community.postgresql.postgresql_db: Create & Manage PostgreSQL Databases

How to Create a PostgreSQL Database with Ansible?

I'm going to show you a live Playbook with some simple Ansible code. I'm Luca Berton and welcome to today's episode of Ansible Pilot.

See also: Automate PostgreSQL Backups with Ansible Playbook

Ansible Create a PostgreSQL Database

> community.postgresql.postgresql_db Add or remove PostgreSQL databases from a remote host

Let's talk about the Ansible module postgresql_db. The full name is community.postgresql.postgresql_db, which means that is part of the collection of modules "community.postgresql" maintained by the Ansible Community to interact with PostgreSQL. The collection is tested with ansible-core version 2.11+, prior versions such as 2.9 or 2.10 are not supported. The purpose of the module is to add or remove PostgreSQL databases from a remote host.

Parameters

• name _string_ - Name of database • state _string_ - present/absent/dump/restore/rename - The operation

Let me summarize the main parameters of the module postgresql_db. Ansible supposes that PostgreSQL is in the target node. The only required parameter is "name", the name of the database to interact with. The parameter "state" specify the desired state or the operation for the selected database. The option "present" means that the database should be created and the option "absent" means that the database should be deleted. Other useful operations are "dump" and "restore" that uses pg_dump, the embedded PostgreSQL utility to backup and restore to the target file. Another useful operation is rename, from name to target. This module uses psycopg2, a Python PostgreSQL database library. You must ensure that python3-psycopg2 is installed on the host before using this module.

See also: Drop a PostgreSQL Database - Ansible module postgresql_db

Links

• community.postgresql.postgresql_db

## Playbook

Let's jump into a real-life Ansible Playbook to Create a PostgreSQL Database. I'm going to show you how to create the testdb database in the current PostgreSQL server.

code

---
- name: postgresql Playbook
  hosts: all
  become: true
  vars:
    db_name: testdb
  tasks:
    - name: Utility present
      ansible.builtin.package:
        name: python3-psycopg2
        state: present
    - name: Create db
      community.postgresql.postgresql_db:
        state: present
        name: "{{ db_name }}"
      become: true
      become_user: postgres

execution

$ ansible-playbook -i virtualmachines/demo/inventory postgresql/db_create.yml
PLAY [postgresql Playbook] ************************************************************************************
TASK [Gathering Facts] ************************************************************************************
ok: [demo.example.com]
TASK [utility present] ************************************************************************************
ok: [demo.example.com]
TASK [Create db] ******************************************************************************************
[WARNING]: Module remote_tmp /var/lib/pgsql/.ansible/tmp did not exist and was created with a mode of
0700, this may cause issues when running as another user. To avoid this, create the remote_tmp dir with
the correct permissions manually
changed: [demo.example.com]
PLAY RECAP ************************************************************************************************
demo.example.com           : ok=3    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

idempotency

$ ansible-playbook -i virtualmachines/demo/inventory postgresql/db_create.yml
PLAY [postgresql Playbook] ************************************************************************************
TASK [Gathering Facts] ************************************************************************************
ok: [demo.example.com]
TASK [utility present] ************************************************************************************
ok: [demo.example.com]
TASK [Create db] ******************************************************************************************
ok: [demo.example.com]
PLAY RECAP ************************************************************************************************
demo.example.com           : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

before execution

$ ssh devops@demo.example.com
Last login: Wed Jun  8 15:09:44 2022 from 192.168.178.26
[devops@demo ~]$ sudo su
[root@demo devops]# su - postgres
Last login: Wed Jun  8 15:07:05 UTC 2022 on pts/1
[postgres@Playbook ~]$ psql testdb
psql: FATAL:  database "testdb" does not exist
[postgres@Playbook ~]$

after execution

$ ssh devops@demo.example.com
Last login: Wed Jun  8 15:39:11 2022 from 192.168.178.26
[devops@demo ~]$ sudo su
[root@demo devops]# su - postgres
Last login: Wed Jun  8 15:37:54 UTC 2022 on pts/0
[postgres@Playbook ~]$ psql testdb
psql (10.21)
Type "help" for help.
testdb=# \q
[postgres@Playbook ~]$

code with ❤️ in GitHub

Set Encoding, Owner, and Template

For anything beyond a throwaway database you usually want to control its encoding, locale, and owner. The postgresql_db module exposes these through the encoding, lc_collate, lc_ctype, owner, and template parameters. Because PostgreSQL copies collation settings from a template, pair a non-default lc_collate/lc_ctype with template: template0:

---
- name: postgresql Playbook
  hosts: all
  become: true
  become_user: postgres
  vars:
    db_name: appdb
    db_owner: appuser
  tasks:
    - name: Create db with encoding and owner
      community.postgresql.postgresql_db:
        name: "{{ db_name }}"
        state: present
        owner: "{{ db_owner }}"
        encoding: UTF-8
        lc_collate: en_US.UTF-8
        lc_ctype: en_US.UTF-8
        template: template0

The owner role must already exist — create it first with the postgresql_user module. Note that encoding, lc_collate, lc_ctype, and template are only applied when the database is created; PostgreSQL cannot change them on an existing database, so the module leaves them untouched on later runs.

See also: Rename a PostgreSQL Database - Ansible module postgresql_db

Conclusion

Now you know how to Create a PostgreSQL Database with Ansible.

Related Articles

• Create a PostgreSQL user or role (postgresql_user) • Run a SQL query on PostgreSQL (postgresql_query) • Grant privileges on a PostgreSQL database (postgresql_privs) • become and privilege escalation explained • the Ansible inventory deep-dive