Ansible Playbooks for PostgreSQL Clusters

Ansible playbooks that set up various PostgreSQL clusters for testing, such as streaming replication, Pgpool-II, Pacemaker and DRBD.

Requirements

The requirements are as follow:

• VirtualBox 6.0.x
• Vagrant 2.2.x
• Vagrant box centos/8 or centos/7
• Ansible 2.9.x

Usage

For example, when setting up a PostgreSQL cluster with Pgpool-II, the usage is as follows:

$ git clone https://github.com/tom-sato/ansible-postgresql-cluster.git
$ cd ansible-postgresql-cluster
$ PLAYBOOK=pgpool2 vagrant up --provision
(snip)
PLAY RECAP *********************************************************************
node-1                     : ok=64   changed=47   unreachable=0    failed=0    skipped=28   rescued=0    ignored=0
node-2                     : ok=61   changed=44   unreachable=0    failed=0    skipped=31   rescued=0    ignored=0
node-3                     : ok=61   changed=44   unreachable=0    failed=0    skipped=31   rescued=0    ignored=0

$ PLAYBOOK=pgpool2 vagrant ssh node-1
$ sudo su - postgres
$ psql -c "SHOW pool_nodes" -h vip-1 -p 9999
 node_id | hostname | port | status | lb_weight |  role   | select_cnt | load_balance_node | replication_delay | replication_state | replication_sync_state | last_status_change
---------+----------+------+--------+-----------+---------+------------+-------------------+-------------------+-------------------+------------------------+---------------------
 0       | node-1   | 5432 | up     | 0.333333  | primary | 0          | true              | 0                 |                   |                        | 2021-02-02 23:56:16
 1       | node-2   | 5432 | up     | 0.333333  | standby | 0          | false             | 0                 | streaming         | async                  | 2021-02-02 23:56:16
 2       | node-3   | 5432 | up     | 0.333333  | standby | 0          | false             | 0                 | streaming         | async                  | 2021-02-02 23:56:16
(3 rows)

Environment Variables

The Vagrantfile file receives the following environment variables:

• PLAYBOOK - Specifies the playbook name. The default is postgresql. See here for available playbooks.
• NUM_NODES - Specifies the number of nodes. The default is 3 for not using DRBD, and 2 otherwise.
• BOX - Specifies the box name. The default is centos/8.
• PROXY - Specifies the proxy to set for the virtual machine. The default is an empty string. The vagrant-proxyconf plugin should be installed in advance.

Playbooks

The following playbooks are available:

• postgresql.yml - Sets up a PostgreSQL cluster with streaming replication.
• pgpool2.yml - Sets up a PostgreSQL cluster with Pgpool-II.
• pacemaker-drbd.yml - Sets up a PostgreSQL cluster with Pacemaker and DRBD.
• pacemaker-replication.yml - Sets up a PostgreSQL cluster with Pacemaker and streaming replication.
• pacemaker-paf.yml - Sets up a PostgreSQL cluster with Pacemaker and streaming replication using PAF.
• lifekeeper-datakeeper.yml - Sets up a PostgreSQL cluster with LifeKeeper and DataKeeper.
• repmgr.yml - Sets up a PostgreSQL cluster with repmgr. (experimental)

Roles

Each playbook calls the following roles. Some playbooks overwrite role variables as needed.

locale

Configures locale settings.

• locale - Specifies the locale. The default is ja_JP.UTF-8.
• keymap - Specifies the keymap. The default is jp.
• x11_keymap_layout - Specifies the X11 keymap layout. The default is jp.
• x11_keymap_model - Specifies the X11 keymap model. The default is jp106.
• timezone - Specifies the timezone. The default is Asia/Tokyo.

hosts

Configures the /etc/hosts file.

• public_interface - Specifies the device name of the public interface. The default is eth1.

postgresql

Sets up PostgreSQL servers.

• postgresql_version - Specifies the PostgreSQL version. The default is 13.
• postgresql_data_directory - Specifies the data directory path. The default is /var/lib/pgsql/{{ postgresql_version }}/data.
• postgresql_syslog_facility - Specifies the syslog facility. The default is LOCAL0.
• postgresql_syslog_file - Specifies the syslog file path. The default is /var/log/postgresql-{{ postgresql_version }}.
• postgresql_port - Specifies the port number. The default is 5432.
• postgresql_password - Specifies the password for the postgres user. The default is postgres.
• postgresql_auth_method - Specifies the authentication method for local connections in pg_hba.conf. The default is scram-sha-256 for PostgreSQL 10 or later, and md5 otherwise.
• postgresql_extra_initdb_options - Specifies extra options for the initdb command. The default is -E UTF8 --locale=C.
• postgresql_extra_config_parameters - Specifies extra parameters in postgresql.conf. The default is an empty string.
• postgresql_extra_hba_records - Specifies extra records in pg_hba.conf. The default is to use the authentication method specified by postgresql_auth_method for connections from the same network.
• postgresql_control_as_service - Specifies whether to control as a service. The default is yes.
• postgresql_setup_stage - Specifies which stage to set up. install installs PostgreSQL, initdb creates a database cluster, basebackup takes a base backup, write_recovery_conf writes settings for the standby server. The default is write_recovery_conf.
• postgresql_primary_hostname - Specifies the host name of the primary server. The default is the host name of the first node of all.
• postgresql_extra_recovery_config_parameters - Specifies extra parameters for the standby server in postgresql.auto.conf for PostgreSQL 12 or later, and in recovery.conf otherwise. The default is an empty string.
• postgresql_use_rewind - Specifies whether to use the pg_rewind command when following the primary server with Pgpool-II. The default is no.
• postgresql_use_replication_slot - Specifies whether to use the replication slot. The default is yes.

pgpool2

Sets up Pgpool-II servers.

• pgpool2_version - Specifies the Pgpool-II version. The default is 4.2.
• pgpool2_syslog_facility - Specifies the syslog facility. The default is LOCAL1.
• pgpool2_syslog_file - Specifies the syslog file path. The default is /var/log/pgpool2.
• pgpool2_delegate_ip - Specifies the virtual IP address. The default is an unused IP address in all nodes.
• pgpool2_delegate_hostname - Specifies the host name of the virtual IP address. The default is vip-1.
• pgpool2_pcp_port - Specifies the PCP port number. The default is 9898.
• pgpool2_pcp_username - Specifies the PCP user name. The default is postgres.
• pgpool2_pcp_password - Specifies the PCP password. The default is postgres.
• pgpool2_backend_clustering_mode - Specifies the backend clustering mode. Valid values are streaming_replication (the default), native_replication, snapshot_isolation (for Pgpool-II 4.2 or later), and raw. logical_replication and slony are not supported.
• pgpool2_port - Specifies the port number. The default is 9999.
• pgpool2_trusted_servers - Specifies trusted servers separated by commas. The default is the IP address of the default gateway.
• pgpool2_wd_port - Specifies the watchdog port number. The default is 9000.
• pgpool2_heartbeat_port - Specifies the heartbeat port umber. The default is 9694.
• pgpool2_extra_config_parameters - Specifies extra parameters in pgpool.conf. The default is an empty string.
• pgpool2_extra_hba_records - Specifies extra records in pool_hba.conf. The default is to use the authentication method specified by postgresql_auth_method for connections from the same network.
• pgpool2_encryption_key - Specifies the encryption key stored in the ~/.pgpoolkey file. The default is postgres.

drbd

Sets up a DRBD filesystem.

• drbd_version - Specifies the DRBD version. The default is 9.0.
• drbd_disk - Specifies the disk device path. The default is /dev/sdb1.
• drbd_resource_name - Specifies the resource name. The default is my_resource.
• drbd_device - Specifies the DRBD device path. The default is /dev/drbd0.
• drbd_port - Specifies the port number. The default is 7789.
• drbd_control_as_service - Specifies whether to control as a service. The default is no.
• drbd_mount_directory - Specifies the mount directory path. The default is /mnt/mirror.
• drbd_fstype - Specifies the filesystem type. The default is xfs.
• drbd_primary_hostname - Specifies the host name of the primary server. The default is the host name of the first node of all.

pacemaker

Sets up a Pacemaker cluster.

• pacemaker_password - Specifies the password for the hacluster user. The default is hacluster.
• pacemaker_cluster_name - Specifies the cluster name. The default is my_cluster.
• pacemaker_migration_threshold - Specifies the value of the migration-threshold attribute. The default is 2. See the Resource Meta-Attributes in the Pacemaker Explained for details.
• pacemaker_failure_timeout - Specifies the value of the failure-timeout attribute. The default is 60s. See the Resource Meta-Attributes in the Pacemaker Explained for details.
• pacemaker_no_quorum_policy - Specifies the value of the no-quorum-policy options. The default is stop, and ignore for 2 nodes. See the Cluster Options in the Pacemaker Explained for details.
• pacemaker_use_softdog - Specifies whether to use the software watchdog. The default is no.

pacemaker-*

Creates resources on the Pacemaker cluster.

• pacemaker_resource_prefix - Specifies the prefix to be added to the beginning of the resource name. The default is my_.
• pacemaker_virtual_ip - Specifies the virtual IP address. The default is an unused IP address in all nodes.
• pacemaker_virtual_hostname - Specifies the host name of the virtual IP address. The default is vip-1.
• pacemaker_pgsql_rep_mode - Specifies the replication mode in the pacemaker-replication role. Valid values are async (the default), sync, and slave.
• pacemaker_pgsql_replication_slot_name - Specifies the slot name when using the replication slot in the pacemaker-replication role. The default is {{ pacemaker_resource_prefix + 'slot' }}.

lifekeeper

Set up a LifeKeeper cluster.

• lifekeeper_media_file - Specifies the media file path. The dafault is /path/to/LKL_V951_100620.iso.
• lifekeeper_license_file - Specifies the license file path. The default is /path/to/evalkeys-60day.txt.
• lifekeeper_recovery_kits - Specifies the recovery kits to install. The default is empty. Valid values are steeleye-lkPGSQL (PostgreSQL Recovery Kit), steeleye-lkDR (DataKeeper), and so on.

lifekeeper-*

Creates resources on the LifeKeeper cluster.

• lifekeeper_resource_prefix - Specifies the prefix to be added to the beginning of the resource name. The default is my_.
• lifekeeper_virtual_ip - Specifies the virtual IP address. The default is an unused IP address in all nodes.
• lifekeeper_virtual_hostname - Specifies the host name of the virtual IP address. The default is vip-1.
• lifekeeper_pinglist - Specifies ping list separated by commas. The default is the IP address of the default gateway.

datakeeper

Sets up a DataKeeper resource on the LifeKeeper cluster.

• datakeeper_disk - Specifies the disk device path. The default is /dev/sdb1.
• datakeeper_fstype - Specifies the filesystem type. The default is xfs.
• datakeeper_mount_directory - Specifies the mount directory path. The default is /mnt/mirror.
• datakeeper_source_hostname - Specifies the host name of the source server. The default is the host name of the first node of all.

repmgr

Sets up repmgr servers.

• repmgr_syslog_facility - Specifies the syslog facility. The default is LOCAL1.
• repmgr_syslog_file - Specifies the syslog file path. The default is /var/log/repmgr{{ postgresql_version | regex_replace('\.') }}.

License

BSD

Author Information

Tomoaki Sato