is lower than 3.3.0, authentication is not supported',
+                                       cluster_version_str)
+                    self.version_prefix = '/v3alpha'
+            elif self._cluster_version < (3, 4):
+                self.version_prefix = '/v3beta'
+            else:
+                self.version_prefix = '/v3'
+
+    def _prepare_get_members(self, etcd_nodes):
+        kwargs = self._prepare_common_parameters(etcd_nodes)
+        self._prepare_request(kwargs, {})
+        return kwargs
+
+    def _get_members(self, base_uri, **kwargs):
+        self._ensure_version_prefix(base_uri, **kwargs)
+        resp = self.http.urlopen(self._MPOST, base_uri + self.version_prefix + '/cluster/member/list', **kwargs)
+        members = self._handle_server_response(resp)['members']
+        return set(url for member in members for url in member.get('clientURLs', []))
+
+    def call_rpc(self, method, fields, retry=None):
+        fields['retry'] = retry
+        return self.api_execute(self.version_prefix + method, self._MPOST, fields)
+
+    def authenticate(self):
+        if self._cluster_version >= (3, 3) and self.username and self.password:
+            logger.info('Trying to authenticate on Etcd...')
+            old_token, self._token = self._token, None
+            try:
+                response = self.call_rpc('/auth/authenticate', {'name': self.username, 'password': self.password})
+            except AuthNotEnabled:
+                logger.info('Etcd authentication is not enabled')
+                self._token = None
+            except Exception:
+                self._token = old_token
+                raise
+            else:
+                self._token = response.get('token')
+            return old_token != self._token
+
+    def _handle_auth_errors(func):
+        def wrapper(self, *args, **kwargs):
+            def retry(ex):
+                if self.username and self.password:
+                    self.authenticate()
+                    return func(self, *args, **kwargs)
+                else:
+                    logger.fatal('Username or password not set, authentication is not possible')
+                    raise ex
+
+            try:
+                return func(self, *args, **kwargs)
+            except (UserEmpty, PermissionDenied) as e:  # no token provided
+                # PermissionDenied is raised on 3.0 and 3.1
+                if self._cluster_version < (3, 3) and (not isinstance(e, PermissionDenied)
+                                                       or self._cluster_version < (3, 2)):
+                    raise UnsupportedEtcdVersion('Authentication is required by Etcd cluster but not '
+                                                 'supported on version lower than 3.3.0. Cluster version: '
+                                                 '{0}'.format('.'.join(map(str, self._cluster_version))))
+                return retry(e)
+            except InvalidAuthToken as e:
+                logger.error('Invalid auth token: %s', self._token)
+                return retry(e)
+
+        return wrapper
+
+    @_handle_auth_errors
+    def range(self, key, range_end=None, retry=None):
+        params = build_range_request(key, range_end)
+        params['serializable'] = True  # For better performance. We can tolerate stale reads.
+        return self.call_rpc('/kv/range', params, retry)
+
+    def prefix(self, key, retry=None):
+        return self.range(key, prefix_range_end(key), retry)
+
+    def lease_grant(self, ttl, retry=None):
+        return self.call_rpc('/lease/grant', {'TTL': ttl}, retry)['ID']
+
+    def lease_keepalive(self, ID, retry=None):
+        return self.call_rpc('/lease/keepalive', {'ID': ID}, retry).get('result', {}).get('TTL')
+
+    def txn(self, compare, success, retry=None):
+        return self.call_rpc('/kv/txn', {'compare': [compare], 'success': [success]}, retry).get('succeeded')
+
+    @_handle_auth_errors
+    def put(self, key, value, lease=None, create_revision=None, mod_revision=None, retry=None):
+        fields = {'key': base64_encode(key), 'value': base64_encode(value)}
+        if lease:
+            fields['lease'] = lease
+        if create_revision is not None:
+            compare = {'target': 'CREATE', 'create_revision': create_revision}
+        elif mod_revision is not None:
+            compare = {'target': 'MOD', 'mod_revision': mod_revision}
+        else:
+            return self.call_rpc('/kv/put', fields, retry)
+        compare['key'] = fields['key']
+        return self.txn(compare, {'request_put': fields}, retry)
+
+    @_handle_auth_errors
+    def deleterange(self, key, range_end=None, mod_revision=None, retry=None):
+        fields = build_range_request(key, range_end)
+        if mod_revision is None:
+            return self.call_rpc('/kv/deleterange', fields, retry)
+        compare = {'target': 'MOD', 'mod_revision': mod_revision, 'key': fields['key']}
+        return self.txn(compare, {'request_delete_range': fields}, retry)
+
+    def deleteprefix(self, key, retry=None):
+        return self.deleterange(key, prefix_range_end(key), retry=retry)
+
+    def watchrange(self, key, range_end=None, start_revision=None, filters=None):
+        """returns: response object"""
+        params = build_range_request(key, range_end)
+        if start_revision is not None:
+            params['start_revision'] = start_revision
+        params['filters'] = filters or []
+        kwargs = self._prepare_common_parameters(1, self.read_timeout)
+        request_executor = self._prepare_request(kwargs, {'create_request': params})
+        kwargs.update(timeout=urllib3.Timeout(connect=kwargs['timeout']), retries=0)
+        return request_executor(self._MPOST, self._base_uri + self.version_prefix + '/watch', **kwargs)
+
+    def watchprefix(self, key, start_revision=None, filters=None):
+        return self.watchrange(key, prefix_range_end(key), start_revision, filters)
+
+
+class KVCache(Thread):
+
+    def __init__(self, dcs, client):
+        Thread.__init__(self)
+        self.daemon = True
+        self._dcs = dcs
+        self._client = client
+        self.condition = Condition()
+        self._config_key = base64_encode(dcs.config_path)
+        self._leader_key = base64_encode(dcs.leader_path)
+        self._optime_key = base64_encode(dcs.leader_optime_path)
+        self._name = base64_encode(dcs._name)
+        self._is_ready = False
+        self._response = None
+        self._response_lock = Lock()
+        self._object_cache = {}
+        self._object_cache_lock = Lock()
+        self.start()
+
+    def set(self, value, overwrite=False):
+        with self._object_cache_lock:
+            name = value['key']
+            old_value = self._object_cache.get(name)
+            ret = not old_value or int(old_value['mod_revision']) < int(value['mod_revision'])
+            if ret or overwrite and old_value['mod_revision'] == value['mod_revision']:
+                self._object_cache[name] = value
+        return ret, old_value
+
+    def delete(self, name, mod_revision):
+        with self._object_cache_lock:
+            old_value = self._object_cache.get(name)
+            ret = old_value and int(old_value['mod_revision']) < int(mod_revision)
+            if ret:
+                del self._object_cache[name]
+        return not old_value or ret, old_value
+
+    def copy(self):
+        with self._object_cache_lock:
+            return [v.copy() for v in self._object_cache.values()]
+
+    def get(self, name):
+        with self._object_cache_lock:
+            return self._object_cache.get(name)
+
+    def _process_event(self, event):
+        kv = event['kv']
+        key = kv['key']
+        if event.get('type') == 'DELETE':
+            success, old_value = self.delete(key, kv['mod_revision'])
+        else:
+            success, old_value = self.set(kv, True)
+
+        if success:
+            old_value = old_value and old_value.get('value')
+            new_value = kv.get('value')
+
+            value_changed = old_value != new_value and \
+                (key == self._leader_key or key == self._optime_key and new_value is not None or
+                 key == self._config_key and old_value is not None and new_value is not None)
+
+            if value_changed:
+                logger.debug('%s changed from %s to %s', key, old_value, new_value)
+
+            # We also want to wake up HA loop on replicas if leader optime was updated
+            if value_changed and (key != self._optime_key or self.get(self._leader_key) != self._name):
+                self._dcs.event.set()
+
+    def _process_message(self, message):
+        logger.debug('Received message: %s', message)
+        if 'error' in message:
+            _raise_for_data(message)
+        for event in message.get('result', {}).get('events', []):
+            self._process_event(event)
+
+    @staticmethod
+    def _finish_response(response):
+        try:
+            response.close()
+        finally:
+            response.release_conn()
+
+    def _do_watch(self, revision):
+        with self._response_lock:
+            self._response = None
+        response = self._client.watchprefix(self._dcs.cluster_prefix, revision)
+        with self._response_lock:
+            if self._response is None:
+                self._response = response
+
+        if not self._response:
+            return self._finish_response(response)
+
+        for message in iter_response_objects(response):
+            self._process_message(message)
+
+    def _build_cache(self):
+        result = self._dcs.retry(self._client.prefix, self._dcs.cluster_prefix)
+        with self._object_cache_lock:
+            self._object_cache = {node['key']: node for node in result.get('kvs', [])}
+        with self.condition:
+            self._is_ready = True
+            self.condition.notify()
+
+        try:
+            self._do_watch(result['header']['revision'])
+        except Exception as e:
+            logger.error('watchprefix failed: %r', e)
+        finally:
+            with self.condition:
+                self._is_ready = False
+            with self._response_lock:
+                response, self._response = self._response, None
+            if response:
+                self._finish_response(response)
+
+    def run(self):
+        while True:
+            try:
+                self._build_cache()
+            except Exception as e:
+                logger.error('KVCache.run %r', e)
+                time.sleep(1)
+
+    def kill_stream(self):
+        sock = None
+        with self._response_lock:
+            if self._response:
+                try:
+                    sock = self._response.connection.sock
+                except Exception:
+                    sock = None
+            else:
+                self._response = False
+        if sock:
+            try:
+                sock.shutdown(socket.SHUT_RDWR)
+                sock.close()
+            except Exception as e:
+                logger.debug('Error on socket.shutdown: %r', e)
+
+    def is_ready(self):
+        """Must be called only when holding the lock on `condition`"""
+        return self._is_ready
+
+
+class PatroniEtcd3Client(Etcd3Client):
+
+    def __init__(self, *args, **kwargs):
+        self._kv_cache = None
+        super(PatroniEtcd3Client, self).__init__(*args, **kwargs)
+
+    def configure(self, etcd3):
+        self._etcd3 = etcd3
+
+    def start_watcher(self):
+        if self._cluster_version >= (3, 1):
+            self._kv_cache = KVCache(self._etcd3, self)
+
+    def _restart_watcher(self):
+        if self._kv_cache:
+            self._kv_cache.kill_stream()
+
+    def set_base_uri(self, value):
+        super(PatroniEtcd3Client, self).set_base_uri(value)
+        self._restart_watcher()
+
+    def authenticate(self):
+        ret = super(PatroniEtcd3Client, self).authenticate()
+        if ret:
+            self._restart_watcher()
+        return ret
+
+    def _wait_cache(self, timeout):
+        stop_time = time.time() + timeout
+        while not self._kv_cache.is_ready():
+            timeout = stop_time - time.time()
+            if timeout <= 0:
+                raise RetryFailedError('Exceeded retry deadline')
+            self._kv_cache.condition.wait(timeout)
+
+    def get_cluster(self):
+        if self._kv_cache:
+            with self._kv_cache.condition:
+                self._wait_cache(self._etcd3._retry.deadline)
+                return self._kv_cache.copy()
+        else:
+            return self._etcd3.retry(self.prefix, self._etcd3.cluster_prefix).get('kvs', [])
+
+    def call_rpc(self, method, fields, retry=None):
+        ret = super(PatroniEtcd3Client, self).call_rpc(method, fields, retry)
+
+        if self._kv_cache:
+            value = delete = None
+            if method == '/kv/txn' and ret.get('succeeded'):
+                on_success = fields['success'][0]
+                value = on_success.get('request_put')
+                delete = on_success.get('request_delete_range')
+            elif method == '/kv/put' and ret:
+                value = fields
+            elif method == '/kv/deleterange' and ret:
+                delete = fields
+
+            if value:
+                value['mod_revision'] = ret['header']['revision']
+                self._kv_cache.set(value)
+            elif delete and 'range_end' not in delete:
+                self._kv_cache.delete(delete['key'], ret['header']['revision'])
+
+        return ret
+
+
+class Etcd3(AbstractEtcd):
+
+    def __init__(self, config):
+        super(Etcd3, self).__init__(config, PatroniEtcd3Client, (DeadlineExceeded, Unavailable, FailedPrecondition))
+        self.__do_not_watch = False
+        self._lease = None
+        self._last_lease_refresh = 0
+
+        self._client.configure(self)
+        if not self._ctl:
+            self._client.start_watcher()
+            self.create_lease()
+
+    def set_socket_options(self, sock, socket_options):
+        enable_keepalive(sock, self.ttl, int(self.loop_wait + self._retry.deadline))
+
+    def set_ttl(self, ttl):
+        self.__do_not_watch = super(Etcd3, self).set_ttl(ttl)
+        if self.__do_not_watch:
+            self._lease = None
+
+    def _do_refresh_lease(self, retry=None):
+        if self._lease and self._last_lease_refresh + self._loop_wait > time.time():
+            return False
+
+        if self._lease and not self._client.lease_keepalive(self._lease, retry):
+            self._lease = None
+
+        ret = not self._lease
+        if ret:
+            self._lease = self._client.lease_grant(self._ttl, retry)
+
+        self._last_lease_refresh = time.time()
+        return ret
+
+    def refresh_lease(self):
+        try:
+            return self.retry(self._do_refresh_lease)
+        except (Etcd3ClientError, RetryFailedError):
+            logger.exception('refresh_lease')
+        raise Etcd3Error('Failed ro keepalive/grant lease')
+
+    def create_lease(self):
+        while not self._lease:
+            try:
+                self.refresh_lease()
+            except Etcd3Error:
+                logger.info('waiting on etcd')
+                time.sleep(5)
+
+    @property
+    def cluster_prefix(self):
+        return self.client_path('')
+
+    @staticmethod
+    def member(node):
+        return Member.from_node(node['mod_revision'], os.path.basename(node['key']), node['lease'], node['value'])
+
+    def _load_cluster(self):
+        cluster = None
+        try:
+            path_len = len(self.cluster_prefix)
+
+            nodes = {}
+            for node in self._client.get_cluster():
+                node['key'] = base64_decode(node['key'])
+                node['value'] = base64_decode(node.get('value', ''))
+                node['lease'] = node.get('lease')
+                nodes[node['key'][path_len:].lstrip('/')] = node
+
+            # get initialize flag
+            initialize = nodes.get(self._INITIALIZE)
+            initialize = initialize and initialize['value']
+
+            # get global dynamic configuration
+            config = nodes.get(self._CONFIG)
+            config = config and ClusterConfig.from_node(config['mod_revision'], config['value'])
+
+            # get timeline history
+            history = nodes.get(self._HISTORY)
+            history = history and TimelineHistory.from_node(history['mod_revision'], 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'])
+
+            # get list of members
+            members = [self.member(n) for k, n in nodes.items() if k.startswith(self._MEMBERS) and k.count('/') == 1]
+
+            # get leader
+            leader = nodes.get(self._LEADER)
+            if not self._ctl and leader and leader['value'] == self._name and self._lease != leader.get('lease'):
+                logger.warning('I am the leader but not owner of the lease')
+
+            if leader:
+                member = Member(-1, leader['value'], None, {})
+                member = ([m for m in members if m.name == leader['value']] or [member])[0]
+                leader = Leader(leader['mod_revision'], leader['lease'], member)
+
+            # failover key
+            failover = nodes.get(self._FAILOVER)
+            if failover:
+                failover = Failover.from_node(failover['mod_revision'], failover['value'])
+
+            # get synchronization state
+            sync = nodes.get(self._SYNC)
+            sync = SyncState.from_node(sync and sync['mod_revision'], sync and sync['value'])
+
+            cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+        except UnsupportedEtcdVersion:
+            raise
+        except Exception as e:
+            self._handle_exception(e, 'get_cluster', raise_ex=Etcd3Error('Etcd is not responding properly'))
+        self._has_failed = False
+        return cluster
+
+    @catch_etcd_errors
+    def touch_member(self, data, permanent=False):
+        if not permanent:
+            try:
+                self.refresh_lease()
+            except Etcd3Error:
+                return False
+
+        cluster = self.cluster
+        member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
+
+        if member and member.session == self._lease and deep_compare(data, member.data):
+            return True
+
+        data = json.dumps(data, separators=(',', ':'))
+        try:
+            return self._client.put(self.member_path, data, None if permanent else self._lease)
+        except LeaseNotFound:
+            self._lease = None
+            logger.error('Our lease disappeared from Etcd, can not "touch_member"')
+
+    @catch_etcd_errors
+    def take_leader(self):
+        return self.retry(self._client.put, self.leader_path, self._name, self._lease)
+
+    @catch_etcd_errors
+    def _do_attempt_to_acquire_leader(self, permanent):
+        try:
+            return self.retry(self._client.put, self.leader_path, self._name, None if permanent else self._lease, 0)
+        except LeaseNotFound:
+            self._lease = None
+            logger.error('Our lease disappeared from Etcd. Will try to get a new one and retry attempt')
+            self.refresh_lease()
+            return self.retry(self._client.put, self.leader_path, self._name, None if permanent else self._lease, 0)
+
+    def attempt_to_acquire_leader(self, permanent=False):
+        if not self._lease and not permanent:
+            self.refresh_lease()
+
+        ret = self._do_attempt_to_acquire_leader(permanent)
+        if not ret:
+            logger.info('Could not take out TTL lock')
+        return ret
+
+    @catch_etcd_errors
+    def set_failover_value(self, value, index=None):
+        return self._client.put(self.failover_path, value, mod_revision=index)
+
+    @catch_etcd_errors
+    def set_config_value(self, value, index=None):
+        return self._client.put(self.config_path, value, mod_revision=index)
+
+    @catch_etcd_errors
+    def _write_leader_optime(self, last_operation):
+        return self._client.put(self.leader_optime_path, last_operation)
+
+    @catch_etcd_errors
+    def _update_leader(self):
+        if not self._lease:
+            self.refresh_lease()
+        elif self.retry(self._client.lease_keepalive, self._lease):
+            self._last_lease_refresh = time.time()
+
+        if self._lease:
+            cluster = self.cluster
+            leader_lease = cluster and isinstance(cluster.leader, Leader) and cluster.leader.session
+            if leader_lease != self._lease:
+                self.take_leader()
+        return bool(self._lease)
+
+    @catch_etcd_errors
+    def initialize(self, create_new=True, sysid=""):
+        return self.retry(self._client.put, self.initialize_path, sysid, None, 0 if create_new else None)
+
+    @catch_etcd_errors
+    def _delete_leader(self):
+        cluster = self.cluster
+        if cluster and isinstance(cluster.leader, Leader) and cluster.leader.name == self._name:
+            return self._client.deleterange(self.leader_path, mod_revision=cluster.leader.index)
+
+    @catch_etcd_errors
+    def cancel_initialization(self):
+        return self.retry(self._client.deleterange, self.initialize_path)
+
+    @catch_etcd_errors
+    def delete_cluster(self):
+        return self.retry(self._client.deleteprefix, self.cluster_prefix)
+
+    @catch_etcd_errors
+    def set_history_value(self, value):
+        return self._client.put(self.history_path, value)
+
+    @catch_etcd_errors
+    def set_sync_state_value(self, value, index=None):
+        return self.retry(self._client.put, self.sync_path, value, mod_revision=index)
+
+    @catch_etcd_errors
+    def delete_sync_state(self, index=None):
+        return self.retry(self._client.deleterange, self.sync_path, mod_revision=index)
+
+    def watch(self, leader_index, timeout):
+        if self.__do_not_watch:
+            self.__do_not_watch = False
+            return True
+
+        try:
+            return super(Etcd3, self).watch(None, timeout)
+        finally:
+            self.event.clear()

patroni/dcs/kubernetes.py

@@ -1,13 +1,16 @@
-from __future__ import absolute_import
 import datetime
 import functools
 import json
 import logging
+import os
+import random
 import socket
+import six
 import sys
 import time
+import urllib3
+import yaml
 
-from kubernetes import client as k8s_client, config as k8s_config, watch as k8s_watch
 from urllib3 import Timeout
 from urllib3.exceptions import HTTPError
 from six.moves.http_client import HTTPException
@@ -15,15 +18,410 @@ from threading import Condition, Lock, Thread
 
 from . import AbstractDCS, Cluster, ClusterConfig, Failover, Leader, Member, SyncState, TimelineHistory
 from ..exceptions import DCSError
-from ..utils import deep_compare, Retry, RetryFailedError, tzutc, USER_AGENT
+from ..utils import deep_compare, iter_response_objects, keepalive_socket_options,\
+        Retry, RetryFailedError, tzutc, uri, USER_AGENT
 
 logger = logging.getLogger(__name__)
 
+KUBE_CONFIG_DEFAULT_LOCATION = os.environ.get('KUBECONFIG', '~/.kube/config')
+SERVICE_HOST_ENV_NAME = 'KUBERNETES_SERVICE_HOST'
+SERVICE_PORT_ENV_NAME = 'KUBERNETES_SERVICE_PORT'
+SERVICE_TOKEN_FILENAME = '/var/run/secrets/kubernetes.io/serviceaccount/token'
+SERVICE_CERT_FILENAME = '/var/run/secrets/kubernetes.io/serviceaccount/ca.crt'
+
 
 class KubernetesError(DCSError):
     pass
 
 
+# this function does the same mapping of snake_case => camelCase for > 97% of cases as autogenerated swagger code
+def to_camel_case(value):
+    reserved = {'api', 'apiv3', 'cidr', 'cpu', 'csi', 'id', 'io', 'ip', 'ipc', 'pid', 'tls', 'uri', 'url', 'uuid'}
+    words = value.split('_')
+    return words[0] + ''.join(w.upper() if w in reserved else w.title() for w in words[1:])
+
+
+class K8sConfig(object):
+
+    class ConfigException(Exception):
+        pass
+
+    def __init__(self):
+        self.pool_config = {'maxsize': 10, 'num_pools': 10}  # configuration for urllib3.PoolManager
+        self._make_headers()
+
+    def _make_headers(self, token=None, **kwargs):
+        self._headers = urllib3.make_headers(user_agent=USER_AGENT, **kwargs)
+        if token:
+            self._headers['authorization'] = 'Bearer ' + token
+
+    def load_incluster_config(self):
+        if SERVICE_HOST_ENV_NAME not in os.environ or SERVICE_PORT_ENV_NAME not in os.environ:
+            raise self.ConfigException('Service host/port is not set.')
+        if not os.environ[SERVICE_HOST_ENV_NAME] or not os.environ[SERVICE_PORT_ENV_NAME]:
+            raise self.ConfigException('Service host/port is set but empty.')
+        if not os.path.isfile(SERVICE_CERT_FILENAME):
+            raise self.ConfigException('Service certificate file does not exists.')
+        with open(SERVICE_CERT_FILENAME) as f:
+            if not f.read():
+                raise self.ConfigException('Cert file exists but empty.')
+        if not os.path.isfile(SERVICE_TOKEN_FILENAME):
+            raise self.ConfigException('Service token file does not exists.')
+        with open(SERVICE_TOKEN_FILENAME) as f:
+            token = f.read()
+            if not token:
+                raise self.ConfigException('Token file exists but empty.')
+            self._make_headers(token=token)
+        self.pool_config['ca_certs'] = SERVICE_CERT_FILENAME
+        self._server = uri('https', (os.environ[SERVICE_HOST_ENV_NAME], os.environ[SERVICE_PORT_ENV_NAME]))
+
+    @staticmethod
+    def _get_by_name(config, section, name):
+        for c in config[section + 's']:
+            if c['name'] == name:
+                return c[section]
+
+    def load_kube_config(self, context=None):
+        with open(os.path.expanduser(KUBE_CONFIG_DEFAULT_LOCATION)) as f:
+            config = yaml.safe_load(f)
+
+        context = self._get_by_name(config, 'context', context or config['current-context'])
+        cluster = self._get_by_name(config, 'cluster', context['cluster'])
+        user = self._get_by_name(config, 'user', context['user'])
+
+        self._server = cluster['server'].rstrip('/')
+        if self._server.startswith('https'):
+            self.pool_config.update({v: user[k] for k, v in {'client-certificate': 'cert_file',
+                                                             'client-key': 'key_file'}.items() if k in user})
+            if 'certificate-authority' in cluster:
+                self.pool_config['ca_certs'] = cluster['certificate-authority']
+            self.pool_config['cert_reqs'] = 'CERT_NONE' if cluster.get('insecure-skip-tls-verify') else 'CERT_REQUIRED'
+        if user.get('token'):
+            self._make_headers(token=user['token'])
+        elif 'username' in user and 'password' in user:
+            self._headers = self._make_headers(basic_auth=':'.join((user['username'],  user['password'])))
+
+    @property
+    def server(self):
+        return self._server
+
+    @property
+    def headers(self):
+        return self._headers.copy()
+
+
+class K8sObject(object):
+
+    def __init__(self, kwargs):
+        self._dict = {k: self._wrap(k, v) for k, v in kwargs.items()}
+
+    def get(self, name, default=None):
+        return self._dict.get(name, default)
+
+    def __getattr__(self, name):
+        return self.get(to_camel_case(name))
+
+    @classmethod
+    def _wrap(cls, parent, value):
+        if isinstance(value, dict):
+            # we know that `annotations` and `labels` are dicts and therefore don't want to convert them into K8sObject
+            return value if parent in {'annotations', 'labels'} and \
+                    all(isinstance(v, six.string_types) for v in value.values()) else cls(value)
+        elif isinstance(value, list):
+            return [cls._wrap(None, v) for v in value]
+        else:
+            return value
+
+    def to_dict(self):
+        return self._dict
+
+    def __repr__(self):
+        return json.dumps(self, indent=4, default=lambda o: o.to_dict())
+
+
+class K8sException(Exception):
+    pass
+
+
+class K8sConnectionFailed(K8sException):
+    pass
+
+
+class K8sClient(object):
+
+    class rest(object):
+
+        class ApiException(Exception):
+            def __init__(self, status=None, reason=None, http_resp=None):
+                self.status = http_resp.status if http_resp else status
+                self.reason = http_resp.reason if http_resp else reason
+                self.body = http_resp.data if http_resp else None
+                self.headers = http_resp.getheaders() if http_resp else None
+
+            def __str__(self):
+                error_message = "({0})\nReason: {1}\n".format(self.status, self.reason)
+                if self.headers:
+                    error_message += "HTTP response headers: {0}\n".format(self.headers)
+                if self.body:
+                    error_message += "HTTP response body: {0}\n".format(self.body)
+                return error_message
+
+    class ApiClient(object):
+
+        _API_URL_PREFIX = '/api/v1/namespaces/'
+
+        def __init__(self, bypass_api_service=False):
+            self._bypass_api_service = bypass_api_service
+            self.pool_manager = urllib3.PoolManager(**k8s_config.pool_config)
+            self._base_uri = k8s_config.server
+            self._api_servers_cache = [k8s_config.server]
+            self._api_servers_cache_updated = 0
+            self.set_api_servers_cache_ttl(10)
+            self.set_read_timeout(10)
+            try:
+                self._load_api_servers_cache()
+            except K8sException:
+                pass
+
+        def set_read_timeout(self, timeout):
+            self._read_timeout = timeout
+
+        def set_api_servers_cache_ttl(self, ttl):
+            self._api_servers_cache_ttl = ttl - 0.5
+
+        def set_base_uri(self, value):
+            logger.info('Selected new K8s API server endpoint %s', value)
+            # We will connect by IP of the master node which is not listed as alternative name
+            self.pool_manager.connection_pool_kw['assert_hostname'] = False
+            self._base_uri = value
+
+        @staticmethod
+        def _handle_server_response(response, _preload_content):
+            if response.status not in range(200, 206):
+                raise k8s_client.rest.ApiException(http_resp=response)
+            return K8sObject(json.loads(response.data.decode('utf-8'))) if _preload_content else response
+
+        @staticmethod
+        def _make_headers(headers):
+            ret = k8s_config.headers
+            ret.update(headers or {})
+            return ret
+
+        @property
+        def api_servers_cache(self):
+            base_uri, cache = self._base_uri, self._api_servers_cache
+            return ([base_uri] if base_uri in cache else []) + [machine for machine in cache if machine != base_uri]
+
+        def _get_api_servers(self, api_servers_cache):
+            _, per_node_timeout, per_node_retries = self._calculate_timeouts(len(api_servers_cache))
+            kwargs = {'headers': self._make_headers({}), 'preload_content': True, 'retries': per_node_retries,
+                      'timeout': urllib3.Timeout(connect=max(1, per_node_timeout/2.0), total=per_node_timeout)}
+            path = self._API_URL_PREFIX + 'default/endpoints/kubernetes'
+            for base_uri in api_servers_cache:
+                try:
+                    response = self.pool_manager.request('GET', base_uri + path, **kwargs)
+                    endpoint = self._handle_server_response(response, True)
+                    for subset in endpoint.subsets:
+                        for port in subset.ports:
+                            if port.name == 'https' and port.protocol == 'TCP':
+                                addresses = [uri('https', (a.ip, port.port)) for a in subset.addresses]
+                                if addresses:
+                                    random.shuffle(addresses)
+                                    return addresses
+                except Exception as e:
+                    if isinstance(e, k8s_client.rest.ApiException) and e.status == 403:
+                        raise
+                    self.pool_manager.clear()
+                    logger.error('Failed to get "kubernetes" endpoint from %s: %r', base_uri, e)
+            raise K8sConnectionFailed('No more K8s API server nodes in the cluster')
+
+        def _refresh_api_servers_cache(self, updating_cache=False):
+            if self._bypass_api_service:
+                try:
+                    api_servers_cache = [k8s_config.server] if updating_cache else self.api_servers_cache
+                    self._api_servers_cache = self._get_api_servers(api_servers_cache)
+                    if updating_cache:
+                        self.pool_manager.clear()
+                except k8s_client.rest.ApiException:  # 403 Permission denied
+                    logger.warning("Kubernetes RBAC doesn't allow GET access to the 'kubernetes' "
+                                   "endpoint in the 'default' namespace. Disabling 'bypass_api_service'.")
+                    self._bypass_api_service = False
+                    self._api_servers_cache = [k8s_config.server]
+                    if not updating_cache:
+                        self.pool_manager.clear()
+                except K8sConnectionFailed:
+                    if updating_cache:
+                        raise K8sException("Could not get the list of K8s API server nodes")
+                    return
+            else:
+                self._api_servers_cache = [k8s_config.server]
+
+            if self._base_uri not in self._api_servers_cache:
+                self.set_base_uri(self._api_servers_cache[0])
+            self._api_servers_cache_updated = time.time()
+
+        def refresh_api_servers_cache(self):
+            if self._bypass_api_service and time.time() - self._api_servers_cache_updated > self._api_servers_cache_ttl:
+                self._refresh_api_servers_cache()
+
+        def _load_api_servers_cache(self):
+            self._update_api_servers_cache = True
+            self._refresh_api_servers_cache(True)
+            self._update_api_servers_cache = False
+
+        def _calculate_timeouts(self, api_servers, timeout=None):
+            """Calculate a request timeout and number of retries per single K8s API server node.
+            In case if the timeout per node is too small (less than one second) we will reduce the number of nodes.
+            For the cluster with only one API server node we will try to do 1 retry.
+            No retries for clusters with 2 or more API server nodes. We better rely on switching to a different node."""
+
+            per_node_timeout = timeout = float(timeout or self._read_timeout)
+
+            max_retries = 3 - min(api_servers, 2)
+            per_node_retries = 1
+            min_timeout = 1.0
+
+            while api_servers > 0:
+                per_node_timeout = float(timeout) / api_servers
+                if per_node_timeout >= min_timeout:
+                    # for small clusters we will try to do more than one try on every node
+                    while per_node_retries < max_retries and per_node_timeout / (per_node_retries + 1) >= min_timeout:
+                        per_node_retries += 1
+                    per_node_timeout /= per_node_retries
+                    break
+                # if the timeout per one node is to small try to reduce number of nodes
+                api_servers -= 1
+                max_retries = 1
+
+            return api_servers, per_node_timeout, per_node_retries - 1
+
+        def _do_http_request(self, retry, api_servers_cache, method, path, **kwargs):
+            some_request_failed = False
+            for i, base_uri in enumerate(api_servers_cache):
+                if i > 0:
+                    logger.info('Retrying on %s', base_uri)
+                try:
+                    response = self.pool_manager.request(method, base_uri + path, **kwargs)
+                    if some_request_failed:
+                        self.set_base_uri(base_uri)
+                        self._refresh_api_servers_cache()
+                    return response
+                except (HTTPError, HTTPException, socket.error, socket.timeout) as e:
+                    self.pool_manager.clear()
+                    if not retry:
+                        # switch to the next node if request failed and retry is not allowed
+                        if i + 1 < len(api_servers_cache):
+                            self.set_base_uri(api_servers_cache[i + 1])
+                        raise K8sException('{0} {1} request failed'.format(method, path))
+                    logger.error('Request to server %s failed: %r', base_uri, e)
+                    some_request_failed = True
+
+            raise K8sConnectionFailed('No more API server nodes in the cluster')
+
+        def request(self, retry, method, path, timeout=None, **kwargs):
+            if self._update_api_servers_cache:
+                self._load_api_servers_cache()
+
+            api_servers_cache = self.api_servers_cache
+            api_servers = len(api_servers_cache)
+
+            if timeout:
+                if isinstance(timeout, six.integer_types + (float,)):
+                    timeout = urllib3.Timeout(total=timeout)
+                elif isinstance(timeout, tuple) and len(timeout) == 2:
+                    timeout = urllib3.Timeout(connect=timeout[0], read=timeout[1])
+                retries = 0
+            else:
+                _, timeout, retries = self._calculate_timeouts(api_servers)
+                timeout = urllib3.Timeout(connect=max(1, timeout/2.0), total=timeout)
+            kwargs.update(retries=retries, timeout=timeout)
+
+            while True:
+                try:
+                    return self._do_http_request(retry, api_servers_cache, method, path, **kwargs)
+                except K8sConnectionFailed as ex:
+                    try:
+                        self._load_api_servers_cache()
+                        api_servers_cache = self.api_servers_cache
+                        api_servers = len(api_servers)
+                    except Exception as e:
+                        logger.debug('Failed to update list of K8s master nodes: %r', e)
+
+                    sleeptime = retry.sleeptime
+                    remaining_time = retry.stoptime - sleeptime - time.time()
+                    nodes, timeout, retries = self._calculate_timeouts(api_servers, remaining_time)
+                    if nodes == 0:
+                        self._update_api_servers_cache = True
+                        raise ex
+                    retry.sleep_func(sleeptime)
+                    retry.update_delay()
+                    # We still have some time left. Partially reduce `api_servers_cache` and retry request
+                    kwargs.update(timeout=urllib3.Timeout(connect=max(1, timeout/2.0), total=timeout), retries=retries)
+                    api_servers_cache = api_servers_cache[:nodes]
+
+        def call_api(self, method, path, headers=None, body=None, _retry=None,
+                     _preload_content=True, _request_timeout=None, **kwargs):
+            headers = self._make_headers(headers)
+            fields = {to_camel_case(k): v for k, v in kwargs.items()}  # resource_version => resourceVersion
+            body = json.dumps(body, default=lambda o: o.to_dict()) if body is not None else None
+
+            response = self.request(_retry, method, self._API_URL_PREFIX + path, headers=headers, fields=fields,
+                                    body=body, preload_content=_preload_content, timeout=_request_timeout)
+
+            return self._handle_server_response(response, _preload_content)
+
+    class CoreV1Api(object):
+
+        def __init__(self, api_client=None):
+            self._api_client = api_client or k8s_client.ApiClient()
+
+        def __getattr__(self, func):  # `func` name pattern: (action)_namespaced_(kind)
+            action, kind = func.split('_namespaced_')  # (read|list|create|patch|replace|delete|delete_collection)
+            kind = kind.replace('_', '') + ('s' * int(kind[-1] != 's'))  # plural, single word
+
+            def wrapper(*args, **kwargs):
+                method = {'read': 'GET', 'list': 'GET', 'create': 'POST',
+                          'replace': 'PUT'}.get(action, action.split('_')[0]).upper()
+
+                if action == 'create' or len(args) == 1:  # namespace is a first argument and name in not in arguments
+                    path = '/'.join([args[0], kind])
+                else:  # name, namespace followed by optional body
+                    path = '/'.join([args[1], kind, args[0]])
+
+                headers = {'Content-Type': 'application/strategic-merge-patch+json'} if action == 'patch' else {}
+
+                if len(args) == 3:  # name, namespace, body
+                    body = args[2]
+                elif action == 'create':  # namespace, body
+                    body = args[1]
+                elif action == 'delete':  # name, namespace
+                    body = kwargs.pop('body', None)
+                else:
+                    body = None
+
+                return self._api_client.call_api(method, path, headers, body, **kwargs)
+            return wrapper
+
+    class _K8sObjectTemplate(K8sObject):
+        """The template for objects which we create locally, e.g. k8s_client.V1ObjectMeta & co"""
+        def __init__(self, **kwargs):
+            self._dict = {to_camel_case(k): v for k, v in kwargs.items()}
+
+    def __init__(self):
+        self.__cls_cache = {}
+        self.__cls_lock = Lock()
+
+    def __getattr__(self, name):
+        with self.__cls_lock:
+            if name not in self.__cls_cache:
+                self.__cls_cache[name] = type(name, (self._K8sObjectTemplate,), {})
+        return self.__cls_cache[name]
+
+
+k8s_client = K8sClient()
+k8s_config = K8sConfig()
+
+
 class KubernetesRetriableException(k8s_client.rest.ApiException):
 
     def __init__(self, orig):
@@ -41,11 +439,9 @@ class KubernetesRetriableException(k8s_client.rest.ApiException):
 
 class CoreV1ApiProxy(object):
 
-    def __init__(self, use_endpoints=False):
-        self._api = k8s_client.CoreV1Api()
-        self._api.api_client.user_agent = USER_AGENT
-        self._api.api_client.rest_client.pool_manager.connection_pool_kw['maxsize'] = 10
-        self._request_timeout = None
+    def __init__(self, use_endpoints=False, bypass_api_service=False):
+        self._api_client = k8s_client.ApiClient(bypass_api_service)
+        self._core_v1_api = k8s_client.CoreV1Api(self._api_client)
         self._use_endpoints = bool(use_endpoints)
 
     def configure_timeouts(self, loop_wait, retry_timeout, ttl):
@@ -53,27 +449,21 @@ class CoreV1ApiProxy(object):
         # If we didn't received anything after the loop_wait + retry_timeout it is a time
         # to start worrying (send keepalive messages). Finally, the connection should be
         # considered as dead if we received nothing from the socket after the ttl seconds.
-        cnt = 3
-        idle = int(loop_wait + retry_timeout)
-        intvl = max(1, int(float(ttl - idle) / cnt))
-        self._api.api_client.rest_client.pool_manager.connection_pool_kw['socket_options'] = [
-            (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1),
-            (socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, idle),
-            (socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, intvl),
-            (socket.IPPROTO_TCP, socket.TCP_KEEPCNT, cnt),
-            (socket.IPPROTO_TCP, 18, int(ttl * 1000))  # TCP_USER_TIMEOUT
-        ]
-        self._request_timeout = (1, retry_timeout / 3.0)
+        self._api_client.pool_manager.connection_pool_kw['socket_options'] = \
+                list(keepalive_socket_options(ttl, int(loop_wait + retry_timeout)))
+        self._api_client.set_read_timeout(retry_timeout)
+        self._api_client.set_api_servers_cache_ttl(loop_wait)
+
+    def refresh_api_servers_cache(self):
+        self._api_client.refresh_api_servers_cache()
 
     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)
+                return getattr(self._core_v1_api, func)(*args, **kwargs)
             except k8s_client.rest.ApiException as e:
                 if e.status in (500, 503, 504) or e.headers and 'retry-after' in e.headers:  # XXX
                     raise KubernetesRetriableException(e)
@@ -95,7 +485,7 @@ def catch_kubernetes_errors(func):
             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):
+        except (RetryFailedError, K8sException):
             return False
     return wrapper
 
@@ -105,7 +495,6 @@ class ObjectCache(Thread):
     def __init__(self, dcs, func, retry, condition, name=None):
         Thread.__init__(self)
         self.daemon = True
-        self._api_client = k8s_client.ApiClient()
         self._dcs = dcs
         self._func = func
         self._retry = retry
@@ -119,7 +508,7 @@ class ObjectCache(Thread):
 
     def _list(self):
         try:
-            return self._func(_request_timeout=(self._retry.deadline, Timeout.DEFAULT_TIMEOUT))
+            return self._func(_retry=self._retry.copy())
         except Exception:
             time.sleep(1)
             raise
@@ -163,8 +552,7 @@ class ObjectCache(Thread):
 
         response = self._watch(objects.metadata.resource_version)
         try:
-            for line in k8s_watch.watch.iter_resp_lines(response):
-                event = json.loads(line)
+            for event in iter_response_objects(response):
                 obj = event['object']
                 if obj.get('code') == 410:
                     break
@@ -173,8 +561,7 @@ class ObjectCache(Thread):
                 name = obj['metadata']['name']
 
                 if ev_type in ('ADDED', 'MODIFIED'):
-                    obj = k8s_watch.watch.SimpleNamespace(data=json.dumps(obj))
-                    obj = self._api_client.deserialize(obj, return_type)
+                    obj = K8sObject(obj)
                     success, old_value = self.set(name, obj)
                     if success:
                         new_value = (obj.metadata.annotations or {}).get(self._annotations_map.get(name))
@@ -229,8 +616,7 @@ class Kubernetes(AbstractDCS):
         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))
+                            retry_exceptions=KubernetesRetriableException)
         self._ttl = None
         try:
             k8s_config.load_incluster_config()
@@ -245,7 +631,7 @@ class Kubernetes(AbstractDCS):
             port.update({n: p[n] for n in ('name', 'protocol') if p.get(n)})
             self.__ports.append(k8s_client.V1EndpointPort(**port))
 
-        self._api = CoreV1ApiProxy(config.get('use_endpoints'))
+        self._api = CoreV1ApiProxy(config.get('use_endpoints'), config.get('bypass_api_service'))
         self._should_create_config_service = self._api.use_endpoints
         self.reload_config(config)
         # leader_observed_record, leader_resource_version, and leader_observed_time are used only for leader race!
@@ -265,7 +651,9 @@ class Kubernetes(AbstractDCS):
         self._kinds = ObjectCache(self, kinds_func, self._retry, self._condition, self._name)
 
     def retry(self, *args, **kwargs):
-        return self._retry.copy()(*args, **kwargs)
+        retry = self._retry.copy()
+        kwargs['_retry'] = retry
+        return retry(*args, **kwargs)
 
     def client_path(self, path):
         return super(Kubernetes, self).client_path(path)[1:].replace('/', '-')
@@ -297,8 +685,7 @@ class Kubernetes(AbstractDCS):
         member.data['pod_labels'] = pod.metadata.labels
         return member
 
-    def _wait_caches(self):
-        stop_time = time.time() + self._retry.deadline
+    def _wait_caches(self, stop_time):
         while not (self._pods.is_ready() and self._kinds.is_ready()):
             timeout = stop_time - time.time()
             if timeout <= 0:
@@ -306,9 +693,11 @@ class Kubernetes(AbstractDCS):
             self._condition.wait(timeout)
 
     def _load_cluster(self):
+        stop_time = time.time() + self._retry.deadline
+        self._api.refresh_api_servers_cache()
         try:
             with self._condition:
-                self._wait_caches()
+                self._wait_caches(stop_time)
 
                 members = [self.member(pod) for pod in self._pods.copy().values()]
                 nodes = self._kinds.copy()
@@ -501,6 +890,7 @@ class Kubernetes(AbstractDCS):
         retry = self._retry.copy()
 
         def _retry(*args, **kwargs):
+            kwargs['_retry'] = retry
             return retry(*args, **kwargs)
 
         try:
@@ -511,7 +901,7 @@ class Kubernetes(AbstractDCS):
             else:
                 logger.exception('Permission denied' if e.status == 403 else 'Unexpected error from Kubernetes API')
                 return False
-        except RetryFailedError:
+        except (RetryFailedError, K8sException):
             return False
 
         deadline = retry.stoptime - time.time()

patroni/dcs/raft.py

@@ -0,0 +1,416 @@
+import json
+import logging
+import os
+import threading
+import time
+
+from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
+from pysyncobj import SyncObj, SyncObjConf, replicated, FAIL_REASON
+from pysyncobj.transport import Node, TCPTransport, CONNECTION_STATE
+
+logger = logging.getLogger(__name__)
+
+
+class MessageNode(Node):
+
+    def __init__(self, address):
+        self.address = address
+
+
+class UtilityTransport(TCPTransport):
+
+    def __init__(self, syncObj, selfNode, otherNodes):
+        super(UtilityTransport, self).__init__(syncObj, selfNode, otherNodes)
+        self._selfIsReadonlyNode = False
+
+    def _connectIfNecessarySingle(self, node):
+        pass
+
+    def connectionState(self, node):
+        return self._connections[node].state
+
+    def isDisconnected(self, node):
+        return self.connectionState(node) == CONNECTION_STATE.DISCONNECTED
+
+    def connectIfRequiredSingle(self, node):
+        if self.isDisconnected(node):
+            return self._connections[node].connect(node.ip, node.port)
+
+    def disconnectSingle(self, node):
+        self._connections[node].disconnect()
+
+
+class SyncObjUtility(SyncObj):
+
+    def __init__(self, otherNodes, conf):
+        autoTick = conf.autoTick
+        conf.autoTick = False
+        super(SyncObjUtility, self).__init__(None, otherNodes, conf, transportClass=UtilityTransport)
+        conf.autoTick = autoTick
+        self._SyncObj__transport.setOnMessageReceivedCallback(self._onMessageReceived)
+        self.__result = None
+
+    def setPartnerNode(self, partner):
+        self.__node = partner
+
+    def sendMessage(self, message):
+        # Abuse the fact that node address is send as a first message
+        self._SyncObj__transport._selfNode = MessageNode(message)
+        self._SyncObj__transport.connectIfRequiredSingle(self.__node)
+        while not self._SyncObj__transport.isDisconnected(self.__node):
+            self._poller.poll(0.5)
+        return self.__result
+
+    def _onMessageReceived(self, _, message):
+        self.__result = message
+        self._SyncObj__transport.disconnectSingle(self.__node)
+
+
+class MyTCPTransport(TCPTransport):
+
+    def _onIncomingMessageReceived(self, conn, message):
+        if self._syncObj.encryptor and not conn.sendRandKey:
+            conn.sendRandKey = message
+            conn.recvRandKey = os.urandom(32)
+            conn.send(conn.recvRandKey)
+            return
+
+        # Utility messages
+        if isinstance(message, list) and message[0] == 'members':
+            conn.send(self._syncObj._get_members())
+            return True
+
+        return super(MyTCPTransport, self)._onIncomingMessageReceived(conn, message)
+
+
+class DynMemberSyncObj(SyncObj):
+
+    def __init__(self, selfAddress, partnerAddrs, conf):
+        add_self = False
+        utility = SyncObjUtility(partnerAddrs, conf)
+        for node in utility._SyncObj__otherNodes:
+            utility.setPartnerNode(node)
+            response = utility.sendMessage(['members'])
+            if response:
+                partnerAddrs = [member['addr'] for member in response if member['addr'] != selfAddress]
+                add_self = selfAddress and len(partnerAddrs) == len(response)
+                break
+
+        super(DynMemberSyncObj, self).__init__(selfAddress, partnerAddrs, conf, transportClass=MyTCPTransport)
+        if add_self:
+            threading.Thread(target=utility.sendMessage, args=(['add', selfAddress],)).start()
+
+    def _get_members(self):
+        ret = [{'addr': node.id, 'leader': node == self._getLeader(),
+                'status': CONNECTION_STATE.CONNECTED if node in self._SyncObj__connectedNodes
+                else CONNECTION_STATE.DISCONNECTED} for node in self._SyncObj__otherNodes]
+        ret.append({'addr': self._SyncObj__selfNode.id, 'leader': self._isLeader(),
+                    'status': CONNECTION_STATE.CONNECTED})
+        return ret
+
+    def _SyncObj__doChangeCluster(self, request, reverse=False):
+        ret = False
+        if not self._SyncObj__selfNode or request[0] != 'add' or reverse or request[1] != self._SyncObj__selfNode.id:
+            ret = super(DynMemberSyncObj, self)._SyncObj__doChangeCluster(request, reverse)
+            if ret:
+                self.forceLogCompaction()
+        return ret
+
+
+class KVStoreTTL(DynMemberSyncObj):
+
+    def __init__(self, selfAddress, partnerAddrs, conf, on_set=None, on_delete=None):
+        self.__on_set = on_set
+        self.__on_delete = on_delete
+        self.__limb = {}
+        self.__retry_timeout = None
+        self.__early_apply_local_log = selfAddress is not None
+        self.applied_local_log = False
+        super(KVStoreTTL, self).__init__(selfAddress, partnerAddrs, conf)
+        self.__data = {}
+
+    @staticmethod
+    def __check_requirements(old_value, **kwargs):
+        return ('prevExist' not in kwargs or bool(kwargs['prevExist']) == bool(old_value)) and \
+            ('prevValue' not in kwargs or old_value and old_value['value'] == kwargs['prevValue']) and \
+            (not kwargs.get('prevIndex') or old_value and old_value['index'] == kwargs['prevIndex'])
+
+    def set_retry_timeout(self, retry_timeout):
+        self.__retry_timeout = retry_timeout
+
+    def retry(self, func, *args, **kwargs):
+        event = threading.Event()
+        ret = {'result': None, 'error': -1}
+
+        def callback(result, error):
+            ret.update(result=result, error=error)
+            event.set()
+
+        kwargs['callback'] = callback
+        timeout = kwargs.pop('timeout', None) or self.__retry_timeout
+        deadline = timeout and time.time() + timeout
+
+        while True:
+            event.clear()
+            func(*args, **kwargs)
+            event.wait(timeout)
+            if ret['error'] == FAIL_REASON.SUCCESS:
+                return ret['result']
+            elif ret['error'] == FAIL_REASON.REQUEST_DENIED:
+                break
+            elif deadline:
+                timeout = deadline - time.time()
+                if timeout <= 0:
+                    break
+            time.sleep(1)
+        return False
+
+    @replicated
+    def _set(self, key, value, **kwargs):
+        old_value = self.__data.get(key, {})
+        if not self.__check_requirements(old_value, **kwargs):
+            return False
+
+        if old_value and old_value['created'] != value['created']:
+            value['created'] = value['updated']
+        value['index'] = self._SyncObj__raftLastApplied + 1
+
+        self.__data[key] = value
+        if self.__on_set:
+            self.__on_set(key, value)
+        return True
+
+    def set(self, key, value, ttl=None, **kwargs):
+        old_value = self.__data.get(key, {})
+        if not self.__check_requirements(old_value, **kwargs):
+            return False
+
+        value = {'value': value, 'updated': time.time()}
+        value['created'] = old_value.get('created', value['updated'])
+        if ttl:
+            value['expire'] = value['updated'] + ttl
+        return self.retry(self._set, key, value, **kwargs)
+
+    def __pop(self, key):
+        self.__data.pop(key)
+        if self.__on_delete:
+            self.__on_delete(key)
+
+    @replicated
+    def _delete(self, key, recursive=False, **kwargs):
+        if recursive:
+            for k in list(self.__data.keys()):
+                if k.startswith(key):
+                    self.__pop(k)
+        elif not self.__check_requirements(self.__data.get(key, {}), **kwargs):
+            return False
+        else:
+            self.__pop(key)
+        return True
+
+    def delete(self, key, recursive=False, **kwargs):
+        if not recursive and not self.__check_requirements(self.__data.get(key, {}), **kwargs):
+            return False
+        return self.retry(self._delete, key, recursive=recursive, **kwargs)
+
+    @staticmethod
+    def __values_match(old, new):
+        return all(old.get(n) == new.get(n) for n in ('created', 'updated', 'expire', 'value'))
+
+    @replicated
+    def _expire(self, key, value, callback=None):
+        current = self.__data.get(key)
+        if current and self.__values_match(current, value):
+            self.__pop(key)
+
+    def __expire_keys(self):
+        for key, value in self.__data.items():
+            if value and 'expire' in value and value['expire'] <= time.time() and \
+                    not (key in self.__limb and self.__values_match(self.__limb[key], value)):
+                self.__limb[key] = value
+
+                def callback(*args):
+                    if key in self.__limb and self.__values_match(self.__limb[key], value):
+                        self.__limb.pop(key)
+                self._expire(key, value, callback=callback)
+
+    def get(self, key, recursive=False):
+        if not recursive:
+            return self.__data.get(key)
+        return {k: v for k, v in self.__data.items() if k.startswith(key)}
+
+    def _onTick(self, timeToWait=0.0):
+        # The SyncObj starts applying the local log only when there is at least one node connected.
+        # We want to change this behavior and apply the local log even when there is nobody except us.
+        # It gives us at least some picture about the last known cluster state.
+        if self.__early_apply_local_log and not self.applied_local_log and self._SyncObj__needLoadDumpFile:
+            self._SyncObj__raftCommitIndex = self._SyncObj__getCurrentLogIndex()
+            self._SyncObj__raftCurrentTerm = self._SyncObj__getCurrentLogTerm()
+
+        super(KVStoreTTL, self)._onTick(timeToWait)
+
+        # The SyncObj calls onReady callback only when cluster got the leader and is ready for writes.
+        # In some cases for us it is safe to "signal" the Raft object when the local log is fully applied.
+        # We are using the `applied_local_log` property for that, but not calling the callback function.
+        if self.__early_apply_local_log and not self.applied_local_log and self._SyncObj__raftCommitIndex != 1 and \
+                self._SyncObj__raftLastApplied == self._SyncObj__raftCommitIndex:
+            self.applied_local_log = True
+
+        if self._isLeader():
+            self.__expire_keys()
+        else:
+            self.__limb.clear()
+
+
+class Raft(AbstractDCS):
+
+    def __init__(self, config):
+        super(Raft, self).__init__(config)
+        self._ttl = int(config.get('ttl') or 30)
+
+        self_addr = config.get('self_addr')
+        partner_addrs = config.get('partner_addrs', [])
+        if self._ctl:
+            if self_addr:
+                partner_addrs.append(self_addr)
+            self_addr = None
+
+        ready_event = threading.Event()
+        file_template = os.path.join(config.get('data_dir', ''), (self_addr or ''))
+        conf = SyncObjConf(password=config.get('password'), appendEntriesUseBatch=False,
+                           bindAddress=config.get('bind_addr'), commandsWaitLeader=False,
+                           fullDumpFile=(file_template + '.dump' if self_addr else None),
+                           journalFile=(file_template + '.journal' if self_addr else None),
+                           onReady=ready_event.set, dynamicMembershipChange=True)
+
+        self._sync_obj = KVStoreTTL(self_addr, partner_addrs, conf, self._on_set, self._on_delete)
+        while True:
+            ready_event.wait(5)
+            if ready_event.isSet() or self._sync_obj.applied_local_log:
+                break
+            else:
+                logger.info('waiting on raft')
+        self._sync_obj.forceLogCompaction()
+        self.set_retry_timeout(int(config.get('retry_timeout') or 10))
+
+    def _on_set(self, key, value):
+        leader = (self._sync_obj.get(self.leader_path) or {}).get('value')
+        if key == value['created'] == value['updated'] and \
+                (key.startswith(self.members_path) or key == self.leader_path and leader != self._name) or \
+                key == self.leader_optime_path and leader != self._name or key in (self.config_path, self.sync_path):
+            self.event.set()
+
+    def _on_delete(self, key):
+        if key == self.leader_path:
+            self.event.set()
+
+    def set_ttl(self, ttl):
+        self._ttl = ttl
+
+    @property
+    def ttl(self):
+        return self._ttl
+
+    def set_retry_timeout(self, retry_timeout):
+        self._sync_obj.set_retry_timeout(retry_timeout)
+
+    @staticmethod
+    def member(key, value):
+        return Member.from_node(value['index'], os.path.basename(key), None, value['value'])
+
+    def _load_cluster(self):
+        prefix = self.client_path('')
+        response = self._sync_obj.get(prefix, recursive=True)
+        if not response:
+            return Cluster(None, None, None, None, [], None, None, None)
+        nodes = {os.path.relpath(key, prefix).replace('\\', '/'): value for key, value in response.items()}
+
+        # get initialize flag
+        initialize = nodes.get(self._INITIALIZE)
+        initialize = initialize and initialize['value']
+
+        # get global dynamic configuration
+        config = nodes.get(self._CONFIG)
+        config = config and ClusterConfig.from_node(config['index'], config['value'])
+
+        # get timeline history
+        history = nodes.get(self._HISTORY)
+        history = history and TimelineHistory.from_node(history['index'], 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'])
+
+        # get list of members
+        members = [self.member(k, n) for k, n in nodes.items() if k.startswith(self._MEMBERS) and k.count('/') == 1]
+
+        # get leader
+        leader = nodes.get(self._LEADER)
+        if leader:
+            member = Member(-1, leader['value'], None, {})
+            member = ([m for m in members if m.name == leader['value']] or [member])[0]
+            leader = Leader(leader['index'], None, member)
+
+        # failover key
+        failover = nodes.get(self._FAILOVER)
+        if failover:
+            failover = Failover.from_node(failover['index'], failover['value'])
+
+        # get synchronization state
+        sync = nodes.get(self._SYNC)
+        sync = SyncState.from_node(sync and sync['index'], sync and sync['value'])
+
+        return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+
+    def _write_leader_optime(self, last_operation):
+        return self._sync_obj.set(self.leader_optime_path, last_operation, timeout=1)
+
+    def _update_leader(self):
+        ret = self._sync_obj.set(self.leader_path, self._name, ttl=self._ttl, prevValue=self._name)
+        if not ret and self._sync_obj.get(self.leader_path) is None:
+            ret = self.attempt_to_acquire_leader()
+        return ret
+
+    def attempt_to_acquire_leader(self, permanent=False):
+        return self._sync_obj.set(self.leader_path, self._name, prevExist=False,
+                                  ttl=None if permanent else self._ttl)
+
+    def set_failover_value(self, value, index=None):
+        return self._sync_obj.set(self.failover_path, value, prevIndex=index)
+
+    def set_config_value(self, value, index=None):
+        return self._sync_obj.set(self.config_path, value, prevIndex=index)
+
+    def touch_member(self, data, permanent=False):
+        data = json.dumps(data, separators=(',', ':'))
+        return self._sync_obj.set(self.member_path, data, None if permanent else self._ttl, timeout=2)
+
+    def take_leader(self):
+        return self._sync_obj.set(self.leader_path, self._name, ttl=self._ttl)
+
+    def initialize(self, create_new=True, sysid=''):
+        return self._sync_obj.set(self.initialize_path, sysid, prevExist=(not create_new))
+
+    def _delete_leader(self):
+        return self._sync_obj.delete(self.leader_path, prevValue=self._name, timeout=1)
+
+    def cancel_initialization(self):
+        return self._sync_obj.delete(self.initialize_path)
+
+    def delete_cluster(self):
+        return self._sync_obj.delete(self.client_path(''), recursive=True)
+
+    def set_history_value(self, value):
+        return self._sync_obj.set(self.history_path, value)
+
+    def set_sync_state_value(self, value, index=None):
+        return self._sync_obj.set(self.sync_path, value, prevIndex=index)
+
+    def delete_sync_state(self, index=None):
+        return self._sync_obj.delete(self.sync_path, prevIndex=index)
+
+    def watch(self, leader_index, timeout):
+        try:
+            return super(Raft, self).watch(leader_index, timeout)
+        finally:
+            self.event.clear()

patroni/dcs/zookeeper.py

@@ -63,13 +63,18 @@ class ZooKeeper(AbstractDCS):
         if isinstance(hosts, list):
             hosts = ','.join(hosts)
 
+        mapping = {'use_ssl': 'use_ssl', 'verify': 'verify_certs', 'cacert': 'ca',
+                   'cert': 'certfile', 'key': 'keyfile', 'key_password': 'keyfile_password'}
+        kwargs = {v: config[k] for k, v in mapping.items() if k in config}
+
         self._client = KazooClient(hosts, handler=PatroniSequentialThreadingHandler(config['retry_timeout']),
                                    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))
+                                   max_delay=1, max_tries=-1, sleep_func=time.sleep), **kwargs)
         self._client.add_listener(self.session_listener)
 
         self._fetch_cluster = True
+        self._fetch_optime = True
 
         self._orig_kazoo_connect = self._client._connection._connect
         self._client._connection._connect = self._kazoo_connect
@@ -95,9 +100,13 @@ class ZooKeeper(AbstractDCS):
         if state in [KazooState.SUSPENDED, KazooState.LOST]:
             self.cluster_watcher(None)
 
+    def optime_watcher(self, event):
+        self._fetch_optime = True
+        self.event.set()
+
     def cluster_watcher(self, event):
         self._fetch_cluster = True
-        self.event.set()
+        self.optime_watcher(event)
 
     def reload_config(self, config):
         self.set_retry_timeout(config['retry_timeout'])
@@ -141,6 +150,12 @@ class ZooKeeper(AbstractDCS):
         except NoNodeError:
             return None
 
+    def get_leader_optime(self, leader):
+        watch = self.optime_watcher if not leader or leader.name != self._name else None
+        optime = self.get_node(self.leader_optime_path, watch)
+        self._fetch_optime = False
+        return optime and int(optime[0]) or 0
+
     @staticmethod
     def member(name, value, znode):
         return Member.from_node(znode.version, name, znode.ephemeralOwner, value)
@@ -154,7 +169,7 @@ class ZooKeeper(AbstractDCS):
     def load_members(self, sync_standby):
         members = []
         for member in self.get_children(self.members_path, self.cluster_watcher):
-            watch = member == sync_standby and self.cluster_watcher or None
+            watch = member in 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))
@@ -178,16 +193,12 @@ class ZooKeeper(AbstractDCS):
         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
-        sync_standby = sync.leader == self._name and sync.sync_standby or None
+        sync_standby = sync.leader == self._name and sync.members or []
         members = self.load_members(sync_standby) if self._MEMBERS[:-1] in nodes else []
 
         # get leader
@@ -206,6 +217,9 @@ class ZooKeeper(AbstractDCS):
                 leader = Leader(leader[1].version, leader[1].ephemeralOwner, member)
                 self._fetch_cluster = member.index == -1
 
+        # get last leader operation
+        last_leader_operation = self._OPTIME in nodes and self.get_leader_optime(leader)
+
         # failover key
         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])
@@ -221,6 +235,15 @@ class ZooKeeper(AbstractDCS):
                 logger.exception('get_cluster')
                 self.cluster_watcher(None)
                 raise ZooKeeperError('ZooKeeper in not responding properly')
+        # Optime ZNode was updated or doesn't exist and we are not leader
+        elif (self._fetch_optime and not self._fetch_cluster or not cluster.last_leader_operation) and\
+                not (cluster.leader and cluster.leader.name == self._name):
+            try:
+                optime = self.get_leader_optime(cluster.leader)
+                cluster = Cluster(cluster.initialize, cluster.config, cluster.leader, optime,
+                                  cluster.members, cluster.failover, cluster.sync, cluster.history)
+            except Exception:
+                pass
         return cluster
 
     def _bypass_caches(self):
@@ -349,6 +372,6 @@ class ZooKeeper(AbstractDCS):
         return self.set_sync_state_value("{}", index)
 
     def watch(self, leader_index, timeout):
-        if super(ZooKeeper, self).watch(leader_index, timeout):
+        if super(ZooKeeper, self).watch(leader_index, timeout) and not self._fetch_optime:
             self._fetch_cluster = True
         return self._fetch_cluster

patroni/exceptions.py

@@ -13,6 +13,10 @@ class PatroniException(Exception):
         return repr(self.value)
 
 
+class PatroniFatalException(PatroniException):
+    pass
+
+
 class PostgresException(PatroniException):
     pass
 

patroni/ha.py

@@ -10,7 +10,7 @@ import uuid
 from collections import namedtuple
 from multiprocessing.pool import ThreadPool
 from patroni.async_executor import AsyncExecutor, CriticalTask
-from patroni.exceptions import DCSError, PostgresConnectionException, PatroniException
+from patroni.exceptions import DCSError, PostgresConnectionException, PatroniFatalException
 from patroni.postgresql import ACTION_ON_START, ACTION_ON_ROLE_CHANGE
 from patroni.postgresql.misc import postgres_version_to_int
 from patroni.postgresql.rewind import Rewind
@@ -70,8 +70,9 @@ class Ha(object):
         self._was_paused = False
         self._leader_timeline = None
         self.recovering = False
-        self._post_bootstrap_task = None
+        self._async_response = CriticalTask()
         self._crash_recovery_executed = False
+        self._crash_recovery_started = None
         self._start_timeout = None
         self._async_executor = AsyncExecutor(self.state_handler.cancellable, self.wakeup)
         self.watchdog = patroni.watchdog
@@ -87,6 +88,9 @@ class Ha(object):
         # already running as replica was aborted due to cluster not beeing initialized in DCS.
         self._join_aborted = False
 
+        # used only in backoff after failing a pre_promote script
+        self._released_leader_key_timestamp = 0
+
     def check_mode(self, mode):
         # Try to protect from the case when DCS was wiped out during pause
         if self.cluster and self.cluster.config and self.cluster.config.modify_index:
@@ -153,7 +157,11 @@ class Ha(object):
                 last_operation = self.state_handler.last_operation()
             except Exception:
                 logger.exception('Exception when called state_handler.last_operation()')
-        ret = self.dcs.update_leader(last_operation, self._leader_access_is_restricted)
+        try:
+            ret = self.dcs.update_leader(last_operation, self._leader_access_is_restricted)
+        except Exception:
+            logger.exception('Unexpected exception raised from update_leader, please report it as a BUG')
+            ret = False
         self.set_is_leader(ret)
         if ret:
             self.watchdog.keepalive()
@@ -252,7 +260,8 @@ class Ha(object):
         elif self.cluster.initialize is None and not self.patroni.nofailover and 'bootstrap' in self.patroni.config:
             if self.dcs.initialize(create_new=True):  # race for initialization
                 self.state_handler.bootstrapping = True
-                self._post_bootstrap_task = CriticalTask()
+                with self._async_response:
+                    self._async_response.reset()
 
                 if self.is_standby_cluster():
                     ret = self._async_executor.try_run_async('bootstrap_standby_leader', self.bootstrap_standby_leader)
@@ -279,7 +288,8 @@ class Ha(object):
         clone_source = self.get_remote_master()
         msg = 'clone from remote master {0}'.format(clone_source.conn_url)
         result = self.clone(clone_source, msg)
-        self._post_bootstrap_task.complete(result)
+        with self._async_response:  # pretend that post_bootstrap was already executed
+            self._async_response.complete(result)
         if result:
             self.state_handler.set_role('standby_leader')
 
@@ -324,6 +334,7 @@ class Ha(object):
                 and not self._crash_recovery_executed and \
                 (self.cluster.is_unlocked() or self._rewind.can_rewind):
             self._crash_recovery_executed = True
+            self._crash_recovery_started = time.time()
             msg = 'doing crash recovery in a single user mode'
             return self._async_executor.try_run_async(msg, self._rewind.ensure_clean_shutdown) or msg
 
@@ -366,7 +377,7 @@ class Ha(object):
         elif self.patroni.replicatefrom and self.patroni.replicatefrom != self.state_handler.name:
             node_to_follow = cluster.get_member(self.patroni.replicatefrom)
         else:
-            node_to_follow = cluster.leader
+            node_to_follow = cluster.leader if cluster.leader and cluster.leader.name else None
 
         node_to_follow = node_to_follow if node_to_follow and node_to_follow.name != self.state_handler.name else None
 
@@ -447,28 +458,34 @@ class Ha(object):
         promoting standbys that were guaranteed to be replicating synchronously.
         """
         if self.is_synchronous_mode():
-            current = self.cluster.sync.leader and self.cluster.sync.sync_standby
-            picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster)
-            if picked != current:
-                # We need to revoke privilege from current before replacing it in the config
-                if current:
-                    logger.info("Removing synchronous privilege from %s", current)
-                    if not self.dcs.write_sync_state(self.state_handler.name, None, index=self.cluster.sync.index):
+            sync_node_count = self.patroni.config['synchronous_node_count']
+            current = self.cluster.sync.leader and self.cluster.sync.members or []
+            picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster, sync_node_count)
+            if set(picked) != set(current):
+                # update synchronous standby list in dcs temporarily to point to common nodes in current and picked
+                sync_common = list(set(current).intersection(set(allow_promote)))
+                if set(sync_common) != set(current):
+                    logger.info("Updating synchronous privilege temporarily from %s to %s", current, sync_common)
+                    if not self.dcs.write_sync_state(self.state_handler.name,
+                                                     sync_common or None,
+                                                     index=self.cluster.sync.index):
                         logger.info('Synchronous replication key updated by someone else.')
                         return
 
-                if self.is_synchronous_mode_strict() and picked is None:
-                    picked = '*'
+                # Update  db param and wait for x secs
+                if self.is_synchronous_mode_strict() and not picked:
+                    picked = ['*']
                     logger.warning("No standbys available!")
 
                 logger.info("Assigning synchronous standby status to %s", picked)
                 self.state_handler.config.set_synchronous_standby(picked)
 
-                if picked and picked != '*' and not allow_promote:
+                if picked and picked[0] != '*' and set(allow_promote) != set(picked) and not allow_promote:
                     # Wait for PostgreSQL to enable synchronous mode and see if we can immediately set sync_standby
                     time.sleep(2)
-                    picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster)
-                if allow_promote:
+                    _, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster,
+                                                                                   sync_node_count)
+                if allow_promote and set(allow_promote) != set(sync_common):
                     try:
                         cluster = self.dcs.get_cluster()
                     except DCSError:
@@ -476,18 +493,18 @@ class Ha(object):
                     if cluster.sync.leader and cluster.sync.leader != self.state_handler.name:
                         logger.info("Synchronous replication key updated by someone else")
                         return
-                    if not self.dcs.write_sync_state(self.state_handler.name, picked, index=cluster.sync.index):
+                    if not self.dcs.write_sync_state(self.state_handler.name, allow_promote, index=cluster.sync.index):
                         logger.info("Synchronous replication key updated by someone else")
                         return
-                    logger.info("Synchronous standby status assigned to %s", picked)
+                    logger.info("Synchronous standby status assigned to %s", allow_promote)
         else:
             if self.cluster.sync.leader and self.dcs.delete_sync_state(index=self.cluster.sync.index):
                 logger.info("Disabled synchronous replication")
-            self.state_handler.config.set_synchronous_standby(None)
+            self.state_handler.config.set_synchronous_standby([])
 
     def is_sync_standby(self, cluster):
         return cluster.leader and cluster.sync.leader == cluster.leader.name \
-            and cluster.sync.sync_standby == self.state_handler.name
+            and self.state_handler.name in cluster.sync.members
 
     def while_not_sync_standby(self, func):
         """Runs specified action while trying to make sure that the node is not assigned synchronous standby status.
@@ -550,13 +567,27 @@ class Ha(object):
         return self.follow(demote_reason, message)
 
     def enforce_master_role(self, message, promote_message):
-        if not self.is_paused() and not self.watchdog.is_running and not self.watchdog.activate():
-            if self.state_handler.is_leader():
-                self.demote('immediate')
-                return 'Demoting self because watchdog could not be activated'
-            else:
-                self.release_leader_key_voluntarily()
-                return 'Not promoting self because watchdog could not be activated'
+        """
+        Ensure the node that has won the race for the leader key meets criteria
+        for promoting its PG server to the 'master' role.
+        """
+        if not self.is_paused():
+            if not self.watchdog.is_running and not self.watchdog.activate():
+                if self.state_handler.is_leader():
+                    self.demote('immediate')
+                    return 'Demoting self because watchdog could not be activated'
+                else:
+                    self.release_leader_key_voluntarily()
+                    return 'Not promoting self because watchdog could not be activated'
+
+            with self._async_response:
+                if self._async_response.result is False:
+                    logger.warning("Releasing the leader key voluntarily because the pre-promote script failed")
+                    self._released_leader_key_timestamp = time.time()
+                    self.release_leader_key_voluntarily()
+                    # discard the result of the failed pre-promote script to be able to re-try promote
+                    self._async_response.reset()
+                    return 'Promotion cancelled because the pre-promote script failed'
 
         if self.state_handler.is_leader():
             # Inform the state handler about its master role.
@@ -576,7 +607,7 @@ class Ha(object):
                     # Somebody else updated sync state, it may be due to us losing the lock. To be safe, postpone
                     # promotion until next cycle. TODO: trigger immediate retry of run_cycle
                     return 'Postponing promotion because synchronous replication state was updated by somebody else'
-                self.state_handler.config.set_synchronous_standby('*' if self.is_synchronous_mode_strict() else None)
+                self.state_handler.config.set_synchronous_standby(['*'] if self.is_synchronous_mode_strict() else [])
             if self.state_handler.role != 'master':
                 self.set_leader_access_is_restricted(self.cluster.has_permanent_logical_slots(self.state_handler.name))
 
@@ -584,8 +615,10 @@ class Ha(object):
                     self._rewind.reset_state()
                     logger.info("cleared rewind state after becoming the leader")
 
+                with self._async_response:
+                    self._async_response.reset()
                 self._async_executor.try_run_async('promote', self.state_handler.promote,
-                                                   args=(self.dcs.loop_wait, on_success,
+                                                   args=(self.dcs.loop_wait, self._async_response, on_success,
                                                          self._leader_access_is_restricted))
             return promote_message
 
@@ -721,6 +754,10 @@ class Ha(object):
         return self._is_healthiest_node(members, check_replication_lag=False)
 
     def is_healthiest_node(self):
+        if time.time() - self._released_leader_key_timestamp < self.dcs.ttl:
+            logger.info('backoff: skip leader race after pre_promote script failure and releasing the lock voluntarily')
+            return False
+
         if self.is_paused() and not self.patroni.nofailover and \
                 self.cluster.failover and not self.cluster.failover.scheduled_at:
             ret = self.manual_failover_process_no_leader()
@@ -730,8 +767,10 @@ class Ha(object):
         if self.state_handler.is_starting():  # postgresql still starting up is unhealthy
             return False
 
-        if self.state_handler.is_leader():  # leader is always the healthiest
-            return True
+        if self.state_handler.is_leader():
+            # in pause leader is the healthiest only when no initialize or sysid matches with initialize!
+            return not self.is_paused() or not self.cluster.initialize\
+                    or self.state_handler.sysid == self.cluster.initialize
 
         if self.is_paused():
             return False
@@ -811,7 +850,7 @@ class Ha(object):
             self._async_executor.try_run_async('starting after demotion', self.state_handler.follow, (node_to_follow,))
         else:
             if self.is_synchronous_mode():
-                self.state_handler.config.set_synchronous_standby(None)
+                self.state_handler.config.set_synchronous_standby([])
             if self._rewind.rewind_or_reinitialize_needed_and_possible(leader):
                 return False  # do not start postgres, but run pg_rewind on the next iteration
             self.state_handler.follow(node_to_follow)
@@ -872,7 +911,7 @@ class Ha(object):
                 else:
                     if self.is_synchronous_mode():
                         if failover.candidate and not self.cluster.sync.matches(failover.candidate):
-                            logger.warning('Failover candidate=%s does not match with sync_standby=%s',
+                            logger.warning('Failover candidate=%s does not match with sync_standbys=%s',
                                            failover.candidate, self.cluster.sync.sync_standby)
                             members = []
                         else:
@@ -910,9 +949,9 @@ class Ha(object):
                 self.load_cluster_from_dcs()
 
                 if self.is_standby_cluster():
-                    # standby leader disappeared, and this is a healthiest
+                    # standby leader disappeared, and this is the healthiest
                     # replica, so it should become a new standby leader.
-                    # This imply that we need to start following a remote master
+                    # This implies we need to start following a remote master
                     msg = 'promoted self to a standby leader by acquiring session lock'
                     return self.enforce_follow_remote_master(msg)
                 else:
@@ -1130,10 +1169,28 @@ class Ha(object):
         self._async_executor.run_async(self._do_reinitialize, args=(self.cluster, ))
 
     def handle_long_action_in_progress(self):
+        """
+        Figure out what to do with the task AsyncExecutor is performing.
+        """
         if self.has_lock() and self.update_lock():
+            if self._async_executor.scheduled_action == 'doing crash recovery in a single user mode':
+                time_left = self.patroni.config['master_start_timeout'] - (time.time() - self._crash_recovery_started)
+                if time_left <= 0 and self.is_failover_possible(self.cluster.members):
+                    logger.info("Demoting self because crash recovery is taking too long")
+                    self.state_handler.cancellable.cancel(True)
+                    self.demote('immediate')
+                    return 'terminated crash recovery because of startup timeout'
+
             return 'updated leader lock during ' + self._async_executor.scheduled_action
         elif not self.state_handler.bootstrapping:
-            # Don't have lock, make sure we are not starting up a master in the background
+            # Don't have lock, make sure we are not promoting or starting up a master in the background
+            if self._async_executor.scheduled_action == 'promote':
+                with self._async_response:
+                    cancel = self._async_response.cancel()
+                if cancel:
+                    self.state_handler.cancellable.cancel()
+                    return 'lost leader before promote'
+
             if self.state_handler.role == 'master':
                 logger.info("Demoting master during " + self._async_executor.scheduled_action)
                 if self._async_executor.scheduled_action == 'restart':
@@ -1144,7 +1201,6 @@ class Ha(object):
                             self.state_handler.terminate_starting_postmaster(postmaster=task.result)
                 self.demote('immediate-nolock')
                 return 'lost leader lock during ' + self._async_executor.scheduled_action
-
         if self.cluster.is_unlocked():
             logger.info('not healthy enough for leader race')
 
@@ -1176,20 +1232,22 @@ class Ha(object):
         self.dcs.cancel_initialization()
         self.state_handler.stop('immediate', stop_timeout=self.patroni.config['retry_timeout'])
         self.state_handler.move_data_directory()
-        raise PatroniException('Failed to bootstrap cluster')
+        raise PatroniFatalException('Failed to bootstrap cluster')
 
     def post_bootstrap(self):
+        with self._async_response:
+            result = self._async_response.result
         # bootstrap has failed if postgres is not running
-        if not self.state_handler.is_running() or self._post_bootstrap_task.result is False:
+        if not self.state_handler.is_running() or result is False:
             self.cancel_initialization()
 
-        if self._post_bootstrap_task.result is None:
+        if result is None:
             if not self.state_handler.is_leader():
                 return 'waiting for end of recovery after bootstrap'
 
             self.state_handler.set_role('master')
             ret = self._async_executor.try_run_async('post_bootstrap', self.state_handler.bootstrap.post_bootstrap,
-                                                     args=(self.patroni.config['bootstrap'], self._post_bootstrap_task))
+                                                     args=(self.patroni.config['bootstrap'], self._async_response))
             return ret or 'running post_bootstrap'
 
         self.state_handler.bootstrapping = False
@@ -1306,6 +1364,8 @@ class Ha(object):
                     self.release_leader_key_voluntarily()
                     return 'released leader key voluntarily as data dir empty and currently leader'
 
+                if self.is_paused():
+                    return 'running with empty data directory'
                 return self.bootstrap()  # new node
             else:
                 # check if we are allowed to join
@@ -1317,9 +1377,16 @@ class Ha(object):
 
                 if self.sysid_valid(self.cluster.initialize):
                     if self.cluster.initialize != data_sysid:
-                        logger.fatal("system ID mismatch, node %s belongs to a different cluster: %s != %s",
-                                     self.state_handler.name, self.cluster.initialize, data_sysid)
-                        sys.exit(1)
+                        if self.is_paused():
+                            logger.warning('system ID has changed while in paused mode. Patroni will exit when resuming'
+                                           ' unless system ID is reset: %s != %s', self.cluster.initialize, data_sysid)
+                            if self.has_lock():
+                                self.release_leader_key_voluntarily()
+                                return 'released leader key voluntarily due to the system ID mismatch'
+                        else:
+                            logger.fatal('system ID mismatch, node %s belongs to a different cluster: %s != %s',
+                                         self.state_handler.name, self.cluster.initialize, data_sysid)
+                            sys.exit(1)
                 elif self.cluster.is_unlocked() and not self.is_paused():
                     # "bootstrap", but data directory is not empty
                     if not self.state_handler.cb_called and self.state_handler.is_running() \
@@ -1332,6 +1399,7 @@ class Ha(object):
 
             if not self.state_handler.is_healthy():
                 if self.is_paused():
+                    self.state_handler.set_state('stopped')
                     if self.has_lock():
                         self._delete_leader()
                         return 'removed leader lock because postgres is not running'
@@ -1344,6 +1412,8 @@ class Ha(object):
                             (self._rewind.is_needed and self._rewind.can_rewind_or_reinitialize_allowed):
                         return 'postgres is not running'
 
+                if self.state_handler.state in ('running', 'starting'):
+                    self.state_handler.set_state('crashed')
                 # try to start dead postgres
                 return self.recover()
 
@@ -1381,6 +1451,8 @@ class Ha(object):
             try:
                 info = self._run_cycle()
                 return (self.is_paused() and 'PAUSE: ' or '') + info
+            except PatroniFatalException:
+                raise
             except Exception:
                 logger.exception('Unexpected exception')
                 return 'Unexpected exception raised, please report it as a BUG'
@@ -1398,7 +1470,7 @@ class Ha(object):
             self.while_not_sync_standby(lambda: self.state_handler.stop(checkpoint=False, on_safepoint=disable_wd,
                                                                         stop_timeout=self.master_stop_timeout()))
             if not self.state_handler.is_running():
-                if self.has_lock():
+                if self.is_leader():
                     checkpoint_location = self.state_handler.latest_checkpoint_location()
                     self.dcs.delete_leader(checkpoint_location)
                 self.touch_member()
@@ -1411,7 +1483,7 @@ class Ha(object):
 
     def watch(self, timeout):
         # watch on leader key changes if the postgres is running and leader is known and current node is not lock owner
-        if self._async_executor.busy or self.cluster.is_unlocked() or self.has_lock(False):
+        if self._async_executor.busy or not self.cluster or self.cluster.is_unlocked() or self.has_lock(False):
             leader_index = None
         else:
             leader_index = self.cluster.leader.index

patroni/postgresql/__init__.py

@@ -20,8 +20,8 @@ from patroni.postgresql.postmaster import PostmasterProcess
 from patroni.postgresql.slots import SlotsHandler
 from patroni.exceptions import PostgresConnectionException
 from patroni.utils import Retry, RetryFailedError, polling_loop, data_directory_is_empty, parse_int
-from threading import current_thread, Lock
 from psutil import TimeoutExpired
+from threading import current_thread, Lock
 
 
 logger = logging.getLogger(__name__)
@@ -459,6 +459,8 @@ class Postgresql(object):
         self._pending_restart = False
 
         try:
+            if not self._major_version:
+                self.configure_server_parameters()
             configuration = self.config.effective_configuration
         except Exception:
             return None
@@ -470,7 +472,7 @@ class Postgresql(object):
         self.config.replace_pg_ident()
 
         options = ['--{0}={1}'.format(p, configuration[p]) for p in self.config.CMDLINE_OPTIONS
-                   if p in configuration and p != 'wal_keep_segments']
+                   if p in configuration and p not in ('wal_keep_segments', 'wal_keep_size')]
 
         if self.cancellable.is_cancelled:
             return False
@@ -698,7 +700,7 @@ class Postgresql(object):
         return True
 
     def get_guc_value(self, name):
-        cmd = [self.pgcommand('postgres'), self._data_dir, '-C', name]
+        cmd = [self.pgcommand('postgres'), '-D', self._data_dir, '-C', name]
         try:
             data = subprocess.check_output(cmd)
             if data:
@@ -795,9 +797,38 @@ class Postgresql(object):
             if data.get('Database cluster state') == 'in production':
                 return True
 
-    def promote(self, wait_seconds, on_success=None, access_is_restricted=False):
+    def _pre_promote(self):
+        """
+        Runs a fencing script after the leader lock is acquired but before the replica is promoted.
+        If the script exits with a non-zero code, promotion does not happen and the leader key is removed from DCS.
+        """
+
+        cmd = self.config.get('pre_promote')
+        if not cmd:
+            return True
+
+        ret = self.cancellable.call(shlex.split(cmd))
+        if ret is not None:
+            logger.info('pre_promote script `%s` exited with %s', cmd, ret)
+        return ret == 0
+
+    def promote(self, wait_seconds, task, on_success=None, access_is_restricted=False):
         if self.role == 'master':
             return True
+
+        ret = self._pre_promote()
+        with task:
+            if task.is_cancelled:
+                return False
+            task.complete(ret)
+
+        if ret is False:
+            return False
+
+        if self.cancellable.is_cancelled:
+            logger.info("PostgreSQL promote cancelled.")
+            return False
+
         ret = self.pg_ctl('promote', '-W')
         if ret:
             self.set_role('master')
@@ -850,10 +881,51 @@ class Postgresql(object):
         self.config.setup_server_parameters()
         return True
 
+    def pg_wal_realpath(self):
+        """Returns a dict containing the symlink (key) and target (value) for the wal directory"""
+        links = {}
+        for pg_wal_dir in ('pg_xlog', 'pg_wal'):
+            pg_wal_path = os.path.join(self._data_dir, pg_wal_dir)
+            if os.path.exists(pg_wal_path) and os.path.islink(pg_wal_path):
+                pg_wal_realpath = os.path.realpath(pg_wal_path)
+                links[pg_wal_path] = pg_wal_realpath
+        return links
+
+    def pg_tblspc_realpaths(self):
+        """Returns a dict containing the symlink (key) and target (values) for the tablespaces"""
+        links = {}
+        pg_tblsp_dir = os.path.join(self._data_dir, 'pg_tblspc')
+        if os.path.exists(pg_tblsp_dir):
+            for tsdn in os.listdir(pg_tblsp_dir):
+                pg_tsp_path = os.path.join(pg_tblsp_dir, tsdn)
+                if parse_int(tsdn) and os.path.islink(pg_tsp_path):
+                    pg_tsp_rpath = os.path.realpath(pg_tsp_path)
+                    links[pg_tsp_path] = pg_tsp_rpath
+        return links
+
     def move_data_directory(self):
         if os.path.isdir(self._data_dir) and not self.is_running():
             try:
-                new_name = '{0}_{1}'.format(self._data_dir, time.strftime('%Y-%m-%d-%H-%M-%S'))
+                postfix = time.strftime('%Y-%m-%d-%H-%M-%S')
+
+                # let's see if the wal directory is a symlink, in this case we
+                # should move the target
+                for (source, pg_wal_realpath) in self.pg_wal_realpath().items():
+                    logger.info('renaming WAL directory and updating symlink: %s', pg_wal_realpath)
+                    new_name = '{0}_{1}'.format(pg_wal_realpath, postfix)
+                    os.rename(pg_wal_realpath, new_name)
+                    os.unlink(source)
+                    os.symlink(source, new_name)
+
+                # Move user defined tablespace directory
+                for (source, pg_tsp_rpath) in self.pg_tblspc_realpaths().items():
+                    logger.info('renaming user defined tablespace directory and updating symlink: %s', pg_tsp_rpath)
+                    new_name = '{0}_{1}'.format(pg_tsp_rpath, postfix)
+                    os.rename(pg_tsp_rpath, new_name)
+                    os.unlink(source)
+                    os.symlink(source, new_name)
+
+                new_name = '{0}_{1}'.format(self._data_dir, postfix)
                 logger.info('renaming data directory to %s', new_name)
                 os.rename(self._data_dir, new_name)
             except OSError:
@@ -871,67 +943,71 @@ class Postgresql(object):
                 os.remove(self._data_dir)
             elif os.path.isdir(self._data_dir):
 
-                # let's see if pg_xlog|pg_wal is a symlink, in this case we
+                # let's see if wal directory is a symlink, in this case we
                 # should clean the target
-                for pg_wal_dir in ('pg_xlog', 'pg_wal'):
-                    pg_wal_path = os.path.join(self._data_dir, pg_wal_dir)
-                    if os.path.exists(pg_wal_path) and os.path.islink(pg_wal_path):
-                        pg_wal_realpath = os.path.realpath(pg_wal_path)
-                        logger.info('Removing WAL directory: %s', pg_wal_realpath)
-                        shutil.rmtree(pg_wal_realpath)
-                # Remove user defined tablespace directory
-                pg_tblsp_dir = os.path.join(self._data_dir, 'pg_tblspc')
-                if os.path.exists(pg_tblsp_dir):
-                    for tsdn in os.listdir(pg_tblsp_dir):
-                        pg_tsp_path = os.path.join(pg_tblsp_dir, tsdn)
-                        if parse_int(tsdn) and os.path.islink(pg_tsp_path):
-                            pg_tsp_rpath = os.path.realpath(pg_tsp_path)
-                            logger.info('Removing user defined tablespace directory: %s', pg_tsp_rpath)
-                            shutil.rmtree(pg_tsp_rpath, ignore_errors=True)
+                for pg_wal_realpath in self.pg_wal_realpath().values():
+                    logger.info('Removing WAL directory: %s', pg_wal_realpath)
+                    shutil.rmtree(pg_wal_realpath)
+
+                # Remove user defined tablespace directories
+                for pg_tsp_rpath in self.pg_tblspc_realpaths().values():
+                    logger.info('Removing user defined tablespace directory: %s', pg_tsp_rpath)
+                    shutil.rmtree(pg_tsp_rpath, ignore_errors=True)
 
                 shutil.rmtree(self._data_dir)
         except (IOError, OSError):
             logger.exception('Could not remove data directory %s', self._data_dir)
             self.move_data_directory()
 
-    def pick_synchronous_standby(self, cluster):
+    def _get_synchronous_commit_param(self):
+        return self.query("SHOW synchronous_commit").fetchone()[0]
+
+    def pick_synchronous_standby(self, cluster, sync_node_count=1):
         """Finds the best candidate to be the synchronous standby.
 
         Current synchronous standby is always preferred, unless it has disconnected or does not want to be a
         synchronous standby any longer.
 
-        :returns tuple of candidate name or None, and bool showing if the member is the active synchronous standby.
+        :returns tuple of candidates list and synchronous standby list.
         """
-        current = cluster.sync.sync_standby
-        current = current.lower() if current else current
+        if self._major_version < 90600:
+            sync_node_count = 1
         members = {m.name.lower(): m for m in cluster.members}
         candidates = []
-        # Pick candidates based on who has flushed WAL farthest.
-        # TODO: for synchronous_commit = remote_write we actually want to order on write_location
+        sync_nodes = []
+        # Pick candidates based on who has higher replay/remote_write/flush lsn.
+        sync_commit_par = self._get_synchronous_commit_param()
+        sort_col = {'remote_apply': 'replay', 'remote_write': 'write'}.get(sync_commit_par, 'flush')
+        # pg_stat_replication.sync_state has 4 possible states - async, potential, quorum, sync.
+        # Sort clause "ORDER BY sync_state DESC" is to get the result in required order and to keep
+        # the result consistent in case if a synchronous standby member is slowed down OR async node
+        # receiving changes faster than the sync member (very rare but possible). Such cases would
+        # trigger sync standby member swapping frequently and the sort on sync_state desc should
+        # help in keeping the query result consistent.
         for app_name, state, sync_state in self.query(
                 "SELECT pg_catalog.lower(application_name), state, sync_state"
                 " FROM pg_catalog.pg_stat_replication"
-                " ORDER BY flush_{0} DESC".format(self.lsn_name)):
+                " WHERE state = 'streaming'"
+                " ORDER BY sync_state DESC, {0}_{1} DESC".format(sort_col, self.lsn_name)):
             member = members.get(app_name)
-            if state != 'streaming' or not member or member.tags.get('nosync', False):
+            if not member or member.tags.get('nosync', False):
                 continue
+            candidates.append(member.name)
             if sync_state == 'sync':
-                return member.name, True
-            if sync_state == 'potential' and app_name == current:
-                # Prefer current even if not the best one any more to avoid indecisivness and spurious swaps.
-                return cluster.sync.sync_standby, False
-            if sync_state in ('async', 'potential'):
-                candidates.append(member.name)
+                sync_nodes.append(member.name)
+            if len(candidates) >= sync_node_count:
+                break
 
-        if candidates:
-            return candidates[0], False
-        return None, False
+        return candidates, sync_nodes
 
     def schedule_sanity_checks_after_pause(self):
         """
             After coming out of pause we have to:
-            1. sync replication slots, because it might happen that slots were removed
-            2. get new 'Database system identifier' to make sure that it wasn't changed
+            1. configure server parameters if necessary
+            2. sync replication slots, because it might happen that slots were removed
+            3. get new 'Database system identifier' to make sure that it wasn't changed
         """
+        if not self._major_version:
+            self.configure_server_parameters()
         self.slots_handler.schedule()
         self._sysid = None

patroni/postgresql/bootstrap.py

@@ -98,7 +98,8 @@ class Bootstrap(object):
 
     def _custom_bootstrap(self, config):
         self._postgresql.set_state('running custom bootstrap script')
-        params = ['--scope=' + self._postgresql.scope, '--datadir=' + self._postgresql.data_dir]
+        params = [] if config.get('no_params') else ['--scope=' + self._postgresql.scope,
+                                                     '--datadir=' + self._postgresql.data_dir]
         try:
             logger.info('Running custom bootstrap script: %s', config['command'])
             if self._postgresql.cancellable.call(shlex.split(config['command']) + params) != 0:
@@ -355,7 +356,8 @@ END;$$""".format(f, rewind['username'])
                     self._running_custom_bootstrap = False
                     # If we don't have custom configuration for pg_hba.conf we need to restore original file
                     if not postgresql.config.get('pg_hba'):
-                        os.unlink(postgresql.config.pg_hba_conf)
+                        if os.path.exists(postgresql.config.pg_hba_conf):
+                            os.unlink(postgresql.config.pg_hba_conf)
                         postgresql.config.restore_configuration_files()
                     postgresql.config.write_postgresql_conf()
                     postgresql.config.replace_pg_ident()

patroni/postgresql/cancellable.py

@@ -11,6 +11,10 @@ logger = logging.getLogger(__name__)
 
 class CancellableExecutor(object):
 
+    """
+    There must be only one such process so that AsyncExecutor can easily cancel it.
+    """
+
     def __init__(self):
         self._process = None
         self._process_cmd = None
@@ -110,16 +114,20 @@ class CancellableSubprocess(CancellableExecutor):
         with self._lock:
             return self._is_cancelled
 
-    def cancel(self):
+    def cancel(self, kill=False):
         with self._lock:
             self._is_cancelled = True
             if self._process is None or not self._process.is_running():
                 return
+
+            logger.info('Terminating %s', self._process_cmd)
             self._process.terminate()
 
         for _ in polling_loop(10):
             with self._lock:
                 if self._process is None or not self._process.is_running():
                     return
+            if kill:
+                break
 
         self._kill_process()

patroni/postgresql/config.py

@@ -6,11 +6,12 @@ import socket
 import stat
 import time
 
-from patroni.exceptions import PatroniException
 from six.moves.urllib_parse import urlparse, parse_qsl, unquote
-from urllib3.response import HTTPHeaderDict
 
+from .validator import CaseInsensitiveDict, recovery_parameters,\
+        transform_postgresql_parameter_value, transform_recovery_parameter_value
 from ..dcs import slot_name_from_member_name, RemoteMember
+from ..exceptions import PatroniFatalException
 from ..utils import compare_values, parse_bool, parse_int, split_host_port, uri, \
         validate_directory, is_subpath
 
@@ -254,21 +255,6 @@ class ConfigWriter(object):
         self.writeline("{0} = '{1}'".format(param, self.escape(value)))
 
 
-class CaseInsensitiveDict(HTTPHeaderDict):
-
-    def add(self, key, val):
-        self[key] = val
-
-    def __getitem__(self, key):
-        return self._container[key.lower()][1]
-
-    def __repr__(self):
-        return str(dict(self.items()))
-
-    def copy(self):
-        return CaseInsensitiveDict(self._container.values())
-
-
 class ConfigHandler(object):
 
     # List of parameters which must be always passed to postmaster as command line options
@@ -294,6 +280,7 @@ class ConfigHandler(object):
         'max_connections': (100, lambda v: int(v) >= 25, 90100),
         'max_wal_senders': (10, lambda v: int(v) >= 3, 90100),
         'wal_keep_segments': (8, lambda v: int(v) >= 1, 90100),
+        'wal_keep_size': ('128MB', lambda v: parse_int(v, 'MB') >= 16, 130000),
         'max_prepared_transactions': (0, lambda v: int(v) >= 0, 90100),
         'max_locks_per_transaction': (64, lambda v: int(v) >= 32, 90100),
         'track_commit_timestamp': ('off', lambda v: parse_bool(v) is not None, 90500),
@@ -302,24 +289,7 @@ class ConfigHandler(object):
         'wal_log_hints': ('on', lambda _: False, 90400)
     })
 
-    _RECOVERY_PARAMETERS = {
-        'archive_cleanup_command',
-        'restore_command',
-        'recovery_end_command',
-        'recovery_target',
-        'recovery_target_name',
-        'recovery_target_time',
-        'recovery_target_xid',
-        'recovery_target_lsn',
-        'recovery_target_inclusive',
-        'recovery_target_timeline',
-        'recovery_target_action',
-        'recovery_min_apply_delay',
-        'primary_conninfo',
-        'primary_slot_name',
-        'promote_trigger_file',
-        'trigger_file'
-    }
+    _RECOVERY_PARAMETERS = set(recovery_parameters.keys())
 
     def __init__(self, postgresql, config):
         self._postgresql = postgresql
@@ -339,8 +309,8 @@ class ConfigHandler(object):
         self._auto_conf_mtime = None
         self._pgpass = os.path.abspath(config.get('pgpass') or os.path.join(os.path.expanduser('~'), 'pgpass'))
         if os.path.exists(self._pgpass) and not os.path.isfile(self._pgpass):
-            raise PatroniException("'{}' exists and it's not a file, check your `postgresql.pgpass` configuration"
-                                   .format(self._pgpass))
+            raise PatroniFatalException("'{0}' exists and it's not a file, check your `postgresql.pgpass` configuration"
+                                        .format(self._pgpass))
         self._passfile = None
         self._passfile_mtime = None
         self._synchronous_standby_names = None
@@ -421,8 +391,9 @@ class ConfigHandler(object):
             include = self._config.get('custom_conf') or self._postgresql_base_conf_name
             f.writeline("include '{0}'\n".format(ConfigWriter.escape(include)))
             for name, value in sorted((configuration or self._server_parameters).items()):
+                value = transform_postgresql_parameter_value(self._postgresql.major_version, name, value)
                 if (not self._postgresql.bootstrap.running_custom_bootstrap or name != 'hba_file') \
-                        and name not in self._RECOVERY_PARAMETERS:
+                        and name not in self._RECOVERY_PARAMETERS and value is not None:
                     f.write_param(name, value)
             # when we are doing custom bootstrap we assume that we don't know superuser password
             # and in order to be able to change it, we are opening trust access from a certain address
@@ -507,7 +478,7 @@ class ConfigHandler(object):
     def format_dsn(self, params, include_dbname=False):
         # A list of keywords that can be found in a conninfo string. Follows what is acceptable by libpq
         keywords = ('dbname', 'user', 'passfile' if params.get('passfile') else 'password', 'host', 'port',
-                    'sslmode', 'sslcompression', 'sslcert', 'sslkey', 'sslrootcert', 'sslcrl',
+                    'sslmode', 'sslcompression', 'sslcert', 'sslkey', 'sslpassword', 'sslrootcert', 'sslcrl',
                     'application_name', 'krbsrvname', 'gssencmode', 'channel_binding')
         if include_dbname:
             params = params.copy()
@@ -525,6 +496,13 @@ class ConfigHandler(object):
                         if kw not in skip and params.get(kw) is not None)
 
     def _write_recovery_params(self, fd, recovery_params):
+        if self._postgresql.major_version >= 90500:
+            pause_at_recovery_target = parse_bool(recovery_params.pop('pause_at_recovery_target', None))
+            if pause_at_recovery_target is not None:
+                recovery_params.setdefault('recovery_target_action', 'pause' if pause_at_recovery_target else 'promote')
+        else:
+            if str(recovery_params.pop('recovery_target_action', None)).lower() == 'promote':
+                recovery_params.setdefault('pause_at_recovery_target', 'false')
         for name, value in sorted(recovery_params.items()):
             if name == 'primary_conninfo':
                 if 'password' in value and self._postgresql.major_version >= 100000:
@@ -532,6 +510,10 @@ class ConfigHandler(object):
                     value['passfile'] = self._passfile = self._pgpass
                     self._passfile_mtime = mtime(self._pgpass)
                 value = self.format_dsn(value)
+            else:
+                value = transform_recovery_parameter_value(self._postgresql.major_version, name, value)
+                if value is None:
+                    continue
             fd.write_param(name, value)
 
     def build_recovery_params(self, member):
@@ -575,7 +557,8 @@ class ConfigHandler(object):
 
     @property
     def _recovery_parameters_to_compare(self):
-        skip_params = {'recovery_target_inclusive', 'recovery_target_action', self._triggerfile_wrong_name}
+        skip_params = {'pause_at_recovery_target', 'recovery_target_inclusive',
+                       'recovery_target_action', 'standby_mode', self._triggerfile_wrong_name}
         return self._RECOVERY_PARAMETERS - skip_params
 
     def _read_recovery_params(self):
@@ -729,6 +712,9 @@ class ConfigHandler(object):
             if param == 'recovery_min_apply_delay':
                 if not compare_values('integer', 'ms', value[0], wanted_recovery_params.get(param, 0)):
                     record_missmatch(value[1])
+            elif param == 'standby_mode':
+                if not compare_values('bool', None, value[0], wanted_recovery_params.get(param, 'on')):
+                    record_missmatch(value[1])
             elif param == 'primary_conninfo':
                 if not self._check_primary_conninfo(value[0], wanted_recovery_params.get('primary_conninfo', {})):
                     record_missmatch(value[1])
@@ -748,7 +734,7 @@ class ConfigHandler(object):
             def escape(value):
                 return re.sub(r'([:\\])', r'\\\1', str(value))
 
-            record = {n: escape(record.get(n, '*')) for n in ('host', 'port', 'user', 'password')}
+            record = {n: escape(record.get(n) or '*') for n in ('host', 'port', 'user', 'password')}
             return '{host}:{port}:*:{user}:{password}'.format(**record)
 
     def write_pgpass(self, record):
@@ -830,8 +816,20 @@ class ConfigHandler(object):
                     parameters.pop('synchronous_standby_names', None)
             else:
                 parameters['synchronous_standby_names'] = self._synchronous_standby_names
-        if self._postgresql.major_version >= 90600 and parameters['wal_level'] == 'hot_standby':
-            parameters['wal_level'] = 'replica'
+
+        # Handle hot_standby <-> replica rename
+        if parameters.get('wal_level') == ('hot_standby' if self._postgresql.major_version >= 90600 else 'replica'):
+            parameters['wal_level'] = 'replica' if self._postgresql.major_version >= 90600 else 'hot_standby'
+
+        # Try to recalcualte wal_keep_segments <-> wal_keep_size assuming that typical wal_segment_size is 16MB.
+        # The real segment size could be estimated from pg_control, but we don't really care, because the only goal of
+        # this exercise is improving cross version compatibility and user must set the correct parameter in the config.
+        if self._postgresql.major_version >= 130000:
+            wal_keep_segments = parameters.pop('wal_keep_segments', self.CMDLINE_OPTIONS['wal_keep_segments'][0])
+            parameters.setdefault('wal_keep_size', str(wal_keep_segments * 16) + 'MB')
+        elif self._postgresql.major_version:
+            wal_keep_size = parse_int(parameters.pop('wal_keep_size', self.CMDLINE_OPTIONS['wal_keep_size'][0]), 'MB')
+            parameters.setdefault('wal_keep_segments', int((wal_keep_size + 8) / 16))
         ret = CaseInsensitiveDict({k: v for k, v in parameters.items() if not self._postgresql.major_version or
                                    self._postgresql.major_version >= self.CMDLINE_OPTIONS.get(k, (0, 1, 90100))[2]})
         ret.update({k: os.path.join(self._config_dir, ret[k]) for k in ('hba_file', 'ident_file') if k in ret})
@@ -1007,16 +1005,20 @@ class ConfigHandler(object):
         else:
             logger.info('No PostgreSQL configuration items changed, nothing to reload.')
 
-    def set_synchronous_standby(self, name):
+    def set_synchronous_standby(self, sync_members):
         """Sets a node to be synchronous standby and if changed does a reload for PostgreSQL."""
-        if name and name != '*':
-            name = quote_ident(name)
-        if name != self._synchronous_standby_names:
-            if name is None:
+        if sync_members and sync_members != ['*']:
+            sync_members = [quote_ident(x) for x in sync_members]
+        if self._postgresql.major_version >= 90600 and len(sync_members) > 1:
+            sync_param = '{0} ({1})'.format(len(sync_members), ','.join(sync_members))
+        else:
+            sync_param = next(iter(sync_members), None)
+        if sync_param != self._synchronous_standby_names:
+            if sync_param is None:
                 self._server_parameters.pop('synchronous_standby_names', None)
             else:
-                self._server_parameters['synchronous_standby_names'] = name
-            self._synchronous_standby_names = name
+                self._server_parameters['synchronous_standby_names'] = sync_param
+            self._synchronous_standby_names = sync_param
             if self._postgresql.state == 'running':
                 self.write_postgresql_conf()
                 self._postgresql.reload()

patroni/postgresql/rewind.py

@@ -1,5 +1,6 @@
 import logging
 import os
+import shlex
 import six
 import subprocess
 
@@ -273,7 +274,7 @@ class Rewind(object):
             i += 1
 
         logger.info('Trying to fetch the missing wal: %s', cmd)
-        return self._postgresql.cancellable.call(cmd, shell=True) == 0
+        return self._postgresql.cancellable.call(shlex.split(cmd)) == 0
 
     def _find_missing_wal(self, data):
         # could not open file "$PGDATA/pg_wal/0000000A00006AA100000068": No such file or directory
@@ -283,9 +284,9 @@ class Rewind(object):
             if b > -1:
                 b += len(pattern)
                 e = line.find('": ', b)
-                if e > -1:
-                    waldir, wal_filename = os.path.split(line[b:e])
-                    if waldir.endswith(os.path.sep + 'pg_' + self._postgresql.wal_name) and len(wal_filename) == 24:
+                if e > -1 and '/' in line[b:e]:
+                    waldir, wal_filename = line[b:e].rsplit('/', 1)
+                    if waldir.endswith('/pg_' + self._postgresql.wal_name) and len(wal_filename) == 24:
                         return wal_filename
 
     def pg_rewind(self, r):
@@ -427,4 +428,4 @@ class Rewind(object):
         opts = self.read_postmaster_opts()
         opts.update({'archive_mode': 'on', 'archive_command': 'false'})
         self._postgresql.config.remove_recovery_conf()
-        return self.single_user_mode(options=opts) == 0 or None
+        return self.single_user_mode(communicate={}, options=opts) == 0 or None

patroni/postgresql/validator.py

@@ -0,0 +1,518 @@
+import abc
+import logging
+import six
+
+from collections import namedtuple
+from urllib3.response import HTTPHeaderDict
+
+from ..utils import parse_bool, parse_int, parse_real
+
+logger = logging.getLogger(__name__)
+
+
+class CaseInsensitiveDict(HTTPHeaderDict):
+
+    def add(self, key, val):
+        self[key] = val
+
+    def __getitem__(self, key):
+        return self._container[key.lower()][1]
+
+    def __repr__(self):
+        return str(dict(self.items()))
+
+    def copy(self):
+        return CaseInsensitiveDict(self._container.values())
+
+
+class Bool(namedtuple('Bool', 'version_from,version_till')):
+
+    @staticmethod
+    def transform(name, value):
+        if parse_bool(value) is not None:
+            return value
+        logger.warning('Removing bool parameter=%s from the config due to the invalid value=%s', name, value)
+
+
+@six.add_metaclass(abc.ABCMeta)
+class Number(namedtuple('Number', 'version_from,version_till,min_val,max_val,unit')):
+
+    @staticmethod
+    @abc.abstractmethod
+    def parse(value, unit):
+        """parse value"""
+
+    def transform(self, name, value):
+        num_value = self.parse(value, self.unit)
+        if num_value is not None:
+            if num_value < self.min_val:
+                logger.warning('Value=%s of parameter=%s is too low, increasing to %s%s',
+                               value, name, self.min_val, self.unit or '')
+                return self.min_val
+            if num_value > self.max_val:
+                logger.warning('Value=%s of parameter=%s is too big, decreasing to %s%s',
+                               value, name, self.max_val, self.unit or '')
+                return self.max_val
+            return value
+        logger.warning('Removing %s parameter=%s from the config due to the invalid value=%s',
+                       self.__class__.__name__.lower(), name, value)
+
+
+class Integer(Number):
+
+    @staticmethod
+    def parse(value, unit):
+        return parse_int(value, unit)
+
+
+class Real(Number):
+
+    @staticmethod
+    def parse(value, unit):
+        return parse_real(value, unit)
+
+
+class Enum(namedtuple('Enum', 'version_from,version_till,possible_values')):
+
+    def transform(self, name, value):
+        if str(value).lower() in self.possible_values:
+            return value
+        logger.warning('Removing enum parameter=%s from the config due to the invalid value=%s', name, value)
+
+
+class EnumBool(Enum):
+
+    def transform(self, name, value):
+        if parse_bool(value) is not None:
+            return value
+        return super(EnumBool, self).transform(name, value)
+
+
+class String(namedtuple('String', 'version_from,version_till')):
+
+    @staticmethod
+    def transform(name, value):
+        return value
+
+
+# Format:
+#  key - parameter name
+#  value - tuple or multiple tuples if something was changing in GUC across postgres versions
+parameters = CaseInsensitiveDict({
+    'allow_system_table_mods': Bool(90300, None),
+    'application_name': String(90300, None),
+    'archive_command': String(90300, None),
+    'archive_mode': (
+        Bool(90300, 90500),
+        EnumBool(90500, None, ('always',))
+    ),
+    'archive_timeout': Integer(90300, None, 0, 1073741823, 's'),
+    'array_nulls': Bool(90300, None),
+    'authentication_timeout': Integer(90300, None,  1, 600, 's'),
+    'autovacuum': Bool(90300, None),
+    'autovacuum_analyze_scale_factor': Real(90300, None, 0, 100, None),
+    'autovacuum_analyze_threshold': Integer(90300, None, 0, 2147483647, None),
+    'autovacuum_freeze_max_age': Integer(90300, None, 100000, 2000000000, None),
+    'autovacuum_max_workers': (
+        Integer(90300, 90600, 1, 8388607, None),
+        Integer(90600, None, 1, 262143, None)
+    ),
+    'autovacuum_multixact_freeze_max_age': Integer(90300, None, 10000, 2000000000, None),
+    'autovacuum_naptime': Integer(90300, None, 1, 2147483, 's'),
+    'autovacuum_vacuum_cost_delay': (
+        Integer(90300, 120000, -1, 100, 'ms'),
+        Real(120000, None, -1, 100, 'ms')
+    ),
+    'autovacuum_vacuum_cost_limit': Integer(90300, None, -1, 10000, None),
+    'autovacuum_vacuum_insert_scale_factor': Real(130000, None, 0, 100, None),
+    'autovacuum_vacuum_insert_threshold': Integer(130000, None, -1, 2147483647, None),
+    'autovacuum_vacuum_scale_factor': Real(90300, None, 0, 100, None),
+    'autovacuum_vacuum_threshold': Integer(90300, None, 0, 2147483647, None),
+    'autovacuum_work_mem': Integer(90400, None, -1, 2147483647, 'kB'),
+    'backend_flush_after': Integer(90600, None, 0, 256, '8kB'),
+    'backslash_quote': EnumBool(90300, None, ('safe_encoding',)),
+    'backtrace_functions': String(130000, None),
+    'bgwriter_delay': Integer(90300, None, 10, 10000, 'ms'),
+    'bgwriter_flush_after': Integer(90600, None, 0, 256, '8kB'),
+    'bgwriter_lru_maxpages': (
+        Integer(90300, 100000, 0, 1000, None),
+        Integer(100000, None, 0, 1073741823, None)
+    ),
+    'bgwriter_lru_multiplier': Real(90300, None, 0, 10, None),
+    'bonjour': Bool(90300, None),
+    'bonjour_name': String(90300, None),
+    'bytea_output': Enum(90300, None, ('escape', 'hex')),
+    'check_function_bodies': Bool(90300, None),
+    'checkpoint_completion_target': Real(90300, None, 0, 1, None),
+    'checkpoint_flush_after': Integer(90600, None, 0, 256, '8kB'),
+    'checkpoint_segments': Integer(90300, 90500, 1, 2147483647, None),
+    'checkpoint_timeout': (
+        Integer(90300, 90600, 30, 3600, 's'),
+        Integer(90600, None, 30, 86400, 's')
+    ),
+    'checkpoint_warning': Integer(90300, None, 0, 2147483647, 's'),
+    'client_encoding': String(90300, None),
+    'client_min_messages': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2',
+                                              'debug1', 'log', 'notice', 'warning', 'error')),
+    'cluster_name': String(90500, None),
+    'commit_delay': Integer(90300, None, 0, 100000, None),
+    'commit_siblings': Integer(90300, None, 0, 1000, None),
+    'config_file': String(90300, None),
+    'constraint_exclusion': EnumBool(90300, None, ('partition',)),
+    'cpu_index_tuple_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'cpu_operator_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'cpu_tuple_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'cursor_tuple_fraction': Real(90300, None, 0, 1, None),
+    'data_directory': String(90300, None),
+    'data_sync_retry': Bool(90400, None),
+    'DateStyle': String(90300, None),
+    'db_user_namespace': Bool(90300, None),
+    'deadlock_timeout': Integer(90300, None, 1, 2147483647, 'ms'),
+    'debug_pretty_print': Bool(90300, None),
+    'debug_print_parse': Bool(90300, None),
+    'debug_print_plan': Bool(90300, None),
+    'debug_print_rewritten': Bool(90300, None),
+    'default_statistics_target': Integer(90300, None, 1, 10000, None),
+    'default_table_access_method': String(120000, None),
+    'default_tablespace': String(90300, None),
+    'default_text_search_config': String(90300, None),
+    'default_transaction_deferrable': Bool(90300, None),
+    'default_transaction_isolation': Enum(90300, None, ('serializable', 'repeatable read',
+                                                        'read committed', 'read uncommitted')),
+    'default_transaction_read_only': Bool(90300, None),
+    'default_with_oids': Bool(90300, 120000),
+    'dynamic_library_path': String(90300, None),
+    'dynamic_shared_memory_type': (
+        Enum(90400, 120000, ('posix', 'sysv', 'mmap', 'none')),
+        Enum(120000, None, ('posix', 'sysv', 'mmap'))
+    ),
+    'effective_cache_size': Integer(90300, None, 1, 2147483647, '8kB'),
+    'effective_io_concurrency': Integer(90300, None, 0, 1000, None),
+    'enable_bitmapscan': Bool(90300, None),
+    'enable_gathermerge': Bool(100000, None),
+    'enable_hashagg': Bool(90300, None),
+    'enable_hashjoin': Bool(90300, None),
+    'enable_incremental_sort': Bool(130000, None),
+    'enable_indexonlyscan': Bool(90300, None),
+    'enable_indexscan': Bool(90300, None),
+    'enable_material': Bool(90300, None),
+    'enable_mergejoin': Bool(90300, None),
+    'enable_nestloop': Bool(90300, None),
+    'enable_parallel_append': Bool(110000, None),
+    'enable_parallel_hash': Bool(110000, None),
+    'enable_partition_pruning': Bool(110000, None),
+    'enable_partitionwise_aggregate': Bool(110000, None),
+    'enable_partitionwise_join': Bool(110000, None),
+    'enable_seqscan': Bool(90300, None),
+    'enable_sort': Bool(90300, None),
+    'enable_tidscan': Bool(90300, None),
+    'escape_string_warning': Bool(90300, None),
+    'event_source': String(90300, None),
+    'exit_on_error': Bool(90300, None),
+    'external_pid_file': String(90300, None),
+    'extra_float_digits': Integer(90300, None, -15, 3, None),
+    'force_parallel_mode': EnumBool(90600, None, ('regress',)),
+    'from_collapse_limit': Integer(90300, None, 1, 2147483647, None),
+    'fsync': Bool(90300, None),
+    'full_page_writes': Bool(90300, None),
+    'geqo': Bool(90300, None),
+    'geqo_effort': Integer(90300, None, 1, 10, None),
+    'geqo_generations': Integer(90300, None, 0, 2147483647, None),
+    'geqo_pool_size': Integer(90300, None, 0, 2147483647, None),
+    'geqo_seed': Real(90300, None, 0, 1, None),
+    'geqo_selection_bias': Real(90300, None, 1.5, 2, None),
+    'geqo_threshold': Integer(90300, None, 2, 2147483647, None),
+    'gin_fuzzy_search_limit': Integer(90300, None, 0, 2147483647, None),
+    'gin_pending_list_limit': Integer(90500, None, 64, 2147483647, 'kB'),
+    'hash_mem_multiplier': Real(130000, None, 1, 1000, None),
+    'hba_file': String(90300, None),
+    'hot_standby': Bool(90300, None),
+    'hot_standby_feedback': Bool(90300, None),
+    'huge_pages': EnumBool(90400, None, ('try',)),
+    'ident_file': String(90300, None),
+    'idle_in_transaction_session_timeout': Integer(90600, None, 0, 2147483647, 'ms'),
+    'ignore_checksum_failure': Bool(90300, None),
+    'ignore_invalid_pages': Bool(130000, None),
+    'ignore_system_indexes': Bool(90300, None),
+    'IntervalStyle': Enum(90300, None, ('postgres', 'postgres_verbose', 'sql_standard', 'iso_8601')),
+    'jit': Bool(110000, None),
+    'jit_above_cost': Real(110000, None, -1, 1.79769e+308, None),
+    'jit_debugging_support': Bool(110000, None),
+    'jit_dump_bitcode': Bool(110000, None),
+    'jit_expressions': Bool(110000, None),
+    'jit_inline_above_cost': Real(110000, None, -1, 1.79769e+308, None),
+    'jit_optimize_above_cost': Real(110000, None, -1, 1.79769e+308, None),
+    'jit_profiling_support': Bool(110000, None),
+    'jit_provider': String(110000, None),
+    'jit_tuple_deforming': Bool(110000, None),
+    'join_collapse_limit': Integer(90300, None, 1, 2147483647, None),
+    'krb_caseins_users': Bool(90300, None),
+    'krb_server_keyfile': String(90300, None),
+    'krb_srvname': String(90300, 90400),
+    'lc_messages': String(90300, None),
+    'lc_monetary': String(90300, None),
+    'lc_numeric': String(90300, None),
+    'lc_time': String(90300, None),
+    'listen_addresses': String(90300, None),
+    'local_preload_libraries': String(90300, None),
+    'lock_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'lo_compat_privileges': Bool(90300, None),
+    'log_autovacuum_min_duration': Integer(90300, None, -1, 2147483647, 'ms'),
+    'log_checkpoints': Bool(90300, None),
+    'log_connections': Bool(90300, None),
+    'log_destination': String(90300, None),
+    'log_directory': String(90300, None),
+    'log_disconnections': Bool(90300, None),
+    'log_duration': Bool(90300, None),
+    'log_error_verbosity': Enum(90300, None, ('terse', 'default', 'verbose')),
+    'log_executor_stats': Bool(90300, None),
+    'log_file_mode': Integer(90300, None, 0, 511, None),
+    'log_filename': String(90300, None),
+    'logging_collector': Bool(90300, None),
+    'log_hostname': Bool(90300, None),
+    'logical_decoding_work_mem': Integer(130000, None, 64, 2147483647, 'kB'),
+    'log_line_prefix': String(90300, None),
+    'log_lock_waits': Bool(90300, None),
+    'log_min_duration_sample': Integer(130000, None, -1, 2147483647, 'ms'),
+    'log_min_duration_statement': Integer(90300, None, -1, 2147483647, 'ms'),
+    'log_min_error_statement': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2', 'debug1', 'info',
+                                                  'notice', 'warning', 'error', 'log', 'fatal', 'panic')),
+    'log_min_messages': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2', 'debug1', 'info',
+                                           'notice', 'warning', 'error', 'log', 'fatal', 'panic')),
+    'log_parameter_max_length': Integer(130000, None, -1, 1073741823, 'B'),
+    'log_parameter_max_length_on_error': Integer(130000, None, -1, 1073741823, 'B'),
+    'log_parser_stats': Bool(90300, None),
+    'log_planner_stats': Bool(90300, None),
+    'log_replication_commands': Bool(90500, None),
+    'log_rotation_age': Integer(90300, None, 0, 35791394, 'min'),
+    'log_rotation_size': Integer(90300, None, 0, 2097151, 'kB'),
+    'log_statement': Enum(90300, None, ('none', 'ddl', 'mod', 'all')),
+    'log_statement_sample_rate': Real(130000, None, 0, 1, None),
+    'log_statement_stats': Bool(90300, None),
+    'log_temp_files': Integer(90300, None, -1, 2147483647, 'kB'),
+    'log_timezone': String(90300, None),
+    'log_transaction_sample_rate': Real(120000, None, 0, 1, None),
+    'log_truncate_on_rotation': Bool(90300, None),
+    'maintenance_io_concurrency': Integer(130000, None, 0, 1000, None),
+    'maintenance_work_mem': Integer(90300, None, 1024, 2147483647, 'kB'),
+    'max_connections': (
+        Integer(90300, 90600, 1, 8388607, None),
+        Integer(90600, None, 1, 262143, None)
+    ),
+    'max_files_per_process': (
+        Integer(90300, 130000, 25, 2147483647, None),
+        Integer(130000, None, 64, 2147483647, None)
+    ),
+    'max_locks_per_transaction': Integer(90300, None, 10, 2147483647, None),
+    'max_logical_replication_workers': Integer(100000, None, 0, 262143, None),
+    'max_parallel_maintenance_workers': Integer(110000, None, 0, 1024, None),
+    'max_parallel_workers': Integer(100000, None, 0, 1024, None),
+    'max_parallel_workers_per_gather': Integer(90600, None, 0, 1024, None),
+    'max_pred_locks_per_page': Integer(100000, None, 0, 2147483647, None),
+    'max_pred_locks_per_relation': Integer(100000, None, -2147483648, 2147483647, None),
+    'max_pred_locks_per_transaction': Integer(90300, None, 10, 2147483647, None),
+    'max_prepared_transactions': (
+        Integer(90300, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'max_replication_slots': (
+        Integer(90400, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'max_slot_wal_keep_size': Integer(130000, None, -1, 2147483647, 'MB'),
+    'max_stack_depth': Integer(90300, None, 100, 2147483647, 'kB'),
+    'max_standby_archive_delay': Integer(90300, None, -1, 2147483647, 'ms'),
+    'max_standby_streaming_delay': Integer(90300, None, -1, 2147483647, 'ms'),
+    'max_sync_workers_per_subscription': Integer(100000, None, 0, 262143, None),
+    'max_wal_senders': (
+        Integer(90300, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'max_wal_size': (
+        Integer(90500, 100000, 2, 2147483647, '16MB'),
+        Integer(100000, None, 2, 2147483647, 'MB')
+    ),
+    'max_worker_processes': (
+        Integer(90400, 90600, 1, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'min_parallel_index_scan_size': Integer(100000, None, 0, 715827882, '8kB'),
+    'min_parallel_relation_size': Integer(90600, 100000, 0, 715827882, '8kB'),
+    'min_parallel_table_scan_size': Integer(100000, None, 0, 715827882, '8kB'),
+    'min_wal_size': (
+        Integer(90500, 100000, 2, 2147483647, '16MB'),
+        Integer(100000, None, 2, 2147483647, 'MB')
+    ),
+    'old_snapshot_threshold': Integer(90600, None, -1, 86400, 'min'),
+    'operator_precedence_warning': Bool(90500, None),
+    'parallel_leader_participation': Bool(110000, None),
+    'parallel_setup_cost': Real(90600, None, 0, 1.79769e+308, None),
+    'parallel_tuple_cost': Real(90600, None, 0, 1.79769e+308, None),
+    'password_encryption': (
+        Bool(90300, 100000),
+        Enum(100000, None, ('md5', 'scram-sha-256'))
+    ),
+    'plan_cache_mode': Enum(120000, None, ('auto', 'force_generic_plan', 'force_custom_plan')),
+    'port': Integer(90300, None, 1, 65535, None),
+    'post_auth_delay': Integer(90300, None, 0, 2147, 's'),
+    'pre_auth_delay': Integer(90300, None, 0, 60, 's'),
+    'quote_all_identifiers': Bool(90300, None),
+    'random_page_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'replacement_sort_tuples': Integer(90600, 110000, 0, 2147483647, None),
+    'restart_after_crash': Bool(90300, None),
+    'row_security': Bool(90500, None),
+    'search_path': String(90300, None),
+    'seq_page_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'session_preload_libraries': String(90400, None),
+    'session_replication_role': Enum(90300, None, ('origin', 'replica', 'local')),
+    'shared_buffers': Integer(90300, None, 16, 1073741823, '8kB'),
+    'shared_memory_type': Enum(120000, None, ('sysv', 'mmap')),
+    'shared_preload_libraries': String(90300, None),
+    'sql_inheritance': Bool(90300, 100000),
+    'ssl': Bool(90300, None),
+    'ssl_ca_file': String(90300, None),
+    'ssl_cert_file': String(90300, None),
+    'ssl_ciphers': String(90300, None),
+    'ssl_crl_file': String(90300, None),
+    'ssl_dh_params_file': String(100000, None),
+    'ssl_ecdh_curve': String(90400, None),
+    'ssl_key_file': String(90300, None),
+    'ssl_max_protocol_version': Enum(120000, None, ('', 'tlsv1', 'tlsv1.1', 'tlsv1.2', 'tlsv1.3')),
+    'ssl_min_protocol_version': Enum(120000, None, ('tlsv1', 'tlsv1.1', 'tlsv1.2', 'tlsv1.3')),
+    'ssl_passphrase_command': String(110000, None),
+    'ssl_passphrase_command_supports_reload': Bool(110000, None),
+    'ssl_prefer_server_ciphers': Bool(90400, None),
+    'ssl_renegotiation_limit': Integer(90300, 90500, 0, 2147483647, 'kB'),
+    'standard_conforming_strings': Bool(90300, None),
+    'statement_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'stats_temp_directory': String(90300, None),
+    'superuser_reserved_connections': (
+        Integer(90300, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None),
+    ),
+    'synchronize_seqscans': Bool(90300, None),
+    'synchronous_commit': (
+        EnumBool(90300, 90600, ('local', 'remote_write')),
+        EnumBool(90600, None, ('local', 'remote_write', 'remote_apply'))
+    ),
+    'synchronous_standby_names': String(90300, None),
+    'syslog_facility': Enum(90300, None, ('local0', 'local1', 'local2', 'local3',
+                                          'local4', 'local5', 'local6', 'local7')),
+    'syslog_ident': String(90300, None),
+    'syslog_sequence_numbers': Bool(90600, None),
+    'syslog_split_messages': Bool(90600, None),
+    'tcp_keepalives_count': Integer(90300, None, 0, 2147483647, None),
+    'tcp_keepalives_idle': Integer(90300, None, 0, 2147483647, 's'),
+    'tcp_keepalives_interval': Integer(90300, None, 0, 2147483647, 's'),
+    'tcp_user_timeout': Integer(120000, None, 0, 2147483647, 'ms'),
+    'temp_buffers': Integer(90300, None, 100, 1073741823, '8kB'),
+    'temp_file_limit': Integer(90300, None, -1, 2147483647, 'kB'),
+    'temp_tablespaces': String(90300, None),
+    'TimeZone': String(90300, None),
+    'timezone_abbreviations': String(90300, None),
+    'trace_notify': Bool(90300, None),
+    'trace_recovery_messages': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2',
+                                                  'debug1', 'log', 'notice', 'warning', 'error')),
+    'trace_sort': Bool(90300, None),
+    'track_activities': Bool(90300, None),
+    'track_activity_query_size': (
+        Integer(90300, 110000, 100, 102400, None),
+        Integer(110000, 130000, 100, 102400, 'B'),
+        Integer(130000, None, 100, 1048576, 'B')
+    ),
+    'track_commit_timestamp': Bool(90500, None),
+    'track_counts': Bool(90300, None),
+    'track_functions': Enum(90300, None, ('none', 'pl', 'all')),
+    'track_io_timing': Bool(90300, None),
+    'transaction_deferrable': Bool(90300, None),
+    'transaction_isolation': Enum(90300, None, ('serializable', 'repeatable read',
+                                                'read committed', 'read uncommitted')),
+    'transaction_read_only': Bool(90300, None),
+    'transform_null_equals': Bool(90300, None),
+    'unix_socket_directories': String(90300, None),
+    'unix_socket_group': String(90300, None),
+    'unix_socket_permissions': Integer(90300, None, 0, 511, None),
+    'update_process_title': Bool(90300, None),
+    'vacuum_cleanup_index_scale_factor': Real(110000, None, 0, 1e+10, None),
+    'vacuum_cost_delay': (
+        Integer(90300, 120000, 0, 100, 'ms'),
+        Real(120000, None, 0, 100, 'ms')
+    ),
+    'vacuum_cost_limit': Integer(90300, None, 1, 10000, None),
+    'vacuum_cost_page_dirty': Integer(90300, None, 0, 10000, None),
+    'vacuum_cost_page_hit': Integer(90300, None, 0, 10000, None),
+    'vacuum_cost_page_miss': Integer(90300, None, 0, 10000, None),
+    'vacuum_defer_cleanup_age': Integer(90300, None, 0, 1000000, None),
+    'vacuum_freeze_min_age': Integer(90300, None, 0, 1000000000, None),
+    'vacuum_freeze_table_age': Integer(90300, None, 0, 2000000000, None),
+    'vacuum_multixact_freeze_min_age': Integer(90300, None, 0, 1000000000, None),
+    'vacuum_multixact_freeze_table_age': Integer(90300, None, 0, 2000000000, None),
+    'wal_buffers': Integer(90300, None, -1, 262143, '8kB'),
+    'wal_compression': Bool(90500, None),
+    'wal_consistency_checking': String(100000, None),
+    'wal_init_zero': Bool(120000, None),
+    'wal_keep_segments': Integer(90300, 130000, 0, 2147483647, None),
+    'wal_keep_size': Integer(130000, None, 0, 2147483647, 'MB'),
+    'wal_level': (
+        Enum(90300, 90400, ('minimal', 'archive', 'hot_standby')),
+        Enum(90400, 90600, ('minimal', 'archive', 'hot_standby', 'logical')),
+        Enum(90600, None, ('minimal', 'replica', 'logical'))
+    ),
+    'wal_log_hints': Bool(90400, None),
+    'wal_receiver_create_temp_slot': Bool(130000, None),
+    'wal_receiver_status_interval': Integer(90300, None, 0, 2147483, 's'),
+    'wal_receiver_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'wal_recycle': Bool(120000, None),
+    'wal_retrieve_retry_interval': Integer(90500, None, 1, 2147483647, 'ms'),
+    'wal_sender_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'wal_skip_threshold': Integer(130000, None, 0, 2147483647, 'kB'),
+    'wal_sync_method': Enum(90300, None, ('fsync', 'fdatasync', 'open_sync', 'open_datasync')),
+    'wal_writer_delay': Integer(90300, None, 1, 10000, 'ms'),
+    'wal_writer_flush_after': Integer(90600, None, 0, 2147483647, '8kB'),
+    'work_mem': Integer(90300, None, 64, 2147483647, 'kB'),
+    'xmlbinary': Enum(90300, None, ('base64', 'hex')),
+    'xmloption': Enum(90300, None, ('content', 'document')),
+    'zero_damaged_pages': Bool(90300, None)
+})
+
+
+recovery_parameters = CaseInsensitiveDict({
+    'archive_cleanup_command': String(90300, None),
+    'pause_at_recovery_target': Bool(90300, 90500),
+    'primary_conninfo': String(90300, None),
+    'primary_slot_name': String(90400, None),
+    'promote_trigger_file': String(120000, None),
+    'recovery_end_command': String(90300, None),
+    'recovery_min_apply_delay': Integer(90400, None, 0, 2147483647, 'ms'),
+    'recovery_target': Enum(90400, None, ('immediate', '')),
+    'recovery_target_action': Enum(90500, None, ('pause', 'promote', 'shutdown')),
+    'recovery_target_inclusive': Bool(90300, None),
+    'recovery_target_lsn': String(100000, None),
+    'recovery_target_name': String(90400, None),
+    'recovery_target_time': String(90300, None),
+    'recovery_target_timeline': String(90300, None),
+    'recovery_target_xid': String(90300, None),
+    'restore_command': String(90300, None),
+    'standby_mode': Bool(90300, 120000),
+    'trigger_file': String(90300, 120000)
+})
+
+
+def _transform_parameter_value(validators, version, name, value):
+    validators = validators.get(name)
+    if validators:
+        for validator in (validators if isinstance(validators[0], tuple) else [validators]):
+            if version >= validator.version_from and\
+                    (validator.version_till is None or version < validator.version_till):
+                return validator.transform(name, value)
+    logger.warning('Removing unexpected parameter=%s value=%s from the config', name, value)
+
+
+def transform_postgresql_parameter_value(version, name, value):
+    if '.' in name:
+        return value
+    return _transform_parameter_value(parameters, version, name, value)
+
+
+def transform_recovery_parameter_value(version, name, value):
+    return _transform_parameter_value(recovery_parameters, version, name, value)

patroni/raft_controller.py

@@ -0,0 +1,34 @@
+import logging
+import os
+
+from patroni.daemon import AbstractPatroniDaemon, abstract_main
+from patroni.dcs.raft import KVStoreTTL
+from pysyncobj import SyncObjConf
+
+logger = logging.getLogger(__name__)
+
+
+class RaftController(AbstractPatroniDaemon):
+
+    def __init__(self, config):
+        super(RaftController, self).__init__(config)
+
+        raft_config = self.config.get('raft')
+        self_addr = raft_config['self_addr']
+        template = os.path.join(raft_config.get('data_dir', ''), self_addr)
+        self._syncobj_config = SyncObjConf(autoTick=False, appendEntriesUseBatch=False, dynamicMembershipChange=True,
+                                           journalFile=template + '.journal', fullDumpFile=template + '.dump')
+        self._raft = KVStoreTTL(self_addr, raft_config.get('partner_addrs', []), self._syncobj_config)
+
+    def _run_cycle(self):
+        try:
+            self._raft.doTick(self._syncobj_config.autoTickPeriod)
+        except Exception:
+            logger.exception('doTick')
+
+    def _shutdown(self):
+        self._raft.destroy()
+
+
+def main():
+    abstract_main(RaftController)

patroni/utils.py

@@ -1,8 +1,11 @@
+import json.decoder as json_decoder
 import logging
 import os
 import platform
 import random
 import re
+import socket
+import sys
 import tempfile
 import time
 
@@ -373,6 +376,27 @@ def uri(proto, netloc, path='', user=None):
     return '{0}://{1}{2}{3}{4}'.format(proto, user, host, port, path)
 
 
+def iter_response_objects(response):
+    prev = ''
+    decoder = json_decoder.JSONDecoder()
+    for chunk in response.read_chunked(decode_content=False):
+        if isinstance(chunk, bytes):
+            chunk = chunk.decode('utf-8')
+        chunk = prev + chunk
+
+        length = len(chunk)
+        idx = json_decoder.WHITESPACE.match(chunk, 0).end()
+        while idx < length:
+            try:
+                message, idx = decoder.raw_decode(chunk, idx)
+            except ValueError:  # malformed or incomplete JSON, unlikely to happen
+                break
+            else:
+                yield message
+                idx = json_decoder.WHITESPACE.match(chunk, idx).end()
+        prev = chunk[idx:]
+
+
 def is_standby_cluster(config):
     # Check whether or not provided configuration describes a standby cluster
     return isinstance(config, dict) and (config.get('host') or config.get('port') or config.get('restore_command'))
@@ -387,7 +411,7 @@ def cluster_as_json(cluster):
         if m.name == leader_name:
             config = cluster.config.data if cluster.config and cluster.config.modify_index else {}
             role = 'standby_leader' if is_standby_cluster(config.get('standby_cluster')) else 'leader'
-        elif m.name == cluster.sync.sync_standby:
+        elif m.name in cluster.sync.members:
             role = 'sync_standby'
         else:
             role = 'replica'
@@ -453,3 +477,38 @@ def data_directory_is_empty(data_dir):
     if not os.path.exists(data_dir):
         return True
     return all(os.name != 'nt' and (n.startswith('.') or n == 'lost+found') for n in os.listdir(data_dir))
+
+
+def keepalive_intvl(timeout, idle, cnt=3):
+    return max(1, int(float(timeout - idle) / cnt))
+
+
+def keepalive_socket_options(timeout, idle, cnt=3):
+    yield (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
+
+    if sys.platform.startswith('linux'):
+        yield (socket.SOL_TCP, 18, int(timeout * 1000))  # TCP_USER_TIMEOUT
+        TCP_KEEPIDLE = getattr(socket, 'TCP_KEEPIDLE', None)
+        TCP_KEEPINTVL = getattr(socket, 'TCP_KEEPINTVL', None)
+        TCP_KEEPCNT = getattr(socket, 'TCP_KEEPCNT', None)
+    elif sys.platform.startswith('darwin'):
+        TCP_KEEPIDLE = 0x10  # (named "TCP_KEEPALIVE" in C)
+        TCP_KEEPINTVL = 0x101
+        TCP_KEEPCNT = 0x102
+    else:
+        return
+
+    intvl = keepalive_intvl(timeout, idle, cnt)
+    yield (socket.IPPROTO_TCP, TCP_KEEPIDLE, idle)
+    yield (socket.IPPROTO_TCP, TCP_KEEPINTVL, intvl)
+    yield (socket.IPPROTO_TCP, TCP_KEEPCNT, cnt)
+
+
+def enable_keepalive(sock, timeout, idle, cnt=3):
+    SIO_KEEPALIVE_VALS = getattr(socket, 'SIO_KEEPALIVE_VALS', None)
+    if SIO_KEEPALIVE_VALS is not None:  # Windows
+        intvl = keepalive_intvl(timeout, idle, cnt)
+        return sock.ioctl(SIO_KEEPALIVE_VALS, (1, idle * 1000, intvl * 1000))
+
+    for opt in keepalive_socket_options(timeout, idle, cnt):
+        sock.setsockopt(*opt)

patroni/version.py

@@ -1 +1 @@
-__version__ = '1.6.5'
+__version__ = '2.0.1'

patroni_raft_controller.py

@@ -0,0 +1,6 @@
+#!/usr/bin/env python
+from patroni.raft_controller import main
+
+
+if __name__ == '__main__':
+    main()

postgres0.yml

@@ -30,6 +30,13 @@ etcd:
   #It is possible to change this behavior through by setting:
   #use_proxies: true
 
+#raft:
+#  data_dir: .
+#  self_addr: 127.0.0.1:2222
+#  partner_addrs:
+#  - 127.0.0.1:2223
+#  - 127.0.0.1:2224
+
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
   # and all other cluster members will use it as a `global configuration`
@@ -108,6 +115,8 @@ postgresql:
     # same as KRB5CCNAME used by the GSS
 #   krb_server_keyfile: /var/spool/keytabs/postgres
     unix_socket_directories: '.'
+  # Additional fencing script executed after acquiring the leader lock but before promoting the replica
+  #pre_promote: /path/to/pre_promote.sh
 
 #watchdog:
 #  mode: automatic # Allowed values: off, automatic, required

postgres1.yml

@@ -30,6 +30,13 @@ etcd:
   #It is possible to change this behavior through by setting:
   #use_proxies: true
 
+#raft:
+#  data_dir: .
+#  self_addr: 127.0.0.1:2223
+#  partner_addrs:
+#  - 127.0.0.1:2222
+#  - 127.0.0.1:2224
+
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
   # and all other cluster members will use it as a `global configuration`
@@ -105,6 +112,9 @@ postgresql:
   basebackup:
       - verbose
       - max-rate: 100M
+  # Additional fencing script executed after acquiring the leader lock but before promoting the replica
+  #pre_promote: /path/to/pre_promote.sh
+
 tags:
     nofailover: false
     noloadbalance: false

postgres2.yml

@@ -30,6 +30,13 @@ etcd:
   #It is possible to change this behavior through by setting:
   #use_proxies: true
 
+#raft:
+#  data_dir: .
+#  self_addr: 127.0.0.1:2224
+#  partner_addrs:
+#  - 127.0.0.1:2222
+#  - 127.0.0.1:2223
+
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
   # and all other cluster members will use it as a `global configuration`

requirements.txt

@@ -1,4 +1,5 @@
 urllib3>=1.19.1,!=1.21
+ipaddress; python_version=="2.7"
 boto
 PyYAML
 six >= 1.7
@@ -6,8 +7,8 @@ kazoo>=1.3.1
 python-etcd>=0.4.3,<0.5
 python-consul>=0.7.1
 click>=4.1
-texttable
+prettytable>=0.7
 python-dateutil
+pysyncobj>=0.3.7
 psutil>=2.0.0
-cdiff
-kubernetes>=2.0.0,<=10.0.1,!=4.0.*,!=5.0.*
+ydiff>=1.2.0

setup.py

@@ -22,8 +22,8 @@ AUTHOR_EMAIL = '[email protected], [email protected], alexk
 KEYWORDS = 'etcd governor patroni postgresql postgres ha haproxy confd' +\
     ' zookeeper exhibitor consul streaming replication kubernetes k8s'
 
-EXTRAS_REQUIRE = {'aws': ['boto'], 'etcd': ['python-etcd'], 'consul': ['python-consul'],
-                  'exhibitor': ['kazoo'], 'zookeeper': ['kazoo'], 'kubernetes': ['kubernetes']}
+EXTRAS_REQUIRE = {'aws': ['boto'], 'etcd': ['python-etcd'], 'etcd3': ['python-etcd'], 'consul': ['python-consul'],
+                  'exhibitor': ['kazoo'], 'zookeeper': ['kazoo'], 'kubernetes': ['ipaddress'], 'raft': ['pysyncobj']}
 COVERAGE_XML = True
 COVERAGE_HTML = False
 
@@ -51,6 +51,7 @@ CLASSIFIERS = [
 
 CONSOLE_SCRIPTS = ['patroni = patroni:main',
                    'patronictl = patroni.ctl:ctl',
+                   'patroni_raft_controller = patroni.raft_controller:main',
                    "patroni_wale_restore = patroni.scripts.wale_restore:main",
                    "patroni_aws = patroni.scripts.aws:main"]
 
@@ -142,9 +143,13 @@ class PyTest(Command):
 
     def run(self):
         from pkg_resources import evaluate_marker
-        requirements = self.distribution.install_requires + ['mock>=2.0.0', 'pytest-cov', 'pytest'] +\
-            [v for k, v in self.distribution.extras_require.items() if not k.startswith(':') or evaluate_marker(k[1:])]
-        self.distribution.fetch_build_eggs(requirements)
+
+        requirements = set(self.distribution.install_requires + ['mock>=2.0.0', 'pytest-cov', 'pytest'])
+        for k, v in self.distribution.extras_require.items():
+            if not k.startswith(':') or evaluate_marker(k[1:]):
+                requirements.update(v)
+
+        self.distribution.fetch_build_eggs(list(requirements))
         self.run_tests()
 
 
@@ -165,8 +170,8 @@ def setup_package(version):
             continue
         extra = False
         for e, v in EXTRAS_REQUIRE.items():
-            if r.startswith(v[0]):
-                EXTRAS_REQUIRE[e] = [r]
+            if v and r.startswith(v[0]):
+                EXTRAS_REQUIRE[e] = [r] if e != 'kubernetes' or sys.version_info < (3, 0, 0) else []
                 extra = True
         if not extra:
             install_requires.append(r)

tests/__init__.py

@@ -22,6 +22,7 @@ class MockResponse(object):
     def __init__(self, status_code=200):
         self.status_code = status_code
         self.content = '{}'
+        self.reason = 'Not Found'
 
     @property
     def data(self):
@@ -35,6 +36,10 @@ class MockResponse(object):
     def getheader(*args):
         return ''
 
+    @staticmethod
+    def getheaders():
+        return {'content-type': 'json'}
+
 
 def requests_get(url, **kwargs):
     members = '[{"id":14855829450254237642,"peerURLs":["http://localhost:2380","http://localhost:7001"],' +\
@@ -93,7 +98,7 @@ class MockCursor(object):
         elif sql.startswith('SELECT pg_catalog.to_char'):
             replication_info = '[{"application_name":"walreceiver","client_addr":"1.2.3.4",' +\
                                '"state":"streaming","sync_state":"async","sync_priority":0}]'
-            self.results = [('', 0, '', '', '', '', False, replication_info)]
+            self.results = [('', 0, '', 0, '', '', False, replication_info)]
         elif sql.startswith('SELECT name, setting'):
             self.results = [('wal_segment_size', '2048', '8kB', 'integer', 'internal'),
                             ('wal_block_size', '8192', None, 'integer', 'internal'),
@@ -160,10 +165,13 @@ class PostgresInit(unittest.TestCase):
                    'search_path': 'public', 'hot_standby': 'on', 'max_wal_senders': 5,
                    'wal_keep_segments': 8, 'wal_log_hints': 'on', 'max_locks_per_transaction': 64,
                    'max_worker_processes': 8, 'max_connections': 100, 'max_prepared_transactions': 0,
-                   'track_commit_timestamp': 'off', 'unix_socket_directories': '/tmp', 'trigger_file': 'bla',
-                   'stats_temp_directory': '/tmp'}
+                   'track_commit_timestamp': 'off', 'unix_socket_directories': '/tmp',
+                   'trigger_file': 'bla', 'stats_temp_directory': '/tmp', 'zero_damaged_pages': '',
+                   'force_parallel_mode': '1', 'constraint_exclusion': '',
+                   'max_stack_depth': 'Z', 'vacuum_cost_limit': -1, 'vacuum_cost_delay': 200}
 
     @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.postgresql.CallbackExecutor', Mock())
     @patch.object(ConfigHandler, 'write_postgresql_conf', Mock())
     @patch.object(ConfigHandler, 'replace_pg_hba', Mock())
     @patch.object(ConfigHandler, 'replace_pg_ident', Mock())

tests/test_api.py

@@ -148,7 +148,8 @@ class MockRestApiServer(RestApiServer):
         self.serve_forever = Mock()
         MockRestApiServer._BaseServer__is_shut_down = Mock()
         MockRestApiServer._BaseServer__shutdown_request = True
-        config = config or {'listen': '127.0.0.1:8008', 'auth': 'test:test', 'certfile': 'dumb', 'verify_client': 'a'}
+        config = config or {'listen': '127.0.0.1:8008', 'auth': 'test:test', 'certfile': 'dumb', 'verify_client': 'a',
+                            'http_extra_headers': {'foo': 'bar'}, 'https_extra_headers': {'foo': 'sbar'}}
         super(MockRestApiServer, self).__init__(MockPatroni(), config)
         Handler(MockRequest(request), ('0.0.0.0', 8080), self)
 
@@ -161,7 +162,11 @@ class TestRestApiHandler(unittest.TestCase):
     _authorization = '\nAuthorization: Basic dGVzdDp0ZXN0'
 
     def test_do_GET(self):
+        MockPatroni.dcs.cluster.last_leader_operation = 20
         MockRestApiServer(RestApiHandler, 'GET /replica')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=10MB')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=10485760')
         MockRestApiServer(RestApiHandler, 'GET /read-only')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={})):
             MockRestApiServer(RestApiHandler, 'GET /replica')
@@ -170,17 +175,17 @@ class TestRestApiHandler(unittest.TestCase):
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'state': 'running'})):
             MockRestApiServer(RestApiHandler, 'GET /health')
         MockRestApiServer(RestApiHandler, 'GET /master')
-        MockPatroni.dcs.cluster.sync.sync_standby = MockPostgresql.name
+        MockPatroni.dcs.cluster.sync.members = [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 = ''
+            MockPatroni.dcs.cluster.sync.members = []
             MockRestApiServer(RestApiHandler, 'GET /asynchronous')
-        MockPatroni.ha.is_leader = Mock(return_value=True)
-        MockRestApiServer(RestApiHandler, 'GET /replica')
-        with patch.object(MockHa, 'is_standby_cluster', Mock(return_value=True)):
-            MockRestApiServer(RestApiHandler, 'GET /standby_leader')
+        with patch.object(MockHa, 'is_leader', Mock(return_value=True)):
+            MockRestApiServer(RestApiHandler, 'GET /replica')
+            with patch.object(MockHa, 'is_standby_cluster', Mock(return_value=True)):
+                MockRestApiServer(RestApiHandler, 'GET /standby_leader')
         MockPatroni.dcs.cluster = None
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
             MockRestApiServer(RestApiHandler, 'GET /master')
@@ -195,6 +200,16 @@ class TestRestApiHandler(unittest.TestCase):
     def test_do_OPTIONS(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'OPTIONS / HTTP/1.0'))
 
+    def test_do_GET_liveness(self):
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /liveness HTTP/1.0'))
+
+    def test_do_GET_readiness(self):
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /readiness HTTP/1.0'))
+        with patch.object(MockHa, 'is_leader', Mock(return_value=True)):
+            self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /readiness HTTP/1.0'))
+        with patch.object(MockPostgresql, 'state', PropertyMock(return_value='stopped')):
+            self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /readiness HTTP/1.0'))
+
     @patch.object(MockPostgresql, 'state', PropertyMock(return_value='stopped'))
     def test_do_GET_patroni(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))
@@ -236,6 +251,8 @@ class TestRestApiHandler(unittest.TestCase):
         MockRestApiServer(RestApiHandler, request)
         mock_dcs.set_config_value.return_value = False
         MockRestApiServer(RestApiHandler, request)
+        mock_dcs.get_cluster.return_value.config = None
+        MockRestApiServer(RestApiHandler, request)
 
     @patch.object(MockPatroni, 'dcs')
     def test_do_PUT_config(self, mock_dcs):
@@ -465,7 +482,9 @@ class TestRestApiServer(unittest.TestCase):
         mock_socket.context.wrap_socket.side_effect = socket.error
         self.srv.process_request_thread((mock_socket, 1), '2')
 
-    @patch.object(socket.socket, 'accept', Mock(return_value=(1, '2')))
-    def test_get_request(self):
+    @patch.object(socket.socket, 'accept')
+    def test_get_request(self, mock_accept):
+        newsock = Mock()
+        mock_accept.return_value = (newsock, '2')
         self.srv.socket = Mock()
-        self.assertEqual(self.srv.get_request(), ((self.srv.socket, 1), '2'))
+        self.assertEqual(self.srv.get_request(), ((self.srv.socket, newsock), '2'))

tests/test_config.py

@@ -1,9 +1,10 @@
 import os
 import sys
 import unittest
+import io
 
 from mock import MagicMock, Mock, patch
-from patroni.config import Config
+from patroni.config import Config, ConfigParseError
 from six.moves import builtins
 
 
@@ -55,6 +56,7 @@ class TestConfig(unittest.TestCase):
             'PATRONI_ZOOKEEPER_HOSTS': "'host1:2181','host2:2181'",
             'PATRONI_EXHIBITOR_HOSTS': 'host1,host2',
             'PATRONI_EXHIBITOR_PORT': '8181',
+            'PATRONI_RAFT_PARTNER_ADDRS': "'host1:1234','host2:1234'",
             'PATRONI_foo_HOSTS': '[host1,host2',  # Exception in parse_list
             'PATRONI_SUPERUSER_USERNAME': 'postgres',
             'PATRONI_SUPERUSER_PASSWORD': 'zalando',
@@ -94,3 +96,46 @@ class TestConfig(unittest.TestCase):
         self.config.set_dynamic_configuration(dynamic_configuration)
         for name, value in dynamic_configuration['standby_cluster'].items():
             self.assertEqual(self.config['standby_cluster'][name], value)
+
+    @patch('os.path.exists', Mock(return_value=True))
+    @patch('os.path.isfile', Mock(side_effect=lambda fname: fname != 'postgres0'))
+    @patch('os.path.isdir', Mock(return_value=True))
+    @patch('os.listdir', Mock(return_value=['01-specific.yml', '00-base.yml']))
+    def test_configuration_directory(self):
+        def open_mock(fname, *args, **kwargs):
+            if fname.endswith('00-base.yml'):
+                return io.StringIO(
+                    u'''
+                    test: True
+                    test2:
+                      child-1: somestring
+                      child-2: 5
+                      child-3: False
+                    test3: True
+                    test4:
+                     - abc: 3
+                     - abc: 4
+                    ''')
+            elif fname.endswith('01-specific.yml'):
+                return io.StringIO(
+                    u'''
+                    test: False
+                    test2:
+                      child-2: 10
+                      child-3: !!null
+                    test4:
+                     - ab: 5
+                    new-attr: True
+                    ''')
+
+        with patch.object(builtins, 'open', MagicMock(side_effect=open_mock)):
+            config = Config('postgres0')
+            self.assertEqual(config._local_configuration,
+                             {'test': False, 'test2': {'child-1': 'somestring', 'child-2': 10},
+                              'test3': True, 'test4': [{'ab': 5}], 'new-attr': True})
+
+    @patch('os.path.exists', Mock(return_value=True))
+    @patch('os.path.isfile', Mock(return_value=False))
+    @patch('os.path.isdir', Mock(return_value=False))
+    def test_invalid_path(self):
+        self.assertRaises(ConfigParseError, Config, 'postgres0')

tests/test_ctl.py

@@ -5,10 +5,10 @@ import unittest
 from click.testing import CliRunner
 from datetime import datetime, timedelta
 from mock import patch, Mock
-from patroni.ctl import ctl, store_config, load_config, output_members, get_dcs, parse_dcs, get_all_members, \
-    get_any_member, get_cursor, query_member, configure, PatroniCtlException, apply_config_changes, show_diff, \
-    format_config_for_editing, invoke_editor, format_pg_version, find_executable, print_output, CONFIG_FILE_PATH
-from patroni.dcs.etcd import Client, Failover
+from patroni.ctl import ctl, store_config, load_config, output_members, get_dcs, parse_dcs, \
+    get_all_members, get_any_member, get_cursor, query_member, configure, PatroniCtlException, apply_config_changes, \
+    format_config_for_editing, show_diff, invoke_editor, format_pg_version, find_executable, CONFIG_FILE_PATH
+from patroni.dcs.etcd import AbstractEtcdClientWithFailover, Failover
 from patroni.utils import tzutc
 from psycopg2 import OperationalError
 from urllib3 import PoolManager
@@ -37,7 +37,7 @@ class TestCtl(unittest.TestCase):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
     def setUp(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(AbstractEtcdClientWithFailover, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
             self.runner = CliRunner()
             self.e = get_dcs({'etcd': {'ttl': 30, 'host': 'ok:2379', 'retry_timeout': 10}}, 'foo')
@@ -165,12 +165,6 @@ class TestCtl(unittest.TestCase):
     def test_get_dcs(self):
         self.assertRaises(PatroniCtlException, get_dcs, {'dummy': {}}, 'dummy')
 
-    @patch('sys.platform', 'win32')
-    @patch('click.echo')
-    def test_print_output(self, mock_click_echo):
-        print_output(['a'], [])
-        mock_click_echo.assert_called_once_with('+---+\n| a |\n+---+')
-
     @patch('psycopg2.connect', psycopg2_connect)
     @patch('patroni.ctl.query_member', Mock(return_value=([['mock column']], None)))
     @patch('patroni.ctl.get_dcs')
@@ -442,7 +436,7 @@ class TestCtl(unittest.TestCase):
         cluster.members.append(cascade_member_wrong_tags)
         mock_get_dcs.return_value.get_cluster = Mock(return_value=cluster)
         result = self.runner.invoke(ctl, ['topology', 'dummy'])
-        assert '+\n| leader          | 127.0.0.1:5435 |  Leader |' in result.output
+        assert '+\n| leader          | 127.0.0.1:5435 | Leader  |' in result.output
         assert '|\n| + other         | 127.0.0.1:5436 | Replica |' in result.output
         assert '|\n|   + cascade     | 127.0.0.1:5437 | Replica |' in result.output
         assert '|\n| + wrong_cascade | 127.0.0.1:5438 | Replica |' in result.output
@@ -567,7 +561,7 @@ class TestCtl(unittest.TestCase):
         self.assertRaises(PatroniCtlException, apply_config_changes, before_editing, config, ['a'])
 
     @patch('sys.stdout.isatty', return_value=False)
-    @patch('cdiff.markup_to_pager')
+    @patch('patroni.ctl.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()
@@ -576,6 +570,9 @@ class TestCtl(unittest.TestCase):
         show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
         mock_markup_to_pager.assert_called_once()
 
+        with patch('patroni.ctl.find_executable', Mock(return_value=None)):
+            show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
+
         # 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'))

tests/test_etcd.py

@@ -5,7 +5,7 @@ import unittest
 
 from dns.exception import DNSException
 from mock import Mock, patch
-from patroni.dcs.etcd import AbstractDCS, Client, Cluster, Etcd, EtcdError, DnsCachingResolver
+from patroni.dcs.etcd import AbstractDCS, EtcdClient, Cluster, Etcd, EtcdError, DnsCachingResolver
 from patroni.exceptions import DCSError
 from patroni.utils import Retry
 from urllib3.exceptions import ReadTimeoutError
@@ -17,7 +17,7 @@ def etcd_watch(self, key, index=None, timeout=None, recursive=None):
     if timeout == 2.0:
         raise etcd.EtcdWatchTimedOut
     elif timeout == 5.0:
-        return etcd.EtcdResult('delete', {})
+        return etcd.EtcdResult('compareAndSwap', {})
     elif 5 < timeout <= 10.0:
         raise etcd.EtcdException
     elif timeout == 20.0:
@@ -123,9 +123,9 @@ class TestClient(unittest.TestCase):
     @patch('socket.getaddrinfo', socket_getaddrinfo)
     @patch('patroni.dcs.etcd.requests_get', requests_get)
     def setUp(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(EtcdClient, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
-            self.client = Client({'srv': 'test', 'retry_timeout': 3}, DnsCachingResolver())
+            self.client = EtcdClient({'srv': 'test', 'retry_timeout': 3}, DnsCachingResolver())
             self.client.http.request = http_request
             self.client.http.request_encode_body = http_request
 
@@ -143,10 +143,9 @@ class TestClient(unittest.TestCase):
         except Exception:
             self.assertIsNone(machines)
 
-    @patch.object(Client, 'machines')
+    @patch.object(EtcdClient, 'machines')
     def test_api_execute(self, mock_machines):
         mock_machines.__get__ = Mock(return_value=['http://localhost:4001', 'http://localhost:2379'])
-        self.assertRaises(ValueError, self.client.api_execute, '', '')
         self.client._base_uri = 'http://localhost:4001'
         self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'POST', timeout=0)
         self.client._base_uri = 'http://localhost:4001'
@@ -157,18 +156,17 @@ class TestClient(unittest.TestCase):
         self.client._machines_cache = [self.client._base_uri]
         self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
         self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
-        self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', '')
 
-        with patch.object(Client, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
-                patch.object(Client, '_load_machines_cache', Mock(side_effect=Exception)):
+        with patch.object(EtcdClient, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
+                patch.object(EtcdClient, '_load_machines_cache', Mock(side_effect=Exception)):
             self.client.http.request = Mock(side_effect=socket.error)
             self.assertRaises(etcd.EtcdException, rtry, self.client.api_execute, '/', 'GET', params={'retry': rtry})
 
-        with patch.object(Client, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
-                patch.object(Client, '_load_machines_cache', Mock(return_value=True)):
+        with patch.object(EtcdClient, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
+                patch.object(EtcdClient, '_load_machines_cache', Mock(return_value=True)):
             self.assertRaises(etcd.EtcdException, rtry, self.client.api_execute, '/', 'GET', params={'retry': rtry})
 
-        with patch.object(Client, '_do_http_request', Mock(side_effect=etcd.EtcdException)):
+        with patch.object(EtcdClient, '_do_http_request', Mock(side_effect=etcd.EtcdException)):
             self.client._read_timeout = 0.01
             self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'GET')
 
@@ -184,7 +182,7 @@ class TestClient(unittest.TestCase):
     def test__get_machines_cache_from_dns(self):
         self.client._get_machines_cache_from_dns('error', 2379)
 
-    @patch.object(Client, 'machines')
+    @patch.object(EtcdClient, 'machines')
     def test__refresh_machines_cache(self, mock_machines):
         mock_machines.__get__ = Mock(side_effect=etcd.EtcdConnectionFailed)
         self.assertIsNone(self.client._refresh_machines_cache())
@@ -205,6 +203,10 @@ class TestClient(unittest.TestCase):
                           timeout=1, source_address=('localhost', 53333),
                           socket_options=[(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)])
 
+    def test___del__(self):
+        self.client.http.clear = Mock(side_effect=TypeError)
+        del self.client
+
 
 @patch('patroni.dcs.etcd.requests_get', requests_get)
 @patch('socket.getaddrinfo', socket_getaddrinfo)
@@ -215,7 +217,7 @@ class TestEtcd(unittest.TestCase):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
     def setUp(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(EtcdClient, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
             self.etcd = Etcd({'namespace': '/patroni/', 'ttl': 30, 'retry_timeout': 10,
                               'host': 'localhost:2379', 'scope': 'test', 'name': 'foo'})
@@ -226,17 +228,18 @@ class TestEtcd(unittest.TestCase):
     @patch('dns.resolver.query', dns_query)
     def test_get_etcd_client(self):
         with patch('time.sleep', Mock(side_effect=SleepException)),\
-                patch.object(Client, 'machines') as mock_machines:
+                patch.object(EtcdClient, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(side_effect=etcd.EtcdException)
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'discovery_srv': 'test', 'retry_timeout': 10, 'cacert': '1', 'key': '1', 'cert': 1})
+                              {'discovery_srv': 'test', 'retry_timeout': 10, 'cacert': '1', 'key': '1', 'cert': 1},
+                              EtcdClient)
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'url': 'https://test:2379', 'retry_timeout': 10})
+                              {'url': 'https://test:2379', 'retry_timeout': 10}, EtcdClient)
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'hosts': 'foo:4001,bar', 'retry_timeout': 10})
+                              {'hosts': 'foo:4001,bar', 'retry_timeout': 10}, EtcdClient)
             mock_machines.__get__ = Mock(return_value=[])
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'proxy': 'https://user:password@test:2379', 'retry_timeout': 10})
+                              {'proxy': 'https://user:password@test:2379', 'retry_timeout': 10}, EtcdClient)
 
     def test_get_cluster(self):
         cluster = self.etcd.get_cluster()
@@ -285,7 +288,8 @@ class TestEtcd(unittest.TestCase):
         self.etcd.watch(None, 0)
         self.etcd.get_cluster()
         self.etcd.watch(20729, 1.5)
-        self.etcd.watch(20729, 4.5)
+        with patch('time.sleep', Mock()):
+            self.etcd.watch(20729, 4.5)
         with patch.object(AbstractDCS, 'watch', Mock()):
             self.assertTrue(self.etcd.watch(20729, 19.5))
             self.assertRaises(SleepException, self.etcd.watch, 20729, 9.5)

tests/test_etcd3.py

@@ -0,0 +1,246 @@
+import etcd
+import json
+import unittest
+import urllib3
+
+from mock import Mock, patch
+from patroni.dcs.etcd3 import PatroniEtcd3Client, Cluster, Etcd3, Etcd3Error, Etcd3ClientError, RetryFailedError,\
+        InvalidAuthToken, Unavailable, Unknown, UnsupportedEtcdVersion, UserEmpty, base64_encode
+from threading import Thread
+
+from . import SleepException, MockResponse
+
+
+def mock_urlopen(self, method, url, **kwargs):
+    ret = MockResponse()
+    if method == 'GET' and url.endswith('/version'):
+        ret.content = '{"etcdserver": "3.3.13", "etcdcluster": "3.3.0"}'
+    elif method != 'POST':
+        raise Exception('Unexpected request method: {0} {1} {2}'.format(method, url, kwargs))
+    elif url.endswith('/cluster/member/list'):
+        ret.content = '{"members":[{"clientURLs":["http://localhost:2379", "http://localhost:4001"]}]}'
+    elif url.endswith('/auth/authenticate'):
+        ret.content = '{"token":"authtoken"}'
+    elif url.endswith('/lease/grant'):
+        ret.content = '{"ID": "123"}'
+    elif url.endswith('/lease/keepalive'):
+        ret.content = '{"result":{"TTL":30}}'
+    elif url.endswith('/kv/range'):
+        ret.content = json.dumps({
+            "header": {"revision": "1"},
+            "kvs": [
+                {"key": base64_encode('/patroni/test/leader'),
+                 "value": base64_encode('foo'), "lease": "bla", "mod_revision": '1'},
+                {"key": base64_encode('/patroni/test/members/foo'),
+                 "value": base64_encode('{}'), "lease": "123", "mod_revision": '1'},
+                {"key": base64_encode('/patroni/test/failover'), "value": base64_encode('{}'), "mod_revision": '1'}
+            ]
+        })
+    elif url.endswith('/watch'):
+        key = base64_encode('/patroni/test/config')
+        ret.read_chunked = Mock(return_value=[json.dumps({
+            'result': {'events': [
+                {'kv': {'key': key, 'value': base64_encode('bar'), 'mod_revision': '2'}},
+                {'kv': {'key': key, 'value': base64_encode('buzz'), 'mod_revision': '3'}},
+                {'type': 'DELETE', 'kv': {'key': key, 'mod_revision': '4'}},
+                {'kv': {'key': base64_encode('/patroni/test/optime/leader'),
+                        'value': base64_encode('1234567'), 'mod_revision': '5'}},
+            ]}
+        })[:-1].encode('utf-8'), b'}{"error":{"grpc_code":14,"message":"","http_code":503}}'])
+    elif url.endswith('/kv/put') or url.endswith('/kv/txn'):
+        ret.status_code = 400
+        ret.content = '{"code":5,"error":"etcdserver: requested lease not found"}'
+    elif not url.endswith('/kv/deleterange'):
+        raise Exception('Unexpected url: {0} {1} {2}'.format(method, url, kwargs))
+    return ret
+
+
+class BaseTestEtcd3(unittest.TestCase):
+
+    @patch.object(Thread, 'start', Mock())
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def setUp(self):
+        self.etcd3 = Etcd3({'namespace': '/patroni/', 'ttl': 30, 'retry_timeout': 10,
+                            'host': 'localhost:2378', 'scope': 'test', 'name': 'foo',
+                            'username': 'etcduser', 'password': 'etcdpassword'})
+        self.client = self.etcd3._client
+        self.kv_cache = self.client._kv_cache
+
+
+class TestKVCache(BaseTestEtcd3):
+
+    def test__do_watch(self):
+        self.client.watchprefix = Mock(return_value=False)
+        self.assertRaises(AttributeError, self.kv_cache._do_watch, '1')
+
+    @patch('time.sleep', Mock(side_effect=SleepException))
+    @patch('patroni.dcs.etcd3.KVCache._build_cache', Mock(side_effect=Exception))
+    def test_run(self):
+        self.assertRaises(SleepException, self.kv_cache.run)
+
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def test_kill_stream(self):
+        self.assertRaises(Unavailable, self.kv_cache._do_watch, '1')
+        self.kv_cache.kill_stream()
+        with patch.object(MockResponse, 'connection', create=True) as mock_conn:
+            self.kv_cache.kill_stream()
+            mock_conn.sock.close.side_effect = Exception
+            self.kv_cache.kill_stream()
+
+
+class TestPatroniEtcd3Client(BaseTestEtcd3):
+
+    @patch('patroni.dcs.etcd3.Etcd3Client.authenticate', Mock(side_effect=Exception))
+    def test__init__(self):
+        self.assertRaises(SystemExit, self.setUp)
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test_call_rpc(self, mock_urlopen):
+        request = {'key': base64_encode('/patroni/test/leader')}
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.content = '{"succeeded":true,"header":{"revision":"1"}}'
+        self.client.call_rpc('/kv/txn', {'success': [{'request_delete_range': request}]})
+        self.client.call_rpc('/kv/put', request)
+        self.client.call_rpc('/kv/deleterange', request)
+
+    @patch('time.time', Mock(side_effect=[1, 10.9, 100]))
+    def test__wait_cache(self):
+        with self.kv_cache.condition:
+            self.assertRaises(RetryFailedError, self.client._wait_cache, 10)
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test__restart_watcher(self, mock_urlopen):
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.status_code = 400
+        mock_urlopen.return_value.content = '{"code":9,"error":"etcdserver: authentication is not enabled"}'
+        self.client.authenticate()
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test__handle_auth_errors(self, mock_urlopen):
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.content = '{"code":3,"error":"etcdserver: user name is empty"}'
+        mock_urlopen.return_value.status_code = 403
+        self.client._cluster_version = (3, 1, 5)
+        self.assertRaises(UnsupportedEtcdVersion, self.client.deleteprefix, 'foo')
+        self.client._cluster_version = (3, 3, 13)
+        self.assertRaises(UserEmpty, self.client.deleteprefix, 'foo')
+        mock_urlopen.return_value.content = '{"code":16,"error":"etcdserver: invalid auth token"}'
+        self.assertRaises(InvalidAuthToken, self.client.deleteprefix, 'foo')
+        with patch.object(PatroniEtcd3Client, 'authenticate', Mock(return_value=True)):
+            self.assertRaises(InvalidAuthToken, self.client.deleteprefix, 'foo')
+            self.client.username = None
+            self.assertRaises(InvalidAuthToken, self.client.deleteprefix, 'foo')
+
+    def test__handle_server_response(self):
+        response = MockResponse()
+        response.content = '{"code":0,"error":"'
+        self.assertRaises(etcd.EtcdException, self.client._handle_server_response, response)
+        response.status_code = 400
+        self.assertRaises(Unknown, self.client._handle_server_response, response)
+        response.content = '{"error":{"grpc_code":0,"message":"","http_code":400}}'
+        try:
+            self.client._handle_server_response(response)
+        except Unknown as e:
+            self.assertEqual(e.as_dict(), {'code': 2, 'codeText': 'OK', 'error': u'', 'status': 400})
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test__ensure_version_prefix(self, mock_urlopen):
+        self.client.version_prefix = None
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.content = '{"etcdserver": "3.0.3", "etcdcluster": "3.0.0"}'
+        self.assertRaises(UnsupportedEtcdVersion, self.client._ensure_version_prefix, '')
+        mock_urlopen.return_value.content = '{"etcdserver": "3.0.4", "etcdcluster": "3.0.0"}'
+        self.client._ensure_version_prefix('')
+        self.assertEqual(self.client.version_prefix, '/v3alpha')
+        mock_urlopen.return_value.content = '{"etcdserver": "3.4.4", "etcdcluster": "3.4.0"}'
+        self.client._ensure_version_prefix('')
+        self.assertEqual(self.client.version_prefix, '/v3')
+
+
+@patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+class TestEtcd3(BaseTestEtcd3):
+
+    @patch.object(Thread, 'start', Mock())
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def setUp(self):
+        super(TestEtcd3, self).setUp()
+        self.assertRaises(AttributeError, self.kv_cache._build_cache)
+        self.kv_cache._is_ready = True
+        self.etcd3.get_cluster()
+
+    def test_get_cluster(self):
+        self.assertIsInstance(self.etcd3.get_cluster(), Cluster)
+        self.client._kv_cache = None
+        with patch.object(urllib3.PoolManager, 'urlopen') as mock_urlopen:
+            mock_urlopen.side_effect = UnsupportedEtcdVersion('')
+            self.assertRaises(UnsupportedEtcdVersion, self.etcd3.get_cluster)
+            mock_urlopen.side_effect = SleepException()
+            self.assertRaises(Etcd3Error, self.etcd3.get_cluster)
+
+    def test_touch_member(self):
+        self.etcd3.touch_member({})
+        self.etcd3._lease = 'bla'
+        self.etcd3.touch_member({})
+        with patch.object(PatroniEtcd3Client, 'lease_grant', Mock(side_effect=Etcd3ClientError)):
+            self.etcd3.touch_member({})
+
+    def test__update_leader(self):
+        self.etcd3._lease = None
+        self.etcd3.update_leader('123')
+        self.etcd3.update_leader('124')
+
+    def test_attempt_to_acquire_leader(self):
+        self.etcd3._lease = None
+        self.assertFalse(self.etcd3.attempt_to_acquire_leader())
+
+    def test_set_ttl(self):
+        self.etcd3.set_ttl(20)
+
+    @patch.object(PatroniEtcd3Client, 'lease_keepalive', Mock(return_value=False))
+    def test_refresh_lease(self):
+        self.etcd3._last_lease_refresh = 0
+        self.etcd3.refresh_lease()
+
+    @patch('time.sleep', Mock(side_effect=SleepException))
+    @patch.object(PatroniEtcd3Client, 'lease_keepalive', Mock(return_value=False))
+    @patch.object(PatroniEtcd3Client, 'lease_grant', Mock(side_effect=Etcd3ClientError))
+    def test_create_lease(self):
+        self.etcd3._lease = None
+        self.etcd3._last_lease_refresh = 0
+        self.assertRaises(SleepException, self.etcd3.create_lease)
+
+    def test_set_failover_value(self):
+        self.etcd3.set_failover_value('', 1)
+
+    def test_set_config_value(self):
+        self.etcd3.set_config_value('')
+
+    def test_initialize(self):
+        self.etcd3.initialize()
+
+    def test_cancel_initialization(self):
+        self.etcd3.cancel_initialization()
+
+    def test_delete_leader(self):
+        self.etcd3.delete_leader()
+
+    def test_delete_cluster(self):
+        self.etcd3.delete_cluster()
+
+    def test_set_history_value(self):
+        self.etcd3.set_history_value('')
+
+    def test_set_sync_state_value(self):
+        self.etcd3.set_sync_state_value('')
+
+    def test_delete_sync_state(self):
+        self.etcd3.delete_sync_state()
+
+    def test_watch(self):
+        self.etcd3.set_ttl(10)
+        self.etcd3.watch(None, 0)
+        self.etcd3.watch(None, 0)
+
+    def test_set_socket_options(self):
+        with patch('socket.SIO_KEEPALIVE_VALS', 1, create=True):
+            self.etcd3.set_socket_options(Mock(), None)

tests/test_ha.py

@@ -6,8 +6,8 @@ import sys
 from mock import Mock, MagicMock, PropertyMock, patch, mock_open
 from patroni.config import Config
 from patroni.dcs import Cluster, ClusterConfig, Failover, Leader, Member, get_dcs, SyncState, TimelineHistory
-from patroni.dcs.etcd import Client
-from patroni.exceptions import DCSError, PostgresConnectionException, PatroniException
+from patroni.dcs.etcd import AbstractEtcdClientWithFailover
+from patroni.exceptions import DCSError, PostgresConnectionException, PatroniFatalException
 from patroni.ha import Ha, _MemberStatus
 from patroni.postgresql import Postgresql
 from patroni.postgresql.bootstrap import Bootstrap
@@ -48,7 +48,7 @@ def get_cluster_not_initialized_without_leader(cluster_config=None):
 def get_cluster_initialized_without_leader(leader=False, failover=None, sync=None, cluster_config=None):
     m1 = Member(0, 'leader', 28, {'conn_url': 'postgres://replicator:[email protected]:5435/postgres',
                                   'api_url': 'http://127.0.0.1:8008/patroni', 'xlog_location': 4})
-    leader = Leader(0, 0, m1) if leader else None
+    leader = Leader(0, 0, m1 if leader else Member(0, '', 28, {}))
     m2 = Member(0, 'other', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres',
                                  'api_url': 'http://127.0.0.1:8011/patroni',
                                  'state': 'running',
@@ -185,7 +185,7 @@ class TestHa(PostgresInit):
     @patch.object(etcd.Client, 'read', etcd_read)
     def setUp(self):
         super(TestHa, self).setUp()
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(AbstractEtcdClientWithFailover, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
             self.p.set_state('running')
             self.p.set_role('replica')
@@ -200,7 +200,8 @@ class TestHa(PostgresInit):
 
     def test_update_lock(self):
         self.p.last_operation = Mock(side_effect=PostgresConnectionException(''))
-        self.assertTrue(self.ha.update_lock(True))
+        self.ha.dcs.update_leader = Mock(side_effect=Exception)
+        self.assertFalse(self.ha.update_lock(True))
 
     @patch.object(Postgresql, 'received_timeline', Mock(return_value=None))
     def test_touch_member(self):
@@ -260,9 +261,17 @@ class TestHa(PostgresInit):
 
     @patch.object(Rewind, 'ensure_clean_shutdown', Mock())
     def test_crash_recovery(self):
+        self.ha.has_lock = true
         self.p.is_running = false
         self.p.controldata = lambda: {'Database cluster state': 'in production', 'Database system identifier': SYSID}
         self.assertEqual(self.ha.run_cycle(), 'doing crash recovery in a single user mode')
+        with patch('patroni.async_executor.AsyncExecutor.busy', PropertyMock(return_value=True)),\
+                patch.object(Ha, 'check_timeline', Mock(return_value=False)):
+            self.ha._async_executor.schedule('doing crash recovery in a single user mode')
+            self.ha.state_handler.cancellable._process = Mock()
+            self.ha._crash_recovery_started -= 600
+            self.ha.patroni.config.set_dynamic_configuration({'maximum_lag_on_failover': 10})
+            self.assertEqual(self.ha.run_cycle(), 'terminated crash recovery because of startup timeout')
 
     @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
     @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
@@ -302,6 +311,19 @@ class TestHa(PostgresInit):
         self.p.is_leader = false
         self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
 
+    def test_promotion_cancelled_after_pre_promote_failed(self):
+        self.p.is_leader = false
+        self.p._pre_promote = false
+        self.ha._is_healthiest_node = true
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'Promotion cancelled because the pre-promote script failed')
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+
+    def test_lost_leader_lock_during_promote(self):
+        with patch('patroni.async_executor.AsyncExecutor.busy', PropertyMock(return_value=True)):
+            self.ha._async_executor.schedule('promote')
+            self.assertEqual(self.ha.run_cycle(), 'lost leader before promote')
+
     def test_long_promote(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
@@ -422,7 +444,7 @@ class TestHa(PostgresInit):
         self.e.initialize = true
         self.ha.bootstrap()
         self.p.is_running = false
-        self.assertRaises(PatroniException, self.ha.post_bootstrap)
+        self.assertRaises(PatroniFatalException, self.ha.post_bootstrap)
 
     def test_bootstrap_release_initialize_key_on_watchdog_failure(self):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
@@ -432,7 +454,7 @@ class TestHa(PostgresInit):
         self.p.is_leader = true
         with patch.object(Watchdog, 'activate', Mock(return_value=False)):
             self.assertEqual(self.ha.post_bootstrap(), 'running post_bootstrap')
-            self.assertRaises(PatroniException, self.ha.post_bootstrap)
+            self.assertRaises(PatroniFatalException, self.ha.post_bootstrap)
 
     @patch('psycopg2.connect', psycopg2_connect)
     def test_reinitialize(self):
@@ -856,7 +878,7 @@ class TestHa(PostgresInit):
         with patch.object(self.ha.dcs, 'delete_sync_state') as mock_delete_sync:
             self.ha.run_cycle()
             mock_delete_sync.assert_called_once()
-            mock_set_sync.assert_called_once_with(None)
+            mock_set_sync.assert_called_once_with([])
 
         mock_set_sync.reset_mock()
         # Test sync key not touched when not there
@@ -864,14 +886,14 @@ class TestHa(PostgresInit):
         with patch.object(self.ha.dcs, 'delete_sync_state') as mock_delete_sync:
             self.ha.run_cycle()
             mock_delete_sync.assert_not_called()
-            mock_set_sync.assert_called_once_with(None)
+            mock_set_sync.assert_called_once_with([])
 
         mock_set_sync.reset_mock()
 
         self.ha.is_synchronous_mode = true
 
         # Test sync standby not touched when picking the same node
-        self.p.pick_synchronous_standby = Mock(return_value=('other', True))
+        self.p.pick_synchronous_standby = Mock(return_value=(['other'], ['other']))
         self.ha.cluster = get_cluster_initialized_with_leader(sync=('leader', 'other'))
         self.ha.run_cycle()
         mock_set_sync.assert_not_called()
@@ -879,10 +901,17 @@ class TestHa(PostgresInit):
         mock_set_sync.reset_mock()
 
         # Test sync standby is replaced when switching standbys
-        self.p.pick_synchronous_standby = Mock(return_value=('other2', False))
+        self.p.pick_synchronous_standby = Mock(return_value=(['other2'], []))
         self.ha.dcs.write_sync_state = Mock(return_value=True)
         self.ha.run_cycle()
-        mock_set_sync.assert_called_once_with('other2')
+        mock_set_sync.assert_called_once_with(['other2'])
+
+        # Test sync standby is replaced when new standby is joined
+        self.p.pick_synchronous_standby = Mock(return_value=(['other2', 'other3'], ['other2']))
+        self.ha.dcs.write_sync_state = Mock(return_value=True)
+        self.ha.run_cycle()
+        self.assertEqual(mock_set_sync.call_args_list[0][0], (['other2'],))
+        self.assertEqual(mock_set_sync.call_args_list[1][0], (['other2', 'other3'],))
 
         mock_set_sync.reset_mock()
         # Test sync standby is not disabled when updating dcs fails
@@ -895,7 +924,7 @@ class TestHa(PostgresInit):
         self.ha.dcs.write_sync_state = Mock(return_value=True)
         self.ha.dcs.get_cluster = Mock(return_value=get_cluster_initialized_with_leader(sync=('leader', 'other')))
         # self.ha.cluster = get_cluster_initialized_with_leader(sync=('leader', 'other'))
-        self.p.pick_synchronous_standby = Mock(return_value=('other2', True))
+        self.p.pick_synchronous_standby = Mock(return_value=(['other2'], ['other2']))
         self.ha.run_cycle()
         self.ha.dcs.get_cluster.assert_called_once()
         self.assertEqual(self.ha.dcs.write_sync_state.call_count, 2)
@@ -918,9 +947,9 @@ class TestHa(PostgresInit):
         # Test sync set to '*' when synchronous_mode_strict is enabled
         mock_set_sync.reset_mock()
         self.ha.is_synchronous_mode_strict = true
-        self.p.pick_synchronous_standby = Mock(return_value=(None, False))
+        self.p.pick_synchronous_standby = Mock(return_value=([], []))
         self.ha.run_cycle()
-        mock_set_sync.assert_called_once_with('*')
+        mock_set_sync.assert_called_once_with(['*'])
 
     def test_sync_replication_become_master(self):
         self.ha.is_synchronous_mode = true
@@ -935,7 +964,7 @@ class TestHa(PostgresInit):
 
         # When we just became master nobody is sync
         self.assertEqual(self.ha.enforce_master_role('msg', 'promote msg'), 'promote msg')
-        mock_set_sync.assert_called_once_with(None)
+        mock_set_sync.assert_called_once_with([])
         mock_write_sync.assert_called_once_with('leader', None, index=0)
 
         mock_set_sync.reset_mock()
@@ -1034,7 +1063,7 @@ class TestHa(PostgresInit):
 
     def test_shutdown(self):
         self.p.is_running = false
-        self.ha.has_lock = true
+        self.ha.is_leader = true
         self.ha.shutdown()
 
     @patch('time.sleep', Mock())
@@ -1088,3 +1117,20 @@ class TestHa(PostgresInit):
     def test_run_cycle(self):
         self.ha.dcs.touch_member = Mock(side_effect=DCSError('foo'))
         self.assertEqual(self.ha.run_cycle(), 'Unexpected exception raised, please report it as a BUG')
+        self.ha.dcs.touch_member = Mock(side_effect=PatroniFatalException('foo'))
+        self.assertRaises(PatroniFatalException, self.ha.run_cycle)
+
+    def test_empty_directory_in_pause(self):
+        self.ha.is_paused = true
+        self.p.data_directory_empty = true
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: running with empty data directory')
+        self.assertEqual(self.p.role, 'uninitialized')
+
+    @patch('patroni.ha.Ha.sysid_valid', MagicMock(return_value=True))
+    def test_sysid_no_match_in_pause(self):
+        self.ha.is_paused = true
+        self.p.controldata = lambda: {'Database cluster state': 'in recovery', 'Database system identifier': '123'}
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
+
+        self.ha.has_lock = true
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: released leader key voluntarily due to the system ID mismatch')

tests/test_kubernetes.py

@@ -1,11 +1,15 @@
 import json
+import socket
 import time
 import unittest
 
-from mock import Mock, patch
-from patroni.dcs.kubernetes import Kubernetes, KubernetesError, k8s_client, RetryFailedError
+from mock import Mock, mock_open, patch
+from patroni.dcs.kubernetes import k8s_client, k8s_config, K8sConfig, K8sConnectionFailed,\
+        K8sException, K8sObject, Kubernetes, KubernetesError, KubernetesRetriableException,\
+        Retry, RetryFailedError, SERVICE_HOST_ENV_NAME, SERVICE_PORT_ENV_NAME
+from six.moves import builtins
 from threading import Thread
-from . import SleepException
+from . import MockResponse, SleepException
 
 
 def mock_list_namespaced_config_map(*args, **kwargs):
@@ -51,35 +55,139 @@ def mock_namespaced_kind(*args, **kwargs):
     return mock
 
 
+def mock_load_k8s_config(self, *args, **kwargs):
+    self._server = ''
+
+
+class TestK8sConfig(unittest.TestCase):
+
+    def test_load_incluster_config(self):
+        for env in ({}, {SERVICE_HOST_ENV_NAME: '', SERVICE_PORT_ENV_NAME: ''}):
+            with patch('os.environ', env):
+                self.assertRaises(k8s_config.ConfigException, k8s_config.load_incluster_config)
+
+        with patch('os.environ', {SERVICE_HOST_ENV_NAME: 'a', SERVICE_PORT_ENV_NAME: '1'}),\
+                patch('os.path.isfile', Mock(side_effect=[False, True, True, False, True, True, True, True])),\
+                patch.object(builtins, 'open', Mock(side_effect=[
+                    mock_open()(), mock_open(read_data='a')(), mock_open(read_data='a')(),
+                    mock_open()(), mock_open(read_data='a')(), mock_open(read_data='a')()])):
+            for _ in range(0, 4):
+                self.assertRaises(k8s_config.ConfigException, k8s_config.load_incluster_config)
+            k8s_config.load_incluster_config()
+            self.assertEqual(k8s_config.server, 'https://a:1')
+
+    def test_load_kube_config(self):
+        config = {
+            "current-context": "local",
+            "contexts": [{"name": "local", "context": {"user": "local", "cluster": "local"}}],
+            "clusters": [{"name": "local", "cluster": {"server": "https://a:1/", "certificate-authority": "a"}}],
+            "users": [{"name": "local", "user": {"username": "a", "password": "b", "client-certificate": "c"}}]
+        }
+        with patch.object(builtins, 'open', mock_open(read_data=json.dumps(config))):
+            k8s_config.load_kube_config()
+            self.assertEqual(k8s_config.server, 'https://a:1')
+            self.assertEqual(k8s_config.pool_config, {'ca_certs': 'a', 'cert_file': 'c', 'cert_reqs': 'CERT_REQUIRED',
+                                                      'maxsize': 10, 'num_pools': 10})
+
+        config["users"][0]["user"]["token"] = "token"
+        with patch.object(builtins, 'open', mock_open(read_data=json.dumps(config))):
+            k8s_config.load_kube_config()
+            self.assertEqual(k8s_config.headers.get('authorization'), 'Bearer token')
+
+
+@patch('urllib3.PoolManager.request')
+class TestApiClient(unittest.TestCase):
+
+    @patch.object(K8sConfig, '_server', '', create=True)
+    @patch('urllib3.PoolManager.request', Mock())
+    def setUp(self):
+        self.a = k8s_client.ApiClient(True)
+        self.mock_get_ep = MockResponse()
+        self.mock_get_ep.content = '{"subsets":[{"ports":[{"name":"https","protocol":"TCP","port":443}],' +\
+                                   '"addresses":[{"ip":"127.0.0.1"},{"ip":"127.0.0.2"}]}]}'
+
+    def test__do_http_request(self, mock_request):
+        mock_request.side_effect = [self.mock_get_ep] + [socket.timeout]
+        self.assertRaises(K8sException, self.a.call_api, 'GET', 'f')
+
+    @patch('time.sleep', Mock())
+    def test_request(self, mock_request):
+        retry = Retry(deadline=10, max_delay=1, max_tries=1, retry_exceptions=KubernetesRetriableException)
+        mock_request.side_effect = [self.mock_get_ep] + 3 * [socket.timeout] + [k8s_client.rest.ApiException(500, '')]
+        self.assertRaises(k8s_client.rest.ApiException, retry, self.a.call_api, 'GET', 'f', _retry=retry)
+        mock_request.side_effect = [self.mock_get_ep, socket.timeout, Mock(), self.mock_get_ep]
+        self.assertRaises(k8s_client.rest.ApiException, retry, self.a.call_api, 'GET', 'f', _retry=retry)
+        retry.deadline = 0.0001
+        mock_request.side_effect = [socket.timeout, socket.timeout, self.mock_get_ep]
+        self.assertRaises(K8sConnectionFailed, retry, self.a.call_api, 'GET', 'f', _retry=retry)
+
+    def test__refresh_api_servers_cache(self, mock_request):
+        mock_request.side_effect = k8s_client.rest.ApiException(403, '')
+        self.a.refresh_api_servers_cache()
+
+
+class TestCoreV1Api(unittest.TestCase):
+
+    @patch('urllib3.PoolManager.request', Mock())
+    @patch.object(K8sConfig, '_server', '', create=True)
+    def setUp(self):
+        self.a = k8s_client.CoreV1Api()
+        self.a._api_client.pool_manager.request = Mock(return_value=MockResponse())
+
+    def test_create_namespaced_service(self):
+        self.assertEqual(str(self.a.create_namespaced_service('default', {}, _request_timeout=2)), '{}')
+
+    def test_list_namespaced_endpoints(self):
+        self.a._api_client.pool_manager.request.return_value.content = '{"items": [1,2,3]}'
+        self.assertIsInstance(self.a.list_namespaced_endpoints('default'), K8sObject)
+
+    def test_patch_namespaced_config_map(self):
+        self.assertEqual(str(self.a.patch_namespaced_config_map('foo', 'default', {}, _request_timeout=(1, 2))), '{}')
+
+    def test_list_namespaced_pod(self):
+        self.a._api_client.pool_manager.request.return_value.status_code = 409
+        self.a._api_client.pool_manager.request.return_value.content = 'foo'
+        try:
+            self.a.list_namespaced_pod('default', label_selector='foo=bar')
+            self.assertFail()
+        except k8s_client.rest.ApiException as e:
+            self.assertTrue('Reason: ' in str(e))
+
+    def test_delete_namespaced_pod(self):
+        self.assertEqual(str(self.a.delete_namespaced_pod('foo', 'default', _request_timeout=(1, 2), body={})), '{}')
+
+
 class BaseTestKubernetes(unittest.TestCase):
 
+    @patch('urllib3.PoolManager.request', Mock())
     @patch('socket.TCP_KEEPIDLE', 4, create=True)
     @patch('socket.TCP_KEEPINTVL', 5, create=True)
     @patch('socket.TCP_KEEPCNT', 6, create=True)
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch('kubernetes.client.api_client.ThreadPool', Mock(), create=True)
     @patch.object(Thread, 'start', Mock())
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod)
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map)
+    @patch.object(K8sConfig, 'load_kube_config', mock_load_k8s_config)
+    @patch.object(K8sConfig, 'load_incluster_config', Mock(side_effect=k8s_config.ConfigException))
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod, create=True)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map, create=True)
     def setUp(self, config=None):
         config = config or {}
-        config.update(ttl=30, scope='test', name='p-0', loop_wait=10, retry_timeout=10, labels={'f': 'b'})
+        config.update(ttl=30, scope='test', name='p-0', loop_wait=10,
+                      retry_timeout=10, labels={'f': 'b'}, bypass_api_service=True)
         self.k = Kubernetes(config)
         self.assertRaises(AttributeError, self.k._pods._build_cache)
         self.k._pods._is_ready = True
-        self.assertRaises(AttributeError, self.k._kinds._build_cache)
+        self.assertRaises(TypeError, self.k._kinds._build_cache)
         self.k._kinds._is_ready = True
         self.k.get_cluster()
 
 
-@patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', mock_namespaced_kind)
+@patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', mock_namespaced_kind, create=True)
 class TestKubernetesConfigMaps(BaseTestKubernetes):
 
     @patch('time.time', Mock(side_effect=[1, 10.9, 100]))
     def test__wait_caches(self):
         self.k._pods._is_ready = False
         with self.k._condition:
-            self.assertRaises(RetryFailedError, self.k._wait_caches)
+            self.assertRaises(RetryFailedError, self.k._wait_caches, time.time() + 10)
 
     @patch('time.time', Mock(return_value=time.time() + 100))
     def test_get_cluster(self):
@@ -95,13 +203,14 @@ class TestKubernetesConfigMaps(BaseTestKubernetes):
         self.k.take_leader()
 
     def test_manual_failover(self):
-        with patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', Mock(side_effect=RetryFailedError(''))):
+        with patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map',
+                          Mock(side_effect=RetryFailedError('')), create=True):
             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')
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', create=True)
     def test_touch_member(self, mock_patch_namespaced_pod):
         mock_patch_namespaced_pod.return_value.metadata.resource_version = '10'
         self.k.touch_member({'role': 'replica'})
@@ -119,7 +228,7 @@ class TestKubernetesConfigMaps(BaseTestKubernetes):
         self.k.cancel_initialization()
 
     @patch.object(k8s_client.CoreV1Api, 'delete_collection_namespaced_config_map',
-                  Mock(side_effect=k8s_client.rest.ApiException(403, '')))
+                  Mock(side_effect=k8s_client.rest.ApiException(403, '')), create=True)
     def test_delete_cluster(self):
         self.k.delete_cluster()
 
@@ -134,11 +243,11 @@ class TestKubernetesConfigMaps(BaseTestKubernetes):
 
 class TestKubernetesEndpoints(BaseTestKubernetes):
 
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_endpoints', mock_list_namespaced_endpoints)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_endpoints', mock_list_namespaced_endpoints, create=True)
     def setUp(self, config=None):
         super(TestKubernetesEndpoints, self).setUp({'use_endpoints': True, 'pod_ip': '10.0.0.0'})
 
-    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints')
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints', create=True)
     def test_update_leader(self, mock_patch_namespaced_endpoints):
         self.assertIsNotNone(self.k.update_leader('123'))
         args = mock_patch_namespaced_endpoints.call_args[0]
@@ -148,11 +257,11 @@ class TestKubernetesEndpoints(BaseTestKubernetes):
         self.k._kinds._object_cache['test'].metadata.annotations['leader'] = 'p-1'
         self.assertFalse(self.k.update_leader('123'))
 
-    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints', mock_namespaced_kind)
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints', mock_namespaced_kind, create=True)
     def test_update_leader_with_restricted_access(self):
         self.assertIsNotNone(self.k.update_leader('123', True))
 
-    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints')
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints', create=True)
     def test__update_leader_with_retry(self, mock_patch):
         mock_patch.side_effect = k8s_client.rest.ApiException(502, '')
         self.assertFalse(self.k.update_leader('123'))
@@ -168,14 +277,15 @@ class TestKubernetesEndpoints(BaseTestKubernetes):
             self.assertIsNotNone(self.k._update_leader_with_retry({}, '1', []))
 
     @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints',
-                  Mock(side_effect=[k8s_client.rest.ApiException(500, ''), k8s_client.rest.ApiException(502, '')]))
+                  Mock(side_effect=[k8s_client.rest.ApiException(500, ''),
+                                    k8s_client.rest.ApiException(502, '')]), create=True)
     def test_delete_sync_state(self):
         self.assertFalse(self.k.delete_sync_state())
 
-    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', mock_namespaced_kind)
-    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', mock_namespaced_kind)
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', mock_namespaced_kind, create=True)
+    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', mock_namespaced_kind, create=True)
     @patch.object(k8s_client.CoreV1Api, 'create_namespaced_service',
-                  Mock(side_effect=[True, False, k8s_client.rest.ApiException(500, '')]))
+                  Mock(side_effect=[True, False, k8s_client.rest.ApiException(500, '')]), create=True)
     def test__create_config_service(self):
         self.assertIsNotNone(self.k.patch_or_create_config({'foo': 'bar'}))
         self.assertIsNotNone(self.k.patch_or_create_config({'foo': 'bar'}))
@@ -184,7 +294,7 @@ class TestKubernetesEndpoints(BaseTestKubernetes):
 
 class TestCacheBuilder(BaseTestKubernetes):
 
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map, create=True)
     @patch('patroni.dcs.kubernetes.ObjectCache._watch')
     def test__build_cache(self, mock_response):
         mock_response.return_value.read_chunked.return_value = [json.dumps(
@@ -195,7 +305,7 @@ class TestCacheBuilder(BaseTestKubernetes):
                 'name': self.k.config_path, 'resourceVersion': '3'}}}
         ) + '\n' + json.dumps(
             {'type': 'MDIFIED', 'object': {'metadata': {'name': self.k.config_path}}}
-        ) + '\n' + json.dumps({'object': {'code': 410}}) + '\n').encode('utf-8')]
+        ) + '\n').encode('utf-8'), b'{"object":{', b'"code":410}}\n']
         self.k._kinds._build_cache()
 
     @patch('patroni.dcs.kubernetes.logger.error', Mock(side_effect=SleepException))

tests/test_log.py

@@ -43,7 +43,8 @@ class TestPatroniLogger(unittest.TestCase):
         _LOG.exception('test')
         logger.start()
 
-        with patch.object(logging.Handler, 'format', Mock(side_effect=Exception)):
+        with patch.object(logging.Handler, 'format', Mock(side_effect=Exception)),\
+                patch('_pytest.logging.LogCaptureHandler.emit', Mock()):
             logging.error('test')
 
         self.assertEqual(logger.log_handler.maxBytes, config['log']['file_size'])

tests/test_patroni.py

@@ -9,7 +9,7 @@ import patroni.config as config
 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.dcs.etcd import AbstractEtcdClientWithFailover
 from patroni.exceptions import DCSError
 from patroni.postgresql import Postgresql
 from patroni.postgresql.config import ConfigHandler
@@ -53,7 +53,7 @@ class TestPatroni(unittest.TestCase):
     @patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
     @patch.object(etcd.Client, 'read', etcd_read)
     @patch.object(Thread, 'start', Mock())
-    @patch.object(Client, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
+    @patch.object(AbstractEtcdClientWithFailover, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
     def setUp(self):
         self._handlers = logging.getLogger().handlers[:]
         RestApiServer._BaseServer__is_shut_down = Mock()
@@ -75,7 +75,7 @@ class TestPatroni(unittest.TestCase):
     @patch('sys.argv', ['patroni.py', 'postgres0.yml'])
     @patch('time.sleep', Mock(side_effect=SleepException))
     @patch.object(etcd.Client, 'delete', Mock())
-    @patch.object(Client, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
+    @patch.object(AbstractEtcdClientWithFailover, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
     @patch.object(Thread, 'join', Mock())
     def test_patroni_patroni_main(self):
         with patch('subprocess.call', Mock(return_value=1)):
@@ -167,7 +167,7 @@ class TestPatroni(unittest.TestCase):
     def test_reload_config(self):
         self.p.reload_config()
         self.p.get_tags = Mock(side_effect=Exception)
-        self.p.reload_config()
+        self.p.reload_config(local=True)
 
     def test_nosync(self):
         self.p.tags['nosync'] = True

tests/test_postgresql.py

@@ -98,7 +98,6 @@ class TestPostgresql(BaseTestPostgresql):
     def setUp(self):
         super(TestPostgresql, self).setUp()
         self.p.config.write_postgresql_conf()
-        self.p._callback_executor = Mock()
 
     @patch('subprocess.Popen')
     @patch.object(Postgresql, 'wait_for_startup')
@@ -273,10 +272,10 @@ class TestPostgresql(BaseTestPostgresql):
     @patch.object(Postgresql, 'major_version', PropertyMock(return_value=100000))
     @patch.object(Postgresql, 'primary_conninfo', Mock(return_value='host=1'))
     def test__read_recovery_params_pre_v12(self):
-        self.p.config.write_recovery_conf({'standby_mode': 'on', 'primary_conninfo': {'password': 'foo'}})
+        self.p.config.write_recovery_conf({'standby_mode': 'off', 'primary_conninfo': {'password': 'foo'}})
         self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
         self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
-        self.p.config.write_recovery_conf({'standby_mode': '\n'})
+        self.p.config.write_recovery_conf({'restore_command': '\n'})
         with patch('patroni.postgresql.config.mtime', mock_mtime):
             self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
 
@@ -358,10 +357,22 @@ class TestPostgresql(BaseTestPostgresql):
         mock_is_running.return_value = False
         self.assertFalse(self.p.is_healthy())
 
-    def test_promote(self):
+    @patch('psutil.Popen')
+    def test_promote(self, mock_popen):
+        mock_popen.return_value.wait.return_value = 0
+        task = CriticalTask()
+        self.assertTrue(self.p.promote(0, task))
+
         self.p.set_role('replica')
-        self.assertIsNone(self.p.promote(0))
-        self.assertTrue(self.p.promote(0))
+        self.p.config._config['pre_promote'] = 'test'
+        with patch('patroni.postgresql.cancellable.CancellableSubprocess.is_cancelled', PropertyMock(return_value=1)):
+            self.assertFalse(self.p.promote(0, task))
+
+        mock_popen.side_effect = Exception
+        self.assertFalse(self.p.promote(0, task))
+        task.reset()
+        task.cancel()
+        self.assertFalse(self.p.promote(0, task))
 
     def test_timeline_wal_position(self):
         self.assertEqual(self.p.timeline_wal_position(), (1, 2, 1))
@@ -402,6 +413,10 @@ class TestPostgresql(BaseTestPostgresql):
 
     @patch('os.rename', Mock())
     @patch('os.path.isdir', Mock(return_value=True))
+    @patch('os.unlink', Mock())
+    @patch('os.symlink', Mock())
+    @patch('patroni.postgresql.Postgresql.pg_wal_realpath', Mock(return_value={'pg_wal': '/mnt/pg_wal'}))
+    @patch('patroni.postgresql.Postgresql.pg_tblspc_realpaths', Mock(return_value={'42': '/mnt/tablespaces/archive'}))
     def test_move_data_directory(self):
         self.p.move_data_directory()
         with patch('os.rename', Mock(side_effect=OSError)):
@@ -415,11 +430,9 @@ class TestPostgresql(BaseTestPostgresql):
 
     def test_remove_data_directory(self):
         def _symlink(src, dst):
-            try:
+            if os.name != 'nt':  # os.symlink under Windows needs admin rights skip it
                 os.symlink(src, dst)
-            except OSError:
-                if os.name == 'nt':  # os.symlink under Windows needs admin rights skip it
-                    pass
+
         os.makedirs(os.path.join(self.p.data_dir, 'foo'))
         _symlink('foo', os.path.join(self.p.data_dir, 'pg_wal'))
         os.makedirs(os.path.join(self.p.data_dir, 'foo_tsp'))
@@ -596,36 +609,43 @@ class TestPostgresql(BaseTestPostgresql):
     def test_pick_sync_standby(self):
         cluster = Cluster(True, None, self.leader, 0, [self.me, self.other, self.leadermem], None,
                           SyncState(0, self.me.name, self.leadermem.name), None)
+        mock_cursor = Mock()
+        mock_cursor.fetchone.return_value = ('remote_apply',)
 
-        with patch.object(Postgresql, "query", return_value=[
-                    (self.leadermem.name, 'streaming', 'sync'),
-                    (self.me.name, 'streaming', 'async'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [(self.leadermem.name, 'streaming', 'sync'),
+                     (self.me.name, 'streaming', 'async'),
+                     (self.other.name, 'streaming', 'async')]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.leadermem.name, True))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.leadermem.name], [self.leadermem.name]))
 
-        with patch.object(Postgresql, "query", return_value=[
-                    (self.me.name, 'streaming', 'async'),
-                    (self.leadermem.name, 'streaming', 'potential'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [(self.leadermem.name, 'streaming', 'potential'),
+                     (self.me.name, 'streaming', 'async'),
+                     (self.other.name, 'streaming', 'async')]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.leadermem.name, False))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.leadermem.name], []))
 
-        with patch.object(Postgresql, "query", return_value=[
-                    (self.me.name, 'streaming', 'async'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [(self.me.name, 'streaming', 'async'),
+                     (self.other.name, 'streaming', 'async')]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.me.name, False))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.me.name], []))
 
-        with patch.object(Postgresql, "query", return_value=[
-                    ('missing', 'streaming', 'sync'),
-                    (self.me.name, 'streaming', 'async'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [('missing', 'streaming', 'sync'),
+                     (self.me.name, 'streaming', 'async'),
+                     (self.other.name, 'streaming', 'async')]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.me.name, False))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.me.name], []))
 
-        with patch.object(Postgresql, "query", return_value=[]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (None, False))
+        with patch.object(Postgresql, "query", side_effect=[mock_cursor, []]):
+            self.p._major_version = 90400
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([], []))
 
     def test_set_sync_standby(self):
         def value_in_conf():
@@ -635,21 +655,21 @@ class TestPostgresql(BaseTestPostgresql):
                         return line.strip()
 
         mock_reload = self.p.reload = Mock()
-        self.p.config.set_synchronous_standby('n1')
+        self.p.config.set_synchronous_standby(['n1'])
         self.assertEqual(value_in_conf(), "synchronous_standby_names = 'n1'")
         mock_reload.assert_called()
 
         mock_reload.reset_mock()
-        self.p.config.set_synchronous_standby('n1')
+        self.p.config.set_synchronous_standby(['n1'])
         mock_reload.assert_not_called()
         self.assertEqual(value_in_conf(), "synchronous_standby_names = 'n1'")
 
-        self.p.config.set_synchronous_standby('n2')
+        self.p.config.set_synchronous_standby(['n1', 'n2'])
         mock_reload.assert_called()
-        self.assertEqual(value_in_conf(), "synchronous_standby_names = 'n2'")
+        self.assertEqual(value_in_conf(), "synchronous_standby_names = '2 (n1,n2)'")
 
         mock_reload.reset_mock()
-        self.p.config.set_synchronous_standby(None)
+        self.p.config.set_synchronous_standby([])
         mock_reload.assert_called()
         self.assertEqual(value_in_conf(), None)
 
@@ -706,3 +726,8 @@ class TestPostgresql(BaseTestPostgresql):
         self.p.set_role('standby_leader')
         self.p.reset_cluster_info_state()
         self.assertRaises(PostgresConnectionException, self.p.received_timeline)
+
+    def test__write_recovery_params(self):
+        self.p.config._write_recovery_params(Mock(), {'pause_at_recovery_target': 'false'})
+        with patch.object(Postgresql, 'major_version', PropertyMock(return_value=90400)):
+            self.p.config._write_recovery_params(Mock(), {'recovery_target_action': 'PROMOTE'})

tests/test_raft.py

@@ -0,0 +1,155 @@
+import os
+import unittest
+import time
+
+from mock import Mock, patch
+from patroni.dcs.raft import DynMemberSyncObj, KVStoreTTL, Raft, SyncObjUtility
+from pysyncobj import SyncObjConf, FAIL_REASON
+
+
+def remove_files(prefix):
+    for f in ('journal', 'dump'):
+        f = prefix + f
+        if os.path.isfile(f):
+            for i in range(0, 15):
+                try:
+                    if os.path.isfile(f):
+                        os.unlink(f)
+                        break
+                    else:
+                        break
+                except Exception:
+                    time.sleep(1.0)
+
+
+@patch('pysyncobj.tcp_server.TcpServer.bind', Mock())
+class TestDynMemberSyncObj(unittest.TestCase):
+
+    @patch('pysyncobj.tcp_server.TcpServer.bind', Mock())
+    def setUp(self):
+        self.conf = SyncObjConf(appendEntriesUseBatch=False, dynamicMembershipChange=True, autoTick=False)
+        self.so = DynMemberSyncObj('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+
+    @patch.object(SyncObjUtility, 'sendMessage')
+    def test_add_member(self, mock_send_message):
+        mock_send_message.return_value = [{'addr': '127.0.0.1:1235'}, {'addr': '127.0.0.1:1236'}]
+        mock_send_message.ver = 0
+        DynMemberSyncObj('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+        self.conf.dynamicMembershipChange = False
+        DynMemberSyncObj('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+
+    def test___onUtilityMessage(self):
+        self.so._SyncObj__encryptor = Mock()
+        mock_conn = Mock()
+        mock_conn.sendRandKey = None
+        self.so._SyncObj__transport._onIncomingMessageReceived(mock_conn, 'randkey')
+        self.so._SyncObj__transport._onIncomingMessageReceived(mock_conn, ['members'])
+        self.so._SyncObj__transport._onIncomingMessageReceived(mock_conn, ['status'])
+
+    def test__SyncObj__doChangeCluster(self):
+        self.so._SyncObj__doChangeCluster(['add', '127.0.0.1:1236'])
+
+    def test_utility(self):
+        utility = SyncObjUtility(['127.0.0.1:1235'], self.conf)
+        utility.setPartnerNode(list(utility._SyncObj__otherNodes)[0])
+        utility.sendMessage(['members'])
+        utility._onMessageReceived(0, '')
+
+
+class TestKVStoreTTL(unittest.TestCase):
+
+    def setUp(self):
+        self.conf = SyncObjConf(appendEntriesUseBatch=False, appendEntriesPeriod=0.001,
+                                raftMinTimeout=0.004, raftMaxTimeout=0.005, autoTickPeriod=0.001)
+        callback = Mock()
+        callback.replicated = False
+        self.so = KVStoreTTL('127.0.0.1:1234', [], self.conf, on_set=callback, on_delete=callback)
+        self.so.set_retry_timeout(10)
+
+    @staticmethod
+    def destroy(so):
+        so.destroy()
+        so._SyncObj__thread.join()
+
+    def tearDown(self):
+        if self.so:
+            self.destroy(self.so)
+
+    def test_set(self):
+        self.assertTrue(self.so.set('foo', 'bar', prevExist=False, ttl=30))
+        self.assertFalse(self.so.set('foo', 'bar', prevExist=False, ttl=30))
+        self.assertFalse(self.so.retry(self.so._set, 'foo', {'value': 'buz', 'created': 1, 'updated': 1}, prevValue=''))
+        self.assertTrue(self.so.retry(self.so._set, 'foo', {'value': 'buz', 'created': 1, 'updated': 1}))
+
+    def test_delete(self):
+        self.conf.autoTickPeriod = 0.1
+        self.so.set('foo', 'bar')
+        self.so.set('fooo', 'bar')
+        self.assertFalse(self.so.delete('foo', prevValue='buz'))
+        self.assertFalse(self.so.delete('foo', prevValue='bar', timeout=0.00001))
+        self.assertFalse(self.so.delete('foo', prevValue='bar'))
+        self.assertTrue(self.so.delete('foo', recursive=True))
+        self.assertFalse(self.so.retry(self.so._delete, 'foo', prevValue=''))
+
+    def test_expire(self):
+        self.so.set('foo', 'bar', ttl=0.001)
+        time.sleep(1)
+        self.assertIsNone(self.so.get('foo'))
+        self.assertEqual(self.so.get('foo', recursive=True), {})
+
+    @patch('time.sleep', Mock())
+    def test_retry(self):
+        return_values = [FAIL_REASON.QUEUE_FULL, FAIL_REASON.SUCCESS, FAIL_REASON.REQUEST_DENIED]
+
+        def test(callback):
+            callback(True, return_values.pop(0))
+        self.assertTrue(self.so.retry(test))
+        self.assertFalse(self.so.retry(test))
+
+    def test_on_ready_override(self):
+        self.assertTrue(self.so.set('foo', 'bar'))
+        self.destroy(self.so)
+        self.so = None
+        self.conf.onReady = Mock()
+        self.conf.autoTick = False
+        so = KVStoreTTL('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+        so.doTick(0)
+        so.destroy()
+
+
+class TestRaft(unittest.TestCase):
+
+    def test_raft(self):
+        raft = Raft({'ttl': 30, 'scope': 'test', 'name': 'pg', 'self_addr': '127.0.0.1:1234', 'retry_timeout': 10})
+        raft.set_retry_timeout(20)
+        raft.set_ttl(60)
+        self.assertTrue(raft.touch_member(''))
+        self.assertTrue(raft.initialize())
+        self.assertTrue(raft.cancel_initialization())
+        self.assertTrue(raft.set_config_value('{}'))
+        self.assertTrue(raft.write_sync_state('foo', 'bar'))
+        self.assertTrue(raft.update_leader('1'))
+        self.assertTrue(raft.manual_failover('foo', 'bar'))
+        raft.get_cluster()
+        self.assertTrue(raft.delete_sync_state())
+        self.assertTrue(raft.delete_leader())
+        self.assertTrue(raft.set_history_value(''))
+        self.assertTrue(raft.delete_cluster())
+        raft.get_cluster()
+        self.assertTrue(raft.take_leader())
+        raft.watch(None, 0.001)
+        raft._sync_obj.destroy()
+        raft._sync_obj._SyncObj__thread.join()
+
+    def tearDown(self):
+        remove_files('127.0.0.1:1234.')
+
+    def setUp(self):
+        self.tearDown()
+
+    @patch('patroni.dcs.raft.KVStoreTTL')
+    @patch('threading.Event')
+    def test_init(self, mock_event, mock_kvstore):
+        mock_kvstore.return_value.applied_local_log = False
+        mock_event.return_value.isSet.side_effect = [False, True]
+        self.assertIsNotNone(Raft({'ttl': 30, 'scope': 'test', 'name': 'pg', 'patronictl': True, 'self_addr': '1'}))

tests/test_raft_controller.py

@@ -0,0 +1,44 @@
+import logging
+import os
+import unittest
+
+from mock import Mock, patch
+from pysyncobj import SyncObj
+from patroni.config import Config
+from patroni.raft_controller import RaftController, main as _main
+
+from . import SleepException
+from .test_raft import remove_files
+
+
+class TestPatroniRaftController(unittest.TestCase):
+
+    SELF_ADDR = '127.0.0.1:5360'
+
+    def remove_files(self):
+        remove_files(self.SELF_ADDR + '.')
+
+    @patch('pysyncobj.tcp_server.TcpServer.bind', Mock())
+    def setUp(self):
+        self._handlers = logging.getLogger().handlers[:]
+        self.remove_files()
+        os.environ['PATRONI_RAFT_SELF_ADDR'] = self.SELF_ADDR
+        config = Config('postgres0.yml', validator=None)
+        self.rc = RaftController(config)
+
+    def tearDown(self):
+        logging.getLogger().handlers[:] = self._handlers
+        self.remove_files()
+
+    def test_reload_config(self):
+        self.rc.reload_config()
+
+    @patch('logging.Logger.error', Mock(side_effect=SleepException))
+    @patch.object(SyncObj, 'doTick', Mock(side_effect=Exception))
+    def test_run(self):
+        self.assertRaises(SleepException, self.rc.run)
+        self.rc.shutdown()
+
+    @patch('sys.argv', ['patroni'])
+    def test_patroni_raft_controller_main(self):
+        self.assertRaises(SystemExit, _main)

tests/test_utils.py

@@ -2,7 +2,7 @@ import unittest
 
 from mock import Mock, patch
 from patroni.exceptions import PatroniException
-from patroni.utils import Retry, RetryFailedError, polling_loop, validate_directory
+from patroni.utils import Retry, RetryFailedError, enable_keepalive, polling_loop, validate_directory
 
 
 class TestUtils(unittest.TestCase):
@@ -33,6 +33,14 @@ class TestUtils(unittest.TestCase):
     def test_validate_directory_is_not_a_directory(self):
         self.assertRaises(PatroniException, validate_directory, "/tmp")
 
+    def test_enable_keepalive(self):
+        with patch('socket.SIO_KEEPALIVE_VALS', 1, create=True):
+            self.assertIsNotNone(enable_keepalive(Mock(), 10, 5))
+        with patch('socket.SIO_KEEPALIVE_VALS', None, create=True):
+            for platform in ('linux2', 'darwin', 'other'):
+                with patch('sys.platform', platform):
+                    self.assertIsNone(enable_keepalive(Mock(), 10, 5))
+
 
 @patch('time.sleep', Mock())
 class TestRetrySleeper(unittest.TestCase):

tests/test_validator.py

@@ -153,6 +153,7 @@ class TestValidator(unittest.TestCase):
         self.assertEqual(['etcd.hosts.1', 'etcd.hosts.2', 'kubernetes.pod_ip', 'postgresql.bin_dir',
                           'postgresql.data_dir', 'restapi.connect_address'], parse_output(output))
 
+    @patch('socket.inet_pton', Mock(), create=True)
     def test_bin_dir_is_empty(self, mock_out, mock_err):
         directories.append(config["postgresql"]["data_dir"])
         directories.append(config["postgresql"]["bin_dir"])

tests/test_zookeeper.py

@@ -37,6 +37,8 @@ class MockKazooClient(Mock):
                 b'postgres://repuser:rep-pass@localhost:5434/postgres?application_name=http://127.0.0.1:8009/patroni',
                 ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0 if self.exists else -1, 0, 0, 0)
             )
+        elif path.endswith('/optime/leader'):
+            return (b'500', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
         elif path.endswith('/leader'):
             if self.leader:
                 return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
@@ -153,6 +155,12 @@ class TestZooKeeper(unittest.TestCase):
         cluster = self.zk.get_cluster(True)
         self.assertIsInstance(cluster.leader, Leader)
         self.zk.touch_member({'foo': 'foo'})
+        self.zk._name = 'bar'
+        self.zk.optime_watcher(None)
+        with patch.object(ZooKeeper, 'get_node', Mock(side_effect=Exception)):
+            self.zk.get_cluster()
+        cluster = self.zk.get_cluster()
+        self.assertEqual(cluster.last_leader_operation, 500)
 
     def test_delete_leader(self):
         self.assertTrue(self.zk.delete_leader())
@@ -213,6 +221,7 @@ class TestZooKeeper(unittest.TestCase):
     def test_watch(self):
         self.zk.watch(None, 0)
         self.zk.event.isSet = Mock(return_value=True)
+        self.zk._fetch_optime = False
         self.zk.watch(None, 0)
 
     def test__kazoo_connect(self):