PostgreSQL

An Ansible role for installing and managing PostgreSQL servers. This role works with both Debian and RedHat based systems, and provides backup scripts for PostgreSQL Continuous Archiving and Point-in-Time Recovery. It does not create or manage PostgreSQL users, roles, groups, databases, and so forth. For that, see galaxyproject.postgresql_objects.

On RedHat-based platforms, the PostgreSQL Global Development Group (PGDG) packages packages will be installed. On Debian-based platforms, you can choose from the distribution's packages (from APT) or the PGDG packages.

Changes that require a restart will not be applied unless you manually restart PostgreSQL. This role will reload the server for those configuration changes that can be updated with only a reload because reloading is a non-intrusive operation, but options that require a full restart will not cause the server to restart.

Requirements

This role requires Ansible 2.4+

Role Variables

All variables are optional

• postgresql_user_name: System username to be used for PostgreSQL (default: postgres).

• postgresql_version: PostgreSQL version to install. On Debian-based platforms, the default is whatever version is pointed to by the postgresql metapackage). On RedHat-based platforms, the default is 10.

• postgresql_flavor: On Debian-based platforms, this specifies whether you want to use PostgreSQL packages from pgdg or the distribution's apt repositories. Possible values: apt, pgdg (default: apt).

• postgresql_conf: A list of hashes (dictionaries) of postgresql.conf options (keys) and values. These options are not added to postgresql.conf directly - the role adds a conf.d subdirectory in the configuration directory and an include statement for that directory to postgresql.conf. Options set in postgresql_conf are then set in conf.d/25ansible_postgresql.conf. For legacy reasons, this can also be a single hash, but the list syntax is preferred because it preserves order.

  Due to YAML parsing, you must take care when defining values in postgresql_conf to ensure they are properly written to the config file. For example:

  postgresql_conf:
    - max_connections: 250
    - archive_mode: "off"
    - work_mem: "'8MB'"

  Becomes the following in 25ansible_postgresql.conf:

  max_connections = 250
  archive_mode = off
  work_mem: '8MB'
  

• postgresql_pg_hba_conf: A list of lines to add to pg_hba.conf

• postgresql_pg_hba_local_postgres_user: If set to false, this will remove the postgres user's entry from pg_hba.conf that is preconfigured on Debian-based PostgreSQL installations. You probably do not want to do this unless you know what you're doing.

• postgresql_pg_hba_local_socket: If set to false, this will remove the local entry from pg_hba.conf that is preconfigured by the PostgreSQL package.

• postgresql_pg_hba_local_ipv4: If set to false, this will remove the host ... 127.0.0.1/32 entry from pg_hba.conf that is preconfigured by the PostgreSQL package.

• postgresql_pg_hba_local_ipv6: If set to false, this will remove the host ... ::1/128 entry from pg_hba.conf that is preconfigured by the PostgreSQL package.

• postgresql_pgdata: Only set this if you have changed the $PGDATA directory from the package default. Note this does not configure PostgreSQL to actually use a different directory, you will need to do that yourself, it just allows the role to properly locate the directory.

• postgresql_conf_dir: As with postgresql_pgdata except for the configuration directory.

• postgresql_install_psycopg2: Attempt to install the correct pacakge providing psycopg2 to the Python interpreter that Ansible is using on the remote side. This allows for the use of the postgresql_* Ansible modules (perhaps via galaxyproject.postgresql_objects), which depend on psycopg2. Defaults to true.

Backups

• postgresql_backup_dir: If set, enables PITR backups. Set this to a directory where your database will be backed up (this can be any format supported by rsync, e.g. user@host:/path). The most recent backup will be in a subdirectory named current.

• postgresql_backup_local_dir: Filesystem path on the PostgreSQL server where backup scripts will be placed.

• postgresql_backup_[hour|minute]: Controls what time the cron job will run to perform a full backup. Defaults to 1:00 AM.

• postgresql_backup_[day|month|weekday]: Additional cron controls for when the full backup is performed (default: *).

• postgresql_backup_post_command: Arbitrary command to run after successful completion of a scheduled backup.

Additional options pertaining to backups can be found in the defaults file.

Dependencies

Backup functionality requires Python 2.7 or 3.5+, psycopg2, and rsync. Note that if installing PGDG versions of PostgreSQL on Enterprise Linux, corresponding psycopg2 packages are available from the PGDG yum repositories.

Example Playbook

Standard install: Default postgresql.conf, pg_hba.conf and default version for the OS:

---

- hosts: dbservers
  remote_user: root
  roles:
    - postgresql

Use the pgdg packages on a Debian-based host:

---

- hosts: dbservers
  remote_user: root
  vars:
    postgresql_flavor: pgdg
  roles:
    - postgresql

Use the PostgreSQL 9.5 packages and set some postgresql.conf options and pg_hba.conf entries:

---

- hosts: dbservers
  remote_user: root
  vars:
    postgresql_version: 9.5
    postgresql_conf:
      - listen_addresses: "''"    # disable network listening (listen on unix socket only)
      - max_connections: 50       # decrease connection limit
    postgresql_pg_hba_conf:
      - host all all 10.0.0.0/8 md5
  roles:
    - postgresql

Enable backups to /archive

- hosts: all
  remote_user: root
  vars:
    postgresql_backup_dir: /archive
  roles:
    - postgresql

License

Academic Free License ("AFL") v. 3.0

Author Information

The Galaxy Community and contributors