PostgreSQL system role

The PostgreSQL system role installs, configures, and starts the PostgreSQL server.

The role also optimizes the database server settings to improve performance.

Requirements

The role currently works with the PostgreSQL server 10, 12, 13, 15 and 16.

Collection requirements

The role requires some external collections. Use this to install them:

ansible-galaxy collection install -vv -r meta/collection-requirements.yml

Role Variables

postgresql_version

You can set the version of the PostgreSQL server to 10, 12, 13, 15 or 16.

postgresql_version: "13"

postgresql_password

Optionally, you can set a password for the postgres database superuser. By default, no password is set, and a datababase is accessible from the postgres system account through a UNIX socket. It is recommended to encrypt the password by using Ansible Vault.

postgresql_password: !vault |
          $ANSIBLE_VAULT;1.2;AES256;dev
          ....

postgresql_pg_hba_conf

The content of the postgresql_pg_hba_conf variable replaces the default upstream configuration in the /var/lib/pgsql/data/pg_hba.conf file.

postgresql_pg_hba_conf:
  - type: local
    database: all
    user: all
    auth_method: peer
  - type: host
    database: all
    user: all
    address: '127.0.0.1/32'
    auth_method: ident
  - type: host
    database: all
    user: all
    address: '::1/128'
    auth_method: ident

postgresql_server_conf

The content of the postgresql_server_conf variable is added to the end of the /var/lib/pgsql/data/postgresql.conf file. As a result, the default settings are overwritten.

postgresql_server_conf:
  ssl: on
  shared_buffers: 128MB
  huge_pages: try

postgresql_ssl_enable

To set up an SSL/TLS connection, set the postgresql_ssl_enable variable to true and provide a server certificate and a private key.

postgresql_ssl_enable: true

postgresql_cert_name

If you want to use your own certificate and private key, use the postgresql_cert_name variable to specify the certificate name. You must keep both certificate and key files in the same directory and under the same name with the .crt and .key suffixes on the managed node. The value should be an absolute path.

For example, if your certificate file is located in /etc/certs/server.crt and your private key in /etc/certs/server.key, set the postgresql_cert_name value to:

postgresql_cert_name: /etc/certs/server

postgresql_certificates

The postgresql_certificates variable requires a list of dict in the same format as used by the fedora.linux_system_roles.certificate role. Specify the postgresql_certificates variable if you want the certificate role to generate certificates for the PostgreSQL server configured by the PostgreSQL role. In the following example, a self-signed certificate postgresql_cert.crt is generated in the /etc/pki/tls/certs/ directory. By default, no certificates are automatically generated ([]).

postgresql_certificates:
  - name: postgresql_cert
    dns: ['localhost', 'www.example.com']
    ca: self-sign

postgresql_input_file

To run an SQL script, define a path to your SQL file by using the postgresql_input_file variable:

postgresql_input_file: "/tmp/mypath/file.sql"

postgresql_server_tuning

By default, the PostgreSQL system role enables server settings optimization based on system resources. To disabe the tuning, set the postgresql_server_tuning variable to false.

postgresql_server_tuning: false

See the examples/ for details.

Idempotence

This section should cover role behavior for repeated runs.

Password change

Once you set the password by using the postgresql_password variable, it is impossible to change the password by setting another value. You must use the postgresql_password variable for every database acces under the superuser, including running an SQL script (the functionality of the postgresql_input_file variable).

Config file redefinition

Configuration files generated from postgresql_pg_hba_conf and postgresql_conf are regenerated within each single run. Therefore, every change rewrites the previous configuration.

Version change

Once the PostgreSQL server is installed, it is impossible to upgrade or downgrade the server by increasing or decreasing the version number in the postgresql_version variable.

Server tunning

This option reflects the setup of the latest run of the role.

SSL usage

This option reflects the setup of the latest run of the role. The PostgreSQL server needs properly defined certificates and keys to run with enabled SSL/TLS.

Example Playbook

- name: Manage postgres
  hosts: all
  vars:
    postgresql_version: "13"
    postgresql_password: !vault |
          $ANSIBLE_VAULT;1.2;AES256;dev
          ....
  roles:
    - linux-system-roles.postgresql

You can find more examples in the examples/ directory.

rpm-ostree

NOTE: By default, get_ostree_data.sh will return the packages for the default version of PostgreSQL. You will need to amend the output if you want to use a different version - e.g. change @postgresql:13/server to @postgresql:15/server

See README-ostree.md for more information.

License

MIT