community.postgresql.postgresql_set module – Change a PostgreSQL server configuration parameter

Note

This module is part of the community.postgresql collection (version 2.4.2).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install community.postgresql. You need further requirements to be able to use this module, see Requirements for details.

To use it in a playbook, specify: community.postgresql.postgresql_set.

Synopsis

  • Allows to change a PostgreSQL server configuration parameter.

  • The module uses ALTER SYSTEM command and applies changes by reload server configuration.

  • ALTER SYSTEM is used for changing server configuration parameters across the entire database cluster.

  • It can be more convenient and safe than the traditional method of manually editing the postgresql.conf file.

  • ALTER SYSTEM writes the given parameter setting to the $PGDATA/postgresql.auto.conf file, which is read in addition to postgresql.conf.

  • The module allows to reset parameter to boot_val (cluster initial value) by reset=true or remove parameter string from postgresql.auto.conf and reload value=default (for settings with postmaster context restart is required).

  • After change you can see in the ansible output the previous and the new parameter value and other information using returned values and ansible.builtin.debug module.

Requirements

The below requirements are needed on the host that executes this module.

  • psycopg2

Parameters

Parameter

Comments

ca_cert

aliases: ssl_rootcert

string

Specifies the name of a file containing SSL certificate authority (CA) certificate(s).

If the file exists, the server’s certificate will be verified to be signed by one of these authorities.

connect_params

dictionary

added in community.postgresql 2.3.0

Any additional parameters to be passed to libpg.

These parameters take precedence.

Default: {}

db

aliases: login_db

string

Name of database to connect.

login_host

aliases: host

string

Host running the database.

If you have connection issues when using localhost, try to use 127.0.0.1 instead.

Default: ""

login_password

string

The password this module should use to establish its PostgreSQL session.

Default: ""

login_unix_socket

aliases: unix_socket

string

Path to a Unix domain socket for local connections.

Default: ""

login_user

aliases: login

string

The username this module should use to establish its PostgreSQL session.

Default: "postgres"

name

string / required

Name of PostgreSQL server parameter. Pay attention that parameters are case sensitive (see examples below).

port

aliases: login_port

integer

Database port to connect to.

Default: 5432

reset

boolean

Restore parameter to initial state (boot_val). Mutually exclusive with value.

Choices:

  • false ← (default)

  • true

session_role

string

Switch to session_role after connecting. The specified session_role must be a role that the current login_user is a member of.

Permissions checking for SQL commands is carried out as though the session_role were the one that had logged in originally.

ssl_cert

path

added in community.postgresql 2.4.0

Specifies the file name of the client SSL certificate.

ssl_key

path

added in community.postgresql 2.4.0

Specifies the location for the secret key used for the client certificate.

ssl_mode

string

Determines whether or with what priority a secure SSL TCP/IP connection will be negotiated with the server.

See https://www.postgresql.org/docs/current/static/libpq-ssl.html for more information on the modes.

Default of prefer matches libpq default.

Choices:

  • "allow"

  • "disable"

  • "prefer" ← (default)

  • "require"

  • "verify-ca"

  • "verify-full"

trust_input

boolean

added in community.postgresql 0.2.0

If false, check whether values of parameters are potentially dangerous.

It makes sense to use false only when SQL injections are possible.

Choices:

  • false

  • true ← (default)

value

string

Parameter value to set.

To remove parameter string from postgresql.auto.conf and reload the server configuration you must pass value=default. With value=default the playbook always returns changed is true.

Attributes

Attribute

Support

Description

check_mode

Support: full

Can run in check_mode and return changed status prediction without modifying target.

Notes

Note

  • Supported version of PostgreSQL is 9.4 and later.

  • Pay attention, change setting with ‘postmaster’ context can return changed is true when actually nothing changes because the same value may be presented in several different form, for example, 1024MB, 1GB, etc. However in pg_settings system view it can be defined like 131072 number of 8kB pages. The final check of the parameter value cannot compare it because the server was not restarted and the value in pg_settings is not updated yet.

  • For some parameters restart of PostgreSQL server is required. See official documentation https://www.postgresql.org/docs/current/view-pg-settings.html.

  • The default authentication assumes that you are either logging in as or sudo’ing to the postgres account on the host.

  • To avoid “Peer authentication failed for user postgres” error, use postgres user as a become_user.

  • This module uses psycopg2, a Python PostgreSQL database adapter. You must ensure that psycopg2 is installed on the host before using this module.

  • If the remote host is the PostgreSQL server (which is the default case), then PostgreSQL must also be installed on the remote host.

  • For Ubuntu-based systems, install the postgresql, libpq-dev, and python-psycopg2 packages on the remote host before using this module.

  • The ca_cert parameter requires at least Postgres version 8.4 and psycopg2 version 2.4.3.

See Also

See also

community.postgresql.postgresql_info

The official documentation on the community.postgresql.postgresql_info module.

PostgreSQL server configuration

General information about PostgreSQL server configuration.

PostgreSQL view pg_settings reference

Complete reference of the pg_settings view documentation.

PostgreSQL ALTER SYSTEM command reference

Complete reference of the ALTER SYSTEM command documentation.

Examples

- name: Restore wal_keep_segments parameter to initial state
  community.postgresql.postgresql_set:
    name: wal_keep_segments
    reset: true

# Set work_mem parameter to 32MB and show what's been changed and restart is required or not
# (output example: "msg": "work_mem 4MB >> 64MB restart_req: False")
- name: Set work mem parameter
  community.postgresql.postgresql_set:
    name: work_mem
    value: 32mb
  register: set

- name: Print the result if the setting changed
  ansible.builtin.debug:
    msg: "{{ set.name }} {{ set.prev_val_pretty }} >> {{ set.value_pretty }} restart_req: {{ set.restart_required }}"
  when: set.changed
# Ensure that the restart of PostgreSQL server must be required for some parameters.
# In this situation you see the same parameter in prev_val_pretty and value_pretty, but 'changed=True'
# (If you passed the value that was different from the current server setting).

- name: Set log_min_duration_statement parameter to 1 second
  community.postgresql.postgresql_set:
    name: log_min_duration_statement
    value: 1s

- name: Set wal_log_hints parameter to default value (remove parameter from postgresql.auto.conf)
  community.postgresql.postgresql_set:
    name: wal_log_hints
    value: default

- name: Set TimeZone parameter (careful, case sensitive)
  community.postgresql.postgresql_set:
    name: TimeZone
    value: 'Europe/Paris'

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key

Description

context

string

PostgreSQL setting context.

Returned: always

Sample: "user"

name

string

Name of PostgreSQL server parameter.

Returned: always

Sample: "shared_buffers"

prev_val_pretty

string

Information about previous state of the parameter.

Returned: always

Sample: "4MB"

restart_required

boolean

Information about parameter current state.

Returned: always

Sample: true

value

dictionary

Dictionary that contains the current parameter value (at the time of playbook finish).

Pay attention that for real change some parameters restart of PostgreSQL server is required.

Returns the current value in the check mode.

Returned: always

Sample: {"unit": "b", "value": 67108864}

value_pretty

string

Information about current state of the parameter.

Returned: always

Sample: "64MB"

Authors

  • Andrew Klychkov (@Andersson007)