postgres: Add Commvault backup compatibility

This slightly changes the default of the role by always installing postgresql-{{ postgres_version }} (and providing a sensible default for postgres_version), but this is usually the correct thing to do in Debian and a release upgrade requires manual work anyway.

postgres/tasks/main.yml

@@ -72,36 +72,37 @@
         mode: '0750'
 
     - name: Configure Postgres WAL archive
-      lineinfile:
-        path: /etc/postgresql/{{ postgres_version }}/main/postgresql.conf
-        regexp: "{{ item.regexp }}"
-        line: "{{ item.line }}"
+      postgresql_set:
+        name: "{{ item.name }}"
+        value: "{{ item.value }}"
       loop:
-        - regexp: ^archive_mode\s*=
-          line: archive_mode = on
-        - regexp: ^archive_command\s*=
-          line: archive_command = 'cp %p /var/backups/pg_wal/%f'
-      notify:
-        - Restart Postgres
+        - name: archive_mode
+          value: "on"
+        - name: archive_command
+          value: 'cp %p /var/backups/pg_wal/%f'
 
     - name: Configure Postgres ident mappings
-      lineinfile:
+      blockinfile:
         path: /etc/postgresql/{{ postgres_version }}/main/pg_ident.conf
-        regexp: "{{ item.regexp }}"
-        line: "{{ item.line }}"
-      loop:
-        - regexp: ^postgres\s+postgres\s+postgres$
-          line: "postgres\tpostgres\t\tpostgres"
-        - regexp: ^postgres\s+root\s+postgres$
-          line: "postgres\troot\t\t\tpostgres"
+        insertafter: '^# MAPNAME\s+SYSTEM-USERNAME\s+PG-USERNAME$'
+        block: '{{ lookup("template", "pg_ident.j2") }}'
+      vars:
+        postgres_ident_mappings:
+          - mapname: postgres
+            system_username: postgres
+            pg_username: postgres
+          - mapname: postgres
+            system_username: root
+            pg_username: postgres
       notify:
         - Restart Postgres
 
     - name: Configure Postgres to use ident mapping for postgres role
-      lineinfile:
-        path: /etc/postgresql/{{ postgres_version }}/main/pg_hba.conf
-        regexp: ^local\s+all\s+postgres\s+peer
-        # yamllint disable-line rule:line-length
-        line: "local   all             postgres                                peer map=postgres"
+      postgresql_pg_hba:
+        dest: /etc/postgresql/{{ postgres_version }}/main/pg_hba.conf
+        contype: local
+        users: postgres
+        method: peer
+        options: map=postgres
       notify:
         - Restart Postgres