Bumped version to 0.7

Feature/patroni cli or ctl tbd

.gitignore

@@ -1,3 +1,11 @@
 data/*
 *.pyc
-helpers/*.pyc
+*.egg/
+*.egg-info/
+.cache/
+.coverage
+.eggs/
+build/
+coverage.xml
+junit.xml
+pgpass

Dockerfile

@@ -13,8 +13,9 @@ RUN apt-get update -y
 RUN apt-get upgrade -y
 
 ENV PGVERSION 9.4
-RUN apt-get install python python-psycopg2 python-yaml python-requests python-boto postgresql-${PGVERSION} python-dnspython python-kazoo python-pip -y
-RUN pip install python-etcd
+RUN apt-get install python python-yaml python-requests python-boto postgresql-${PGVERSION} python-dnspython python-kazoo python-pip -y
+RUN apt-get install python-dev postgresql-server-dev-${PGVERSION} -y
+RUN pip install python-etcd psycopg2
 
 ENV PATH /usr/lib/postgresql/${PGVERSION}/bin:$PATH
 

README.rst

@@ -5,10 +5,10 @@ Patroni: A Template for PostgreSQL HA with ZooKeeper or etcd
 
 Patroni was previously known as Governor.
 
-*There are many ways to run high availability with PostgreSQL; here we
-present a template for you to create your own custom fit high
-availability solution using python and distributed configuration store
-(like ZooKeeper or etcd) for maximum accessibility.*
+*There are many ways to run high availability with PostgreSQL. Here, we
+present a template for you to create your own customized, high-availability 
+solution using Python and — for maximum accessibility — a distributed 
+configuration store like ZooKeeper or etcd.*
 
 Getting Started
 ---------------
@@ -22,8 +22,8 @@ To get started, do the following from different terminals:
     > ./patroni.py postgres1.yml
 
 From there, you will see a high-availability cluster start up. Test
-different settings in the YAML files to see how behavior changes. Kill
-some of the different components to see how the system behaves.
+different settings in the YAML files to see how its behavior changes. Kill
+some of the components to see how the system behaves.
 
 Add more ``postgres*.yml`` files to create an even larger cluster.
 
@@ -39,109 +39,81 @@ run:
 
     > psql --host 127.0.0.1 --port 5000 postgres
 
-How Patroni works
+How Patroni Works
 -----------------
 
-For a diagram of the high availability decision loop, see the included a
-PDF:
+For a diagram of the high availability decision loop, review this PDF:
 `postgres-ha.pdf <https://github.com/zalando/patroni/blob/master/postgres-ha.pdf>`__
 
 YAML Configuration
 ------------------
 
-For an example file, see ``postgres0.yml``. Below is an explanation of
-settings:
+For an example file, see ``postgres0.yml``. Regarding settings:
 
--  *ttl*: the TTL to acquire the leader lock. Think of it as the length
-   of time before automatic failover process is initiated.
+-  *ttl*: the TTL to acquire the leader lock. Think of it as the length of time before initiation of the automatic failover process.
 -  *loop\_wait*: the number of seconds the loop will sleep
 
--  *restapi*
--  *listen*: ip address + port that Patroni will listen to provide
-   health-check information for haproxy.
--  *connect\_address*: ip address + port through which restapi is
-   accessible.
+-  *restapi*:
+    -  *listen*: IP address + port that Patroni will listen to, to provide health-check information for haproxy.
+    -  *connect\_address*: IP address + port through which restapi is accessible.
+    -  *auth*: (optional) 'username:password' to protect dangerous REST API endpoints.
+    -  *certfile*: (optional) Specifies a file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
+    -  *keyfile*: (optional) Specifies a file with the secret key in the PEM format.
 
--  *etcd*
--  *scope*: the relative path used on etcd's http api for this
-   deployment, thus you can run multiple HA deployments from a single
-   etcd
--  *ttl*: the TTL to acquire the leader lock. Think of it as the length
-   of time before automatic failover process is initiated.
--  *host*: the host:port for the etcd endpoint
+-  *etcd*:
+    -  *scope*: the relative path used on etcd's HTTP API for this deployment; makes it possible to run multiple HA deployments from a single etcd.
+    -  *ttl*: the TTL to acquire the leader lock. Think of it as the length of time before initiation of the automatic failover process.
+    -  *host*: the host:port for the etcd endpoint.
 
--  *zookeeper*
--  *scope*: the relative path used on etcd's http api for this
-   deployment, thus you can run multiple HA deployments from a single
-   etcd
--  *session\_timeout*: the TTL to acquire the leader lock. Think of it
-   as the length of time before automatic failover process is initiated.
--  *reconnect\_timeout*: how long we should try to reconnect to
-   ZooKeeper after connection loss. After this timeout we assume that we
-   don't have lock anymore and will restart in read-only mode.
--  *hosts*: list of ZooKeeper cluster members in format: [
-   'host1:port1', 'host2:port2', 'etc...']
--  *exhibitor*: if you are running ZooKeeper cluster under Exhibitor
-   supervisory the following section could be interesting for you
+-  *zookeeper*:
+    -  *scope*: the relative path used on etcd's HTTP API for this deployment; makes it possible to run multiple HA deployments from a single etcd.
+    -  *session\_timeout*: the TTL to acquire the leader lock. Think of it as the length of time before initiation of the automatic failover process.
+    -  *reconnect\_timeout*: how long we should try to reconnect to ZooKeeper after a connection loss. After this timeout, assume that you no longer have a lock and restart in read-only mode.
+    -  *hosts*: list of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...']
+    -  *exhibitor*: if you are running a ZooKeeper cluster under the Exhibitor supervisory, the following section might interest you:
+        -  *poll\_interval*: how often the list of ZooKeeper and Exhibitor nodes should be updated from Exhibitor
+        -  *port*: Exhibitor port.
+        -  *hosts*: initial list of Exhibitor (ZooKeeper) nodes in format: ['host1', 'host2', 'etc...' ]. This list updates automatically whenever the Exhibitor (ZooKeeper) cluster topology changes.
 
-   -  *poll\_interval*: how often list of ZooKeeper and Exhibitor nodes
-      should be updated from Exhibitor
-   -  *port*: Exhibitor port
-   -  *hosts*: initial list of Exhibitor (ZooKeeper) nodes in format: [
-      'host1', 'host2', 'etc...' ]. This list would be updated
-      automatically when Exhibitor (ZooKeeper) cluster topology changes.
+-  *postgresql*:
+    -  *name*: the name of the Postgres host. Must be unique for the cluster.
+    -  *listen*: IP address + port that Postgres listens to; must be accessible from other nodes in the cluster, if you're using streaming replication.
+    -  *connect\_address*: IP address + port through which Postgres is accessible from other nodes and applications.
+    -  *data\_dir*: file path to initialize and store Postgres data files.
+    -  *maximum\_lag\_on\_failover*: the maximum bytes a follower may lag.
+    -  *use\_slots*: whether or not to use replication_slots. Must be False for PostgreSQL 9.3. You should comment out max_replication_slots before it becomes ineligible for leader status.
 
--  *postgresql*
--  *name*: the name of the Postgres host, must be unique for the cluster
--  *listen*: ip address + port that Postgres listening. Must be
-   accessible from other nodes in the cluster if using streaming
-   replication.
--  *connect\_address*: ip address + port through which Postgres is
-   accessible from other nodes and applications.
--  *data\_dir*: file path to initialize and store Postgres data files
--  *maximum\_lag\_on\_failover*: the maximum bytes a follower may lag
--  *use\_slots*: whether or not to use replication_slots.  Must be False for PostgreSQL 9.3, and you should comment out max_replication_slots.
-   before it is not eligible become leader
--  *pg\_hba*: list of lines which should be added to pg\_hba.conf
+    -  *initdb*:  List options to be passed on to initdb
+        -  *encoding*: default encoding for new databases
+        -  *locale*: default locale for new databases
+        -  *data-checksums*  # When pg_rewind is needed on 9.3, this needs to be enabled
 
-   -  *- host all all 0.0.0.0/0 md5*
+    -  *pg\_hba*: list of lines which should be added to pg\_hba.conf.
+        -  *- host all all 0.0.0.0/0 md5*.
 
--  *replication*
+    -  *replication*:
+        -  *username*: replication username; user will be created during initialization.
+        -  *password*: replication password; user will be created during initialization.
+        -  *network*: network setting for replication in pg\_hba.conf.
 
-   -  *username*: replication username, user will be created during
-      initialization
-   -  *password*: replication password, user will be created during
-      initialization
-   -  *network*: network setting for replication in pg\_hba.conf
+    -  *callbacks* callback scripts to run on certain actions. Patroni will pass the action, role and cluster name. See scripts/aws.py as an example on how to write them.
+        -  *on\_start*: a script to run when the cluster starts.
+        -  *on\_stop*: a script to run when the cluster stops.
+        -  *on\_restart*: a script to run when the cluster restarts.
+        -  *on\_reload*: a script to run when configuration reload is triggered.
+        -  *on\_role\_change*: a script to run when the cluster is being promoted or demoted.
 
--  *callbacks* callback scripts to run on certain actions. Patroni will
-   pass current action, role and cluster name. See scripts/aws.py as an
-   example on how to write them.
+    -  *superuser*:
+        -  *password*: password for the Postgres user, set during initialization.
 
-   -  *on\_start*: a script to run when the cluster starts
-   -  *on\_stop*: a script to run when the cluster stops
-   -  *on\_restart*: a script to run when the cluster restarts
-   -  *on\_reload*: a script to run when configuration reload is
-      triggered
-   -  *on\_role\_change*: a script to run when the cluster is being
-      promoted or demoted
+    -  *admin*:
+        -  *username*: admin username; user is created during initialization. It will have CREATEDB and CREATEROLE privileges.
+        -  *password*: admin password; user is created during initialization.
 
--  *superuser*
+    -  *recovery\_conf*: additional configuration settings written to recovery.conf when configuring the follower.
+        -  *parameters*: list of configuration settings for Postgres. Many of these are required for replication to work.
 
-   -  *password*: password for postgres user. It would be set during
-      initialization
-
--  *admin*:
-
-   -  *username*: admin username, user will be created during
-      initialization. It would have CREATEDB and CREATEROLE privileges
-   -  *password*: admin password, user will be created during
-      initialization.
-
--  *recovery\_conf*: additional configuration settings written to recovery.conf when configuring follower
--  *parameters*: list of configuration settings for Postgres.  Many of these are required for replication to work.
-
-Replication choices
+Replication Choices
 -------------------
 
 Patroni uses Postgres' streaming replication. By default, this
@@ -155,43 +127,43 @@ not occur if a follower is more than a certain number of bytes behind
 the follower. This setting should be increased or decreased based on
 business requirements.
 
-When asynchronous replication is not best for your use-case, investigate
+When asynchronous replication is not optimal for your use case, investigate
 how Postgres's `synchronous
 replication <http://www.postgresql.org/docs/current/static/warm-standby.html#SYNCHRONOUS-REPLICATION>`__
 works. Synchronous replication ensures consistency across a cluster by
 confirming that writes are written to a secondary before returning to
 the connecting client with a success. The cost of synchronous
-replication will be reduced throughput on writes. This throughput will
+replication: reduced throughput on writes. This throughput will
 be entirely based on network performance. In hosted datacenter
 environments (like AWS, Rackspace, or any network you do not control),
-synchrous replication increases the variability of write performance
-significantly. If followers become inaccessible from the leader, the
-leader will becomes effectively readonly.
+synchrous replication significantly increases the variability of write 
+performance. If followers become inaccessible from the leader, the
+leader effectively becomes readonly.
 
 To enable a simple synchronous replication test, add the follow lines to
-the ``parameters`` section of your YAML configuration files.
+the ``parameters`` section of your YAML configuration files:
 
 .. code:: YAML
 
         synchronous_commit: "on"
         synchronous_standby_names: "*"
 
-When using synchronous replication, use at least a 3-Postgres data nodes
+When using synchronous replication, use at least three Postgres data nodes
 to ensure write availability if one host fails.
 
-Choosing your replication schema is dependent on the many business
-decisions. Investigate both async and sync replication, as well as other
+Choosing your replication schema is dependent on your business
+considerations. Investigate both async and sync replication, as well as other
 HA solutions, to determine which solution is best for you.
 
-Applications should not use superusers
+Applications Should Not Use Superusers
 --------------------------------------
 
 When connecting from an application, always use a non-superuser. Patroni
 requires access to the database to function properly. By using a
-superuser from application, you can potentially use the entire
+superuser from an application, you can potentially use the entire
 connection pool, including the connections reserved for superusers with
 the ``superuser_reserved_connections`` setting. If Patroni cannot access
-the Primary, because the connection pool is full, behavior will be
+the Primary because the connection pool is full, behavior will be
 undesireable.
 
 Requirements on a Mac
@@ -207,14 +179,13 @@ Run the following on a Mac to install requirements:
 Notice
 ------
 
-There are many different ways to do HA with PostgreSQL, see `the
+There are many different ways to do HA with PostgreSQL: See `the
 PostgreSQL
 documentation <https://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling>`__
 for a complete list.
 
-We call this project a "template" because it is far from a one-size fits
-all, or a plug-and-play replication system. It will have it's own
-caveats. Use wisely.
+We call Patroni a "template" because it is far from being a one-size-fits-all
+or plug-and-play replication system. It will have its own caveats. Use wisely.
 
 .. |Build Status| image:: https://travis-ci.org/zalando/patroni.svg?branch=master
    :target: https://travis-ci.org/zalando/patroni

docker/README.md

@@ -1,7 +1,7 @@
 # Patroni Dockerfile
 You can run Patroni in a docker container using this Dockerfile, or by using one of the Docker image at
 
-    https://os-registry.stups.zalan.do/v1/repositories/acid/patroni/tags
+    https://registry.opensource.zalan.do/v1/repositories/acid/patroni/tags
 
 This Dockerfile is meant in aiding development of Patroni and quick testing of features. It is not a production-worthy
 Dockerfile
@@ -10,7 +10,7 @@ Dockerfile
 
 ## Standalone Patroni
 
-    docker run -d os-registry.stups.zalan.do/acid/patroni:1.0-SNAPSHOT
+    docker run -d registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT
 
 ## Multiple Patroni's communicating with a standalone etcd inside Docker
 
@@ -36,12 +36,12 @@ To automate this you can run the following script:
 
 Example session:
 
-    $ ./dev_patroni_cluster.sh --image os-registry.stups.zalan.do/acid/patroni:1.0-SNAPSHOT --members=2 --name=bravo
+    $ ./dev_patroni_cluster.sh --image registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT --members=2 --name=bravo
     The etcd container is 6be871a11cb373406ca5ea1c6b39e1.0-SNAPSHOTfdde9fb1d6177212d6ad0c0d1bd9b563, ip=172.17.1.24
     Started Patroni container 67e611f2eca7c40f9e6e0e24a4a8f2cba7e3e56d22a420e15ab9240a37a9d7a4, ip=172.17.1.25
     Started Patroni container 47dd12ae635ab83b039f5889e250048b606ed5e48e3650b69e365e7e1d4acbcf, ip=172.17.1.26
     $ docker ps
     CONTAINER ID        IMAGE                                         COMMAND                CREATED             STATUS              PORTS                          NAMES
-    47dd12ae635a        os-registry.stups.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   10 seconds ago      Up 8 seconds        4001/tcp, 5432/tcp, 2380/tcp   bravo_OR64g8bx
-    67e611f2eca7        os-registry.stups.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   11 seconds ago      Up 10 seconds       2380/tcp, 4001/tcp, 5432/tcp   bravo_si9no8iz
-    6be871a11cb3        os-registry.stups.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   12 seconds ago      Up 10 seconds       4001/tcp, 5432/tcp, 2380/tcp   bravo_etcd
+    47dd12ae635a        registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   10 seconds ago      Up 8 seconds        4001/tcp, 5432/tcp, 2380/tcp   bravo_OR64g8bx
+    67e611f2eca7        registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   11 seconds ago      Up 10 seconds       2380/tcp, 4001/tcp, 5432/tcp   bravo_si9no8iz
+    6be871a11cb3        registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT   "/bin/bash /entrypoi   12 seconds ago      Up 10 seconds       4001/tcp, 5432/tcp, 2380/tcp   bravo_etcd

docker/dev_patroni_cluster.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-DOCKER_IMAGE="os-registry.stups.zalan.do/acid/patroni:1.0-SNAPSHOT"
+DOCKER_IMAGE="registry.opensource.zalan.do/acid/patroni:1.0-SNAPSHOT"
 MEMBERS=3
 
 

docker/entrypoint.sh

@@ -3,25 +3,25 @@
 function usage()
 {
     cat <<__EOF__
-Usage: $0 
+Usage: $0
 
 Options:
 
     --etcd      ETCD    Provide an external etcd to connect to
-    --name      NAME    Give the cluster a specific name 
+    --name      NAME    Give the cluster a specific name
     --etcd-only         Do not run Patroni, run a standalone etcd
 
 Examples:
 
     $0 --etcd=127.17.0.84:4001
     $0 --etcd-only
-    $0 
+    $0
     $0 --name=true_scotsman
 __EOF__
 }
 
 DOCKER_IP=$(hostname --ip-address)
-PATRONI_SCOPE=batman
+PATRONI_SCOPE=${PATRONI_SCOPE:-batman}
 
 optspec=":vh-:"
 while getopts "$optspec" optchar; do
@@ -32,7 +32,7 @@ while getopts "$optspec" optchar; do
                     exec etcd --data-dir /tmp/etcd.data \
                         -advertise-client-urls=http://${DOCKER_IP}:4001 \
                         -listen-client-urls=http://0.0.0.0:4001 \
-                        -listen-peer-urls=http://0.0.0.0:2380 
+                        -listen-peer-urls=http://0.0.0.0:2380
                     exit 0
                     ;;
                 cheat)
@@ -83,10 +83,11 @@ cat > /patroni/postgres.yml <<__EOF__
 
 ttl: &ttl 30
 loop_wait: &loop_wait 10
-scope: &scope ${PATRONI_SCOPE}
+scope: &scope '${PATRONI_SCOPE}'
+namespace: 'patroni'
 restapi:
-  listen: 127.0.0.1:8008
-  connect_address: 127.0.0.1:8008
+  listen: 0.0.0.0:8008
+  connect_address: ${DOCKER_IP}:8008
 etcd:
   scope: *scope
   ttl: *ttl
@@ -115,7 +116,7 @@ postgresql:
   parameters:
     archive_mode: "on"
     wal_level: hot_standby
-    archive_command: mkdir -p ../wal_archive && cp %p ../wal_archive/%f
+    archive_command: 'true'
     max_wal_senders: 20
     listen_addresses: 0.0.0.0
     wal_keep_segments: 8

extras/startup-scripts/README.md

@@ -0,0 +1,10 @@
+# startup scripts for Patroni
+
+This directory contains sample startup scripts for various OSes 
+and management tools for Patroni.
+
+Scripts supplied:
+
+### patroni.upstart.conf
+
+Upstart job for Ubuntu 12.04 or 14.04.  Requires Upstart > 1.4. Intended for systems where Patroni has been installed on a base system, rather than in Docker.

extras/startup-scripts/patroni.upstart.conf

@@ -0,0 +1,36 @@
+# patroni - patroni daemon
+#
+# controls startup/shutdown of postgres
+# you should disable any postgres start jobs
+#
+# assumes that patroni has been installed into the
+# pythonpath by using setup.py install
+
+description    "patroni start daemon"
+
+start on net-device-up
+stop on runlevel [06]
+
+respawn
+respawn limit 5 10
+
+# set location of patroni
+env PATRONI=/usr/local/bin/patroni
+# virtualenv example
+# env PATRONI=/var/lib/postgresql/patronienv/bin/patroni
+
+# set location of config file
+env PATRONICONF=/etc/patroni/patroni.yml
+
+# set log dir for patroni logs
+# postgres user must have write permission
+env POSTGRESLOGDIR=/var/log/postgresql
+
+setuid postgres
+setgid postgres
+
+script
+    exec start-stop-daemon --start \
+        --exec $PATRONI -- $PATRONICONF \
+        >> $POSTGRESLOGDIR/patroni.log 2>&1
+end script

haproxy.cfg

@@ -15,7 +15,7 @@ frontend ft_postgresql
 	default_backend bk_db
 
 backend bk_db
-	option httpchk GET
+	option httpchk
 
-  server postgresql_127.0.0.1_5432 127.0.0.1:5432 maxconn 100 check port 8008
-  server postgresql_127.0.0.1_5433 127.0.0.1:5433 maxconn 100 check port 8009
+    server postgresql_127.0.0.1_5432 127.0.0.1:5432 maxconn 100 check port 8008
+    server postgresql_127.0.0.1_5433 127.0.0.1:5433 maxconn 100 check port 8009

patroni/__init__.py

@@ -6,10 +6,9 @@ import yaml
 
 from patroni.api import RestApiServer
 from patroni.etcd import Etcd
-from patroni.exceptions import DCSError
 from patroni.ha import Ha
 from patroni.postgresql import Postgresql
-from patroni.utils import setup_signal_handlers, sleep, reap_children
+from patroni.utils import setup_signal_handlers, reap_children
 from patroni.zookeeper import ZooKeeper
 
 logger = logging.getLogger(__name__)
@@ -19,12 +18,16 @@ class Patroni:
 
     def __init__(self, config):
         self.nap_time = config['loop_wait']
+        self.tags = config.get('tags', dict())
         self.postgresql = Postgresql(config['postgresql'])
-        self.ha = Ha(self.postgresql, self.get_dcs(self.postgresql.name, config))
-        host, port = config['restapi']['listen'].split(':')
+        self.dcs = self.get_dcs(self.postgresql.name, config)
         self.api = RestApiServer(self, config['restapi'])
+        self.ha = Ha(self)
         self.next_run = time.time()
-        self.shutdown_member_ttl = 300
+
+    @property
+    def nofailover(self):
+        return self.tags.get('nofailover', False)
 
     @staticmethod
     def get_dcs(name, config):
@@ -32,82 +35,23 @@ class Patroni:
             return Etcd(name, config['etcd'])
         if 'zookeeper' in config:
             return ZooKeeper(name, config['zookeeper'])
-        raise Exception('Can not find sutable configuration of distributed configuration store')
-
-    def touch_member(self, ttl=None):
-        connection_string = self.postgresql.connection_string + '?application_name=' + self.api.connection_string
-        if self.ha.cluster:
-            for m in self.ha.cluster.members:
-                # Do not update member TTL when it is far from being expired
-                if m.name == self.postgresql.name and m.real_ttl() > self.shutdown_member_ttl:
-                    return True
-        return self.ha.dcs.touch_member(connection_string, ttl)
-
-    def cleanup_on_failed_initialization(self):
-        """ cleanup the DCS if initialization was not successfull """
-        logger.info("removing initialize key after failed attempt to initialize the cluster")
-        self.ha.dcs.cancel_initialization()
-        self.touch_member(self.shutdown_member_ttl)
-        self.postgresql.stop()
-        self.postgresql.move_data_directory()
-
-    def initialize(self):
-        # wait for etcd to be available
-        while not self.touch_member():
-            logger.info('waiting on DCS')
-            sleep(5)
-
-        # is data directory empty?
-        if self.postgresql.data_directory_empty():
-            while True:
-                try:
-                    cluster = self.ha.dcs.get_cluster()
-                    if not cluster.is_unlocked():  # the leader already exists
-                        if not cluster.initialize:
-                            self.ha.dcs.initialize()
-                        self.postgresql.bootstrap(cluster.leader)
-                        break
-                    # racing to initialize
-                    elif not cluster.initialize and self.ha.dcs.initialize():
-                        try:
-                            self.postgresql.bootstrap()
-                        except:
-                            # bail out and clean the initialize flag.
-                            self.cleanup_on_failed_initialization()
-                            raise
-                        self.ha.dcs.take_leader()
-                        break
-                except DCSError:
-                    logger.info('waiting on DCS')
-                sleep(5)
-        elif self.postgresql.is_running():
-            self.postgresql.load_replication_slots()
+        raise Exception('Can not find suitable configuration of distributed configuration store')
 
     def schedule_next_run(self):
-        if self.postgresql.is_promoted:
-            self.next_run = time.time()
         self.next_run += self.nap_time
         current_time = time.time()
         nap_time = self.next_run - current_time
         if nap_time <= 0:
             self.next_run = current_time
-        else:
-            self.ha.dcs.watch(nap_time)
+        elif self.dcs.watch(nap_time):
+            self.next_run = time.time()
 
     def run(self):
         self.api.start()
         self.next_run = time.time()
 
         while True:
-            self.touch_member()
             logger.info(self.ha.run_cycle())
-            try:
-                if self.ha.state_handler.is_leader():
-                    self.ha.cluster and self.ha.state_handler.create_replication_slots(self.ha.cluster)
-                else:
-                    self.ha.state_handler.drop_replication_slots()
-            except:
-                logger.exception('Exception when changing replication slots')
             reap_children()
             self.schedule_next_run()
 
@@ -125,12 +69,11 @@ def main():
         config = yaml.load(f)
 
     patroni = Patroni(config)
-    patroni.initialize()
     try:
         patroni.run()
     except KeyboardInterrupt:
         pass
     finally:
-        patroni.touch_member(patroni.shutdown_member_ttl)  # schedule member removal
+        patroni.api.shutdown()
         patroni.postgresql.stop()
-        patroni.ha.dcs.delete_leader()
+        patroni.dcs.delete_leader()

patroni/api.py

@@ -1,8 +1,13 @@
+import base64
 import fcntl
 import json
 import logging
 import psycopg2
+import socket
+import time
 
+from patroni.exceptions import PostgresConnectionException
+from patroni.utils import Retry, RetryFailedError
 from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from six.moves.socketserver import ThreadingMixIn
 from threading import Thread
@@ -10,33 +15,224 @@ from threading import Thread
 logger = logging.getLogger(__name__)
 
 
+def check_auth(func):
+    """Decorator function to check authorization header.
+
+    Usage example:
+    @check_auth
+    def do_PUT_foo():
+        pass
+    """
+    def wrapper(handler):
+        if handler.check_auth_header():
+            return func(handler)
+    return wrapper
+
+
 class RestApiHandler(BaseHTTPRequestHandler):
 
-    def do_GET(self):
-        response = self.get_postgresql_status()
+    def send_auth_request(self, body):
+        self.send_response(401)
+        self.send_header('WWW-Authenticate', 'Basic realm=\"Patroni\"')
+        self.send_header('Content-type', 'text/html')
+        self.end_headers()
+        self.wfile.write(body.encode('utf-8'))
+
+    def finish(self, *args, **kwargs):
+        try:
+            if not self.wfile.closed:
+                self.wfile.flush()
+                self.wfile.close()
+        except socket.error:
+            pass
+        self.rfile.close()
+
+    def check_auth_header(self):
+        auth_header = self.headers.get('Authorization')
+        status = self.server.check_auth_header(auth_header)
+        return not status or self.send_auth_request(status)
+
+    def do_OPTIONS(self):
+        self.do_GET(options=True)
+
+    def do_GET(self, options=False):
+        """Default method for processing all GET requests which can not be routed to other methods"""
 
         path = '/master' if self.path == '/' else self.path
-        status_code = 200 if response['running'] and 'role' in response and response['role'] in path else 503
+        response = self.get_postgresql_status()
+        response.update(self.get_tags())
+
+        patroni = self.server.patroni
+        cluster = patroni.dcs.cluster
+        if cluster:  # dcs available
+            if cluster.leader and cluster.leader.name == patroni.postgresql.name:  # is_leader
+                status_code = 200 if 'master' in path else 503
+            elif 'role' not in response:
+                status_code = 503
+            elif response['role'] == 'master':  # running as master but without leader lock!!!!
+                status_code = 503
+            elif response['role'] in path:
+                status_code = 200
+            else:
+                status_code = 503
+        elif 'role' in response and response['role'] in path:
+            status_code = 200
+        elif patroni.ha.restart_scheduled() and patroni.postgresql.role == 'master' and 'master' in path:
+            # exceptional case for master node when the postgres is being restarted via API
+            status_code = 200
+        else:
+            status_code = 503
 
         self.send_response(status_code)
+        if not options:
+            self.send_header('Content-Type', 'application/json')
+            self.end_headers()
+            self.wfile.write(json.dumps(response).encode('utf-8'))
+
+    def do_GET_patroni(self):
+        response = self.get_postgresql_status(True)
+        response.update(self.get_tags())
+
+        self.send_response(200)
         self.send_header('Content-Type', 'application/json')
         self.end_headers()
         self.wfile.write(json.dumps(response).encode('utf-8'))
 
-    def get_postgresql_status(self):
+    @check_auth
+    def do_POST_restart(self):
+        status_code = 503
+        data = b'restart failed'
         try:
-            row = self.server.query("""SELECT to_char(pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),
-                                              pg_is_in_recovery(),
-                                              CASE WHEN pg_is_in_recovery()
-                                                   THEN null
-                                                   ELSE pg_current_xlog_location() END,
-                                              pg_last_xlog_receive_location(),
-                                              pg_last_xlog_replay_location(),
-                                              pg_is_in_recovery() AND pg_is_xlog_replay_paused()""")[0]
+            status, msg = self.server.patroni.ha.restart()
+            status_code = 200 if status else 503
+            data = msg.encode('utf-8')
+        except:
+            logger.exception('Exception during restart')
+
+        self.send_response(status_code)
+        self.send_header('Content-Type', 'text/html')
+        self.end_headers()
+        self.wfile.write(data)
+
+    @check_auth
+    def do_POST_reinitialize(self):
+        ha = self.server.patroni.ha
+        cluster = ha.dcs.get_cluster()
+        if cluster.is_unlocked():
+            status_code = 503
+            data = b'Cluster has no leader, can not reinitialize'
+        elif cluster.leader.name == ha.state_handler.name:
+            status_code = 503
+            data = b'I am the leader, can not reinitialize'
+        else:
+            action = ha.schedule_reinitialize()
+            if action is not None:
+                status_code = 503
+                data = (action + ' already in progress').encode('utf-8')
+            else:
+                status_code = 200
+                data = b'reinitialize scheduled'
+
+        self.send_response(status_code)
+        self.send_header('Content-Type', 'text/html')
+        self.end_headers()
+        self.wfile.write(data)
+
+    def poll_failover_result(self, leader, member):
+        for a in range(0, 15):
+            time.sleep(1)
+            try:
+                cluster = self.server.patroni.dcs.get_cluster()
+                if cluster.leader and cluster.leader.name != leader:
+                    return 200, ('Successfully failed over to ' + cluster.leader.name).encode('utf-8')
+                if not cluster.failover:
+                    return 503, b'Failover failed'
+            except:
+                pass
+        return 503, b'Failover status unknown'
+
+    def is_failover_possible(self, cluster, leader, member):
+        if leader and not cluster.leader or cluster.leader.name != leader:
+            return b'leader name does not match'
+        if member:
+            members = [m for m in cluster.members if m.name == member]
+            if not members:
+                return b'member does not exists'
+        else:
+            members = [m for m in cluster.members if m.name != cluster.leader.name and m.api_url]
+            if not members:
+                return b'failover is not possible: cluster does not have members except leader'
+        for member, reachable, in_recovery, xlog_location, tags in self.server.patroni.ha.fetch_nodes_statuses(members):
+            if reachable and not tags.get('nofailover', False):
+                return None
+        return b'failover is not possible: no good candidates have been found'
+
+    @check_auth
+    def do_POST_failover(self):
+        content_length = int(self.headers.get('content-length', 0))
+        request = json.loads(self.rfile.read(content_length).decode('utf-8'))
+        leader = request.get('leader', None)
+        member = request.get('member', None)
+        cluster = self.server.patroni.ha.dcs.get_cluster()
+        status_code = 503
+        data = self.is_failover_possible(cluster, leader, member)
+        if not data:
+            if not self.server.patroni.dcs.manual_failover(leader, member):
+                data = b'failed to write failover key into DCS'
+            else:
+                self.server.patroni.dcs.event.set()
+                status_code, data = self.poll_failover_result(cluster.leader and cluster.leader.name, member)
+
+        self.send_response(status_code)
+        self.send_header('Content-Type', 'text/html')
+        self.end_headers()
+        self.wfile.write(data)
+
+    def parse_request(self):
+        """Override parse_request method to enrich basic functionality of `BaseHTTPRequestHandler` class
+
+        Original class can only invoke do_GET, do_POST, do_PUT, etc method implementations if they are defined.
+        But we would like to have at least some simple routing mechanism, i.e.:
+        GET /uri1/part2 request should invoke `do_GET_uri1()`
+        POST /other should invoke `do_POST_other()`
+
+        If the `do_<REQUEST_METHOD>_<first_part_url>` method does not exists we'll fallback to original behavior."""
+
+        ret = BaseHTTPRequestHandler.parse_request(self)
+        if ret:
+            mname = self.path.lstrip('/').split('/')[0]
+            mname = self.command + ('_' + mname if mname else '')
+            if hasattr(self, 'do_' + mname):
+                self.command = mname
+        return ret
+
+    def handle_one_request(self):
+        try:
+            BaseHTTPRequestHandler.handle_one_request(self)
+        except socket.error:
+            pass
+
+    def query(self, sql, *params, **kwargs):
+        if not kwargs.get('retry', False):
+            return self.server.query(sql, *params)
+        retry = Retry(delay=1, retry_exceptions=PostgresConnectionException)
+        return retry(self.server.query, sql, *params)
+
+    def get_postgresql_status(self, retry=False):
+        try:
+            row = self.query("""SELECT to_char(pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),
+                                       pg_is_in_recovery(),
+                                       CASE WHEN pg_is_in_recovery()
+                                            THEN 0
+                                            ELSE pg_xlog_location_diff(pg_current_xlog_location(), '0/0')::bigint
+                                       END,
+                                       pg_xlog_location_diff(pg_last_xlog_receive_location(), '0/0')::bigint,
+                                       pg_xlog_location_diff(pg_last_xlog_replay_location(), '0/0')::bigint,
+                                       pg_is_in_recovery() AND pg_is_xlog_replay_paused()""", retry=retry)[0]
             return {
-                'running': True,
+                'state': self.server.patroni.postgresql.state,
                 'postmaster_start_time': row[0],
-                'role': 'slave' if row[1] else 'master',
+                'role': 'replica' if row[1] else 'master',
                 'xlog': ({
                     'received_location': row[3],
                     'replayed_location': row[4],
@@ -44,30 +240,63 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     'location': row[2]
                 })
             }
-        except (psycopg2.OperationalError, psycopg2.InterfaceError):
-            logger.exception('get_postgresql_status')
-            return {'running': self.server.patroni.postgresql.is_running()}
+        except (psycopg2.Error, RetryFailedError, PostgresConnectionException):
+            state = self.server.patroni.postgresql.state
+            if state in ['stopped', 'starting', 'stopping', 'restarting', 'running']:
+                logger.exception('get_postgresql_status')
+                state = 'unknown' if state == 'running' else state
+            return {'state': state}
+
+    def get_tags(self):
+        return {'tags': self.server.patroni.tags}
 
 
 class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
 
     def __init__(self, patroni, config):
-        self.connection_string = 'http://{}/patroni'.format(config.get('connect_address', None) or config['listen'])
+        self._auth_key = base64.b64encode(config['auth'].encode('utf-8')).decode('utf-8') if 'auth' in config else None
         host, port = config['listen'].split(':')
         HTTPServer.__init__(self, (host, int(port)), RestApiHandler)
         Thread.__init__(self, target=self.serve_forever)
         self._set_fd_cloexec(self.socket)
+
+        protocol = 'http'
+
+        # wrap socket with ssl if 'certfile' is defined in a config.yaml
+        # Sometime it's also needed to pass reference to a 'keyfile'.
+        options = {option: config[option] for option in ['certfile', 'keyfile'] if option in config}
+        if options.get('certfile', None):
+            import ssl
+            self.socket = ssl.wrap_socket(self.socket, server_side=True, **options)
+            protocol = 'https'
+
+        self.connection_string = '{}://{}/patroni'.format(protocol, config.get('connect_address', config['listen']))
+
         self.patroni = patroni
         self.daemon = True
 
     def query(self, sql, *params):
-        cursor = self.patroni.postgresql.connection().cursor()
-        cursor.execute(sql, params)
-        ret = [r for r in cursor]
-        cursor.close()
-        return ret
+        cursor = None
+        try:
+            with self.patroni.postgresql.connection().cursor() as cursor:
+                cursor.execute(sql, params)
+                return [r for r in cursor]
+        except psycopg2.Error as e:
+            if cursor and cursor.connection.closed == 0:
+                raise e
+            raise PostgresConnectionException('connection problems')
 
     @staticmethod
     def _set_fd_cloexec(fd):
         flags = fcntl.fcntl(fd, fcntl.F_GETFD)
         fcntl.fcntl(fd, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)
+
+    def check_basic_auth_key(self, key):
+        return self._auth_key == key
+
+    def check_auth_header(self, auth_header):
+        if self._auth_key:
+            if auth_header is None:
+                return 'no auth header received'
+            if not auth_header.startswith('Basic ') or not self.check_basic_auth_key(auth_header[6:]):
+                return 'not authenticated'

patroni/async_executor.py

@@ -0,0 +1,55 @@
+import logging
+from threading import Lock, Thread
+
+logger = logging.getLogger(__name__)
+
+
+class AsyncExecutor:
+
+    def __init__(self):
+        Lock.__init__(self)
+        self._busy = False
+        self._thread_lock = Lock()
+        self._scheduled_action = None
+        self._scheduled_action_lock = Lock()
+
+    @property
+    def busy(self):
+        return self._busy
+
+    def schedule(self, action, immediately=False):
+        with self._scheduled_action_lock:
+            if self._scheduled_action is not None:
+                return self._scheduled_action
+            self._scheduled_action = action
+            self._busy = immediately
+        return None
+
+    @property
+    def scheduled_action(self):
+        with self._scheduled_action_lock:
+            return self._scheduled_action
+
+    def reset_scheduled_action(self):
+        with self._scheduled_action_lock:
+            self._scheduled_action = None
+
+    def run(self, func, args=()):
+        try:
+            return func(*args) if args else func()
+        except:
+            logger.exception('Exception during execution of long running task %s', self.scheduled_action)
+        finally:
+            with self:
+                self._busy = False
+                self.reset_scheduled_action()
+
+    def run_async(self, func, args=()):
+        self._busy = True
+        Thread(target=self.run, args=(func, args)).start()
+
+    def __enter__(self):
+        self._thread_lock.acquire()
+
+    def __exit__(self, type, value, traceback):
+        self._thread_lock.release()

patroni/ctl.py

@@ -0,0 +1,613 @@
+'''
+Patroni Control
+'''
+
+import click
+import os
+import yaml
+import json
+import time
+import psycopg2
+import random
+import requests
+import datetime
+from prettytable import PrettyTable
+from six.moves.urllib_parse import urlparse
+import logging
+
+from .etcd import Etcd
+from .exceptions import PatroniCtlException
+from .postgresql import parseurl
+
+CONFIG_DIR_PATH = click.get_app_dir('patroni')
+CONFIG_FILE_PATH = os.path.join(CONFIG_DIR_PATH, 'patronictl.yaml')
+LOGLEVEL = 'WARNING'
+
+
+def parse_dcs(dcs):
+    """
+    Break up the provided dcs string
+    >>> parse_dcs('localhost') == {'scheme': 'etcd', 'hostname': 'localhost', 'port': 4001}
+    True
+    >>> parse_dcs('localhost:8500') == {'scheme': 'consul', 'hostname': 'localhost', 'port': 8500}
+    True
+    >>> parse_dcs('zookeeper://localhost') == {'scheme': 'zookeeper', 'hostname': 'localhost', 'port': 2181}
+    True
+    """
+
+    if not dcs:
+        return {}
+
+    parsed = urlparse(dcs)
+    scheme = parsed.scheme
+    if scheme == '' and parsed.netloc == '':
+        parsed = urlparse('//' + dcs)
+
+    if scheme == '':
+        default_schemes = {'2181': 'zookeeper', '8500': 'consul'}
+        scheme = default_schemes.get(str(parsed.port), 'etcd')
+
+    port = parsed.port
+    if port is None:
+        default_ports = {'consul': 8500, 'zookeeper': 2181}
+        port = default_ports.get(str(scheme), 4001)
+
+    return {'scheme': str(scheme), 'hostname': str(parsed.hostname), 'port': int(port)}
+
+
+def load_config(path, dcs):
+    logging.debug('Loading configuration from file {}'.format(path))
+    config = dict()
+    try:
+        with open(path, 'rb') as fd:
+            config = yaml.safe_load(fd)
+    except:
+        logging.exception('Could not load configuration file')
+
+    if dcs:
+        config['dcs'] = parse_dcs(dcs)
+    else:
+        config['dcs'] = parse_dcs(config.get('dcs_api'))
+
+    return config
+
+
+def store_config(config, path):
+    dir_path = os.path.dirname(path)
+    if dir_path:
+        if not os.path.isdir(dir_path):
+            os.makedirs(dir_path)
+    with open(path, 'w') as fd:
+        yaml.dump(config, fd)
+
+
+option_config_file = click.option('--config-file', '-c', help='Configuration file', default=CONFIG_FILE_PATH)
+option_format = click.option('--format', '-f', help='Output format (pretty, json)', default='pretty')
+option_dcs = click.option('--dcs', '-d', help='Use this DCS', envvar='DCS')
+option_watchrefresh = click.option('-w', '--watch', type=float, help='Auto update the screen every X seconds')
+option_watch = click.option('-W', is_flag=True, help='Auto update the screen every 2 seconds')
+option_force = click.option('--force', is_flag=True, help='Do not ask for confirmation at any point')
+
+
+@click.group()
+@click.pass_context
+def ctl(ctx):
+    global LOGLEVEL
+    LOGLEVEL = os.environ.get('LOGLEVEL', LOGLEVEL)
+
+    logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s', level=LOGLEVEL)
+
+
+def get_dcs(config, scope):
+    scheme, hostname, port = map(config.get('dcs', {}).get, ('scheme', 'hostname', 'port'))
+
+    if scheme == 'etcd':
+        return Etcd(name=scope, config={'scope': scope, 'host': '{}:{}'.format(hostname, port)})
+
+    raise PatroniCtlException('Can not find suitable configuration of distributed configuration store')
+
+
+def post_patroni(member, endpoint, content, headers={'Content-Type': 'application/json'}):
+    url = urlparse(member.api_url)
+    logging.debug(url)
+    return requests.post('{}://{}/{}'.format(url.scheme, url.netloc, endpoint), headers=headers,
+                         data=json.dumps(content), timeout=5)
+
+
+def print_output(columns, rows=[], alignment=None, format='pretty', header=True, delimiter='\t'):
+    if format == 'pretty':
+        t = PrettyTable(columns)
+        for k, v in (alignment or {}).items():
+            t.align[k] = v
+        for r in rows:
+            t.add_row(r)
+        click.echo(t)
+        return
+
+    if format == 'json':
+        elements = list()
+        for r in rows:
+            elements.append(dict(zip(columns, r)))
+
+        click.echo(json.dumps(elements))
+
+    if format == 'tsv':
+        if columns is not None and header:
+            click.echo(delimiter.join(columns) + '\n')
+
+        for r in rows or []:
+            c = [str(c) for c in r]
+            click.echo(delimiter.join(c))
+
+
+def watching(w, watch, max_count=None, clear=True):
+    """
+    >>> len(list(watching(True, 1, 0)))
+    1
+    >>> len(list(watching(True, 1, 1)))
+    2
+    >>> len(list(watching(True, None, 0)))
+    1
+    """
+
+    if w and not watch:
+        watch = 2
+    if watch and clear:
+        click.clear()
+    yield 0
+
+    if max_count is not None and max_count < 1:
+        return
+
+    counter = 1
+    while watch and counter <= (max_count or counter):
+        time.sleep(watch)
+        counter += 1
+        if clear:
+            click.clear()
+        yield 0
+
+
+def build_connect_parameters(conn_url, connect_parameters={}):
+    params = connect_parameters.copy()
+    parsed = parseurl(conn_url)
+    params['host'] = parsed['host']
+    params['port'] = parsed['port']
+    params['fallback_application_name'] = 'Patroni ctl'
+    params['connect_timeout'] = '5'
+
+    return params
+
+
+def get_all_members(cluster, role='master'):
+    if role == 'master':
+        if cluster.leader is not None:
+            yield cluster.leader
+        return
+
+    leader_name = (cluster.leader.member.name if cluster.leader else None)
+    for m in cluster.members:
+        if role == 'any' or role == 'replica' and m.name != leader_name:
+            yield m
+
+
+def get_any_member(cluster, role='master', member=None):
+    members = get_all_members(cluster=cluster, role=role)
+    for m in members:
+        if member is None or m.name == member:
+            return m
+
+    return None
+
+
+def get_cursor(cluster, role='master', member=None, connect_parameters={}):
+    member = get_any_member(cluster=cluster, role=role, member=member)
+    if member is None:
+        return None
+
+    params = build_connect_parameters(member.conn_url, connect_parameters=connect_parameters)
+
+    conn = psycopg2.connect(**params)
+    conn.autocommit = True
+    cursor = conn.cursor()
+    if role == 'any':
+        return cursor
+
+    cursor.execute('SELECT pg_is_in_recovery()')
+    in_recovery = cursor.fetchone()[0]
+
+    if in_recovery and role == 'replica' or not in_recovery and role == 'master':
+        return cursor
+
+    conn.close()
+
+    return None
+
+
+@ctl.command('dsn', help='Generate a dsn for the provided member, defaults to a dsn of the master')
+@click.option('--role', '-r', help='Give a dsn of any member with this role', type=click.Choice(['master', 'replica',
+              'any']), default=None)
+@click.option('--member', '-m', help='Generate a dsn for this member', type=str)
+@option_dcs
+@option_config_file
+@click.argument('cluster_name')
+def dsn(cluster_name, config_file, dcs, role, member):
+    if role is not None and member is not None:
+        raise PatroniCtlException('--role and --member are mutually exclusive options')
+    if member is None and role is None:
+        role = 'master'
+
+    config, dcs, cluster = ctl_load_config(cluster_name, config_file, dcs)
+    m = get_any_member(cluster=cluster, role=role, member=member)
+    if m is None:
+        raise PatroniCtlException('Can not find a suitable member')
+
+    params = build_connect_parameters(m.conn_url)
+    click.echo('host={} port={}'.format(params['host'], params['port']))
+
+
+@ctl.command('query', help='Query a Patroni PostgreSQL member')
+@click.argument('cluster_name')
+@option_config_file
+@option_format
+@click.option('--format', help='Output format (pretty, json)', default='tsv')
+@click.option('--file', '-f', help='Execute the SQL commands from this file', type=click.File('rb'))
+@option_dcs
+@option_watch
+@option_watchrefresh
+@click.option('--role', '-r', help='The role of the query', type=click.Choice(['master', 'replica', 'any']),
+              default=None)
+@click.option('--member', '-m', help='Query a specific member', type=str)
+@click.option('--delimiter', help='The column delimiter', default='\t')
+@click.option('--command', '-c', help='The SQL commands to execute')
+def query(
+    cluster_name,
+    config_file,
+    dcs,
+    role,
+    member,
+    w,
+    watch,
+    delimiter,
+    command,
+    file,
+    format='tsv',
+):
+    if role is not None and member is not None:
+        raise PatroniCtlException('--role and --member are mutually exclusive options')
+    if member is None and role is None:
+        role = 'master'
+
+    if file is not None and command is not None:
+        raise PatroniCtlException('--file and --command are mutually exclusive options')
+
+    if file is not None:
+        command = file.read()
+
+    config, dcs, cluster = ctl_load_config(cluster_name, config_file, dcs)
+
+    cursor = None
+    for _ in watching(w, watch, clear=False):
+
+        output, cursor = query_member(cluster=cluster, cursor=cursor, member=member, role=role, command=command)
+        print_output(None, output, format=format, delimiter=delimiter)
+
+        if cursor is None:
+            cluster = dcs.get_cluster()
+
+
+def query_member(cluster, cursor, member, role, command):
+    try:
+        if cursor is None:
+            cursor = get_cursor(cluster, role=role, member=member)
+
+        if cursor is None:
+            if role is None:
+                message = 'No connection to member {} is available'.format(member)
+            else:
+                message = 'No connection to role={} is available'.format(role)
+            logging.debug(message)
+            return [[timestamp(0), message]], None
+
+        cursor.execute('SELECT pg_is_in_recovery()')
+        in_recovery = cursor.fetchone()[0]
+
+        if in_recovery and role == 'master' or not in_recovery and role == 'replica':
+            cursor.connection.close()
+            return None, None
+
+        cursor.execute(command)
+        return cursor.fetchall(), cursor
+    except (psycopg2.OperationalError, psycopg2.DatabaseError) as oe:
+        logging.debug(oe)
+        if cursor is not None and not cursor.connection.closed:
+            cursor.connection.close()
+        message = oe.pgcode or oe.pgerror or str(oe)
+        message = message.replace('\n', ' ')
+        return [[timestamp(0), 'ERROR, SQLSTATE: {}'.format(message)]], None
+
+
+@ctl.command('remove', help='Remove cluster from DCS')
+@click.argument('cluster_name')
+@option_config_file
+@option_format
+@option_dcs
+def remove(config_file, cluster_name, format, dcs):
+    config, dcs, cluster = ctl_load_config(cluster_name, config_file, dcs)
+
+    if not isinstance(dcs, Etcd):
+        raise PatroniCtlException('We have not implemented this for DCS of type {}'.format(type(dcs)))
+
+    output_members(cluster, format=format)
+
+    confirm = click.prompt('Please confirm the cluster name to remove', type=str)
+    if confirm != cluster_name:
+        raise PatroniCtlException('Cluster names specified do not match')
+
+    message = 'Yes I am aware'
+    confirm = \
+        click.prompt('You are about to remove all information in DCS for {}, please type: "{}"'.format(cluster_name,
+                     message), type=str)
+    if message != confirm:
+        raise PatroniCtlException('You did not exactly type "{}"'.format(message))
+
+    if cluster.leader:
+        confirm = click.prompt('This cluster currently is healthy. Please specify the master name to continue')
+        if confirm != cluster.leader.name:
+            raise PatroniCtlException('You did not specify the current master of the cluster')
+
+    dcs.client.delete(dcs._base_path, recursive=True)
+
+
+def wait_for_leader(dcs, timeout=30):
+    t_stop = time.time() + timeout
+    timeout /= 2
+
+    while time.time() < t_stop:
+        dcs.watch(timeout)
+        cluster = dcs.get_cluster()
+
+        if cluster.leader:
+            return cluster
+
+    raise PatroniCtlException('Timeout occured')
+
+
+def empty_post_to_members(cluster, member_names, force, endpoint):
+    candidates = dict()
+    for m in cluster.members:
+        candidates[m.name] = m
+
+    if len(member_names) == 0:
+        member_names = [click.prompt('Which member do you want to {} [{}]?'.format(endpoint,
+                        ', '.join(candidates.keys())), type=str, default='')]
+
+    for mn in member_names:
+        if mn not in candidates.keys():
+            raise PatroniCtlException('{} is not a member of cluster'.format(mn))
+
+    if not force:
+        confirm = click.confirm('Are you sure you want to {} members {}?'.format(endpoint, ', '.join(member_names)))
+        if not confirm:
+            raise PatroniCtlException('Aborted {}'.format(endpoint))
+
+    for mn in member_names:
+        r = post_patroni(candidates[mn], endpoint, '')
+        if r.status_code != 200:
+            click.echo('{} failed for member {}, status code={}, ({})'.format(endpoint, mn, r.status_code, r.text))
+        else:
+            click.echo('Succesful {} on member {}'.format(endpoint, mn))
+
+
+def ctl_load_config(cluster_name, config_file, dcs):
+    config = load_config(config_file, dcs)
+    dcs = get_dcs(config, cluster_name)
+    cluster = dcs.get_cluster()
+
+    return config, dcs, cluster
+
+
+@ctl.command('restart', help='Restart cluster member')
+@click.argument('cluster_name')
+@click.argument('member_names', nargs=-1)
+@click.option('--role', '-r', help='Restart only members with this role', default='any',
+              type=click.Choice(['master', 'replica', 'any']))
+@click.option('--any', help='Restart a single member only', is_flag=True)
+@option_config_file
+@option_force
+@option_dcs
+def restart(cluster_name, member_names, config_file, dcs, force, role, any):
+    config, dcs, cluster = ctl_load_config(cluster_name, config_file, dcs)
+
+    role_names = [m.name for m in get_all_members(cluster=cluster, role=role)]
+
+    if len(member_names) > 0:
+        member_names = list(set(member_names) & set(role_names))
+    else:
+        member_names = role_names
+
+    if any:
+        random.shuffle(member_names)
+        member_names = member_names[:1]
+
+    output_members(cluster)
+    empty_post_to_members(cluster, member_names, force, 'restart')
+
+
+@ctl.command('reinit', help='Reinitialize cluster member')
+@click.argument('cluster_name')
+@click.argument('member_names', nargs=-1)
+@option_config_file
+@option_force
+@option_dcs
+def reinit(cluster_name, member_names, config_file, dcs, force):
+    config, dcs, cluster = ctl_load_config(cluster_name, config_file, dcs)
+    empty_post_to_members(cluster, member_names, force, 'reinitialize')
+
+
+@ctl.command('failover', help='Failover to a replica')
+@click.argument('cluster_name')
+@click.option('--master', help='The name of the current master', default=None)
+@click.option('--candidate', help='The name of the candidate', default=None)
+@click.option('--force', is_flag=True)
+@option_config_file
+@option_dcs
+def failover(config_file, cluster_name, master, candidate, force, dcs):
+    """
+        We want to trigger a failover for the specified cluster name.
+
+        We verify that the cluster name, master name and candidate name are correct.
+        If so, we trigger a failover and keep the client up to date.
+    """
+
+    config, dcs, cluster = ctl_load_config(cluster_name, config_file, dcs)
+
+    if cluster.leader is None:
+        raise PatroniCtlException('This cluster has no master')
+
+    if master is None:
+        if force:
+            master = cluster.leader.member.name
+        else:
+            master = click.prompt('Master', type=str, default=cluster.leader.member.name)
+
+    if cluster.leader.member.name != master:
+        raise PatroniCtlException('Member {} is not the leader of cluster {}'.format(master, cluster_name))
+
+    candidate_names = [str(m.name) for m in cluster.members if m.name != master]
+    # We sort the names for consistent output to the client
+    candidate_names.sort()
+
+    if len(candidate_names) == 0:
+        raise PatroniCtlException('No candidates found to failover to')
+
+    if candidate is None and not force:
+        candidate = click.prompt('Candidate ' + str(candidate_names), type=str, default='')
+
+    if candidate == master:
+        raise PatroniCtlException('Failover target and source are the same.')
+
+    if candidate and candidate not in candidate_names:
+        raise PatroniCtlException('Member {} does not exist in cluster {}'.format(candidate, cluster_name))
+
+    # By now we have established that the leader exists and the candidate exists
+    click.echo('Current cluster topology')
+    output_members(dcs.get_cluster(), name=cluster_name)
+
+    if not force:
+        a = \
+            click.confirm('Are you sure you want to failover cluster {}, demoting current master {}?'.format(
+                cluster_name, master))
+        if not a:
+            raise PatroniCtlException('Aborting failover')
+
+    failover_value = '{}:{}'.format(master, candidate or '')
+
+    t_started = time.time()
+    r = None
+    try:
+        r = post_patroni(cluster.leader.member, 'failover', {'leader': master, 'candidate': candidate or ''})
+        if r.status_code == 200:
+            logging.debug(r)
+            logging.debug(r.text)
+            cluster = dcs.get_cluster()
+            click.echo(timestamp() + ' Failing over to new leader: {}'.format(cluster.leader.member.name))
+        else:
+            click.echo('Failover failed, details: {}, {}'.format(r.status_code, r.text))
+            return
+    except:
+        logging.exception(r)
+        logging.warning('Failing over to DCS')
+        click.echo(timestamp() + ' Could not failover using Patroni api, falling back to DCS')
+        dcs.set_failover_value(failover_value)
+        click.echo(timestamp() + ' Initialized failover from master {}'.format(master))
+        # The failover process should within a minute update the failover key, we will keep watching it until it changes
+        # or we timeout
+        cluster = wait_for_leader(dcs, timeout=60)
+        if cluster.leader.member.name == master:
+            click.echo('Failover failed, master did not change after {:0.1f} seconds'.format(time.time() - t_started))
+            return
+
+    click.echo(timestamp() + ' Failover completed in {:0.1f} seconds, new leader is {}'.format(time.time() - t_started,
+               str(cluster.leader.member.name)))
+    output_members(cluster, name=cluster_name)
+
+
+def output_members(cluster, name=None, format='pretty'):
+    rows = []
+    logging.debug(cluster)
+    leader_name = None
+    if cluster.leader:
+        leader_name = cluster.leader.member.name
+
+    # Mainly for consistent pretty printing and watching we sort the output
+    cluster.members.sort(key=lambda x: x.name)
+    for m in cluster.members:
+        logging.debug(m)
+
+        leader = ''
+        if m.name == leader_name:
+            leader = '*'
+
+        host = build_connect_parameters(m.conn_url)['host']
+
+        xlog_location = m.data.get('xlog_location')
+        lag = ''
+        if xlog_location is not None:
+            lag = round(((cluster.last_leader_operation or 0) - m.data.get('xlog_location', 0)) / 1024 / 1024)
+
+        rows.append([
+            name,
+            m.name,
+            host,
+            leader,
+            m.data.get('state', ''),
+            lag,
+        ])
+
+    columns = [
+        'Cluster',
+        'Member',
+        'Host',
+        'Leader',
+        'State',
+        'Lag in MB',
+    ]
+    alignment = {'Cluster': 'l', 'Member': 'l', 'Host': 'l'}
+
+    print_output(columns, rows, alignment, format)
+
+
+@ctl.command('list', help='List the Patroni members for a given Patroni')
+@click.argument('cluster_names', nargs=-1)
+@option_config_file
+@option_format
+@option_watch
+@option_watchrefresh
+@option_dcs
+def members(config_file, cluster_names, format, watch, w, dcs):
+    if len(cluster_names) == 0:
+        logging.warning('Listing members: No cluster names were provided')
+        return
+
+    config = load_config(config_file, dcs)
+    for cn in cluster_names:
+        dcs = get_dcs(config, cn)
+
+        for _ in watching(w, watch):
+            output_members(dcs.get_cluster(), name=cn, format=format)
+
+
+def timestamp(precision=6):
+    return datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')[:precision - 7]
+
+
+@ctl.command('configure', help='Create configuration file')
+@click.option('--config-file', '-c', help='Configuration file', prompt='Configuration file', default=CONFIG_FILE_PATH)
+@click.option('--dcs', '-d', help='The DCS connect url', prompt='DCS connect url', default='etcd://localhost:4001')
+@click.option('--namespace', '-n', help='The namespace', prompt='Namespace', default='/service/')
+def configure(config_file, dcs, namespace):
+    config = dict()
+    config['dcs_api'] = str(dcs)
+    config['namespace'] = str(namespace)
+    store_config(config, config_file)

patroni/dcs.py

@@ -1,9 +1,10 @@
 import abc
+import json
 
 from collections import namedtuple
 from patroni.exceptions import DCSError
-from patroni.utils import calculate_ttl, sleep
 from six.moves.urllib_parse import urlparse, urlunparse, parse_qsl
+from threading import Event, Lock
 
 
 def parse_connection_string(value):
@@ -23,28 +24,56 @@ def parse_connection_string(value):
     return conn_url, api_url
 
 
-class Member(namedtuple('Member', 'index,name,conn_url,api_url,expiration,ttl')):
+class Member(namedtuple('Member', 'index,name,session,data')):
 
     """Immutable object (namedtuple) which represents single member of PostgreSQL cluster.
     Consists of the following fields:
     :param index: modification index of a given member key in a Configuration Store
     :param name: name of PostgreSQL cluster member
-    :param conn_url: connection string containing host, user and password which could be used to access this member.
-    :param api_url: REST API url of patroni instance
-    :param expiration: expiration time of given member key
-    :param ttl: ttl of given member key in seconds"""
+    :param session: either session id or just ttl in seconds
+    :param data: arbitrary data i.e. conn_url, api_url, xlog location, state, role, tags, etc...
 
-    def real_ttl(self):
-        return calculate_ttl(self.expiration) or -1
+    There are two mandatory keys in a data:
+    conn_url: connection string containing host, user and password which could be used to access this member.
+    api_url: REST API url of patroni instance"""
+
+    @staticmethod
+    def from_node(index, name, session, data):
+        """
+        >>> Member.from_node(-1, '', '', '{"conn_url": "postgres://foo@bar/postgres"}') is not None
+        True
+        >>> Member.from_node(-1, '', '', '{')
+        Member(index=-1, name='', session='', data={})
+        """
+        if data.startswith('postgres'):
+            conn_url, api_url = parse_connection_string(data)
+            data = {'conn_url': conn_url, 'api_url': api_url}
+        else:
+            try:
+                data = json.loads(data)
+            except:
+                data = {}
+        return Member(index, name, session, data)
+
+    @property
+    def conn_url(self):
+        return self.data.get('conn_url', None)
+
+    @property
+    def api_url(self):
+        return self.data.get('api_url', None)
+
+    @property
+    def nofailover(self):
+        return self.data.get('tags', {}).get('nofailover', False)
 
 
-class Leader(namedtuple('Leader', 'index,expiration,ttl,member')):
+class Leader(namedtuple('Leader', 'index,session,member')):
 
     """Immutable object (namedtuple) which represents leader key.
     Consists of the following fields:
     :param index: modification index of a leader key in a Configuration Store
-    :param expiration: expiration time of the leader key
-    :param ttl: ttl of the leader key
+    :param session: either session id or just ttl in seconds
     :param member: reference to a `Member` object which represents current leader (see `Cluster.members`)"""
 
     @property
@@ -56,7 +85,15 @@ class Leader(namedtuple('Leader', 'index,expiration,ttl,member')):
         return self.member.conn_url
 
 
-class Cluster(namedtuple('Cluster', 'initialize,leader,last_leader_operation,members')):
+class Failover(namedtuple('Failover', 'index,leader,member')):
+
+    @staticmethod
+    def from_node(index, value):
+        t = [a.strip() for a in value.split(':')] + ['']
+        return Failover(index, t[0], t[1]) if t[0] or t[1] else None
+
+
+class Cluster(namedtuple('Cluster', 'initialize,leader,last_leader_operation,members,failover')):
 
     """Immutable object (namedtuple) which represents PostgreSQL cluster.
     Consists of the following fields:
@@ -64,7 +101,8 @@ class Cluster(namedtuple('Cluster', 'initialize,leader,last_leader_operation,mem
     :param leader: `Leader` object which represents current leader of the cluster
     :param last_leader_operation: int or long object containing position of last known leader operation.
         This value is stored in `/optime/leader` key
-    :param members: list of Member object, all PostgreSQL cluster members including leader"""
+    :param members: list of Member object, all PostgreSQL cluster members including leader
+    :param failover: reference to `Failover` object"""
 
     def is_unlocked(self):
         return not (self.leader and self.leader.name)
@@ -76,6 +114,7 @@ class AbstractDCS:
 
     _INITIALIZE = 'initialize'
     _LEADER = 'leader'
+    _FAILOVER = 'failover'
     _MEMBERS = 'members/'
     _OPTIME = 'optime'
     _LEADER_OPTIME = _OPTIME + '/' + _LEADER
@@ -87,8 +126,12 @@ class AbstractDCS:
             i.e.: `zookeeper` for zookeeper, `etcd` for etcd, etc...
         """
         self._name = name
-        self._scope = config['scope']
-        self._base_path = '/service/' + self._scope
+        self._namespace = '/{}'.format(config.get('namespace', '/service/').strip('/'))
+        self._base_path = '/'.join([self._namespace, config['scope']])
+
+        self._cluster = None
+        self._cluster_thread_lock = Lock()
+        self.event = Event()
 
     def client_path(self, path):
         return '/'.join([self._base_path, path.lstrip('/')])
@@ -109,25 +152,54 @@ class AbstractDCS:
     def leader_path(self):
         return self.client_path(self._LEADER)
 
+    @property
+    def failover_path(self):
+        return self.client_path(self._FAILOVER)
+
     @property
     def leader_optime_path(self):
         return self.client_path(self._LEADER_OPTIME)
 
     @abc.abstractmethod
+    def _load_cluster(self):
+        """Internally this method should build  `Cluster` object which
+           represents current state and topology of the cluster in DCS.
+           this method supposed to be called only by `get_cluster` method.
+
+           raise `~DCSError` in case of communication or other problems with DCS.
+           If the current node was running as a master and exception raised,
+           instance would be demoted."""
+
     def get_cluster(self):
-        """:returns: `Cluster` object which represent current state and topology of the cluster
-        raise `~DCSError` in case of communication or other problems with DCS. If current instance was
-            running as a master and exception raised instance would be demoted."""
+        with self._cluster_thread_lock:
+            try:
+                self._load_cluster()
+            except:
+                self._cluster = None
+                raise
+            return self._cluster
+
+    @property
+    def cluster(self):
+        with self._cluster_thread_lock:
+            return self._cluster
+
+    def reset_cluster(self):
+        with self._cluster_thread_lock:
+            self._cluster = None
 
     @abc.abstractmethod
-    def update_leader(self, state_handler):
-        """Update leader key (or session) ttl and `/optime/leader` key in DCS.
+    def write_leader_optime(self, last_operation):
+        """write current xlog location into `/optime/leader` key in DCS
+        :param last_operation: absolute xlog location in bytes"""
+
+    @abc.abstractmethod
+    def update_leader(self):
+        """Update leader key (or session) ttl
 
-        :param state_handler: reference to `Postgresql` object
         :returns: `!True` if leader key (or session) has been updated successfully.
             If not, `!False` must be returned and current instance would be demoted.
 
-        If you failed to update `/optime/leader` this error is not critical and you can return `!True`
         You have to use CAS (Compare And Swap) operation in order to update leader key,
         for example for etcd `prevValue` parameter must be used."""
 
@@ -140,6 +212,13 @@ class AbstractDCS:
         Key must be created atomically. In case if key already exists it should not be
         overwritten and `!False` must be returned"""
 
+    @abc.abstractmethod
+    def set_failover_value(self, value, index=None):
+        """Create or update `/failover` key"""
+
+    def manual_failover(self, leader, member, index=None):
+        return self.set_failover_value(leader + (':' + member if member else ''), index)
+
     def current_leader(self):
         try:
             cluster = self.get_cluster()
@@ -165,8 +244,11 @@ class AbstractDCS:
         overwriting the key if necessary."""
 
     @abc.abstractmethod
-    def initialize(self):
+    def initialize(self, create_new=True, sysid=""):
         """Race for cluster initialization.
+
+        :param create_new: False if the key should already exist (in the case we are setting the system_id)
+        :param sysid: PostgreSQL cluster system identifier, if specified, is written to the key
         :returns: `!True` if key has been created successfully.
 
         this method should create atomically initialize key and return `!True`
@@ -182,4 +264,11 @@ class AbstractDCS:
         """ Removes the initialize key for a cluster """
 
     def watch(self, timeout):
-        sleep(timeout)
+        """If the current node is a master it should just sleep.
+        Any other node should watch for changes of leader key with a given timeout
+
+        :param timeout: timeout in seconds
+        :returns: `!True` if you would like to reschedule the next run of ha cycle"""
+
+        self.event.wait(timeout)
+        return self.event.isSet()

patroni/etcd.py

@@ -10,7 +10,8 @@ import urllib3
 
 from dns.exception import DNSException
 from dns import resolver
-from patroni.dcs import AbstractDCS, Cluster, DCSError, Leader, Member, parse_connection_string
+from patroni.dcs import AbstractDCS, Cluster, Failover, Leader, Member
+from patroni.exceptions import DCSError
 from patroni.utils import Retry, RetryFailedError, sleep
 from requests.exceptions import RequestException
 
@@ -51,7 +52,11 @@ class Client(etcd.Client):
     def api_execute(self, path, method, **kwargs):
         # Update machines_cache if previous attempt of update has failed
         self._update_machines_cache and self._load_machines_cache()
-        return super(Client, self).api_execute(path, method, **kwargs)
+        try:
+            return super(Client, self).api_execute(path, method, **kwargs)
+        except etcd.EtcdConnectionFailed:
+            self._update_machines_cache = True
+            raise
 
     @staticmethod
     def get_srv_record(host):
@@ -80,7 +85,7 @@ class Client(etcd.Client):
         for host, port in self.get_srv_record(discovery_srv):
             url = '{}://{}:{}/members'.format(self._protocol, host, port)
             try:
-                response = requests.get(url)
+                response = requests.get(url, timeout=5)
                 if response.ok:
                     for member in response.json():
                         ret.extend(member['clientURLs'])
@@ -138,6 +143,10 @@ def catch_etcd_errors(func):
             return not func(*args, **kwargs) is None
         except (RetryFailedError, etcd.EtcdException):
             return False
+        except:
+            logger.exception("")
+            raise EtcdError("unexpected error")
+
     return wrapper
 
 
@@ -145,15 +154,13 @@ class Etcd(AbstractDCS):
 
     def __init__(self, name, config):
         super(Etcd, self).__init__(name, config)
-        self.ttl = config['ttl']
-        self.member_ttl = config.get('member_ttl', 3600)
+        self.ttl = config.get('ttl', 30)
         self._retry = Retry(deadline=10, max_delay=1, max_tries=-1,
                             retry_exceptions=(etcd.EtcdConnectionFailed,
                                               etcd.EtcdLeaderElectionInProgress,
                                               etcd.EtcdWatcherCleared,
                                               etcd.EtcdEventIndexCleared))
         self.client = self.get_etcd_client(config)
-        self.cluster = None
 
     def retry(self, *args, **kwargs):
         return self._retry.copy()(*args, **kwargs)
@@ -170,16 +177,16 @@ class Etcd(AbstractDCS):
 
     @staticmethod
     def member(node):
-        conn_url, api_url = parse_connection_string(node.value)
-        return Member(node.modifiedIndex, os.path.basename(node.key), conn_url, api_url, node.expiration, node.ttl)
+        return Member.from_node(node.modifiedIndex, os.path.basename(node.key), node.ttl, node.value)
 
-    def get_cluster(self):
+    def _load_cluster(self):
         try:
             result = self.retry(self.client.read, self.client_path(''), recursive=True)
             nodes = {os.path.relpath(node.key, result.key): node for node in result.leaves}
 
             # get initialize flag
-            initialize = bool(nodes.get(self._INITIALIZE, False))
+            initialize = nodes.get(self._INITIALIZE, None)
+            initialize = initialize and initialize.value
 
             # get last leader operation
             last_leader_operation = nodes.get(self._LEADER_OPTIME, None)
@@ -191,22 +198,25 @@ class Etcd(AbstractDCS):
             # get leader
             leader = nodes.get(self._LEADER, None)
             if leader:
-                member = Member(-1, leader.value, None, None, None, None)
+                member = Member(-1, leader.value, None, {})
                 member = ([m for m in members if m.name == leader.value] or [member])[0]
-                leader = Leader(leader.modifiedIndex, leader.expiration, leader.ttl, member)
+                leader = Leader(leader.modifiedIndex, leader.ttl, member)
 
-            self.cluster = Cluster(initialize, leader, last_leader_operation, members)
+            # failover key
+            failover = nodes.get(self._FAILOVER, None)
+            if failover:
+                failover = Failover.from_node(failover.modifiedIndex, failover.value)
+
+            self._cluster = Cluster(initialize, leader, last_leader_operation, members, failover)
         except etcd.EtcdKeyNotFound:
-            self.cluster = Cluster(False, None, None, [])
+            self._cluster = Cluster(False, None, None, [], None)
         except:
-            self.cluster = None
             logger.exception('get_cluster')
             raise EtcdError('Etcd is not responding properly')
-        return self.cluster
 
     @catch_etcd_errors
     def touch_member(self, connection_string, ttl=None):
-        return self.retry(self.client.set, self.member_path, connection_string, ttl or self.member_ttl)
+        return self.retry(self.client.set, self.member_path, connection_string, ttl or self.ttl)
 
     @catch_etcd_errors
     def take_leader(self):
@@ -222,18 +232,20 @@ class Etcd(AbstractDCS):
         return False
 
     @catch_etcd_errors
-    def write_leader_optime(self, state_handler):
-        return self.client.set(self.leader_optime_path, state_handler.last_operation())
+    def set_failover_value(self, value, index=None):
+        return self.client.write(self.failover_path, value, prevIndex=index or 0)
 
     @catch_etcd_errors
-    def update_leader(self, state_handler):
-        ret = self.retry(self.client.test_and_set, self.leader_path, self._name, self._name, self.ttl)
-        ret and self.write_leader_optime(state_handler)
-        return ret
+    def write_leader_optime(self, last_operation):
+        return self.client.set(self.leader_optime_path, last_operation)
 
     @catch_etcd_errors
-    def initialize(self):
-        return self.client.write(self.initialize_path, self._name, prevExist=False)
+    def update_leader(self):
+        return self.retry(self.client.test_and_set, self.leader_path, self._name, self._name, self.ttl)
+
+    @catch_etcd_errors
+    def initialize(self, create_new=True, sysid=""):
+        return self.retry(self.client.write, self.initialize_path, sysid, prevExist=(not create_new))
 
     @catch_etcd_errors
     def delete_leader(self):
@@ -241,25 +253,30 @@ class Etcd(AbstractDCS):
 
     @catch_etcd_errors
     def cancel_initialization(self):
-        return self.client.delete(self.initialize_path, prevValue=self._name)
+        return self.retry(self.client.delete, self.initialize_path)
 
     def watch(self, timeout):
+        cluster = self.cluster
         # watch on leader key changes if it is defined and current node is not lock owner
-        if self.cluster and self.cluster.leader and self.cluster.leader.name != self._name:
+        if cluster and cluster.leader and cluster.leader.name != self._name:
             end_time = time.time() + timeout
-            index = self.cluster.leader.index
+            index = cluster.leader.index
+
             while index and timeout >= 1:  # when timeout is too small urllib3 doesn't have enough time to connect
                 try:
-                    res = self.client.watch(self.leader_path, index=index + 1, timeout=timeout)
-                    if res.action not in ['set', 'compareAndSwap'] or res.value != self.cluster.leader.name:
-                        return
-                    index = res.modifiedIndex
+                    self.client.watch(self.leader_path, index=index + 1, timeout=timeout + 0.5)
+                    # Synchronous work of all cluster members with etcd is less expensive
+                    # than reestablishing http connection every time from every replica.
+                    return True
                 except urllib3.exceptions.TimeoutError:
                     self.client.http.clear()
-                    return
+                    return False
                 except etcd.EtcdException:
-                    index = None
+                    logging.exception('watch')
 
                 timeout = end_time - time.time()
 
-        timeout > 0 and super(Etcd, self).watch(timeout)
+        try:
+            return super(Etcd, self).watch(timeout)
+        finally:
+            self.event.clear()

patroni/exceptions.py

@@ -7,15 +7,23 @@ class PatroniException(Exception):
 
     def __str__(self):
         """
-        >>> str(DCSError('foo'))
+        >>> str(PatroniException('foo'))
         "'foo'"
         """
         return repr(self.value)
 
 
+class PatroniCtlException(Exception):
+    pass
+
+
 class PostgresException(PatroniException):
     pass
 
 
 class DCSError(PatroniException):
     pass
+
+
+class PostgresConnectionException(PostgresException):
+    pass

patroni/ha.py

@@ -1,26 +1,31 @@
+import json
 import logging
+import psycopg2
+import requests
+import sys
 
-from patroni.dcs import DCSError
-from psycopg2 import InterfaceError, OperationalError
+from patroni.async_executor import AsyncExecutor
+from patroni.exceptions import DCSError, PostgresConnectionException
+from multiprocessing.pool import ThreadPool
 
 logger = logging.getLogger(__name__)
 
 
 class Ha:
 
-    def __init__(self, state_handler, etcd):
-        self.state_handler = state_handler
-        self.dcs = etcd
+    def __init__(self, patroni):
+        self.patroni = patroni
+        self.state_handler = patroni.postgresql
+        self.dcs = patroni.dcs
         self.cluster = None
         self.old_cluster = None
+        self._async_executor = AsyncExecutor()
 
     def load_cluster_from_dcs(self):
         cluster = self.dcs.get_cluster()
 
         # We want to keep the state of cluster when it was healhy
-        if cluster.is_unlocked() and self.cluster and not self.cluster.is_unlocked():
-            self.old_cluster = self.cluster
-        if not self.old_cluster:
+        if not cluster.is_unlocked() or not self.old_cluster:
             self.old_cluster = cluster
         self.cluster = cluster
 
@@ -28,74 +33,407 @@ class Ha:
         return self.dcs.attempt_to_acquire_leader()
 
     def update_lock(self):
-        return self.dcs.update_leader(self.state_handler)
+        ret = self.dcs.update_leader()
+        if ret:
+            try:
+                self.dcs.write_leader_optime(self.state_handler.last_operation())
+            except:
+                pass
+        return ret
 
     def has_lock(self):
         lock_owner = self.cluster.leader and self.cluster.leader.name
         logger.info('Lock owner: %s; I am %s', lock_owner, self.state_handler.name)
         return lock_owner == self.state_handler.name
 
-    def demote(self):
-        return self.state_handler.demote(self.cluster.leader)
+    def touch_member(self):
+        data = {
+            'conn_url': self.state_handler.connection_string,
+            'api_url': self.patroni.api.connection_string,
+            'state': self.state_handler.state,
+            'role': self.state_handler.role,
+            'tags': self.patroni.tags
+        }
+        if data['state'] in ['running', 'restarting', 'starting']:
+            try:
+                data['xlog_location'] = self.state_handler.xlog_position()
+            except:
+                pass
+        self.dcs.touch_member(json.dumps(data, separators=(',', ':')))
 
-    def follow_the_leader(self):
-        return self.state_handler.follow_the_leader(self.cluster.leader)
+    def copy_backup_from_leader(self, leader):
+        if self.state_handler.bootstrap(leader):
+            logger.info('bootstrapped from leader')
+        else:
+            self.state_handler.stop('immediate')
+            self.state_handler.remove_data_directory()
+            logger.error('failed to bootstrap from leader')
 
-    def run_cycle(self):
+    def bootstrap(self):
+        if not self.cluster.is_unlocked():  # cluster already has leader
+            self._async_executor.schedule('bootstrap from leader')
+            self._async_executor.run_async(self.copy_backup_from_leader, args=(self.cluster.leader, ))
+            return 'trying to bootstrap from leader'
+        elif not self.cluster.initialize and not self.patroni.nofailover:  # no initialize key
+            if self.dcs.initialize(create_new=True):  # race for initialization
+                try:
+                    self.state_handler.bootstrap()
+                    self.dcs.initialize(create_new=False, sysid=self.state_handler.sysid)
+                except:  # initdb or start failed
+                    # remove initialization key and give a chance to other members
+                    logger.info("removing initialize key after failed attempt to initialize the cluster")
+                    self.dcs.cancel_initialization()
+                    self.state_handler.stop('immediate')
+                    self.state_handler.move_data_directory()
+                    raise
+                self.dcs.take_leader()
+                return 'initialized a new cluster'
+            else:
+                return 'failed to acquire initialize lock'
+        else:
+            return 'waiting for leader to bootstrap'
+
+    def recover(self):
+        has_lock = self.has_lock()
+
+        # try to see if we are the former master that crashed. If so - we likely need to run pg_rewind
+        # in order to join the former standby being promoted.
+        pg_controldata = self.state_handler.controldata()
+        if not has_lock and pg_controldata and\
+                pg_controldata.get('Database cluster state', '') == 'in production':  # crashed master
+            self.state_handler.require_rewind()
+
+        # XXX: follow the leader calls stop, which might take quite some time.
+        # perhaps we should run sync asynchronously
+        # (we still need the exit code from follow_the_leader)
+        ret = self.state_handler.follow_the_leader(None if has_lock else self.cluster.leader, recovery=True)
+        if not ret:
+            if not has_lock:
+                return 'failed to start postgres'
+            self.dcs.delete_leader()
+            self.dcs.reset_cluster()
+            return 'removed leader key after trying and failing to start postgres'
+        if not has_lock:
+            return 'started as a secondary'
+        logger.info('started as readonly because i had the session lock')
+        self.load_cluster_from_dcs()
+
+    def follow_the_leader(self, demote_reason, follow_reason, refresh=True):
+        refresh and self.load_cluster_from_dcs()
+        ret = demote_reason if self.state_handler.is_leader() else follow_reason
+        leader = self.cluster.leader
+        leader = None if (leader and leader.name) == self.state_handler.name else leader
+        if not self.state_handler.check_recovery_conf(leader):
+            self._async_executor.schedule('changing primary_conninfo and restarting')
+            self._async_executor.run_async(self.state_handler.follow_the_leader, (leader, ))
+        return ret
+
+    def enforce_master_role(self, message, promote_message):
+        if self.state_handler.is_leader() or self.state_handler.role == 'master':
+            return message
+        else:
+            self.state_handler.promote()
+            self.touch_member()
+            return promote_message
+
+    @staticmethod
+    def fetch_node_status(member):
+        """This function perform http get request on member.api_url and fetches its status
+        :returns: tuple(`member`, reachable, in_recovery, xlog_location)
+
+        reachable - `!False` if the node is not reachable or is not responding with correct JSON
+        in_recovery - `!True` if pg_is_in_recovery() == true
+        xlog_location - value of `replayed_location` or `location` from JSON, dependin on its role.
+        tags - dictionary with values of different tags (i.e. nofailover)
+        """
+
+        try:
+            response = requests.get(member.api_url, timeout=2, verify=False)
+            logger.info('Got response from %s %s: %s', member.name, member.api_url, response.content)
+            json = response.json()
+            is_master = json['role'] == 'master'
+            xlog_location = json['xlog']['location' if is_master else 'replayed_location']
+            tags = json.get('tags', dict())
+            return (member, True, not is_master, xlog_location, tags)
+        except:
+            logging.exception('request failed: GET %s', member.api_url)
+        return (member, False, None, 0, {})
+
+    def fetch_nodes_statuses(self, members):
+        pool = ThreadPool(len(members))
+        results = pool.map(self.fetch_node_status, members)  # Run API calls on members in parallel
+        pool.close()
+        pool.join()
+        return results
+
+    def _is_healthiest_node(self, members, check_replication_lag=True):
+        """This method tries to determine whether I am healthy enough to became a new leader candidate or not."""
+
+        if self.state_handler.is_leader():
+            return True
+
+        if self.patroni.nofailover is True:
+            return False
+
+        if check_replication_lag and not self.state_handler.check_replication_lag(self.cluster.last_leader_operation):
+            return False  # Too far behind last reported xlog location on master
+
+        # Prepare list of nodes to run check against
+        members = [m for m in members if m.name != self.state_handler.name and not m.nofailover and m.api_url]
+
+        if members:
+            my_xlog_location = self.state_handler.xlog_position()
+            for member, reachable, in_recovery, xlog_location, tags in self.fetch_nodes_statuses(members):
+                if reachable and not tags.get('nofailover', False):  # If the node is unreachable it's not healhy
+                    if not in_recovery:
+                        logger.warning('Master (%s) is still alive', member.name)
+                        return False
+                    if my_xlog_location < xlog_location:
+                        return False
+        return True
+
+    def is_failover_possible(self, members):
+        ret = False
+        members = [m for m in members if m.name != self.state_handler.name and not m.nofailover and m.api_url]
+        if members:
+            for member, reachable, in_recovery, xlog_location, tags in self.fetch_nodes_statuses(members):
+                if reachable and not tags.get('nofailover', False):
+                    ret = True  # TODO: check xlog_location
+                elif not reachable:
+                    logger.info('Member %s is not reachable', member.name)
+                elif tags.get('nofailover', False):
+                    logger.info('Member %s is not allowed to promote', member.name)
+        else:
+            logger.warning('manual failover: members list is empty')
+        return ret
+
+    def manual_failover_process_no_leader(self):
+        failover = self.cluster.failover
+        if failover.member:  # manual failover to specific member
+            if failover.member == self.state_handler.name:  # manual failover to me
+                return True
+
+            # find specific node and check that it is healthy
+            members = [m for m in self.cluster.members if m.name == failover.member]
+            if members:
+                member, reachable, in_recovery, xlog_location, tags = self.fetch_node_status(members[0])
+                if reachable and not tags.get('nofailover', False):  # node is healthy
+                    logger.info('manual failover: to %s, i am %s', member.name, self.state_handler.name)
+                    return False
+                # we wanted to failover to specific member but it is not healthy
+                if not reachable:
+                    logger.warning('manual failover: member %s is unhealthy', member.name)
+                elif tags.get('nofailover', False):
+                    logger.warning('manual failover: member %s is not allowed to promote', member.name)
+
+            # at this point we should consider all members as a candidates for failover
+            # i.e. we assume that failover.member is None
+
+        # try to pick some other members to failover and check that they are healthy
+        if failover.leader:
+            if self.state_handler.name == failover.leader:  # I was the leader
+                # exclude me and desired member which is unhealthy (failover.member can be None)
+                members = [m for m in self.cluster.members if m.name not in (failover.member, failover.leader)]
+                if self.is_failover_possible(members):  # check that there are healthy members
+                    return False
+                else:  # I was the leader and it looks like currently I am the only healthy member
+                    return True
+
+            # at this point we assume that our node is a candidate for a failover among all nodes except former leader
+
+        # exclude former leader from the list (failover.leader can be None)
+        members = [m for m in self.cluster.members if m.name != failover.leader]
+        return self._is_healthiest_node(members, check_replication_lag=False)
+
+    def is_healthiest_node(self):
+
+        if self.state_handler.is_leader():  # leader is always the healthiest
+            return True
+
+        if self.patroni.nofailover:  # nofailover tag makes node always unhealthy
+            return False
+
+        if self.cluster.failover:
+            return self.manual_failover_process_no_leader()
+
+        # run usual health check
+        members = {m.name: m for m in self.cluster.members + self.old_cluster.members}
+        return self._is_healthiest_node(members.values())
+
+    def demote(self, delete_leader=True):
+        if delete_leader:
+            self.state_handler.stop()
+            self.dcs.delete_leader()
+            self.touch_member()
+            self.dcs.reset_cluster()
+        self.state_handler.follow_the_leader(None)
+
+    def process_manual_failover_from_leader(self):
+        failover = self.cluster.failover
+        if not failover.leader or failover.leader == self.state_handler.name:
+            if not failover.member or failover.member != self.state_handler.name:
+                members = [m for m in self.cluster.members if not failover.member or m.name == failover.member]
+                if self.is_failover_possible(members):  # check that there are healthy members
+                    self._async_executor.schedule('manual failover: demote')
+                    self._async_executor.run_async(self.demote)
+                    return 'manual failover: demoting myself'
+                else:
+                    logger.warning('manual failover: no healthy members found, failover is not possible')
+            else:
+                logger.warning('manual failover: I am already the leader, no need to failover')
+        else:
+            logger.warning('manual failover: leader name does not match: %s != %s',
+                           self.cluster.failover.leader, self.state_handler.name)
+
+        logger.info('Trying to clean up failover key')
+        self.dcs.manual_failover('', '', self.cluster.failover.index)
+
+    def process_unhealthy_cluster(self):
+        if self.is_healthiest_node():
+            if self.acquire_lock():
+                if self.cluster.failover:
+                    logger.info('Cleaning up failover key after acquiring leader lock...')
+                    self.dcs.manual_failover('', '')
+                self.dcs.get_cluster()
+                return self.enforce_master_role('acquired session lock as a leader',
+                                                'promoted self to leader by acquiring session lock')
+            else:
+                return self.follow_the_leader('demoted self due after trying and failing to obtain lock',
+                                              'following new leader after trying and failing to obtain lock')
+        else:
+            if self.patroni.nofailover:
+                return self.follow_the_leader('demoting self because I am not allowed to become master',
+                                              'following a different leader because I am not allowed to promote')
+            return self.follow_the_leader('demoting self because i am not the healthiest node',
+                                          'following a different leader because i am not the healthiest node')
+
+    def process_healthy_cluster(self):
+        if self.has_lock():
+            if self.cluster.failover:
+                msg = self.process_manual_failover_from_leader()
+                if msg is not None:
+                    return msg
+
+            if self.update_lock():
+                return self.enforce_master_role('no action.  i am the leader with the lock',
+                                                'promoted self to leader because i had the session lock')
+            else:
+                # Either there is no connection to DCS or someone else acquired the lock
+                logger.error('failed to update leader lock')
+                self.load_cluster_from_dcs()
+        else:
+            logger.info('does not have lock')
+        return self.follow_the_leader('demoting self because i do not have the lock and i was a leader',
+                                      'no action.  i am a secondary and i am following a leader', False)
+
+    def schedule(self, action):
+        with self._async_executor:
+            return self._async_executor.schedule(action)
+
+    def restart_scheduled(self):
+        return self._async_executor.scheduled_action == 'restart'
+
+    def schedule_reinitialize(self):
+        return self.schedule('reinitialize')
+
+    def reinitialize_scheduled(self):
+        return self._async_executor.scheduled_action == 'reinitialize'
+
+    def restart(self):
+        with self._async_executor:
+            prev = self._async_executor.schedule('restart', True)
+            if prev is not None:
+                return (False, prev + ' already in progress')
+        if self._async_executor.run(self.state_handler.restart):
+            return (True, 'restarted successfully')
+        else:
+            return (False, 'restart failed')
+
+    def reinitialize(self, cluster):
+        self.state_handler.stop('immediate')
+        self.state_handler.remove_data_directory()
+        self.copy_backup_from_leader(cluster.leader)
+
+    def process_scheduled_action(self):
+        if self.reinitialize_scheduled():
+            if self.cluster.is_unlocked():
+                logger.error('Cluster has no leader, can not reinitialize')
+                self._async_executor.reset_scheduled_action()
+            elif self.has_lock():
+                logger.error('I am the leader, can not reinitialize')
+                self._async_executor.reset_scheduled_action()
+            else:
+                self._async_executor.run_async(self.reinitialize, args=(self.cluster, ))
+                return 'reinitialize started'
+
+    def handle_long_action_in_progress(self):
+        if self.has_lock():
+            if self.update_lock():
+                return 'updated leader lock during ' + self._async_executor.scheduled_action
+            else:
+                return 'failed to update leader lock during ' + self._async_executor.scheduled_action
+        elif self.cluster.is_unlocked():
+            return 'not healthy enough for leader race'
+        else:
+            return self._async_executor.scheduled_action + ' in progress'
+
+    def sysid_valid(self, sysid):
+        # sysid does tv_sec << 32, where tv_sec is the number of seconds sine 1970,
+        # so even 1 << 32 would have 10 digits.
+        return str(sysid) and len(str(sysid)) >= 10 and str(sysid).isdigit()
+
+    def _run_cycle(self):
         try:
             self.load_cluster_from_dcs()
-            if not self.state_handler.is_healthy():
-                has_lock = self.has_lock()
-                self.state_handler.write_recovery_conf(None if has_lock else self.cluster.leader)
-                self.state_handler.start()
-                if not has_lock:
-                    return 'started as a secondary'
-                logger.info('started as readonly because i had the session lock')
-                self.load_cluster_from_dcs()
 
-            if self.cluster.is_unlocked():
-                if self.state_handler.is_healthiest_node(self.old_cluster):
-                    if self.acquire_lock():
-                        if self.state_handler.is_leader() or self.state_handler.is_promoted:
-                            return 'acquired session lock as a leader'
-                        else:
-                            self.state_handler.promote()
-                            return 'promoted self to leader by acquiring session lock'
-                    else:
-                        self.load_cluster_from_dcs()
-                        if self.state_handler.is_leader():
-                            self.demote()
-                            return 'demoted self due after trying and failing to obtain lock'
-                        else:
-                            self.follow_the_leader()
-                            return 'following new leader after trying and failing to obtain lock'
-                else:
-                    self.load_cluster_from_dcs()
-                    if self.state_handler.is_leader():
-                        self.demote()
-                        return 'demoting self because i am not the healthiest node'
-                    else:
-                        self.follow_the_leader()
-                        return 'following a different leader because i am not the healthiest node'
+            self.touch_member()
+
+            # cluster has leader key but not initialize key
+            if not self.cluster.is_unlocked() and not self.sysid_valid(self.cluster.initialize) and self.has_lock():
+                self.dcs.initialize(create_new=(self.cluster.initialize is None), sysid=self.state_handler.sysid)
+
+            if self._async_executor.busy:
+                return self.handle_long_action_in_progress()
+
+            # currently it can trigger only reinitialize
+            msg = self.process_scheduled_action()
+            if msg is not None:
+                return msg
+
+            # is data directory empty?
+            if self.state_handler.data_directory_empty():
+                return self.bootstrap()  # new node
+            # "bootstrap", but data directory is not empty
+            elif not self.sysid_valid(self.cluster.initialize) and self.cluster.is_unlocked():
+                self.dcs.initialize(create_new=(self.cluster.initialize is None), sysid=self.state_handler.sysid)
             else:
-                if self.has_lock() and self.update_lock():
-                    if self.state_handler.is_leader() or self.state_handler.is_promoted:
-                        return 'no action.  i am the leader with the lock'
-                    else:
-                        self.state_handler.promote()
-                        return 'promoted self to leader because i had the session lock'
+                # check if we are allowed to join
+                if self.sysid_valid(self.cluster.initialize) and self.cluster.initialize != self.state_handler.sysid:
+                    logger.fatal("system ID mismatch, node {0} belongs to a different cluster".
+                                 format(self.state_handler.name))
+                    sys.exit(1)
+
+            # try to start dead postgres
+            if not self.state_handler.is_healthy():
+                msg = self.recover()
+                if msg is not None:
+                    return msg
+
+            try:
+                if self.cluster.is_unlocked():
+                    return self.process_unhealthy_cluster()
                 else:
-                    logger.info('does not have lock')
-                    if self.state_handler.is_leader():
-                        self.demote()
-                        return 'demoting self because i do not have the lock and i was a leader'
-                    else:
-                        self.follow_the_leader()
-                        return 'no action.  i am a secondary and i am following a leader'
+                    return self.process_healthy_cluster()
+            finally:
+                self.state_handler.sync_replication_slots(self.cluster)
         except DCSError:
             logger.error('Error communicating with DCS')
-            if self.state_handler.is_leader():
-                self.state_handler.demote(None)
+            if self.state_handler.is_running() and self.state_handler.is_leader():
+                self.demote(delete_leader=False)
                 return 'demoted self because DCS is not accessible and i was a leader'
-        except (InterfaceError, OperationalError):
-            logger.error('Error communicating with Postgresql.  Will try again')
+        except (psycopg2.Error, PostgresConnectionException):
+            logger.exception('Error communicating with Postgresql. Will try again later')
+
+    def run_cycle(self):
+        with self._async_executor:
+            return self._run_cycle()

patroni/postgresql.py

@@ -4,11 +4,14 @@ import psycopg2
 import shlex
 import shutil
 import subprocess
+import tempfile
 import time
 
-from patroni.exceptions import PostgresException
-from patroni.utils import sleep
+from patroni.exceptions import PostgresConnectionException, PostgresException
+from patroni.utils import Retry, RetryFailedError
+from six import string_types
 from six.moves.urllib_parse import urlparse
+from threading import Lock
 
 logger = logging.getLogger(__name__)
 
@@ -41,21 +44,25 @@ class Postgresql:
     def __init__(self, config):
         self.config = config
         self.name = config['name']
+        self.server_parameters = config.get('parameters', {})
         self.scope = config['scope']
         self.listen_addresses, self.port = config['listen'].split(':')
         self.data_dir = config['data_dir']
         self.replication = config['replication']
         self.superuser = config['superuser']
         self.admin = config['admin']
+        self.initdb_options = config.get('initdb', [])
+        self.pgpass = config.get('pgpass', None) or os.path.join(os.path.expanduser('~'), 'pgpass')
+        self.pg_rewind = config.get('pg_rewind', {})
         self.callback = config.get('callbacks', {})
         self.use_slots = config.get('use_slots', True)
+        self.schedule_load_slots = self.use_slots
         self.recovery_conf = os.path.join(self.data_dir, 'recovery.conf')
         self.configuration_to_save = (os.path.join(self.data_dir, 'pg_hba.conf'),
                                       os.path.join(self.data_dir, 'postgresql.conf'))
         self.postmaster_pid = os.path.join(self.data_dir, 'postmaster.pid')
         self.trigger_file = config.get('recovery_conf', {}).get('trigger_file', None) or 'promote'
         self.trigger_file = os.path.abspath(os.path.join(self.data_dir, self.trigger_file))
-        self.is_promoted = False
 
         self._pg_ctl = ['pg_ctl', '-w', '-D', self.data_dir]
 
@@ -66,7 +73,50 @@ class Postgresql:
 
         self._connection = None
         self._cursor_holder = None
-        self.members = []  # list of already existing replication slots
+        self._need_rewind = False
+        self._sysid = None
+        self.replication_slots = []  # list of already existing replication slots
+        self.retry = Retry(max_tries=-1, deadline=5, max_delay=1, retry_exceptions=PostgresConnectionException)
+
+        self._state = 'stopped'
+        self._state_lock = Lock()
+        self._role = 'replica'
+        self._role_lock = Lock()
+
+        if self.is_running():
+            self._state = 'running'
+            self._role = 'master' if self.is_leader() else 'replica'
+
+    @property
+    def can_rewind(self):
+        """ check if pg_rewind executable is there and that pg_controldata indicates
+            we have either wal_log_hints or checksums turned on
+        """
+        # low-hanging fruit: check if pg_rewind configuration is there
+        if not self.pg_rewind or\
+           not (self.pg_rewind.get('username', '') and self.pg_rewind.get('password', '')):
+            return False
+
+        cmd = ['pg_rewind', '--help']
+        try:
+            ret = subprocess.call(cmd, stdout=open(os.devnull, 'w'), stderr=subprocess.STDOUT)
+            if ret != 0:  # pg_rewind is not there, close up the shop and go home
+                return False
+        except OSError:
+            return False
+        # check if the cluster's configuration permits pg_rewind
+        data = self.controldata()
+        return data.get('wal_log_hints setting', 'off') == 'on' or data.get('Data page checksum version', '0') != '0'
+
+    @property
+    def sysid(self):
+        if not self._sysid:
+            data = self.controldata()
+            self._sysid = data.get('Database system identifier', "")
+        return self._sysid
+
+    def require_rewind(self):
+        self._need_rewind = True
 
     def get_local_address(self):
         listen_addresses = self.listen_addresses.split(',')
@@ -86,56 +136,93 @@ class Postgresql:
         return self._connection
 
     def _cursor(self):
-        if not self._cursor_holder or self._cursor_holder.closed:
+        if not self._cursor_holder or self._cursor_holder.closed or self._cursor_holder.connection.closed != 0:
+            logger.info("established a new patroni connection to the postgres cluster")
             self._cursor_holder = self.connection().cursor()
         return self._cursor_holder
 
-    def disconnect(self):
-        self._connection and self._connection.close()
-        self._connection = self._cursor_holder = None
+    def close_connection(self):
+        if self._cursor_holder and self._cursor_holder.connection and self._cursor_holder.connection.closed == 0:
+            self._cursor_holder.connection.close()
+            logger.info("closed patroni connection to the postgresql cluster")
+
+    def _query(self, sql, *params):
+        cursor = None
+        try:
+            cursor = self._cursor()
+            cursor.execute(sql, params)
+            return cursor
+        except psycopg2.Error as e:
+            if cursor and cursor.connection.closed == 0:
+                raise e
+            if self.state == 'restarting':
+                raise RetryFailedError('cluster is being restarted')
+            raise PostgresConnectionException('connection problems')
 
     def query(self, sql, *params):
-        max_attempts = 0
-        while True:
-            ex = None
-            try:
-                cursor = self._cursor()
-                cursor.execute(sql, params)
-                return cursor
-            except psycopg2.InterfaceError as e:
-                ex = e
-            except psycopg2.OperationalError as e:
-                if self._connection and self._connection.closed == 0:
-                    raise e
-                ex = e
-            if ex:
-                self.disconnect()
-                max_attempts += 1
-                if max_attempts >= 3:
-                    raise ex
-                sleep(5)
+        try:
+            return self.retry(self._query, sql, *params)
+        except RetryFailedError as e:
+            raise PostgresConnectionException(str(e))
 
     def data_directory_empty(self):
         return not os.path.exists(self.data_dir) or os.listdir(self.data_dir) == []
 
+    @staticmethod
+    def initdb_allowed_option(name):
+        if name in ['pgdata', 'nosync', 'pwfile', 'sync-only']:
+            raise Exception('{} option for initdb is not allowed'.format(name))
+        return True
+
+    def get_initdb_options(self):
+        options = []
+        for o in self.initdb_options:
+            if isinstance(o, string_types) and self.initdb_allowed_option(o):
+                options.append('--{}'.format(o))
+            elif isinstance(o, dict):
+                keys = list(o.keys())
+                if len(keys) != 1 or not isinstance(keys[0], string_types) or not self.initdb_allowed_option(keys[0]):
+                    raise Exception('Invalid option: {}'.format(o))
+                options.append('--{}={}'.format(keys[0], o[keys[0]]))
+            else:
+                raise Exception('Unknown type of initdb option: {}'.format(o))
+        return options
+
     def initialize(self):
-        ret = subprocess.call(self._pg_ctl + ['initdb', '-o', '--encoding=UTF8']) == 0
-        ret and self.write_pg_hba()
+        self.set_state('initalizing new cluster')
+        options = self.get_initdb_options()
+        pwfile = None
+        if self.superuser and 'username' not in self.superuser and 'password' in self.superuser:
+            (fd, pwfile) = tempfile.mkstemp()
+            os.write(fd, self.superuser['password'].encode())
+            os.close(fd)
+            options.append('--pwfile={}'.format(pwfile))
+
+        ret = subprocess.call(self._pg_ctl + ['initdb'] + ['-o', ' '.join(options)] if options else []) == 0
+        if pwfile:
+            os.remove(pwfile)
+        if ret:
+            self.write_pg_hba()
+        else:
+            self.set_state('initdb failed')
         return ret
 
     def delete_trigger_file(self):
         os.path.exists(self.trigger_file) and os.unlink(self.trigger_file)
 
+    def write_pgpass(self, record):
+        with open(self.pgpass, 'w') as f:
+            os.fchmod(f.fileno(), 0o600)
+            f.write('{host}:{port}:*:{user}:{password}\n'.format(**record))
+
+        env = os.environ.copy()
+        env['PGPASSFILE'] = self.pgpass
+        return env
+
     def sync_from_leader(self, leader):
         r = parseurl(leader.conn_url)
 
-        pgpass = 'pgpass'
-        with open(pgpass, 'w') as f:
-            os.fchmod(f.fileno(), 0o600)
-            f.write('{host}:{port}:*:{user}:{password}\n'.format(**r))
-
-        env = os.environ.copy()
-        env['PGPASSFILE'] = pgpass
+        env = self.write_pgpass(r)
         return self.create_replica(r, env) == 0
 
     @staticmethod
@@ -143,6 +230,7 @@ class Postgresql:
         return "host={host} port={port} user={user}".format(**conn)
 
     def create_replica(self, master_connection, env):
+        self.set_state('building replica from {host}:{port}'.format(**master_connection))
         connstring = self.build_connstring(master_connection)
         cmd = self.config['restore']
         try:
@@ -150,86 +238,126 @@ class Postgresql:
             self.delete_trigger_file()
         except:
             logger.exception('Error when creating replica')
-            return 1
+            ret = 1
+        if ret != 0:
+            self.set_state('failed to build replica from {host}:{port}'.format(**master_connection))
         return ret
 
-    def is_leader(self, check_only=False):
-        ret = not self.query('SELECT pg_is_in_recovery()').fetchone()[0]
-        if ret and self.is_promoted and not check_only:
-            self.delete_trigger_file()
-            self.is_promoted = False
-        return ret
+    def is_leader(self):
+        return not self.query('SELECT pg_is_in_recovery()').fetchone()[0]
 
     def is_running(self):
         return subprocess.call(' '.join(self._pg_ctl) + ' status > /dev/null 2>&1', shell=True) == 0
 
-    def call_nowait(self, cb_name, is_leader=None):
+    def call_nowait(self, cb_name):
         """ pick a callback command and call it without waiting for it to finish """
         if not self.callback or cb_name not in self.callback:
             return False
         cmd = self.callback[cb_name]
-        if is_leader is None:
-            try:
-                is_leader = self.is_leader(check_only=True)
-            except psycopg2.OperationalError as e:
-                logger.warning("unable to perform {0} action, cannot obtain the cluster role: {1}".format(cb_name, e))
-                return False
         try:
-            role = "master" if is_leader else "replica"
-            subprocess.Popen(shlex.split(cmd) + [cb_name, role, self.scope])
+            subprocess.Popen(shlex.split(cmd) + [cb_name, self.role, self.scope])
         except:
-            logger.exception('callback %s %s %s %s failed', cmd, cb_name, role, self.scope)
+            logger.exception('callback %s %s %s %s failed', cmd, cb_name, self.role, self.scope)
             return False
         return True
 
-    def start(self):
-        if self.is_running():
-            self.load_replication_slots()
-            logger.error('Cannot start PostgreSQL because one is already running.')
-            return False
+    @property
+    def role(self):
+        with self._role_lock:
+            return self._role
 
+    def set_role(self, value):
+        with self._role_lock:
+            self._role = value
+
+    @property
+    def state(self):
+        with self._state_lock:
+            return self._state
+
+    def set_state(self, value):
+        with self._state_lock:
+            self._state = value
+
+    def start(self, block_callbacks=False):
+        if self.is_running():
+            logger.error('Cannot start PostgreSQL because one is already running.')
+            return True
+
+        self.set_role('replica' if os.path.exists(self.recovery_conf) else 'master')
         if os.path.exists(self.postmaster_pid):
             os.remove(self.postmaster_pid)
             logger.info('Removed %s', self.postmaster_pid)
 
+        if not block_callbacks:
+            self.set_state('starting')
+
         ret = subprocess.call(self._pg_ctl + ['start', '-o', self.server_options()]) == 0
-        ret and self.load_replication_slots()
+
+        self.set_state('running' if ret else 'start failed')
+
+        self.schedule_load_slots = ret and self.use_slots
         self.save_configuration_files()
-        if ret and ACTION_ON_START in self.callback:
-            self.call_nowait(ACTION_ON_START)
+        # block_callbacks is used during restart to avoid
+        # running start/stop callbacks in addition to restart ones
+        ret and not block_callbacks and self.call_nowait(ACTION_ON_START)
         return ret
 
-    def stop(self):
+    def checkpoint(self):
         try:
-            is_leader = self.is_leader(check_only=True)
+            r = parseurl('postgres://{}/postgres'.format(self.local_address))
+            r['options'] = '-c statement_timeout=0'
+            with psycopg2.connect(**r) as conn:
+                conn.autocommit = True
+                with conn.cursor() as cur:
+                    cur.execute('CHECKPOINT')
         except:
-            is_leader = None
-            pass
-        ret = subprocess.call(self._pg_ctl + ['stop', '-m', 'fast'])
-        if ret == 0 and ACTION_ON_STOP in self.callback:
-            self.call_nowait(ACTION_ON_STOP, is_leader=is_leader)
-        return ret == 0
+            logging.exception('Exception during CHECKPOINT')
+
+    def stop(self, mode='fast', block_callbacks=False):
+        # make sure we close all connections established against
+        # the former node, otherwise, we might get a stalled one
+        # after kill -9, which would report incorrect data to
+        # patroni.
+
+        self.close_connection()
+        if not self.is_running():
+            if not block_callbacks:
+                self.set_state('stopped')
+            return True
+
+        if block_callbacks:
+            self.checkpoint()
+        else:
+            self.set_state('stopping')
+
+        ret = subprocess.call(self._pg_ctl + ['stop', '-m', mode]) == 0
+        # block_callbacks is used during restart to avoid
+        # running start/stop callbacks in addition to restart ones
+        if not ret:
+            self.set_state('stop failed')
+        elif not block_callbacks:
+            self.set_state('stopped')
+            self.call_nowait(ACTION_ON_STOP)
+        return ret
 
     def reload(self):
-        ret = subprocess.call(self._pg_ctl + ['reload'])
-        if ret == 0 and ACTION_ON_RELOAD in self.callback:
-            self.call_nowait(ACTION_ON_RELOAD)
-        return ret == 0
+        ret = subprocess.call(self._pg_ctl + ['reload']) == 0
+        ret and self.call_nowait(ACTION_ON_RELOAD)
+        return ret
 
     def restart(self):
-        try:
-            is_leader = self.is_leader(check_only=True)
-        except:
-            is_leader = None
-            pass
-        ret = subprocess.call(self._pg_ctl + ['restart', '-m', 'fast'])
-        if ret == 0 and ACTION_ON_RESTART in self.callback:
-            self.call_nowait(ACTION_ON_RESTART, is_leader=is_leader)
-        return ret == 0
+        self.set_state('restarting')
+        ret = self.stop(block_callbacks=True) and self.start(block_callbacks=True)
+        if ret:
+            self.call_nowait(ACTION_ON_RESTART)
+        else:
+            self.set_state('restart failed ({})'.format(self.state))
+        return ret
 
     def server_options(self):
         options = "--listen_addresses='{}' --port={}".format(self.listen_addresses, self.port)
-        for setting, value in self.config['parameters'].items():
+        for setting, value in self.server_parameters.items():
             options += " --{}='{}'".format(setting, value)
         return options
 
@@ -239,42 +367,15 @@ class Postgresql:
             return False
         return True
 
-    def is_healthiest_node(self, cluster):
-        if self.is_leader():
-            return True
-
-        if cluster.last_leader_operation - self.xlog_position() > self.config.get('maximum_lag_on_failover', 0):
-            return False
-
-        for member in cluster.members:
-            if member.name == self.name:
-                continue
-            try:
-                r = parseurl(member.conn_url)
-                member_conn = psycopg2.connect(**r)
-                member_conn.autocommit = True
-                member_cursor = member_conn.cursor()
-                member_cursor.execute(
-                    "SELECT pg_is_in_recovery(), %s - pg_xlog_location_diff(pg_last_xlog_replay_location(), '0/0')",
-                    (self.xlog_position(),))
-                row = member_cursor.fetchone()
-                member_cursor.close()
-                member_conn.close()
-                logger.error([self.name, member.name, row])
-                if not row[0]:
-                    logger.warning('Master (%s) is still alive', member.name)
-                    return False
-                if row[1] < 0:
-                    return False
-            except psycopg2.Error:
-                continue
-        return True
+    def check_replication_lag(self, last_leader_operation):
+        return (last_leader_operation if last_leader_operation else 0) - self.xlog_position() <=\
+            self.config.get('maximum_lag_on_failover', 0)
 
     def write_pg_hba(self):
         with open(os.path.join(self.data_dir, 'pg_hba.conf'), 'a') as f:
             f.write('\nhost replication {username} {network} md5\n'.format(**self.replication))
             for line in self.config.get('pg_hba', []):
-                if line.split()[0].strip() == 'hostssl' and self.config['parameters'].get('ssl', 'off').lower() != 'on':
+                if line.split()[0].strip() == 'hostssl' and self.server_parameters.get('ssl', 'off').lower() != 'on':
                     continue
                 f.write(line + '\n')
 
@@ -292,10 +393,7 @@ class Postgresql:
         with open(self.recovery_conf, 'r') as f:
             for line in f:
                 if line.startswith('primary_conninfo'):
-                    if not pattern:
-                        return False
-                    return pattern in line
-
+                    return pattern and (pattern in line)
         return not pattern
 
     def write_recovery_conf(self, leader):
@@ -310,86 +408,209 @@ recovery_target_timeline = 'latest'
                 for name, value in self.config.get('recovery_conf', {}).items():
                     f.write("{} = '{}'\n".format(name, value))
 
-    def follow_the_leader(self, leader):
-        if not self.check_recovery_conf(leader):
+    def rewind(self, leader):
+        # prepare pg_rewind connection
+        r = parseurl(leader.conn_url)
+        r.update(self.pg_rewind)
+        r['user'] = r['username']
+        env = self.write_pgpass(r)
+        pc = "user={user} host={host} port={port} dbname=postgres sslmode=prefer sslcompression=1".format(**r)
+        logger.info("running pg_rewind from {}".format(pc))
+        pg_rewind = ['pg_rewind', '-D', self.data_dir, '--source-server', pc]
+        try:
+            ret = (subprocess.call(pg_rewind, env=env) == 0)
+        except:
+            ret = False
+        if ret:
             self.write_recovery_conf(leader)
-            self.restart()
-            if ACTION_ON_ROLE_CHANGE in self.callback:
-                self.call_nowait(ACTION_ON_ROLE_CHANGE)
+        return ret
+
+    def controldata(self):
+        """ return the contents of pg_controldata, or non-True value if pg_controldata call failed """
+        result = {}
+        try:
+            data = subprocess.check_output(['pg_controldata', self.data_dir])
+            if data:
+                data = data.decode().splitlines()
+                result = {l.split(':')[0].replace('Current ', '', 1): l.split(':')[1].strip() for l in data if l}
+        except subprocess.CalledProcessError:
+            logger.exception("Error when calling pg_controldata")
+        finally:
+            return result
+
+    def read_postmaster_opts(self):
+        """ returns the list of option names/values from postgres.opts, Empty dict if read failed or no file """
+        result = {}
+        try:
+            with open(os.path.join(self.data_dir, "postmaster.opts")) as f:
+                data = f.read()
+                opts = [opt.strip('"\n') for opt in data.split(' "')]
+                for opt in opts:
+                    if '=' in opt and opt.startswith('--'):
+                        name, val = opt.split('=', 1)
+                        name = name.strip('-')
+                        result[name] = val
+        except IOError:
+            logger.exception('Error when reading postmaster.opts')
+        finally:
+            return result
+
+    def single_user_mode(self, command=None, options={}):
+        """ run a given command in a single-user mode. If the command is empty - then just start and stop """
+        cmd = ['postgres', '--single', '-D', self.data_dir]
+        for opt in sorted(options):
+            cmd.extend(['-c', '{0}={1}'.format(opt, options[opt])])
+        # need a database name to connect
+        cmd.append('postgres')
+        p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=open(os.devnull, 'w'), stderr=subprocess.STDOUT)
+        if p:
+            command and p.communicate('{}\n'.format(command))
+            p.stdin.close()
+            return p.wait()
+        return 1
+
+    def cleanup_archive_status(self):
+        status_dir = os.path.join(self.data_dir, 'pg_xlog', 'archive_status')
+        if os.path.isdir(status_dir):
+            for f in os.listdir(status_dir):
+                path = os.path.join(status_dir, f)
+                try:
+                    if os.path.islink(path):
+                        os.unlink(path)
+                    elif os.path.isfile(path):
+                        os.remove(path)
+                except:
+                    logger.exception("Unable to remove {}".format(path))
+
+    def follow_the_leader(self, leader, recovery=False):
+        if not self.check_recovery_conf(leader) or recovery:
+            change_role = (self.role == 'master')
+
+            self._need_rewind = (self._need_rewind or change_role) and self.can_rewind
+            if self._need_rewind:
+                logger.info("set the rewind flag after demote")
+            self.write_recovery_conf(leader)
+            if not leader or not self._need_rewind:  # do not rewind until the leader becomes available
+                ret = self.restart()
+            else:  # we have a leader and need to rewind
+                if self.is_running():
+                    self.stop()
+                # at present, pg_rewind only runs when the cluster is shut down cleanly
+                # and not shutdown in recovery. We have to remove the recovery.conf if present
+                # and start/shutdown in a single user mode to emulate this.
+                # XXX: if recovery.conf is linked, it will be written anew as a normal file.
+                if os.path.islink(self.recovery_conf):
+                    os.unlink(self.recovery_conf)
+                else:
+                    os.remove(self.recovery_conf)
+                # Archived segments might be useful to pg_rewind,
+                # clean the flags that tell we should remove them.
+                self.cleanup_archive_status()
+                # Start in a single user mode and stop to produce a clean shutdown
+                opts = self.read_postmaster_opts()
+                opts['archive_mode'] = 'on'
+                opts['archive_command'] = 'false'
+                self.single_user_mode(options=opts)
+                if self.rewind(leader):
+                    ret = self.start()
+                else:
+                    logger.error("unable to rewind the former master")
+                    self.remove_data_directory()
+                    ret = True
+                self._need_rewind = False
+            change_role and ret and self.call_nowait(ACTION_ON_ROLE_CHANGE)
+            return ret
+        else:
+            return True
 
     def save_configuration_files(self):
         """
-            copy postgresql.conf to postgresql.conf.backup to preserve it in the WAL-e backup.
-            see http://comments.gmane.org/gmane.comp.db.postgresql.wal-e/239
+            copy postgresql.conf to postgresql.conf.backup to be able to retrive configuration files
+            - originally stored as symlinks, those are normally skipped by pg_basebackup
+            - in case of WAL-E basebackup (see http://comments.gmane.org/gmane.comp.db.postgresql.wal-e/239)
         """
-        for f in self.configuration_to_save:
-            shutil.copy(f, f + '.backup')
+        try:
+            for f in self.configuration_to_save:
+                os.path.isfile(f) and shutil.copy(f, f + '.backup')
+        except:
+            logger.exception('unable to create backup copies of configuration files')
 
     def restore_configuration_files(self):
         """ restore a previously saved postgresql.conf """
         try:
             for f in self.configuration_to_save:
-                shutil.copy(f + '.backup', f)
+                not os.path.isfile(f) and os.path.isfile(f+'.backup') and shutil.copy(f + '.backup', f)
         except:
-            logger.exception('unable to restore configuration from WAL-E backup')
+            logger.exception('unable to restore configuration files from backup')
 
     def promote(self):
-        self.is_promoted = subprocess.call(self._pg_ctl + ['promote']) == 0
-        if self.is_promoted and ACTION_ON_ROLE_CHANGE in self.callback:
+        if self.role == 'master':
+            return True
+        ret = subprocess.call(self._pg_ctl + ['promote']) == 0
+        if ret:
+            self.set_role('master')
+            logger.info("cleared rewind flag after becoming the leader")
+            self._need_rewind = False
             self.call_nowait(ACTION_ON_ROLE_CHANGE)
-        return self.is_promoted
+        return ret
 
-    def demote(self, leader):
-        self.follow_the_leader(leader)
+    def demote(self):
+        self.follow_the_leader(None)
+
+    def create_or_update_role(self, name, password, options):
+        self.query("""DO $$
+BEGIN
+    SET local synchronous_commit = 'local';
+    PERFORM * FROM pg_authid WHERE rolname = %s;
+    IF FOUND THEN
+        ALTER ROLE "{0}" WITH LOGIN {1} PASSWORD %s;
+    ELSE
+        CREATE ROLE "{0}" WITH LOGIN {1} PASSWORD %s;
+    END IF;
+END;
+$$""".format(name, options), name, password, password)
 
     def create_replication_user(self):
-        self.query('CREATE USER "{}" WITH REPLICATION ENCRYPTED PASSWORD %s'.format(
-            self.replication['username']), self.replication['password'])
+        self.create_or_update_role(self.replication['username'], self.replication['password'], 'REPLICATION')
 
     def create_connection_users(self):
-        if self.superuser:
-            if 'username' in self.superuser:
-                self.query('CREATE ROLE "{0}" WITH LOGIN SUPERUSER PASSWORD %s'.format(
-                    self.superuser['username']), self.superuser['password'])
-            else:
-                rolsuper = self.query("""SELECT rolname FROM pg_authid WHERE rolsuper = 't'""").fetchone()[0]
-                self.query('ALTER ROLE "{0}" WITH PASSWORD %s'.format(rolsuper), self.superuser['password'])
+        if 'username' in self.superuser:
+            self.create_or_update_role(self.superuser['username'], self.superuser['password'], 'SUPERUSER')
         if self.admin:
-            self.query('CREATE ROLE "{0}" WITH LOGIN CREATEDB CREATEROLE PASSWORD %s'.format(
-                self.admin['username']), self.admin['password'])
+            self.create_or_update_role(self.admin['username'], self.admin['password'], 'CREATEDB CREATEROLE')
 
     def xlog_position(self):
         return self.query("""SELECT pg_xlog_location_diff(CASE WHEN pg_is_in_recovery()
                                                                THEN pg_last_xlog_replay_location()
                                                                ELSE pg_current_xlog_location()
-                                                          END, '0/0')""").fetchone()[0]
+                                                          END, '0/0')::bigint""").fetchone()[0]
 
     def load_replication_slots(self):
-        if self.use_slots:
+        if self.use_slots and self.schedule_load_slots:
             cursor = self.query("SELECT slot_name FROM pg_replication_slots WHERE slot_type='physical'")
-            self.members = [r[0] for r in cursor]
+            self.replication_slots = [r[0] for r in cursor]
+            self.schedule_load_slots = False
 
-    def sync_replication_slots(self, members):
+    def sync_replication_slots(self, cluster):
         if self.use_slots:
-            # drop unused slots
-            for slot in set(self.members) - set(members):
-                self.query("""SELECT pg_drop_replication_slot(%s)
-                               WHERE EXISTS(SELECT 1 FROM pg_replication_slots
-                               WHERE slot_name = %s)""", slot, slot)
+            try:
+                self.load_replication_slots()
+                slots = [m.name for m in cluster.members if m.name != self.name] if self.role == 'master' else []
+                # drop unused slots
+                for slot in set(self.replication_slots) - set(slots):
+                    self.query("""SELECT pg_drop_replication_slot(%s)
+                                   WHERE EXISTS(SELECT 1 FROM pg_replication_slots
+                                   WHERE slot_name = %s)""", slot, slot)
 
-            # create new slots
-            for slot in set(members) - set(self.members):
-                self.query("""SELECT pg_create_physical_replication_slot(%s)
-                               WHERE NOT EXISTS (SELECT 1 FROM pg_replication_slots
-                               WHERE slot_name = %s)""", slot, slot)
+                # create new slots
+                for slot in set(slots) - set(self.replication_slots):
+                    self.query("""SELECT pg_create_physical_replication_slot(%s)
+                                   WHERE NOT EXISTS (SELECT 1 FROM pg_replication_slots
+                                   WHERE slot_name = %s)""", slot, slot)
 
-        self.members = members
-
-    def create_replication_slots(self, cluster):
-        self.sync_replication_slots([m.name for m in cluster.members if m.name != self.name])
-
-    def drop_replication_slots(self):
-        self.sync_replication_slots([])
+                self.replication_slots = slots
+            except:
+                logger.exception('Exception when changing replication slots')
 
     def last_operation(self):
         return str(self.xlog_position())
@@ -414,6 +635,7 @@ recovery_target_timeline = 'latest'
                 raise PostgresException("Could not bootstrap master PostgreSQL")
         else:
             if self.sync_from_leader(current_leader):
+                self.restore_configuration_files()
                 self.write_recovery_conf(current_leader)
                 ret = self.start()
         return ret
@@ -421,6 +643,23 @@ recovery_target_timeline = 'latest'
     def move_data_directory(self):
         if os.path.isdir(self.data_dir) and not self.is_running():
             try:
-                os.rename(self.data_dir, '{0}_{1}'.format(self.data_dir, time.strftime('%Y-%m-%d-%H-%M-%S')))
+                new_name = '{0}_{1}'.format(self.data_dir, time.strftime('%Y-%m-%d-%H-%M-%S'))
+                logger.info('renaming data directory to %s', new_name)
+                os.rename(self.data_dir, new_name)
             except:
-                logger.exception("Could not rename data directory {0}".format(self.data_dir))
+                logger.exception("Could not rename data directory %s", self.data_dir)
+
+    def remove_data_directory(self):
+        logger.info('Removing data directory: %s', self.data_dir)
+        try:
+            if os.path.islink(self.data_dir):
+                os.unlink(self.data_dir)
+            elif not os.path.exists(self.data_dir):
+                return
+            elif os.path.isfile(self.data_dir):
+                os.remove(self.data_dir)
+            elif os.path.isdir(self.data_dir):
+                shutil.rmtree(self.data_dir)
+        except:
+            logger.exception('Could not remove data directory %s', self.data_dir)
+            self.move_data_directory()

patroni/scripts/aws.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 import logging
 import requests

patroni/scripts/restore.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # arguments are:
 #   - cluster scope
 #   - cluster role

patroni/utils.py

@@ -6,8 +6,9 @@ import signal
 import sys
 import time
 
-from patroni.exceptions import DCSError
+from patroni.exceptions import PatroniException
 
+ignore_sigterm = False
 interrupted_sleep = False
 reap_children = False
 
@@ -35,6 +36,8 @@ def calculate_ttl(expiration):
     """
     >>> calculate_ttl(None)
     >>> calculate_ttl('2015-06-10 12:56:30.552539016Z')
+    >>> calculate_ttl('2015-06-10T12:56:30.552539016Z') < 0
+    True
     """
     if not expiration:
         return None
@@ -46,7 +49,10 @@ def calculate_ttl(expiration):
 
 
 def sigterm_handler(signo, stack_frame):
-    sys.exit()
+    global ignore_sigterm
+    if not ignore_sigterm:
+        ignore_sigterm = True
+        sys.exit()
 
 
 def sigchld_handler(signo, stack_frame):
@@ -86,7 +92,7 @@ def reap_children():
             reap_children = False
 
 
-class RetryFailedError(DCSError):
+class RetryFailedError(PatroniException):
 
     """Raised when retrying an operation ultimately failed, after retrying the maximum number of attempts."""
 
@@ -96,7 +102,7 @@ class Retry:
     """Helper for retrying a method in the face of retry-able exceptions"""
 
     def __init__(self, max_tries=1, delay=0.1, backoff=2, max_jitter=0.8, max_delay=3600,
-                 sleep_func=time.sleep, deadline=None, retry_exceptions=DCSError):
+                 sleep_func=sleep, deadline=None, retry_exceptions=PatroniException):
         """Create a :class:`Retry` instance for retrying function calls
 
         :param max_tries: How many times to retry the command. -1 means infinite tries.
@@ -150,13 +156,10 @@ class Retry:
                 if self._attempts == self.max_tries:
                     raise RetryFailedError("Too many retry attempts")
                 self._attempts += 1
-                sleeptime = self._cur_delay + (
-                    random.randint(0, self.max_jitter) / 100.0)
+                sleeptime = self._cur_delay + (random.randint(0, self.max_jitter) / 100.0)
 
-                if self._cur_stoptime is not None and \
-                   time.time() + sleeptime >= self._cur_stoptime:
+                if self._cur_stoptime is not None and time.time() + sleeptime >= self._cur_stoptime:
                     raise RetryFailedError("Exceeded retry deadline")
                 else:
                     self.sleep_func(sleeptime)
-                self._cur_delay = min(self._cur_delay * self.backoff,
-                                      self.max_delay)
+                self._cur_delay = min(self._cur_delay * self.backoff, self.max_delay)

patroni/version.py

@@ -1 +1 @@
-__version__ = '0.2'
+__version__ = '0.7'

patroni/zookeeper.py

@@ -5,7 +5,8 @@ import time
 
 from kazoo.client import KazooClient, KazooState
 from kazoo.exceptions import NoNodeError, NodeExistsError
-from patroni.dcs import AbstractDCS, Cluster, DCSError, Leader, Member, parse_connection_string
+from patroni.dcs import AbstractDCS, Cluster, Failover, Leader, Member
+from patroni.exceptions import DCSError
 from patroni.utils import sleep
 from requests.exceptions import RequestException
 
@@ -90,9 +91,8 @@ class ZooKeeper(AbstractDCS):
                                       'max_tries': -1},
                                   connection_retry={'max_delay': 1, 'max_tries': -1})
         self.client.add_listener(self.session_listener)
-        self.cluster_event = self.client.handler.event_object()
 
-        self.cluster = None
+        self._my_member_data = None
         self.fetch_cluster = True
         self.last_leader_operation = 0
 
@@ -104,18 +104,18 @@ class ZooKeeper(AbstractDCS):
 
     def cluster_watcher(self, event):
         self.fetch_cluster = True
-        self.cluster_event.set()
+        self.event.set()
 
     def get_node(self, key, watch=None):
         try:
-            return self.client.get(key, watch)
+            ret = self.client.get(key, watch)
+            return (ret[0].decode('utf-8'), ret[1])
         except NoNodeError:
             return None
 
     @staticmethod
     def member(name, value, znode):
-        conn_url, api_url = parse_connection_string(value)
-        return Member(znode.mzxid, name, conn_url, api_url, None, None)
+        return Member.from_node(znode.version, name, znode.ephemeralOwner, value)
 
     def get_children(self, key, watch=None):
         try:
@@ -132,17 +132,20 @@ class ZooKeeper(AbstractDCS):
         return members
 
     def _inner_load_cluster(self):
-        self.cluster_event.clear()
-        nodes = set(self.get_children(self.client_path('')))
+        self.fetch_cluster = False
+        self.event.clear()
+        nodes = set(self.get_children(self.client_path(''), self.cluster_watcher))
+        if not nodes:
+            self.fetch_cluster = True
 
         # get initialize flag
-        initialize = self._INITIALIZE in nodes
+        initialize = (self.get_node(self.initialize_path) or [None])[0] if self._INITIALIZE in nodes else None
 
         # get list of members
         members = self.load_members() if self._MEMBERS[:-1] in nodes else []
 
         # get leader
-        leader = self.get_node(self.leader_path, self.cluster_watcher) if self._LEADER in nodes else None
+        leader = self.get_node(self.leader_path) if self._LEADER in nodes else None
         if leader:
             client_id = self.client.client_id
             if leader[0] == self._name and client_id is not None and client_id[0] != leader[1].ephemeralOwner:
@@ -151,17 +154,22 @@ class ZooKeeper(AbstractDCS):
                 leader = None
 
             if leader:
-                member = Member(-1, leader[0], None, None, None, None)
+                member = Member(-1, leader[0], None, {})
                 member = ([m for m in members if m.name == leader[0]] or [member])[0]
-                leader = Leader(leader[1].mzxid, None, None, member)
+                leader = Leader(leader[1].version, leader[1].ephemeralOwner, member)
                 self.fetch_cluster = member.index == -1
 
-        # get last leader operation
-        self.last_leader_operation = self.get_node(self.leader_optime_path) if self.fetch_cluster else None
-        self.last_leader_operation = 0 if self.last_leader_operation is None else int(self.last_leader_operation[0])
-        self.cluster = Cluster(initialize, leader, self.last_leader_operation, members)
+        # failover key
+        failover = self.get_node(self.failover_path, watch=self.cluster_watcher) if self._FAILOVER in nodes else None
+        if failover:
+            failover = Failover.from_node(failover[1].version, failover[0])
 
-    def get_cluster(self):
+        # get last leader operation
+        optime = self.get_node(self.leader_optime_path) if self._OPTIME in nodes and self.fetch_cluster else None
+        self.last_leader_operation = 0 if optime is None else int(optime[0])
+        self._cluster = Cluster(initialize, leader, self.last_leader_operation, members, failover)
+
+    def _load_cluster(self):
         if self.exhibitor and self.exhibitor.poll():
             self.client.set_hosts(self.exhibitor.zookeeper_hosts)
 
@@ -172,11 +180,10 @@ class ZooKeeper(AbstractDCS):
                 logger.exception('get_cluster')
                 self.session_listener(KazooState.LOST)
                 raise ZooKeeperError('ZooKeeper in not responding properly')
-        return self.cluster
 
     def _create(self, path, value, **kwargs):
         try:
-            self.client.retry(self.client.create, path, value, **kwargs)
+            self.client.retry(self.client.create, path, value.encode('utf-8'), **kwargs)
             return True
         except:
             return False
@@ -186,30 +193,61 @@ class ZooKeeper(AbstractDCS):
         ret or logger.info('Could not take out TTL lock')
         return ret
 
-    def initialize(self):
-        return self._create(self.initialize_path, self._name, makepath=True)
-
-    def touch_member(self, connection_string, ttl=None):
-        if self.cluster and any(m.name == self._name for m in self.cluster.members):
-            return True
-        path = self.member_path
+    def set_failover_value(self, value, index=None):
         try:
-            self.client.retry(self.client.create, path, connection_string, makepath=True, ephemeral=True)
+            self.client.retry(self.client.set, self.failover_path, value.encode('utf-8'), version=index or -1)
+            return True
+        except NoNodeError:
+            return value == '' or (not index and self._create(self.failover_path, value))
+        except:
+            logging.exception('set_failover_value')
+            return False
+
+    def initialize(self, create_new=True, sysid=""):
+        return self._create(self.initialize_path, sysid, makepath=True) if create_new \
+            else self.client.retry(self.client.set, self.initialize_path,  sysid.encode("utf-8"))
+
+    def touch_member(self, data, ttl=None):
+        cluster = self.cluster
+        me = cluster and ([m for m in cluster.members if m.name == self._name] or [None])[0]
+        path = self.member_path
+        data = data.encode('utf-8')
+        create = not me
+        if me and self.client.client_id is not None and me.session != self.client.client_id[0]:
+            try:
+                self.client.retry(self.client.delete, path)
+            except NoNodeError:
+                pass
+            except:
+                return False
+            create = True
+
+        if not create and data == self._my_member_data:
+            return True
+
+        try:
+            if create:
+                self.client.retry(self.client.create, path, data, makepath=True, ephemeral=True)
+            else:
+                self.client.retry(self.client.set, path, data)
+            self._my_member_data = data
             return True
         except NodeExistsError:
             try:
-                self.client.retry(self.client.delete, path)
-                self.client.retry(self.client.create, path, connection_string, makepath=True, ephemeral=True)
+                self.client.retry(self.client.set, path, data)
+                self._my_member_data = data
                 return True
             except:
                 logger.exception('touch_member')
+        except:
+            logger.exception('touch_member')
         return False
 
     def take_leader(self):
         return self.attempt_to_acquire_leader()
 
-    def update_leader(self, state_handler):
-        last_operation = state_handler.last_operation()
+    def write_leader_optime(self, last_operation):
+        last_operation = last_operation.encode('utf-8')
         if last_operation != self.last_leader_operation:
             self.last_leader_operation = last_operation
             path = self.leader_optime_path
@@ -222,16 +260,19 @@ class ZooKeeper(AbstractDCS):
                     logger.exception('Failed to create %s', path)
             except:
                 logger.exception('Failed to update %s', path)
+
+    def update_leader(self):
         return True
 
     def delete_leader(self):
-        if isinstance(self.cluster, Cluster) and self.cluster.leader.name == self._name:
-            self.client.delete(self.leader_path, version=self.cluster.leader.index)
+        self.client.restart()
+        self._my_member_data = None
+        return True
 
     def _cancel_initialization(self):
         node = self.get_node(self.initialize_path)
-        if node and node[0] == self._name:
-            self.client.delete(self.initialize_path, version=node[1].mzxid)
+        if node:
+            self.client.delete(self.initialize_path, version=node[1].version)
 
     def cancel_initialization(self):
         try:
@@ -240,6 +281,6 @@ class ZooKeeper(AbstractDCS):
             logger.exception("Unable to delete initialize key")
 
     def watch(self, timeout):
-        self.cluster_event.wait(timeout)
-        if self.cluster_event.isSet():
+        if super(ZooKeeper, self).watch(timeout):
             self.fetch_cluster = True
+        return self.fetch_cluster

patronictl.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+from patroni.ctl import ctl
+
+if __name__ == '__main__':
+    ctl()

postgres0.yml

@@ -4,6 +4,9 @@ scope: &scope batman
 restapi:
   listen: 127.0.0.1:8008
   connect_address: 127.0.0.1:8008
+  auth: 'username:password'
+#  certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
+#  keyfile: /etc/ssl/private/ssl-cert-snakeoil.key
 etcd:
   scope: *scope
   ttl: *ttl
@@ -31,6 +34,27 @@ postgresql:
   data_dir: data/postgresql0
   maximum_lag_on_failover: 1048576 # 1 megabyte in bytes
   use_slots: True
+  pgpass: /tmp/pgpass0
+  initdb:  ## We allow the following options to be passed on to initdb
+  # - auth: authmethod
+  # - auth-host: authmethod
+  # - auth-local: authmethod
+  - encoding: UTF8
+  # - data-checksums  # When pg_rewind is needed on 9.3, this needs to be enabled
+  # - locale: locale
+  # - lc-collate: locale
+  # - lc-ctype: locale
+  # - lc-messages: locale
+  # - lc-monetary: locale
+  # - lc-numeric: locale
+  # - lc-time: locale
+  # - text-search-config: CFG
+  # - xlogdir: directory
+  # - debug
+  # - noclean
+  pg_rewind:
+    username: postgres
+    password: zalando
   pg_hba:
   - host all all 0.0.0.0/0 md5
   - hostssl all all 0.0.0.0/0 md5
@@ -39,6 +63,7 @@ postgresql:
     password: rep-pass
     network:  127.0.0.1/32
   superuser:
+    username: postgres
     password: zalando
   admin:
     username: admin
@@ -59,3 +84,9 @@ postgresql:
     archive_timeout: 1800s
     max_replication_slots: 5
     hot_standby: "on"
+    wal_log_hints: "on"
+tags:
+    nofailover: False
+    noloadbalance: False
+    clonefrom: False
+    replicatefrom: 127.0.0.1

postgres1.yml

@@ -4,6 +4,9 @@ scope: &scope batman
 restapi:
   listen: 127.0.0.1:8009
   connect_address: 127.0.0.1:8009
+  auth: 'username:password'
+#  certfile: /etc/ssl/certs/ssl-cert-snakeoil.pem
+#  keyfile: /etc/ssl/private/ssl-cert-snakeoil.key
 etcd:
   scope: *scope
   ttl: *ttl
@@ -31,6 +34,27 @@ postgresql:
   data_dir: data/postgresql1
   maximum_lag_on_failover: 1048576 # 1 megabyte in bytes
   use_slots: True
+  pgpass: /tmp/pgpass1
+  initdb:  ## We allow the following options to be passed on to initdb
+  # - auth: authmethod
+  # - auth-host: authmethod
+  # - auth-local: authmethod
+  - encoding: UTF8
+  # - data-checksums  # When pg_rewind is needed on 9.3, this needs to be enabled
+  # - locale: locale
+  # - lc-collate: locale
+  # - lc-ctype: locale
+  # - lc-messages: locale
+  # - lc-monetary: locale
+  # - lc-numeric: locale
+  # - lc-time: locale
+  # - text-search-config: CFG
+  # - xlogdir: directory
+  # - debug
+  # - noclean
+  pg_rewind:
+    username: postgres
+    password: zalando
   pg_hba:
   - host all all 0.0.0.0/0 md5
   - hostssl all all 0.0.0.0/0 md5
@@ -39,6 +63,7 @@ postgresql:
     password: rep-pass
     network: 127.0.0.1/32
   superuser:
+    user: postgres
     password: zalando
   admin:
     username: admin
@@ -59,3 +84,9 @@ postgresql:
     archive_timeout: 1800s
     max_replication_slots: 5
     hot_standby: "on"
+    wal_log_hints: "on"
+tags:
+    nofailover: False
+    noloadbalance: False
+    clonefrom: False
+    replicatefrom: 127.0.0.1

requirements-py2.txt

@@ -1,9 +1,11 @@
 boto
 dnspython
 mock
-psycopg2
+psycopg2>=2.6.1
 PyYAML
 requests
 six >= 1.7
 kazoo>=2.2.1
 python-etcd>=0.4.1
+click>=4.1
+prettytable>=0.7

requirements-py3.txt

@@ -1,9 +1,11 @@
 boto
 mock
 dnspython3
-psycopg2
+psycopg2>=2.6.1
 PyYAML
 requests
 six
 kazoo>=2.2.1
 python-etcd>=0.4.1
+click>=4.1
+prettytable>=0.7

setup.py

@@ -56,7 +56,7 @@ CLASSIFIERS = [
     'Programming Language :: Python :: Implementation :: CPython',
 ]
 
-CONSOLE_SCRIPTS = ['patroni = patroni:main']
+CONSOLE_SCRIPTS = ['patroni = patroni:main', 'patronictl = patroni.ctl:ctl']
 
 
 class PyTest(TestCommand):
@@ -89,7 +89,6 @@ class PyTest(TestCommand):
         params = {'args': self.test_args}
         if self.cov:
             params['args'] += self.cov
-            params['plugins'] = ['cov']
         if self.junitxml:
             params['args'] += self.junitxml
         params['args'] += ['--doctest-modules', MAIN_PACKAGE, '-s', '-vv']

tests/test_api.py

@@ -1,16 +1,21 @@
 import psycopg2
 import unittest
 
+from mock import Mock, patch
 from patroni.api import RestApiHandler, RestApiServer
+from patroni.dcs import Member
 from six import BytesIO as IO
-from test_postgresql import psycopg2_connect
+from six.moves import BaseHTTPServer
+from six.moves.BaseHTTPServer import BaseHTTPRequestHandler
+import socket
+from test_postgresql import psycopg2_connect, MockCursor
 
 
-def throws(*args, **kwargs):
-    raise psycopg2.OperationalError()
+class MockPostgresql(Mock):
 
-
-class MockPostgresql:
+    name = 'test'
+    state = 'running'
+    role = 'master'
 
     def connection(self):
         return psycopg2_connect()
@@ -19,10 +24,33 @@ class MockPostgresql:
         return True
 
 
+class MockHa(Mock):
+
+    dcs = Mock()
+    state_handler = MockPostgresql()
+
+    def schedule_restart(self):
+        return 'restart'
+
+    def schedule_reinitialize(self):
+        return 'reinitialize'
+
+    def restart(self):
+        return (True, '')
+
+    def restart_scheduled(self):
+        return False
+
+    def fetch_nodes_statuses(self, members):
+        return [[None, True, None, None, {}]]
+
+
 class MockPatroni:
 
-    def __init__(self):
-        self.postgresql = MockPostgresql()
+    postgresql = MockPostgresql()
+    ha = MockHa()
+    dcs = Mock()
+    tags = {}
 
 
 class MockRequest:
@@ -36,18 +64,105 @@ class MockRequest:
 
 class MockRestApiServer(RestApiServer):
 
-    def __init__(self, Handler, path, *args):
-        self.patroni = MockPatroni()
-        if len(args) > 0:
-            self.query = args[0]
+    def __init__(self, Handler, path):
+        self.socket = 0
+        BaseHTTPServer.HTTPServer.__init__ = Mock()
+        MockRestApiServer._BaseServer__is_shut_down = Mock()
+        MockRestApiServer._BaseServer__shutdown_request = True
+        config = {'listen': '127.0.0.1:8008', 'auth': 'test:test', 'certfile': 'dumb'}
+        super(MockRestApiServer, self).__init__(MockPatroni(), config)
         Handler(MockRequest(path), ('0.0.0.0', 8080), self)
 
 
+@patch('ssl.wrap_socket', Mock(return_value=0))
 class TestRestApiHandler(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        super(TestRestApiHandler, self).__init__(method_name)
-
     def test_do_GET(self):
-        MockRestApiServer(RestApiHandler, b'GET /')
-        MockRestApiServer(RestApiHandler, b'GET /', throws)
+        MockRestApiServer(RestApiHandler, b'GET /replica')
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={})):
+            MockRestApiServer(RestApiHandler, b'GET /replica')
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
+            MockRestApiServer(RestApiHandler, b'GET /replica')
+        MockRestApiServer(RestApiHandler, b'GET /master')
+        MockPatroni.dcs.cluster.leader.name = MockPostgresql.name
+        MockRestApiServer(RestApiHandler, b'GET /replica')
+        MockPatroni.dcs.cluster = None
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
+            MockRestApiServer(RestApiHandler, b'GET /master')
+        with patch.object(MockHa, 'restart_scheduled', Mock(return_value=True)):
+            MockRestApiServer(RestApiHandler, b'GET /master')
+        MockRestApiServer(RestApiHandler, b'GET /master')
+
+    def test_do_OPTIONS(self):
+        MockRestApiServer(RestApiHandler, b'OPTIONS / HTTP/1.0')
+
+        with patch.object(BaseHTTPRequestHandler, 'handle_one_request') as mock_handle_request:
+            mock_handle_request.side_effect = socket.error("foo")
+            MockRestApiServer(RestApiHandler, b'OPTIONS / HTTP/1.0')
+
+        # make sure socket.error gets propagated via wfile object in finalize()
+        with patch.object(MockRequest, 'makefile') as makefile:
+            makefile.return_value.closed = False
+            makefile.return_value.readline.side_effect = lambda x: b"foo"
+            makefile.return_value.flush = Mock(side_effect=socket.error("foo"))
+            MockRestApiServer(RestApiHandler, b'OPTIONS / HTTP/1.0')
+
+    def test_do_GET_patroni(self):
+        MockRestApiServer(RestApiHandler, b'GET /patroni')
+
+    def test_basicauth(self):
+        MockRestApiServer(RestApiHandler, b'POST /restart HTTP/1.0')
+        MockRestApiServer(RestApiHandler, b'POST /restart HTTP/1.0\nAuthorization:')
+
+    def test_do_POST_restart(self):
+        request = b'POST /restart HTTP/1.0\nAuthorization: Basic dGVzdDp0ZXN0'
+        MockRestApiServer(RestApiHandler, request)
+        with patch.object(MockHa, 'restart', Mock(side_effect=Exception)):
+            MockRestApiServer(RestApiHandler, request)
+
+    @patch.object(MockHa, 'dcs')
+    def test_do_POST_reinitialize(self, dcs):
+        cluster = dcs.get_cluster.return_value
+        request = b'POST /reinitialize HTTP/1.0\nAuthorization: Basic dGVzdDp0ZXN0'
+        MockRestApiServer(RestApiHandler, request)
+        cluster.is_unlocked.return_value = False
+        MockRestApiServer(RestApiHandler, request)
+        with patch.object(MockHa, 'schedule_reinitialize', Mock(return_value=None)):
+            MockRestApiServer(RestApiHandler, request)
+        cluster.leader.name = 'test'
+        MockRestApiServer(RestApiHandler, request)
+
+    @patch('time.sleep', Mock())
+    def test_RestApiServer_query(self):
+        with patch.object(MockCursor, 'execute', Mock(side_effect=psycopg2.OperationalError)):
+            MockRestApiServer(RestApiHandler, b'GET /patroni')
+        with patch.object(MockPostgresql, 'connection', Mock(side_effect=psycopg2.OperationalError)):
+            MockRestApiServer(RestApiHandler, b'GET /patroni')
+
+    @patch('time.sleep', Mock())
+    @patch.object(MockHa, 'dcs')
+    def test_do_POST_failover(self, dcs):
+        cluster = dcs.get_cluster.return_value
+        request = b'POST /failover HTTP/1.0\nAuthorization: Basic dGVzdDp0ZXN0\n' +\
+                  b'Content-Length: 25\n\n{"leader": "postgresql1"}'
+        MockRestApiServer(RestApiHandler, request)
+        cluster.leader.name = 'postgresql1'
+        MockRestApiServer(RestApiHandler, request)
+        cluster.members = [Member(0, 'postgresql0', 30, {'api_url': 'http'})]
+        MockRestApiServer(RestApiHandler, request)
+        with patch.object(MockPatroni, 'dcs') as d:
+            cluster = d.get_cluster.return_value
+            cluster.leader.name = 'postgresql0'
+            MockRestApiServer(RestApiHandler, request)
+            cluster.leader.name = 'postgresql1'
+            cluster.failover = None
+            MockRestApiServer(RestApiHandler, request)
+            d.get_cluster = Mock(side_effect=Exception())
+            MockRestApiServer(RestApiHandler, request)
+            d.manual_failover.return_value = False
+            MockRestApiServer(RestApiHandler, request)
+        with patch.object(MockHa, 'fetch_nodes_statuses', Mock(return_value=[])):
+            MockRestApiServer(RestApiHandler, request)
+        request = b'POST /failover HTTP/1.0\nAuthorization: Basic dGVzdDp0ZXN0\n' +\
+                  b'Content-Length: 50\n\n{"leader": "postgresql1", "member": "postgresql2"}'
+        MockRestApiServer(RestApiHandler, request)

tests/test_async_executor.py

@@ -0,0 +1,18 @@
+import unittest
+
+from mock import Mock, patch
+from patroni.async_executor import AsyncExecutor
+from threading import Thread
+
+
+class TestAsyncExecutor(unittest.TestCase):
+
+    def setUp(self):
+        self.a = AsyncExecutor()
+
+    @patch.object(Thread, 'start', Mock())
+    def test_run_async(self):
+        self.a.run_async(Mock(return_value=True))
+
+    def test_run(self):
+        self.a.run(Mock(side_effect=Exception()))

tests/test_ctl.py

@@ -0,0 +1,376 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import os
+import pytest
+import unittest
+import psycopg2
+import requests
+import patroni.exceptions
+import etcd
+from mock import patch, Mock
+
+from click.testing import CliRunner
+from patroni.ctl import ctl, members, store_config, load_config, output_members, post_patroni, get_dcs, \
+    wait_for_leader, get_all_members, get_any_member, get_cursor, query_member, configure
+from patroni.ha import Ha
+from patroni.etcd import Etcd, Client
+from test_ha import get_cluster_initialized_without_leader, get_cluster_initialized_with_leader, \
+    get_cluster_initialized_with_only_leader, MockPostgresql, MockPatroni, run_async, \
+    get_cluster_not_initialized_without_leader
+from test_etcd import etcd_read, etcd_write, requests_get, MockResponse
+from test_postgresql import MockConnect, psycopg2_connect
+
+CONFIG_FILE_PATH = './test-ctl.yaml'
+
+def test_rw_config():
+    runner = CliRunner()
+    config = {'a':'b'}
+    with runner.isolated_filesystem():
+        store_config(config, CONFIG_FILE_PATH + '/dummy')
+        os.remove(CONFIG_FILE_PATH + '/dummy')
+        os.rmdir(CONFIG_FILE_PATH)
+
+        with pytest.raises(Exception):
+            result = load_config(CONFIG_FILE_PATH, None)
+            assert 'Could not load configuration file' in result.output
+
+        os.mkdir(CONFIG_FILE_PATH)
+        with pytest.raises(Exception):
+            store_config(config, CONFIG_FILE_PATH)
+
+        os.rmdir(CONFIG_FILE_PATH)
+
+    store_config(config, CONFIG_FILE_PATH)
+    load_config(CONFIG_FILE_PATH, None)
+    load_config(CONFIG_FILE_PATH, '0.0.0.0')
+
+@patch('patroni.ctl.load_config', Mock(return_value={'dcs': {'scheme': 'etcd', 'hostname': 'localhost', 'port': 4001}}))
+class TestCtl(unittest.TestCase):
+
+    @patch.object(Client, 'machines')
+    def setUp(self, mock_machines):
+        mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
+        self.p = MockPostgresql()
+        self.e = Etcd('foo', {'ttl': 30, 'host': 'ok:2379', 'scope': 'test'})
+        self.e.client.read = etcd_read
+        self.e.client.write = etcd_write
+        self.e.client.delete = Mock(side_effect=etcd.EtcdException())
+        self.ha = Ha(MockPatroni(self.p, self.e))
+        self.ha._async_executor.run_async = run_async
+        self.ha.old_cluster = self.e.get_cluster()
+        self.ha.cluster = get_cluster_not_initialized_without_leader()
+        self.ha.load_cluster_from_dcs = Mock()
+
+    @patch('psycopg2.connect', psycopg2_connect)
+    def test_get_cursor(self):
+        c = get_cursor(get_cluster_initialized_without_leader(), role='master')
+        assert c is None
+
+        c = get_cursor(get_cluster_initialized_with_leader(), role='master')
+        assert c is not None
+
+        c = get_cursor(get_cluster_initialized_with_leader(), role='replica')
+        # # MockCursor returns pg_is_in_recovery as false
+        assert c is None
+
+        c = get_cursor(get_cluster_initialized_with_leader(), role='any')
+        assert c is not None
+
+    def test_output_members(self):
+        cluster = get_cluster_initialized_with_leader()
+        output_members(cluster, name='abc', format='pretty')
+        output_members(cluster, name='abc', format='json')
+        output_members(cluster, name='abc', format='tsv')
+
+    @patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
+    @patch('patroni.etcd.Etcd.get_etcd_client', Mock(return_value=None))
+    @patch('patroni.etcd.Etcd.set_failover_value', Mock(return_value=None))
+    @patch('patroni.ctl.wait_for_leader', Mock(return_value=get_cluster_initialized_with_leader()))
+    @patch('requests.get', requests_get)
+    @patch('requests.post', requests_get)
+    @patch('patroni.ctl.post_patroni', Mock(return_value=MockResponse()))
+    def test_failover(self):
+        runner = CliRunner()
+
+        with patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_leader())):
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+other
+y''')
+            assert 'Failing over to new leader' in result.output
+
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+other
+N''')
+            assert 'Aborting failover' in str(result.exception)
+
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+leader
+y''')
+            assert 'target and source are the same' in str(result.exception)
+
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+Reality
+y''')
+            assert 'Reality does not exist' in str(result.exception)
+
+            result = runner.invoke(ctl, ['failover', 'dummy', '--force'])
+            assert 'Failing over to new leader' in result.output
+
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='dummy')
+            assert 'is not the leader of cluster' in str(result.exception)
+
+        with patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_only_leader())):
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+other
+y''')
+            assert 'No candidates found to failover to' in str(result.exception)
+
+        with patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_without_leader())):
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+other
+y''')
+            assert 'This cluster has no master' in str(result.exception)
+
+        with patch('patroni.ctl.post_patroni', Mock(side_effect=Exception())):
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+other
+y''')
+            assert 'falling back to DCS' in result.output
+            assert 'Failover failed' in result.output
+
+        mocked = Mock()
+        mocked.return_value.status_code = 500
+        with patch('patroni.ctl.post_patroni', Mock(return_value=mocked)):
+            result = runner.invoke(ctl, ['failover', 'dummy', '--dcs', '8.8.8.8'], input='''leader
+other
+y''')
+            assert 'Failover failed, details' in result.output
+
+#        with patch('patroni.dcs.AbstractDCS.get_cluster', Mock(return_value=get_cluster_initialized_with_leader())):
+#            result = runner.invoke(ctl, ['failover', 'alpha', '--dcs', '8.8.8.8'], input='nonsense')
+#            assert 'is not the leader of cluster' in str(result.exception)
+
+            # result = runner.invoke(ctl, ['failover', 'alpha', '--dcs', '8.8.8.8', '--master', 'nonsense'])
+            # assert 'is not the leader of cluster' in str(result.exception)
+
+            # result = runner.invoke(ctl, ['failover', 'alpha', '--dcs', '8.8.8.8'], input='leader\nother\nn')
+            # assert 'Aborting failover' in str(result.exception)
+
+            # with patch('patroni.ctl.wait_for_leader', Mock(return_value = get_cluster_initialized_with_leader())):
+                # result = runner.invoke(ctl, ['failover', 'alpha', '--dcs', '8.8.8.8'], input='leader\nother\nY')
+                # assert 'master did not change after' in result.output
+
+                # result = runner.invoke(ctl, ['failover', 'alpha', '--dcs', '8.8.8.8'], input='leader\nother\nY')
+                # assert 'Failover failed' in result.output
+
+    def test_(self):
+        self.assertRaises(patroni.exceptions.PatroniCtlException, get_dcs, {'scheme': 'dummy'}, 'dummy')
+
+    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.ctl.query_member', Mock(return_value=([['mock column']], None)))
+    def test_query(self):
+        runner = CliRunner()
+
+        with patch('patroni.ctl.get_dcs', Mock(return_value=self.e)):
+            result = runner.invoke(ctl, [
+                'query',
+                'alpha',
+                '--member',
+                'abc',
+                '--role',
+                'master',
+            ])
+            assert 'mutually exclusive' in str(result.exception)
+
+            with runner.isolated_filesystem():
+                dummy_file = open('dummy', 'w')
+                dummy_file.write('SELECT 1')
+                dummy_file.close()
+
+                result = runner.invoke(ctl, [
+                    'query',
+                    'alpha',
+                    '--file',
+                    'dummy',
+                    '--command',
+                    'dummy',
+                ])
+                assert 'mutually exclusive' in str(result.exception)
+
+                result = runner.invoke(ctl, ['query', 'alpha', '--file', 'dummy'])
+
+                os.remove('dummy')
+
+            result = runner.invoke(ctl, ['query', 'alpha', '--command', 'SELECT 1'])
+            assert 'mock column' in result.output
+
+    @patch('patroni.ctl.get_cursor', Mock(return_value=MockConnect().cursor()))
+    def test_query_member(self):
+        rows = query_member(None, None, None, 'master', 'SELECT pg_is_in_recovery()')
+        assert 'False' in str(rows)
+
+        rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()')
+        assert rows == (None, None)
+
+        with patch('patroni.ctl.get_cursor', Mock(return_value=None)):
+            rows = query_member(None, None, None, None, 'SELECT pg_is_in_recovery()')
+            assert 'No connection to' in str(rows)
+
+            rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()')
+            assert 'No connection to' in str(rows)
+
+        with patch('patroni.ctl.get_cursor', Mock(side_effect=psycopg2.OperationalError('bla'))):
+            rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()')
+
+        with patch('test_postgresql.MockCursor.execute', Mock(side_effect=psycopg2.OperationalError('bla'))):
+            rows = query_member(None, None, None, 'replica', 'SELECT pg_is_in_recovery()')
+
+    @patch('patroni.dcs.AbstractDCS.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
+    def test_dsn(self):
+        runner = CliRunner()
+
+        with patch('patroni.ctl.get_dcs', Mock(return_value=self.e)):
+            result = runner.invoke(ctl, ['dsn', 'alpha', '--dcs', '8.8.8.8'])
+            assert 'host=127.0.0.1 port=5435' in result.output
+
+            result = runner.invoke(ctl, [
+                'dsn',
+                'alpha',
+                '--role',
+                'master',
+                '--member',
+                'dummy',
+            ])
+            assert 'mutually exclusive' in str(result.exception)
+
+            result = runner.invoke(ctl, ['dsn', 'alpha', '--member', 'dummy'])
+            assert 'Can not find' in str(result.exception)
+
+        # result = runner.invoke(ctl, ['dsn', 'alpha', '--dcs', '8.8.8.8', '--role', 'replica'])
+        # assert 'host=127.0.0.1 port=5436' in result.output
+
+    @patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
+    @patch('patroni.etcd.Etcd.get_etcd_client', Mock(return_value=None))
+    @patch('requests.get', requests_get)
+    @patch('requests.post', requests_get)
+    def test_restart_reinit(self):
+        runner = CliRunner()
+
+        result = runner.invoke(ctl, ['restart', 'alpha', '--dcs', '8.8.8.8'], input='y')
+        result = runner.invoke(ctl, ['reinit', 'alpha', '--dcs', '8.8.8.8'], input='y')
+
+        result = runner.invoke(ctl, ['restart', 'alpha', '--dcs', '8.8.8.8'], input='N')
+        result = runner.invoke(ctl, [
+            'restart',
+            'alpha',
+            '--dcs',
+            '8.8.8.8',
+            'dummy',
+            '--any',
+        ], input='y')
+        assert 'not a member' in str(result.exception)
+
+        with patch('requests.post', Mock(return_value=MockResponse())):
+            result = runner.invoke(ctl, ['restart', 'alpha', '--dcs', '8.8.8.8'], input='y')
+
+    @patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
+    @patch('patroni.etcd.Etcd.get_etcd_client', Mock(return_value=None))
+    def test_remove(self):
+        runner = CliRunner()
+
+        result = runner.invoke(ctl, ['remove', 'alpha', '--dcs', '8.8.8.8'], input='alpha\nslave')
+        assert 'Please confirm' in result.output
+        assert 'You are about to remove all' in result.output
+        assert 'You did not exactly type' in str(result.exception)
+
+        result = runner.invoke(ctl, ['remove', 'alpha', '--dcs', '8.8.8.8'], input='''alpha
+Yes I am aware
+slave''')
+        assert 'You did not specify the current master of the cluster' in str(result.exception)
+
+        result = runner.invoke(ctl, ['remove', 'alpha', '--dcs', '8.8.8.8'], input='beta\nleader')
+        assert 'Cluster names specified do not match' in str(result.exception)
+
+        with patch('patroni.etcd.Etcd.get_cluster', get_cluster_initialized_with_leader):
+            result = runner.invoke(ctl, ['remove', 'alpha', '--dcs', '8.8.8.8'],
+                                   input='''alpha
+Yes I am aware
+leader''')
+            assert 'object has no attribute' in str(result.exception)
+
+        with patch('patroni.ctl.get_dcs', Mock(return_value=Mock())):
+            result = runner.invoke(ctl, ['remove', 'alpha', '--dcs', '8.8.8.8'],
+                                   input='''alpha
+Yes I am aware
+leader''')
+            assert 'We have not implemented this for DCS of type' in str(result.exception)
+
+    @patch('patroni.etcd.Etcd.watch', Mock(return_value=None))
+    @patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
+    def test_wait_for_leader(self):
+        dcs = self.e
+        self.assertRaises(patroni.exceptions.PatroniCtlException, wait_for_leader, dcs, 0)
+
+        cluster = wait_for_leader(dcs=dcs, timeout=2)
+        assert cluster.leader.member.name == 'leader'
+
+    def test_post_patroni(self):
+        member = get_cluster_initialized_with_leader().leader.member
+        self.assertRaises(requests.exceptions.ConnectionError, post_patroni, member, 'dummy', {})
+
+    def test_ctl(self):
+        runner = CliRunner()
+
+        runner.invoke(ctl, ['list'])
+
+        result = runner.invoke(ctl, ['--help'])
+        assert 'Usage:' in result.output
+
+    def test_get_any_member(self):
+        m = get_any_member(get_cluster_initialized_without_leader(), role='master')
+        assert m is None
+
+        m = get_any_member(get_cluster_initialized_with_leader(), role='master')
+        assert m.name == 'leader'
+
+    def test_get_all_members(self):
+        r = list(get_all_members(get_cluster_initialized_without_leader(), role='master'))
+        assert len(r) == 0
+
+        r = list(get_all_members(get_cluster_initialized_with_leader(), role='master'))
+        assert len(r) == 1
+        assert r[0].name == 'leader'
+
+        r = list(get_all_members(get_cluster_initialized_with_leader(), role='replica'))
+        assert len(r) == 1
+        assert r[0].name == 'other'
+
+        r = list(get_all_members(get_cluster_initialized_without_leader(), role='replica'))
+        assert len(r) == 2
+
+    @patch('patroni.etcd.Etcd.get_cluster', Mock(return_value=get_cluster_initialized_with_leader()))
+    @patch('patroni.etcd.Etcd.get_etcd_client', Mock(return_value=None))
+    @patch('requests.get', requests_get)
+    @patch('requests.post', requests_get)
+    def test_members(self):
+        runner = CliRunner()
+
+        result = runner.invoke(members, ['alpha'])
+        assert result.exit_code == 0
+
+    def test_configure(self):
+        runner = CliRunner()
+
+        result = runner.invoke(configure, [
+            '--dcs',
+            'abc',
+            '-c',
+            'dummy',
+            '-n',
+            'bla',
+        ])
+
+        assert result.exit_code == 0
+
+

tests/test_etcd.py

@@ -1,17 +1,14 @@
-import datetime
-import dns.resolver
 import etcd
 import json
 import requests
 import urllib3
 import socket
-import time
 import unittest
 
 from dns.exception import DNSException
 from mock import Mock, patch
-from patroni.dcs import Cluster, DCSError, Leader, Member
-from patroni.etcd import Client, Etcd
+from patroni.dcs import Cluster, DCSError, Leader
+from patroni.etcd import Client, Etcd, EtcdError
 
 
 class MockResponse:
@@ -20,6 +17,7 @@ class MockResponse:
         self.status_code = 200
         self.content = '{}'
         self.ok = True
+        self.text = ''
 
     def json(self):
         return json.loads(self.content)
@@ -40,11 +38,10 @@ class MockResponse:
         return ''
 
 
-class MockPostgresql:
-    name = ''
+class MockPostgresql(Mock):
 
     def last_operation(self):
-        return 0
+        return '0'
 
 
 def requests_get(url, **kwargs):
@@ -53,6 +50,8 @@ def requests_get(url, **kwargs):
     response = MockResponse()
     if url.startswith('http://local'):
         raise requests.exceptions.RequestException()
+    elif ':8011/patroni' in url:
+        response.content = '{"role": "replica", "xlog": {"replayed_location": 0}, "tags": {}}'
     elif url.endswith('/members'):
         if url.startswith('http://error'):
             response.content = '[{}]'
@@ -67,11 +66,11 @@ def requests_get(url, **kwargs):
 
 
 def etcd_watch(key, index=None, timeout=None, recursive=None):
-    if timeout == 1:
+    if timeout == 2.0:
         raise urllib3.exceptions.TimeoutError
-    elif timeout == 5:
+    elif timeout == 5.0:
         return etcd.EtcdResult('delete', {})
-    elif timeout == 10:
+    elif timeout == 10.0:
         raise etcd.EtcdException
     elif index == 20729:
         return etcd.EtcdResult('set', {'value': 'postgresql1', 'modifiedIndex': index + 1})
@@ -82,16 +81,12 @@ def etcd_watch(key, index=None, timeout=None, recursive=None):
 def etcd_write(key, value, **kwargs):
     if key == '/service/exists/leader':
         raise etcd.EtcdAlreadyExist
-    if key == '/service/test/leader':
+    if key == '/service/test/leader' or key == '/patroni/test/leader':
         if kwargs.get('prevValue', None) == 'foo' or not kwargs.get('prevExist', True):
             return True
     raise etcd.EtcdException
 
 
-def etcd_delete(key, **kwargs):
-    raise etcd.EtcdException
-
-
 def etcd_read(key, **kwargs):
     if key == '/service/noleader/':
         raise DCSError('noleader')
@@ -99,6 +94,8 @@ def etcd_read(key, **kwargs):
         raise etcd.EtcdKeyNotFound
 
     response = {"action": "get", "node": {"key": "/service/batman5", "dir": True, "nodes": [
+                {"key": "/service/batman5/failover", "value": "",
+                 "modifiedIndex": 1582, "createdIndex": 1582},
                 {"key": "/service/batman5/initialize", "value": "postgresql0",
                  "modifiedIndex": 1582, "createdIndex": 1582},
                 {"key": "/service/batman5/leader", "value": "postgresql1",
@@ -110,31 +107,23 @@ def etcd_read(key, **kwargs):
                  "modifiedIndex": 20437, "createdIndex": 20437},
                 {"key": "/service/batman5/members", "dir": True, "nodes": [
                     {"key": "/service/batman5/members/postgresql1",
-                     "value": "postgres://replicator:[email protected]:5434/postgres"
-                        + "?application_name=http://127.0.0.1:8009/patroni",
+                     "value": "postgres://replicator:[email protected]:5434/postgres" +
+                        "?application_name=http://127.0.0.1:8009/patroni",
                      "expiration": "2015-05-15T09:10:59.949384522Z", "ttl": 21,
                      "modifiedIndex": 20727, "createdIndex": 20727},
                     {"key": "/service/batman5/members/postgresql0",
-                     "value": "postgres://replicator:[email protected]:5433/postgres"
-                        + "?application_name=http://127.0.0.1:8008/patroni",
+                     "value": "postgres://replicator:[email protected]:5433/postgres" +
+                        "?application_name=http://127.0.0.1:8008/patroni",
                      "expiration": "2015-05-15T09:11:09.611860899Z", "ttl": 30,
                      "modifiedIndex": 20730, "createdIndex": 20730}],
                  "modifiedIndex": 1581, "createdIndex": 1581}], "modifiedIndex": 1581, "createdIndex": 1581}}
     return etcd.EtcdResult(**response)
 
 
-def time_sleep(_):
-    pass
-
-
 class SleepException(Exception):
     pass
 
 
-def time_sleep_exception(_):
-    raise SleepException()
-
-
 class MockSRV:
     port = 2380
     target = '127.0.0.1'
@@ -151,7 +140,7 @@ def dns_query(name, type):
 def socket_getaddrinfo(*args):
     if args[0] == 'ok':
         return [(2, 1, 6, '', ('127.0.0.1', 2379)), (2, 1, 6, '', ('127.0.0.1', 2379))]
-    raise socket.error()
+    raise socket.error
 
 
 def http_request(method, url, **kwargs):
@@ -160,28 +149,14 @@ def http_request(method, url, **kwargs):
     raise socket.error
 
 
-class TestMember(unittest.TestCase):
-
-    def __init__(self, method_name='runTest'):
-        super(TestMember, self).__init__(method_name)
-
-    def test_real_ttl(self):
-        now = datetime.datetime.utcnow()
-        member = Member(0, 'a', 'b', 'c', (now + datetime.timedelta(seconds=2)).strftime('%Y-%m-%dT%H:%M:%S.%fZ'), None)
-        self.assertLess(member.real_ttl(), 2)
-        self.assertEquals(Member(0, 'a', 'b', 'c', '', None).real_ttl(), -1)
-
-
+@patch('dns.resolver.query', dns_query)
+@patch('socket.getaddrinfo', socket_getaddrinfo)
+@patch('requests.get', requests_get)
 class TestClient(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        super(TestClient, self).__init__(method_name)
-
-    def set_up(self):
-        socket.getaddrinfo = socket_getaddrinfo
-        requests.get = requests_get
-        dns.resolver.query = dns_query
+    @patch('dns.resolver.query', dns_query)
+    @patch('requests.get', requests_get)
+    def setUp(self):
         with patch.object(etcd.Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
             self.client = Client({'discovery_srv': 'test'})
@@ -191,6 +166,11 @@ class TestClient(unittest.TestCase):
         self.client._base_uri = 'http://localhost:4001'
         self.client._machines_cache = ['http://localhost:2379']
         self.client.api_execute('/', 'GET')
+        self.client._update_machines_cache = False
+        self.client._base_uri = 'http://localhost:4001'
+        self.client._machines_cache = []
+        self.assertRaises(etcd.EtcdConnectionFailed, self.client.api_execute, '/', 'GET')
+        self.assertTrue(self.client._update_machines_cache)
 
     def test_get_srv_record(self):
         self.assertEquals(self.client.get_srv_record('blabla'), [])
@@ -206,11 +186,11 @@ class TestClient(unittest.TestCase):
         self.assertRaises(etcd.EtcdException, self.client._result_from_response, response)
 
     def test__get_machines_cache_from_srv(self):
-        self.client.get_srv_record = lambda e: [('localhost', 2380)]
+        self.client.get_srv_record = Mock(return_value=[('localhost', 2380)])
         self.client._get_machines_cache_from_srv('blabla')
 
     def test__get_machines_cache_from_dns(self):
-        self.client._get_machines_cache_from_dns('ok:2379')
+        self.client._get_machines_cache_from_dns('error:2379')
 
     def test__load_machines_cache(self):
         self.client._config = {}
@@ -219,25 +199,26 @@ class TestClient(unittest.TestCase):
         self.assertRaises(etcd.EtcdException, self.client._load_machines_cache)
 
 
+@patch('requests.get', requests_get)
 class TestEtcd(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        super(TestEtcd, self).__init__(method_name)
-
-    def set_up(self):
-        time.sleep = time_sleep
+    def setUp(self):
         with patch.object(Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
-            self.etcd = Etcd('foo', {'ttl': 30, 'host': 'localhost:2379', 'scope': 'test'})
+            self.etcd = Etcd('foo', {'namespace': '/patroni/', 'ttl': 30, 'host': 'localhost:2379', 'scope': 'test'})
             self.etcd.client.write = etcd_write
             self.etcd.client.read = etcd_read
+            self.etcd.client.delete = Mock(side_effect=etcd.EtcdException())
 
+    def test_base_path(self):
+        self.assertEquals(self.etcd._base_path, '/patroni/test')
+
+    @patch('dns.resolver.query', dns_query)
     def test_get_etcd_client(self):
-        time.sleep = time_sleep_exception
         with patch.object(etcd.Client, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(side_effect=etcd.EtcdException)
-            self.assertRaises(SleepException, self.etcd.get_etcd_client, {'discovery_srv': 'test'})
+            with patch('time.sleep', Mock(side_effect=SleepException())):
+                self.assertRaises(SleepException, self.etcd.get_etcd_client, {'discovery_srv': 'test'})
 
     def test_get_cluster(self):
         self.assertIsInstance(self.etcd.get_cluster(), Cluster)
@@ -257,31 +238,36 @@ class TestEtcd(unittest.TestCase):
     def test_take_leader(self):
         self.assertFalse(self.etcd.take_leader())
 
-    def testattempt_to_acquire_leader(self):
+    def test_attempt_to_acquire_leader(self):
         self.etcd._base_path = '/service/exists'
         self.assertFalse(self.etcd.attempt_to_acquire_leader())
         self.etcd._base_path = '/service/failed'
         self.assertFalse(self.etcd.attempt_to_acquire_leader())
 
+    def test_write_leader_optime(self):
+        self.etcd.write_leader_optime('0')
+
     def test_update_leader(self):
-        self.assertTrue(self.etcd.update_leader(MockPostgresql()))
+        self.assertTrue(self.etcd.update_leader())
 
     def test_initialize(self):
         self.assertFalse(self.etcd.initialize())
 
     def test_cancel_initializion(self):
-        self.etcd.client.delete = etcd_delete
         self.assertFalse(self.etcd.cancel_initialization())
 
     def test_delete_leader(self):
-        self.etcd.client.delete = etcd_delete
         self.assertFalse(self.etcd.delete_leader())
 
     def test_watch(self):
         self.etcd.client.watch = etcd_watch
-        self.etcd.watch(100)
+        self.etcd.watch(0)
         self.etcd.get_cluster()
-        self.etcd.watch(1)
-        self.etcd.watch(5)
-        self.etcd.watch(10)
+        self.etcd.watch(1.5)
+        self.etcd.watch(4.5)
+        self.etcd.watch(9.5)
         self.etcd.watch(100)
+
+    @patch('patroni.etcd.Etcd.retry', Mock(side_effect=AttributeError("foo")))
+    def test_other_exceptions(self):
+        self.assertRaises(EtcdError, self.etcd.cancel_initialization)

tests/test_ha.py

@@ -1,10 +1,12 @@
+import etcd
 import unittest
 
-from mock import Mock, patch
-from patroni.dcs import Cluster, DCSError
+from mock import Mock, MagicMock, patch
+from patroni.dcs import Cluster, Failover, Leader, Member
 from patroni.etcd import Client, Etcd
+from patroni.exceptions import DCSError, PostgresException
 from patroni.ha import Ha
-from test_etcd import etcd_read, etcd_write
+from test_etcd import socket_getaddrinfo, etcd_read, etcd_write, requests_get
 
 
 def true(*args, **kwargs):
@@ -15,18 +17,41 @@ def false(*args, **kwargs):
     return False
 
 
-class MockPostgresql:
+def get_cluster(initialize, leader, members, failover):
+    return Cluster(initialize, leader, None, members, failover)
 
-    def __init__(self):
-        self.name = 'postgresql0'
-        self.is_promoted = False
+
+def get_cluster_not_initialized_without_leader():
+    return get_cluster(None, None, [], None)
+
+
+def get_cluster_initialized_without_leader(leader=False, failover=None):
+    m = Member(0, 'leader', 28, {'conn_url': 'postgres://replicator:[email protected]:5435/postgres',
+                                 'api_url': 'http://127.0.0.1:8008/patroni', 'xlog_location':4})
+    l = Leader(0, 0, m) if leader else None
+    o = Member(0, 'other', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres',
+                                'api_url': 'http://127.0.0.1:8011/patroni'})
+    return get_cluster(True, l, [m, o], failover)
+
+
+def get_cluster_initialized_with_leader(failover=None):
+    return get_cluster_initialized_without_leader(leader=True, failover=failover)
+
+def get_cluster_initialized_with_only_leader(failover=None):
+    l = get_cluster_initialized_without_leader(leader=True, failover=failover).leader
+    return get_cluster(True, l, [l], failover)
+
+
+class MockPostgresql(Mock):
+
+    name = 'postgresql0'
+    role = 'replica'
+    state = 'running'
+    connection_string = 'postgres://foo@bar/postgres'
 
     def is_healthy(self):
         return True
 
-    def write_recovery_conf(self, _):
-        return True
-
     def start(self):
         return True
 
@@ -36,64 +61,89 @@ class MockPostgresql:
     def is_leader(self):
         return True
 
-    def promote(self):
-        return True
-
-    def demote(self, _):
-        return True
-
-    def follow_the_leader(self, _):
-        return True
-
-    def create_replication_slots(self, _):
-        return True
+    def xlog_position(self):
+        return 0
 
     def last_operation(self):
         return 0
 
+    def data_directory_empty(self):
+        return False
 
-def nop(*args, **kwargs):
-    pass
+    def bootstrap(self, *args, **kwargs):
+        return True
+
+    def check_replication_lag(self, last_leader_operation):
+        return True
+
+    def check_recovery_conf(self, leader):
+        return False
 
 
-def dead_etcd():
-    raise DCSError('Etcd is not responding properly')
+class MockPatroni:
+
+    def __init__(self, p, d):
+        self.postgresql = p
+        self.dcs = d
+        self.api = Mock()
+        self.tags = {}
+        self.nofailover = None
+        self.api.connection_string = 'http://127.0.0.1:8008'
 
 
-def get_unlocked_cluster():
-    return Cluster(False, None, None, [])
+def run_async(func, args=()):
+    func(*args) if args else func()
 
 
 class TestHa(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        super(TestHa, self).__init__(method_name)
-
-    def set_up(self):
+    @patch('socket.getaddrinfo', socket_getaddrinfo)
+    @patch.object(Client, 'machines')
+    def setUp(self, mock_machines):
+        mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
         self.p = MockPostgresql()
-        with patch.object(Client, 'machines') as mock_machines:
-            mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
-            self.e = Etcd('foo', {'ttl': 30, 'host': 'remotehost:2379', 'scope': 'test'})
-            self.e.client.read = etcd_read
-            self.e.client.write = etcd_write
-            self.ha = Ha(self.p, self.e)
-            self.ha.load_cluster_from_dcs()
-            self.ha.cluster = get_unlocked_cluster()
-            self.ha.load_cluster_from_dcs = nop
+        self.e = Etcd('foo', {'ttl': 30, 'host': 'ok:2379', 'scope': 'test'})
+        self.e.client.read = etcd_read
+        self.e.client.write = etcd_write
+        self.e.client.delete = Mock(side_effect=etcd.EtcdException())
+        self.ha = Ha(MockPatroni(self.p, self.e))
+        self.ha._async_executor.run_async = run_async
+        self.ha.old_cluster = self.e.get_cluster()
+        self.ha.cluster = get_cluster_not_initialized_without_leader()
+        self.ha.load_cluster_from_dcs = Mock()
 
-    def test_load_cluster_from_dcs(self):
-        ha = Ha(self.p, self.e)
-        ha.load_cluster_from_dcs()
-        self.e.get_cluster = get_unlocked_cluster
-        ha.load_cluster_from_dcs()
+    def test_update_lock(self):
+        self.p.last_operation = Mock(side_effect=PostgresException(''))
+        self.assertTrue(self.ha.update_lock())
 
-    def test_start_as_slave(self):
+    def test_touch_member(self):
+        self.p.xlog_position = Mock(side_effect=Exception)
+        self.ha.touch_member()
+
+    def test_start_as_replica(self):
         self.p.is_healthy = false
         self.assertEquals(self.ha.run_cycle(), 'started as a secondary')
 
+    def test_recover_replica_failed(self):
+        self.p.controldata = lambda: {'Database cluster state': 'in production'}
+        self.p.is_healthy = false
+        self.p.follow_the_leader = false
+        self.assertEquals(self.ha.run_cycle(), 'failed to start postgres')
+
+    def test_recover_master_failed(self):
+        self.p.follow_the_leader = false
+        self.p.is_healthy = false
+        self.ha.has_lock = true
+        self.assertEquals(self.ha.run_cycle(), 'removed leader key after trying and failing to start postgres')
+
+    @patch('sys.exit', return_value=1)
+    @patch('patroni.ha.Ha.sysid_valid', MagicMock(return_value=True))
+    def test_sysid_no_match(self, exit_mock):
+        self.ha.run_cycle()
+        exit_mock.assert_called_once_with(1)
+
+    @patch.object(Cluster, 'is_unlocked', Mock(return_value=False))
     def test_start_as_readonly(self):
-        self.ha.cluster.is_unlocked = false
         self.p.is_leader = self.p.is_healthy = false
         self.ha.has_lock = true
         self.assertEquals(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
@@ -102,6 +152,7 @@ class TestHa(unittest.TestCase):
         self.assertEquals(self.ha.run_cycle(), 'acquired session lock as a leader')
 
     def test_promoted_by_acquiring_lock(self):
+        self.ha.is_healthiest_node = true
         self.p.is_leader = false
         self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
 
@@ -110,16 +161,17 @@ class TestHa(unittest.TestCase):
         self.assertEquals(self.ha.run_cycle(), 'demoted self due after trying and failing to obtain lock')
 
     def test_follow_new_leader_after_failing_to_obtain_lock(self):
+        self.ha.is_healthiest_node = true
         self.ha.acquire_lock = false
         self.p.is_leader = false
         self.assertEquals(self.ha.run_cycle(), 'following new leader after trying and failing to obtain lock')
 
     def test_demote_because_not_healthiest(self):
-        self.p.is_healthiest_node = false
+        self.ha.is_healthiest_node = false
         self.assertEquals(self.ha.run_cycle(), 'demoting self because i am not the healthiest node')
 
     def test_follow_new_leader_because_not_healthiest(self):
-        self.p.is_healthiest_node = false
+        self.ha.is_healthiest_node = false
         self.p.is_leader = false
         self.assertEquals(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
 
@@ -138,11 +190,146 @@ class TestHa(unittest.TestCase):
         self.ha.cluster.is_unlocked = false
         self.assertEquals(self.ha.run_cycle(), 'demoting self because i do not have the lock and i was a leader')
 
+    def test_demote_because_update_lock_failed(self):
+        self.ha.cluster.is_unlocked = false
+        self.ha.has_lock = true
+        self.ha.update_lock = false
+        self.assertEquals(self.ha.run_cycle(), 'demoting self because i do not have the lock and i was a leader')
+
     def test_follow_the_leader(self):
         self.ha.cluster.is_unlocked = false
         self.p.is_leader = false
         self.assertEquals(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
 
     def test_no_etcd_connection_master_demote(self):
-        self.ha.load_cluster_from_dcs = dead_etcd
+        self.ha.load_cluster_from_dcs = Mock(side_effect=DCSError('Etcd is not responding properly'))
         self.assertEquals(self.ha.run_cycle(), 'demoted self because DCS is not accessible and i was a leader')
+
+    def test_bootstrap_from_leader(self):
+        self.ha.cluster = get_cluster_initialized_with_leader()
+        self.p.bootstrap = false
+        self.assertEquals(self.ha.bootstrap(), 'trying to bootstrap from leader')
+
+    def test_bootstrap_waiting_for_leader(self):
+        self.ha.cluster = get_cluster_initialized_without_leader()
+        self.assertEquals(self.ha.bootstrap(), 'waiting for leader to bootstrap')
+
+    def test_bootstrap_initialize_lock_failed(self):
+        self.ha.cluster = get_cluster_not_initialized_without_leader()
+        self.assertEquals(self.ha.bootstrap(), 'failed to acquire initialize lock')
+
+    def test_bootstrap_initialized_new_cluster(self):
+        self.ha.cluster = get_cluster_not_initialized_without_leader()
+        self.e.initialize = true
+        self.assertEquals(self.ha.bootstrap(), 'initialized a new cluster')
+
+    def test_bootstrap_release_initialize_key_on_failure(self):
+        self.ha.cluster = get_cluster_not_initialized_without_leader()
+        self.e.initialize = true
+        self.p.bootstrap = Mock(side_effect=PostgresException("Could not bootstrap master PostgreSQL"))
+        self.assertRaises(PostgresException, self.ha.bootstrap)
+
+    def test_reinitialize(self):
+        self.ha.schedule_reinitialize()
+        self.ha.schedule_reinitialize()
+        self.ha.run_cycle()
+        self.assertIsNone(self.ha._async_executor.scheduled_action)
+
+        self.ha.cluster = get_cluster_initialized_with_leader()
+        self.ha.has_lock = true
+        self.ha.schedule_reinitialize()
+        self.ha.run_cycle()
+        self.assertIsNone(self.ha._async_executor.scheduled_action)
+
+        self.ha.has_lock = false
+        self.ha.schedule_reinitialize()
+        self.ha.run_cycle()
+
+    def test_restart(self):
+        self.assertEquals(self.ha.restart(), (True, 'restarted successfully'))
+        self.p.restart = false
+        self.assertEquals(self.ha.restart(), (False, 'restart failed'))
+        self.ha.schedule_reinitialize()
+        self.assertEquals(self.ha.restart(), (False, 'reinitialize already in progress'))
+
+    def test_restart_in_progress(self):
+        self.ha._async_executor.schedule('restart', True)
+        self.assertTrue(self.ha.restart_scheduled())
+        self.assertEquals(self.ha.run_cycle(), 'not healthy enough for leader race')
+
+        self.ha.cluster = get_cluster_initialized_with_leader()
+        self.assertEquals(self.ha.run_cycle(), 'restart in progress')
+
+        self.ha.has_lock = true
+        self.assertEquals(self.ha.run_cycle(), 'updated leader lock during restart')
+
+        self.ha.update_lock = false
+        self.assertEquals(self.ha.run_cycle(), 'failed to update leader lock during restart')
+
+    @patch('requests.get', requests_get)
+    def test_manual_failover_from_leader(self):
+        self.ha.has_lock = true
+        self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', ''))
+        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', MockPostgresql.name))
+        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', 'blabla'))
+        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        f = Failover(0, MockPostgresql.name, '')
+        self.ha.cluster = get_cluster_initialized_with_leader(f)
+        self.assertEquals(self.ha.run_cycle(), 'manual failover: demoting myself')
+        self.ha.fetch_node_status = lambda e: (e, True, True, 0, {'nofailover': 'True'})
+        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        # manual failover from the previous leader to us won't happen if we hold the nofailover flag
+        self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', MockPostgresql.name))
+        self.assertEquals(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+
+    @patch('requests.get', requests_get)
+    def test_manual_failover_process_no_leader(self):
+        self.p.is_leader = false
+        self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', MockPostgresql.name))
+        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', 'leader'))
+        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.ha.fetch_node_status = lambda e: (e, True, True, 0, {})  # accessible, in_recovery
+        self.assertEquals(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+        self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, MockPostgresql.name, ''))
+        self.assertEquals(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+        self.ha.fetch_node_status = lambda e: (e, False, True, 0, {})  # inaccessible, in_recovery
+        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        # set failover flag to True for all members of the cluster
+        # this should elect the current member, as we are not going to call the API for it.
+        self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, '', 'other'))
+        self.ha.fetch_node_status = lambda e: (e, True, True, 0, {'nofailover': 'True'})  # accessible, in_recovery
+        self.assertEquals(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        # same as previous, but set the current member to nofailover. In no case it should be elected as a leader
+        self.ha.patroni.nofailover = True
+        self.assertEquals(self.ha.run_cycle(), 'following a different leader because I am not allowed to promote')
+
+    def test_is_healthiest_node(self):
+        self.ha.state_handler.is_leader = false
+        self.ha.patroni.nofailover = False
+        self.ha.fetch_node_status = lambda e: (e, True, True, 0, {})
+        self.assertTrue(self.ha.is_healthiest_node())
+
+    def test__is_healthiest_node(self):
+        self.assertTrue(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        self.p.is_leader = false
+        self.ha.fetch_node_status = lambda e: (e, True, True, 0, {})  # accessible, in_recovery
+        self.assertTrue(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        self.ha.fetch_node_status = lambda e: (e, True, False, 0, {})  # accessible, not in_recovery
+        self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        self.ha.fetch_node_status = lambda e: (e, True, True, 1, {})  # accessible, in_recovery, xlog location ahead
+        self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        self.p.check_replication_lag = false
+        self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        self.ha.patroni.nofailover = True
+        self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
+        self.ha.patroni.nofailover = False
+
+    @patch('requests.get', requests_get)
+    def test_fetch_node_status(self):
+        member = Member(0, 'test', 1, {'api_url': 'http://127.0.0.1:8011/patroni'})
+        self.ha.fetch_node_status(member)
+        member = Member(0, 'test', 1, {'api_url': 'http://localhost:8011/patroni'})
+        self.ha.fetch_node_status(member)

tests/test_patroni.py

@@ -1,7 +1,3 @@
-import datetime
-import patroni.zookeeper
-import psycopg2
-import subprocess
 import sys
 import time
 import unittest
@@ -9,192 +5,78 @@ import yaml
 
 from mock import Mock, patch
 from patroni.api import RestApiServer
-from patroni.dcs import Cluster, Member, Leader
+from patroni.async_executor import AsyncExecutor
 from patroni.etcd import Etcd
-from patroni.exceptions import PostgresException
 from patroni import Patroni, main
 from patroni.zookeeper import ZooKeeper
 from six.moves import BaseHTTPServer
-from test_etcd import Client, etcd_read, etcd_write
-from test_ha import true, false
-from test_postgresql import Postgresql, subprocess_call, psycopg2_connect
+from test_etcd import Client, SleepException, etcd_read, etcd_write
+from test_postgresql import Postgresql, psycopg2_connect
 from test_zookeeper import MockKazooClient
 
 
-def nop(*args, **kwargs):
-    pass
-
-
-class SleepException(Exception):
-    pass
-
-
 def time_sleep(*args):
     raise SleepException()
 
 
-class Mock_BaseServer__is_shut_down:
-
-    def set(self):
-        pass
-
-    def clear(self):
-        pass
-
-
-def get_cluster(initialize, leader):
-    return Cluster(initialize, leader, None, None)
-
-
-def get_cluster_not_initialized_without_leader():
-    return get_cluster(None, None)
-
-
-def get_cluster_initialized_without_leader():
-    return get_cluster(True, None)
-
-
-def get_cluster_not_initialized_with_leader():
-    return get_cluster(False, Leader(0, 0, 0,
-                       Member(0, 'leader', 'postgres://replicator:[email protected]:5435/postgres',
-                              None, None, 28)))
-
-
-def get_cluster_initialized_with_leader():
-    return get_cluster(True, Leader(0, 0, 0, 
-                       Member(0, 'leader', 'postgres://replicator:[email protected]:5435/postgres',
-                              None, None, 28)))
-
-
+@patch('time.sleep', Mock())
+@patch('subprocess.call', Mock(return_value=0))
+@patch('psycopg2.connect', psycopg2_connect)
+@patch.object(Postgresql, 'write_pg_hba', Mock())
+@patch.object(Postgresql, 'write_recovery_conf', Mock())
+@patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
+@patch.object(AsyncExecutor, 'run', Mock())
 class TestPatroni(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        self.tearDown = self.tear_down
-        super(TestPatroni, self).__init__(method_name)
-
-    def set_up(self):
+    @patch.object(Client, 'machines')
+    def setUp(self, mock_machines):
+        mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
         self.touched = False
         self.init_cancelled = False
-        subprocess.call = subprocess_call
-        psycopg2.connect = psycopg2_connect
-        self.time_sleep = time.sleep
-        time.sleep = nop
-        self.write_pg_hba = Postgresql.write_pg_hba
-        self.write_recovery_conf = Postgresql.write_recovery_conf
-        Postgresql.write_pg_hba = nop
-        Postgresql.write_recovery_conf = nop
-        BaseHTTPServer.HTTPServer.__init__ = nop
-        RestApiServer._BaseServer__is_shut_down = Mock_BaseServer__is_shut_down()
+        RestApiServer._BaseServer__is_shut_down = Mock()
         RestApiServer._BaseServer__shutdown_request = True
         RestApiServer.socket = 0
         with open('postgres0.yml', 'r') as f:
             config = yaml.load(f)
-            with patch.object(Client, 'machines') as mock_machines:
-                mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
-                self.p = Patroni(config)
-
-    def tear_down(self):
-        time.sleep = self.time_sleep
-        Postgresql.write_pg_hba = self.write_pg_hba
-        Postgresql.write_recovery_conf = self.write_recovery_conf
+            self.p = Patroni(config)
+            self.p.ha.dcs.client.write = etcd_write
+            self.p.ha.dcs.client.read = etcd_read
 
+    @patch('patroni.zookeeper.KazooClient', MockKazooClient())
     def test_get_dcs(self):
-        patroni.zookeeper.KazooClient = MockKazooClient
         self.assertIsInstance(self.p.get_dcs('', {'zookeeper': {'scope': '', 'hosts': ''}}), ZooKeeper)
         self.assertRaises(Exception, self.p.get_dcs, '', {})
 
-    def test_patroni_main(self):
+    @patch('time.sleep', Mock(side_effect=SleepException()))
+    @patch.object(Etcd, 'delete_leader', Mock())
+    @patch.object(Client, 'machines')
+    def test_patroni_main(self, mock_machines):
         main()
         sys.argv = ['patroni.py', 'postgres0.yml']
-        time.sleep = time_sleep
-
-        with patch.object(Client, 'machines') as mock_machines:
-            mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
-            Patroni.initialize = nop
-            touch_member = Patroni.touch_member
-            run = Patroni.run
-
-            Patroni.touch_member = self.touch_member
-            Patroni.run = time_sleep
-
-            Etcd.delete_leader = nop
 
+        mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
+        with patch.object(Patroni, 'run', Mock(side_effect=SleepException())):
             self.assertRaises(SleepException, main)
+        with patch.object(Patroni, 'run', Mock(side_effect=KeyboardInterrupt())):
+            main()
 
-            Patroni.run = run
-            Patroni.touch_member = touch_member
-
-    def test_patroni_run(self):
-        time.sleep = time_sleep
-        self.p.touch_member = self.touch_member
-        self.p.ha.state_handler.sync_replication_slots = time_sleep
-        self.p.ha.dcs.client.read = etcd_read
+    @patch('time.sleep', Mock(side_effect=SleepException()))
+    def test_run(self):
         self.p.ha.dcs.watch = time_sleep
         self.assertRaises(SleepException, self.p.run)
-        self.p.ha.state_handler.is_leader = lambda: False
-        self.p.api.start = nop
+
+        self.p.ha.state_handler.is_leader = Mock(return_value=False)
+        self.p.api.start = Mock()
         self.assertRaises(SleepException, self.p.run)
 
-    def touch_member(self, ttl=None):
-        if not self.touched:
-            self.touched = True
-            return False
-        return True
-
-    def test_touch_member(self):
-        self.p.ha.dcs.client.write = etcd_write
-        self.p.touch_member()
-        now = datetime.datetime.utcnow()
-        member = Member(0, self.p.postgresql.name, 'b', 'c', (now + datetime.timedelta(
-            seconds=self.p.shutdown_member_ttl + 10)).strftime('%Y-%m-%dT%H:%M:%S.%fZ'), None)
-        self.p.ha.cluster = Cluster(True, member, 0, [member])
-        self.p.touch_member()
-
-    def test_patroni_initialize(self):
-        self.p.ha.dcs.client.write = etcd_write
-        self.p.ha.dcs.client.read = etcd_read
-        self.p.touch_member = self.touch_member
-        self.p.postgresql.data_directory_empty = true
-        self.p.ha.dcs.initialize = true
-        self.p.postgresql.initialize = true
-        self.p.postgresql.start = true
-        self.p.ha.dcs.get_cluster = get_cluster_not_initialized_without_leader
-        self.p.initialize()
-
-        self.p.ha.dcs.initialize = false
-        self.p.ha.dcs.get_cluster = get_cluster_initialized_with_leader
-        time.sleep = time_sleep
-        self.p.ha.dcs.client.read = etcd_read
-        self.p.initialize()
-
-        self.p.ha.dcs.get_cluster = get_cluster_initialized_without_leader
-        self.assertRaises(SleepException, self.p.initialize)
-
-        self.p.postgresql.data_directory_empty = false
-        self.p.initialize()
-
-        self.p.ha.dcs.get_cluster = get_cluster_not_initialized_with_leader
-        self.p.postgresql.data_directory_empty = true
-        self.p.initialize()
-
     def test_schedule_next_run(self):
+        self.p.ha.dcs.watch = Mock(return_value=True)
+        self.p.schedule_next_run()
         self.p.next_run = time.time() - self.p.nap_time - 1
         self.p.schedule_next_run()
 
-    def cancel_initialization(self):
-        self.init_cancelled = True
-
-    def test_cleanup_on_initialization(self):
-        self.p.ha.dcs.client.write = etcd_write
-        self.p.ha.dcs.client.read = etcd_read
-        self.p.ha.dcs.get_cluster = get_cluster_not_initialized_without_leader
-        self.p.touch_member = self.touch_member
-        self.p.postgresql.data_directory_empty = true
-        self.p.ha.dcs.initialize = true
-        self.p.postgresql.initialize = true
-        self.p.postgresql.start = false
-
-        self.p.ha.dcs.cancel_initialization = self.cancel_initialization
-        self.assertRaises(PostgresException, self.p.initialize)
-        self.assertTrue(self.init_cancelled)
+    def test_nofailover(self):
+        self.p.tags['nofailover'] = True
+        self.assertTrue(self.p.nofailover)
+        self.p.tags['nofailover'] = None
+        self.assertFalse(self.p.nofailover)

tests/test_postgresql.py

@@ -1,51 +1,41 @@
+import mock  # for the mock.call method, importing it without a namespace breaks python3
 import os
 import psycopg2
 import shutil
-import subprocess
 import unittest
 
+from six.moves import builtins
+from mock import Mock, MagicMock, PropertyMock, patch, mock_open
 from patroni.dcs import Cluster, Leader, Member
+from patroni.exceptions import PostgresException, PostgresConnectionException
 from patroni.postgresql import Postgresql
-from test_ha import true, false
+from patroni.utils import RetryFailedError
+from test_ha import false
+import subprocess
 
 
-def nop(*args, **kwargs):
-    pass
-
-
-def subprocess_call(cmd, shell=False, env=None):
-    return 0
-
-
-def false(*args, **kwargs):
-    return False
+def is_file_raise_on_backup(*args, **kwargs):
+    if args[0].endswith('.backup'):
+        raise Exception("foo")
 
 
 class MockCursor:
 
-    def __init__(self):
+    def __init__(self, connection):
+        self.connection = connection
         self.closed = False
         self.results = []
 
     def execute(self, sql, *params):
-        if sql.startswith('blabla'):
+        if sql.startswith('blabla') or sql == 'CHECKPOINT':
             raise psycopg2.OperationalError()
-        elif sql.startswith('InterfaceError'):
-            raise psycopg2.InterfaceError()
+        elif sql.startswith('RetryFailedError'):
+            raise RetryFailedError('retry')
         elif sql.startswith('SELECT slot_name'):
             self.results = [('blabla',), ('foobar',)]
-        elif sql.startswith('SELECT pg_current_xlog_location()'):
-            self.results = [(0,)]
-        elif sql.startswith('SELECT pg_is_in_recovery(), %s'):
-            if params[0][0] == 1:
-                raise psycopg2.OperationalError()
-            elif params[0][0] == 2:
-                self.results = [(True, -1)]
-            else:
-                self.results = [(False, 0)]
         elif sql.startswith('SELECT pg_xlog_location_diff'):
             self.results = [(0,)]
-        elif sql.startswith('SELECT pg_is_in_recovery()'):
+        elif sql == 'SELECT pg_is_in_recovery()':
             self.results = [(False, )]
         elif sql.startswith('SELECT to_char(pg_postmaster_start_time'):
             self.results = [('', True, '', '', '', False)]
@@ -66,6 +56,9 @@ class MockCursor:
     def fetchone(self):
         return self.results[0]
 
+    def fetchall(self):
+        return self.results
+
     def close(self):
         pass
 
@@ -73,44 +66,108 @@ class MockCursor:
         for i in self.results:
             yield i
 
+    def __enter__(self):
+        return self
 
-class MockConnect:
-
-    def __init__(self):
-        self.autocommit = False
-        self.closed = 0
-
-    def cursor(self):
-        return MockCursor()
-
-    def close(self):
+    def __exit__(self, *args):
         pass
 
 
-def psycopg2_connect(*args, **kwargs):
+class MockConnect(Mock):
 
+    autocommit = False
+    closed = 0
+
+    def cursor(self):
+        return MockCursor(self)
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        pass
+
+
+def pg_controldata_string(*args, **kwargs):
+    return b"""
+pg_control version number:            942
+Catalog version number:               201509161
+Database system identifier:           6200971513092291716
+Database cluster state:               shut down in recovery
+pg_control last modified:             Fri Oct  2 10:57:06 2015
+Latest checkpoint location:           0/30000C8
+Prior checkpoint location:            0/2000060
+Latest checkpoint's REDO location:    0/3000090
+Latest checkpoint's REDO WAL file:    000000020000000000000003
+Latest checkpoint's TimeLineID:       2
+Latest checkpoint's PrevTimeLineID:   2
+Latest checkpoint's full_page_writes: on
+Latest checkpoint's NextXID:          0/943
+Latest checkpoint's NextOID:          24576
+Latest checkpoint's NextMultiXactId:  1
+Latest checkpoint's NextMultiOffset:  0
+Latest checkpoint's oldestXID:        931
+Latest checkpoint's oldestXID's DB:   1
+Latest checkpoint's oldestActiveXID:  943
+Latest checkpoint's oldestMultiXid:   1
+Latest checkpoint's oldestMulti's DB: 1
+Latest checkpoint's oldestCommitTs:   0
+Latest checkpoint's newestCommitTs:   0
+Time of latest checkpoint:            Fri Oct  2 10:56:54 2015
+Fake LSN counter for unlogged rels:   0/1
+Minimum recovery ending location:     0/30241F8
+Min recovery ending loc's timeline:   2
+Backup start location:                0/0
+Backup end location:                  0/0
+End-of-backup record required:        no
+wal_level setting:                    hot_standby
+Current wal_log_hints setting:                on
+Current max_connections setting:              100
+Current max_worker_processes setting:         8
+Current max_prepared_xacts setting:           0
+Current max_locks_per_xact setting:           64
+Current track_commit_timestamp setting:       off
+Maximum data alignment:               8
+Database block size:                  8192
+Blocks per segment of large relation: 131072
+WAL block size:                       8192
+Bytes per WAL segment:                16777216
+Maximum length of identifiers:        64
+Maximum columns in an index:          32
+Maximum size of a TOAST chunk:        1996
+Size of a large-object chunk:         2048
+Date/time type storage:               64-bit integers
+Float4 argument passing:              by value
+Float8 argument passing:              by value
+Data page checksum version:           0
+"""
+
+
+def postmaster_opts_string(*args, **kwargs):
+    return '/usr/local/pgsql/bin/postgres "-D" "data/postgresql0" "--listen_addresses=127.0.0.1" \
+"--port=5432" "--hot_standby=on" "--wal_keep_segments=8" "--wal_level=hot_standby" \
+"--archive_command=mkdir -p ../wal_archive && cp %p ../wal_archive/%f" "--wal_log_hints=on" \
+"--max_wal_senders=5" "--archive_timeout=1800s" "--archive_mode=on" "--max_replication_slots=5"\n'
+
+
+def psycopg2_connect(*args, **kwargs):
     return MockConnect()
 
 
-def is_running():
-    return False
-
-
+@patch('subprocess.call', Mock(return_value=0))
+@patch('psycopg2.connect', psycopg2_connect)
+@patch('shutil.copy', Mock())
 class TestPostgresql(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        self.tearDown = self.tear_down
-        super(TestPostgresql, self).__init__(method_name)
-
-    def set_up(self):
-        subprocess.call = subprocess_call
-        shutil.copy = nop
+    @patch('subprocess.call', Mock(return_value=0))
+    @patch('psycopg2.connect', psycopg2_connect)
+    def setUp(self):
         self.p = Postgresql({'name': 'test0', 'scope': 'batman', 'data_dir': 'data/test0',
                              'listen': '127.0.0.1, *:5432', 'connect_address': '127.0.0.2:5432',
                              'pg_hba': ['hostssl all all 0.0.0.0/0 md5', 'host all all 0.0.0.0/0 md5'],
-                             'superuser': {'password': ''},
+                             'superuser': {'password': 'test'},
                              'admin': {'username': 'admin', 'password': 'admin'},
+                             'pg_rewind': {'username': 'admin', 'password': 'admin'},
                              'replication': {'username': 'replicator',
                                              'password': 'rep-pass',
                                              'network': '127.0.0.1/32'},
@@ -120,44 +177,108 @@ class TestPostgresql(unittest.TestCase):
                                            'on_reload': 'true'
                                            },
                              'restore': 'true'})
-        psycopg2.connect = psycopg2_connect
         if not os.path.exists(self.p.data_dir):
             os.makedirs(self.p.data_dir)
-        self.leadermem = Member(0, 'leader', 'postgres://replicator:[email protected]:5435/postgres', None, None, 28)
-        self.leader = Leader(-1, None, 28, self.leadermem)
-        self.other = Member(0, 'test1', 'postgres://replicator:[email protected]:5433/postgres', None, None, 28)
-        self.me = Member(0, 'test0', 'postgres://replicator:[email protected]:5434/postgres', None, None, 28)
+        self.leadermem = Member(0, 'leader', 28, {'conn_url': 'postgres://replicator:[email protected]:5435/postgres'})
+        self.leader = Leader(-1, 28, self.leadermem)
+        self.other = Member(0, 'test1', 28, {'conn_url': 'postgres://replicator:[email protected]:5433/postgres'})
+        self.me = Member(0, 'test0', 28, {'conn_url': 'postgres://replicator:[email protected]:5434/postgres'})
 
-    def tear_down(self):
+    def tearDown(self):
         shutil.rmtree('data')
 
-    def mock_query(self, p):
-        raise psycopg2.OperationalError("not supported")
-
     def test_data_directory_empty(self):
         self.assertTrue(self.p.data_directory_empty())
 
+    def test_get_initdb_options(self):
+        self.p.initdb_options = [{'encoding': 'UTF8'}, 'data-checksums']
+        self.assertEquals(self.p.get_initdb_options(), ['--encoding=UTF8', '--data-checksums'])
+        self.p.initdb_options = [{'pgdata': 'bar'}]
+        self.assertRaises(Exception, self.p.get_initdb_options)
+        self.p.initdb_options = [{'foo': 'bar', 1: 2}]
+        self.assertRaises(Exception, self.p.get_initdb_options)
+        self.p.initdb_options = [1]
+        self.assertRaises(Exception, self.p.get_initdb_options)
+
     def test_initialize(self):
         self.assertTrue(self.p.initialize())
         self.assertTrue(os.path.exists(os.path.join(self.p.data_dir, 'pg_hba.conf')))
 
-    def test_start_stop(self):
-        self.assertFalse(self.p.start())
-        self.p.is_running = is_running
-        with open(os.path.join(self.p.data_dir, 'postmaster.pid'), 'w'):
-            pass
+    def test_start(self):
+        self.assertTrue(self.p.start())
+        self.p.is_running = false
+        open(os.path.join(self.p.data_dir, 'postmaster.pid'), 'w').close()
         self.assertTrue(self.p.start())
-        self.assertTrue(self.p.stop())
 
+    def test_stop(self):
+        self.assertTrue(self.p.stop())
+        with patch('subprocess.call', Mock(return_value=1)):
+            self.assertTrue(self.p.stop())
+            self.p.is_running = Mock(return_value=True)
+            self.assertFalse(self.p.stop())
+
+    def test_restart(self):
+        self.p.start = false
+        self.p.is_running = false
+        self.assertFalse(self.p.restart())
+        self.assertEquals(self.p.state, 'restart failed (restarting)')
+
+    @patch.object(builtins, 'open', MagicMock())
+    def test_write_pgpass(self):
+        self.p.write_pgpass({'host': 'localhost', 'port': '5432', 'user': 'foo', 'password': 'bar'})
+
+    @patch('patroni.postgresql.Postgresql.write_pgpass', MagicMock(return_value=dict()))
     def test_sync_from_leader(self):
         self.assertTrue(self.p.sync_from_leader(self.leader))
 
-    def test_follow_the_leader(self):
-        self.p.demote(self.leader)
+    @patch('subprocess.call', side_effect=Exception("Test"))
+    @patch('patroni.postgresql.Postgresql.write_pgpass', MagicMock(return_value=dict()))
+    def test_pg_rewind(self, mock_call):
+        self.assertTrue(self.p.rewind(self.leader))
+        subprocess.call = mock_call
+        self.assertFalse(self.p.rewind(self.leader))
+
+    @patch('patroni.postgresql.Postgresql.rewind', return_value=False)
+    @patch('patroni.postgresql.Postgresql.remove_data_directory', MagicMock(return_value=True))
+    @patch('patroni.postgresql.Postgresql.single_user_mode', MagicMock(return_value=1))
+    @patch('patroni.postgresql.Postgresql.write_pgpass', MagicMock(return_value=dict()))
+    def test_follow_the_leader(self, mock_pg_rewind):
+        self.p.demote()
         self.p.follow_the_leader(None)
-        self.p.demote(self.leader)
+        self.p.demote()
         self.p.follow_the_leader(self.leader)
-        self.p.follow_the_leader(Leader(-1, None, 28, self.other))
+        self.p.follow_the_leader(Leader(-1, 28, self.other))
+        self.p.rewind = mock_pg_rewind
+        self.p.follow_the_leader(self.leader)
+        self.p.require_rewind()
+        with mock.patch('os.path.islink', MagicMock(return_value=True)):
+            with mock.patch('patroni.postgresql.Postgresql.can_rewind', new_callable=PropertyMock(return_value=True)):
+                with mock.patch('os.unlink', MagicMock(return_value=True)):
+                    self.p.follow_the_leader(self.leader, recovery=True)
+        self.p.require_rewind()
+        with mock.patch('patroni.postgresql.Postgresql.can_rewind', new_callable=PropertyMock(return_value=True)):
+            self.p.rewind.return_value = True
+            self.p.follow_the_leader(self.leader, recovery=True)
+            self.p.rewind.return_value = False
+            self.p.follow_the_leader(self.leader, recovery=True)
+
+    def test_can_rewind(self):
+        tmp = self.p.pg_rewind
+        self.p.pg_rewind = None
+        self.assertFalse(self.p.can_rewind)
+        self.p.pg_rewind = tmp
+        with mock.patch('subprocess.call', MagicMock(return_value=1)):
+            self.assertFalse(self.p.can_rewind)
+        with mock.patch('subprocess.call', side_effect=OSError("foo")):
+            self.assertFalse(self.p.can_rewind)
+        tmp = self.p.controldata()
+        self.p.controldata = lambda: {'wal_log_hints setting': 'on'}
+        self.assertTrue(self.p.can_rewind)
+        self.p.controldata = tmp
+
+    def test_create_replica(self):
+        self.p.delete_trigger_file = Mock(side_effect=OSError())
+        self.assertEquals(self.p.create_replica({'host': '', 'port': '', 'user': ''}, ''), 1)
 
     def test_create_connection_users(self):
         cfg = self.p.config
@@ -165,62 +286,183 @@ class TestPostgresql(unittest.TestCase):
         p = Postgresql(cfg)
         p.create_connection_users()
 
-    def test_create_replication_slots(self):
+    def test_sync_replication_slots(self):
         self.p.start()
-        cluster = Cluster(True, self.leader, 0, [self.me, self.other, self.leadermem])
-        self.p.create_replication_slots(cluster)
+        cluster = Cluster(True, self.leader, 0, [self.me, self.other, self.leadermem], None)
+        self.p.sync_replication_slots(cluster)
+        self.p.query = Mock(side_effect=psycopg2.OperationalError)
+        self.p.schedule_load_slots = True
+        self.p.sync_replication_slots(cluster)
+
+    @patch.object(MockConnect, 'closed', 2)
+    def test__query(self):
+        self.assertRaises(PostgresConnectionException, self.p._query, 'blabla')
+        self.p._state = 'restarting'
+        self.assertRaises(RetryFailedError, self.p._query, 'blabla')
 
     def test_query(self):
         self.p.query('select 1')
-        self.assertRaises(psycopg2.InterfaceError, self.p.query, 'InterfaceError')
+        self.assertRaises(PostgresConnectionException, self.p.query, 'RetryFailedError')
         self.assertRaises(psycopg2.OperationalError, self.p.query, 'blabla')
-        self.p._connection.closed = 2
-        self.assertRaises(psycopg2.OperationalError, self.p.query, 'blabla')
-        self.p._connection.closed = 2
-        self.p.disconnect = false
-        self.assertRaises(psycopg2.OperationalError, self.p.query, 'blabla')
-
-    def test_is_healthiest_node(self):
-        cluster = Cluster(True, self.leader, 0, [self.me, self.other, self.leadermem])
-        self.assertTrue(self.p.is_healthiest_node(cluster))
-        self.p.is_leader = false
-        self.assertFalse(self.p.is_healthiest_node(cluster))
-        self.p.xlog_position = lambda: 1
-        self.assertTrue(self.p.is_healthiest_node(cluster))
-        self.p.xlog_position = lambda: 2
-        self.assertFalse(self.p.is_healthiest_node(cluster))
-        self.p.config['maximum_lag_on_failover'] = -3
-        self.assertFalse(self.p.is_healthiest_node(cluster))
 
     def test_is_leader(self):
-        self.p.is_promoted = True
         self.assertTrue(self.p.is_leader())
-        self.assertFalse(self.p.is_promoted)
 
     def test_reload(self):
         self.assertTrue(self.p.reload())
 
     def test_is_healthy(self):
         self.assertTrue(self.p.is_healthy())
-        self.p.is_running = is_running
+        self.p.is_running = false
         self.assertFalse(self.p.is_healthy())
 
     def test_promote(self):
+        self.p._role = 'replica'
+        self.assertTrue(self.p.promote())
         self.assertTrue(self.p.promote())
 
     def test_last_operation(self):
         self.assertEquals(self.p.last_operation(), '0')
 
+    @patch('subprocess.Popen', Mock(side_effect=OSError()))
+    def test_call_nowait(self):
+        self.assertFalse(self.p.call_nowait('on_start'))
+
     def test_non_existing_callback(self):
         self.assertFalse(self.p.call_nowait('foobar'))
 
     def test_is_leader_exception(self):
         self.p.start()
-        self.p.query = self.mock_query
+        self.p.query = Mock(side_effect=psycopg2.OperationalError("not supported"))
         self.assertTrue(self.p.stop())
 
+    def test_check_replication_lag(self):
+        self.assertTrue(self.p.check_replication_lag(0))
+
+    @patch('os.rename', Mock())
+    @patch('os.path.isdir', Mock(return_value=True))
     def test_move_data_directory(self):
-        self.p.is_running = is_running
-        os.rename = nop
-        os.path.isdir = true
+        self.p.is_running = false
         self.p.move_data_directory()
+        with patch('os.rename', Mock(side_effect=OSError())):
+            self.p.move_data_directory()
+
+    @patch('patroni.postgresql.Postgresql.write_pgpass', MagicMock(return_value=dict()))
+    def test_bootstrap(self):
+        with patch('subprocess.call', Mock(return_value=1)):
+            self.assertRaises(PostgresException, self.p.bootstrap)
+        self.p.bootstrap()
+        self.p.bootstrap(self.leader)
+
+    def test_remove_data_directory(self):
+        self.p.data_dir = 'data_dir'
+        self.p.remove_data_directory()
+        os.mkdir(self.p.data_dir)
+        self.p.remove_data_directory()
+        open(self.p.data_dir, 'w').close()
+        self.p.remove_data_directory()
+        os.symlink('unexisting', self.p.data_dir)
+        with patch('os.unlink', Mock(side_effect=Exception)):
+            self.p.remove_data_directory()
+        self.p.remove_data_directory()
+
+    @patch('subprocess.check_output', MagicMock(return_value=0, side_effect=pg_controldata_string))
+    @patch('subprocess.check_output', side_effect=subprocess.CalledProcessError)
+    @patch('subprocess.check_output', side_effect=Exception('Failed'))
+    def test_controldata(self, check_output_call_error, check_output_generic_exception):
+        data = self.p.controldata()
+        self.assertEquals(len(data), 50)
+        self.assertEquals(data['Database cluster state'], 'shut down in recovery')
+        self.assertEquals(data['wal_log_hints setting'], 'on')
+        self.assertEquals(int(data['Database block size']), 8192)
+
+        subprocess.check_output = check_output_call_error
+        data = self.p.controldata()
+        self.assertEquals(data, dict())
+
+        subprocess.check_output = check_output_generic_exception
+        self.assertRaises(Exception, self.p.controldata())
+
+    def test_read_postmaster_opts(self):
+        m = mock_open(read_data=postmaster_opts_string())
+        with patch.object(builtins, 'open', m):
+            data = self.p.read_postmaster_opts()
+            self.assertEquals(data['wal_level'], 'hot_standby')
+            self.assertEquals(int(data['max_replication_slots']), 5)
+            self.assertEqual(data.get('D'), None)
+
+            m.side_effect = IOError("foo")
+            data = self.p.read_postmaster_opts()
+            self.assertEqual(data, dict())
+
+            m.side_effect = Exception("foo")
+            self.assertRaises(Exception, self.p.read_postmaster_opts())
+
+    @patch('subprocess.Popen')
+    @patch.object(builtins, 'open', MagicMock(return_value=42))
+    def test_single_user_mode(self, subprocess_popen_mock):
+        subprocess_popen_mock.return_value.wait.return_value = 0
+        self.assertEquals(self.p.single_user_mode(options=dict(archive_mode='on', archive_command='false')), 0)
+        subprocess_popen_mock.assert_called_once_with(['postgres', '--single', '-D', self.p.data_dir,
+                                                      '-c', 'archive_command=false', '-c', 'archive_mode=on',
+                                                       'postgres'], stdin=subprocess.PIPE,
+                                                      stdout=42,
+                                                      stderr=subprocess.STDOUT)
+        subprocess_popen_mock.reset_mock()
+        self.assertEquals(self.p.single_user_mode(command="CHECKPOINT"), 0)
+        subprocess_popen_mock.assert_called_once_with(['postgres', '--single', '-D', self.p.data_dir,
+                                                      'postgres'], stdin=subprocess.PIPE,
+                                                      stdout=42,
+                                                      stderr=subprocess.STDOUT)
+        subprocess_popen_mock.return_value = None
+        self.assertEquals(self.p.single_user_mode(), 1)
+
+    def fake_listdir(path):
+        if path.endswith(os.path.join('pg_xlog', 'archive_status')):
+            return ["a", "b", "c"]
+        return []
+
+    @patch('os.listdir', MagicMock(side_effect=fake_listdir))
+    @patch('os.path.isdir', MagicMock(return_value=True))
+    @patch('os.unlink', return_value=True)
+    @patch('os.remove', return_value=True)
+    @patch('os.path.islink', return_value=False)
+    @patch('os.path.isfile', return_value=True)
+    def test_cleanup_archive_status(self, mock_file, mock_link, mock_remove, mock_unlink):
+        ap = os.path.join(self.p.data_dir, 'pg_xlog', 'archive_status/')
+        self.p.cleanup_archive_status()
+        mock_remove.assert_has_calls([mock.call(ap+'a'), mock.call(ap+'b'), mock.call(ap+'c')])
+        mock_unlink.assert_not_called()
+
+        mock_remove.reset_mock()
+
+        mock_file.return_value = False
+        mock_link.return_value = True
+        self.p.cleanup_archive_status()
+        mock_unlink.assert_has_calls([mock.call(ap+'a'), mock.call(ap+'b'), mock.call(ap+'c')])
+        mock_remove.assert_not_called()
+
+        mock_unlink.reset_mock()
+        mock_remove.reset_mock()
+
+        mock_file.side_effect = Exception("foo")
+        mock_link.side_effect = Exception("foo")
+        self.p.cleanup_archive_status()
+        mock_unlink.assert_not_called()
+        mock_remove.assert_not_called()
+
+    @patch('subprocess.check_output', MagicMock(return_value=0, side_effect=pg_controldata_string))
+    def test_sysid(self):
+        self.assertEqual(self.p.sysid, "6200971513092291716")
+
+    @patch('os.path.isfile', MagicMock(return_value=True))
+    @patch('shutil.copy', side_effect=Exception)
+    def test_save_configuration_files(self, mock_copy):
+        shutil.copy = mock_copy
+        self.p.save_configuration_files()
+
+    @patch('os.path.isfile', MagicMock(side_effect=is_file_raise_on_backup))
+    @patch('shutil.copy', side_effect=Exception)
+    def test_restore_configuration_files(self, mock_copy):
+        shutil.copy = mock_copy
+        self.p.restore_configuration_files()

tests/test_utils.py

@@ -1,56 +1,34 @@
-import os
-import time
 import unittest
 
-from patroni.exceptions import DCSError
+from mock import Mock, patch
+from patroni.exceptions import PatroniException
 from patroni.utils import Retry, RetryFailedError, reap_children, sigchld_handler, sigterm_handler, sleep
 
 
-def nop(*args, **kwargs):
-    pass
-
-
-def os_waitpid(a, b):
-    return (0, 0)
-
-
 def time_sleep(_):
     sigchld_handler(None, None)
 
 
 class TestUtils(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        self.tearDown = self.tear_down
-        super(TestUtils, self).__init__(method_name)
-
-    def set_up(self):
-        self.time_sleep = time.sleep
-        time.sleep = nop
-
-    def tear_down(self):
-        time.sleep = self.time_sleep
-
     def test_sigterm_handler(self):
         self.assertRaises(SystemExit, sigterm_handler, None, None)
 
+    @patch('time.sleep', Mock())
     def test_reap_children(self):
         reap_children()
-        os.waitpid = os_waitpid
-        sigchld_handler(None, None)
-        reap_children()
+        with patch('os.waitpid', Mock(return_value=(0, 0))):
+            sigchld_handler(None, None)
+            reap_children()
 
+    @patch('time.sleep', time_sleep)
     def test_sleep(self):
-        time.sleep = time_sleep
         sleep(0.01)
 
 
+@patch('time.sleep', Mock())
 class TestRetrySleeper(unittest.TestCase):
 
-    def _pass(self):
-        pass
-
     def _fail(self, times=1):
         scope = dict(times=0)
 
@@ -59,7 +37,7 @@ class TestRetrySleeper(unittest.TestCase):
                 pass
             else:
                 scope['times'] += 1
-                raise DCSError('Failed!')
+                raise PatroniException('Failed!')
         return inner
 
     def _makeOne(self, *args, **kwargs):
@@ -78,24 +56,20 @@ class TestRetrySleeper(unittest.TestCase):
         self.assertEquals(retry._attempts, 1)
 
     def test_maximum_delay(self):
-        def sleep_func(_time):
-            pass
-
-        retry = self._makeOne(delay=10, max_tries=100, sleep_func=sleep_func)
+        retry = self._makeOne(delay=10, max_tries=100)
         retry(self._fail(times=10))
         self.assertTrue(retry._cur_delay < 4000, retry._cur_delay)
         # gevent's sleep function is picky about the type
         self.assertEquals(type(retry._cur_delay), float)
 
     def test_deadline(self):
-        def sleep_func(_time):
-            pass
-
-        retry = self._makeOne(deadline=0.0001, sleep_func=sleep_func)
+        retry = self._makeOne(deadline=0.0001)
         self.assertRaises(RetryFailedError, retry, self._fail(times=100))
 
     def test_copy(self):
-        _sleep = lambda t: None
+        def _sleep(t):
+            None
+
         retry = self._makeOne(sleep_func=_sleep)
         rcopy = retry.copy()
         self.assertTrue(rcopy.sleep_func is _sleep)

tests/test_zookeeper.py

@@ -1,136 +1,112 @@
-import patroni.zookeeper
-import requests
+import six
 import unittest
 
+from mock import Mock, patch
 from patroni.dcs import Leader
 from patroni.zookeeper import ExhibitorEnsembleProvider, ZooKeeper, ZooKeeperError
 from kazoo.client import KazooState
 from kazoo.exceptions import NoNodeError, NodeExistsError
 from kazoo.protocol.states import ZnodeStat
-from test_etcd import MockPostgresql, requests_get
+from test_etcd import SleepException, requests_get
 
 
-class MockEvent:
+class MockKazooClient(Mock):
 
-    def clear(self):
-        pass
-
-    def set(self):
-        pass
-
-    def wait(self, timeout):
-        pass
-
-    def isSet(self):
-        return True
-
-
-class MockEventHandler:
-
-    def event_object(self):
-        return MockEvent()
-
-
-class SleepException(Exception):
-    pass
-
-
-class MockKazooClient:
-
-    def __init__(self, **kwargs):
-        self.handler = MockEventHandler()
-        self.leader = False
-        self.exists = True
-
-    def start(self, timeout):
-        pass
+    leader = False
+    exists = True
+    handler = Mock()
 
     @property
     def client_id(self):
         return (-1, '')
 
-    def add_listener(self, cb):
-        pass
-
     def retry(self, func, *args, **kwargs):
         func(*args, **kwargs)
 
     def get(self, path, watch=None):
+        if not isinstance(path, six.string_types):
+            raise TypeError("Invalid type for 'path' (string expected)")
         if path == '/no_node':
             raise NoNodeError
         elif '/members/' in path:
             return (
-                '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, 0, 0, 0)
+                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 '1'
+            return (b'1', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
         elif path.endswith('/leader'):
             if self.leader:
-                return ('foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
-            return ('foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
+                return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
+            return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
         elif path.endswith('/initialize'):
-            return ('foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
+            return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
+        return (b'', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
 
     def get_children(self, path, watch=None, include_data=False):
-        if path == '/no_node':
+        if not isinstance(path, six.string_types):
+            raise TypeError("Invalid type for 'path' (string expected)")
+        if path.startswith('/no_node'):
             raise NoNodeError
         elif path in ['/service/bla/', '/service/test/']:
-            return ['initialize', 'leader', 'members', 'optime']
+            return ['initialize', 'leader', 'members', 'optime', 'failover']
         return ['foo', 'bar', 'buzz']
 
-    def create(self, path, value="", acl=None, ephemeral=False, sequence=False, makepath=False):
+    def create(self, path, value=b"", acl=None, ephemeral=False, sequence=False, makepath=False):
+        if not isinstance(path, six.string_types):
+            raise TypeError("Invalid type for 'path' (string expected)")
+        if not isinstance(value, (six.binary_type,)):
+            raise TypeError("Invalid type for 'value' (must be a byte string)")
         if path.endswith('/initialize') or path == '/service/test/optime/leader':
             raise Exception
-        elif value == 'retry' or (value == 'exists' and self.exists):
+        elif value == b'retry' or (value == b'exists' and self.exists):
             raise NodeExistsError
 
     def set(self, path, value, version=-1):
+        if not isinstance(path, six.string_types):
+            raise TypeError("Invalid type for 'path' (string expected)")
+        if not isinstance(value, (six.binary_type,)):
+            raise TypeError("Invalid type for 'value' (must be a byte string)")
         if path == '/service/bla/optime/leader':
             raise Exception
+        if path == '/service/test/members/bar':
+            if value == b'retry':
+                return
+        if path == '/service/test/failover':
+            if value == b'Exception':
+                raise Exception
+            elif value == b'ok':
+                return
         raise NoNodeError
 
     def delete(self, path, version=-1, recursive=False):
+        if not isinstance(path, six.string_types):
+            raise TypeError("Invalid type for 'path' (string expected)")
         self.exists = False
         if path == '/service/test/leader':
             if self.leader:
                 return
             self.leader = True
             raise Exception
-        elif path.endswith('/initialize'):
+        elif path == '/service/test/members/buzz':
+            raise Exception
+        elif path.endswith('/initialize') or path == '/service/test/members/bar':
             raise NoNodeError
 
-    def set_hosts(self, hosts, randomize_hosts=None):
-        pass
-
-
-def exhibitor_sleep(_):
-    raise SleepException
-
 
+@patch('requests.get', requests_get)
+@patch('patroni.zookeeper.sleep', Mock(side_effect=SleepException()))
 class TestExhibitorEnsembleProvider(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        super(TestExhibitorEnsembleProvider, self).__init__(method_name)
-
-    def set_up(self):
-        requests.get = requests_get
-        patroni.zookeeper.sleep = exhibitor_sleep
-
     def test_init(self):
         self.assertRaises(SleepException, ExhibitorEnsembleProvider, ['localhost'], 8181)
 
 
 class TestZooKeeper(unittest.TestCase):
 
-    def __init__(self, method_name='runTest'):
-        self.setUp = self.set_up
-        super(TestZooKeeper, self).__init__(method_name)
-
-    def set_up(self):
-        requests.get = requests_get
-        patroni.zookeeper.KazooClient = MockKazooClient
+    @patch('requests.get', requests_get)
+    @patch('patroni.zookeeper.KazooClient', MockKazooClient)
+    def setUp(self):
         self.zk = ZooKeeper('foo', {'exhibitor': {'hosts': ['localhost', 'exhibitor'], 'port': 8181}, 'scope': 'test'})
 
     def test_session_listener(self):
@@ -145,6 +121,8 @@ class TestZooKeeper(unittest.TestCase):
     def test__inner_load_cluster(self):
         self.zk._base_path = self.zk._base_path.replace('test', 'bla')
         self.zk._inner_load_cluster()
+        self.zk._base_path = self.zk._base_path = '/no_node'
+        self.zk._inner_load_cluster()
 
     def test_get_cluster(self):
         self.assertRaises(ZooKeeperError, self.zk.get_cluster)
@@ -154,6 +132,11 @@ class TestZooKeeper(unittest.TestCase):
         self.zk.touch_member('foo')
         self.zk.delete_leader()
 
+    def test_set_failover_value(self):
+        self.zk.set_failover_value('')
+        self.zk.set_failover_value('ok')
+        self.zk.set_failover_value('Exception')
+
     def test_initialize(self):
         self.assertFalse(self.zk.initialize())
 
@@ -161,19 +144,33 @@ class TestZooKeeper(unittest.TestCase):
         self.zk.cancel_initialization()
 
     def test_touch_member(self):
+        self.zk._name = 'buzz'
+        self.zk.get_cluster()
         self.zk.touch_member('new')
+        self.zk._name = 'bar'
+        self.zk.touch_member('new')
+        self.zk._name = 'na'
+        self.zk.client.exists = 1
         self.zk.touch_member('exists')
+        self.zk._name = 'bar'
+        self.zk.touch_member('retry')
+        self.zk.fetch_cluster = True
+        self.zk.get_cluster()
         self.zk.touch_member('retry')
 
     def test_take_leader(self):
         self.zk.take_leader()
 
     def test_update_leader(self):
-        self.zk.last_leader_operation = -1
-        self.assertTrue(self.zk.update_leader(MockPostgresql()))
+        self.assertTrue(self.zk.update_leader())
+
+    def test_write_leader_optime(self):
+        self.zk.last_leader_operation = '0'
+        self.zk.write_leader_optime('1')
         self.zk._base_path = self.zk._base_path.replace('test', 'bla')
-        self.zk.last_leader_operation = -1
-        self.assertTrue(self.zk.update_leader(MockPostgresql()))
+        self.zk.write_leader_optime('2')
 
     def test_watch(self):
         self.zk.watch(0)
+        self.zk.event.isSet = lambda: True
+        self.zk.watch(0)