Add Pre-Check Task for the Presence of a pgBackRest Node in the Inven…

…tory

This commit introduces a pre-check task in our Ansible playbook that checks if a host is present in the 'pgbackrest' inventory group when the 'pgbackrest_repo_host' variable is defined.

This helps to ensure that the playbook run will not fail due to misconfigured inventory file settings.

roles/pre-checks/tasks/pgbackrest.yml

@@ -16,6 +16,16 @@
     - archive_command_item is undefined or archive_command_item.value != pgbackrest_archive_command
 
 # Checking parameters for working with a dedicated pgbackrest server
+- name: pgBackRest | Ensure pgbackrest host is in inventory
+  run_once: true # noqa run-once
+  ansible.builtin.fail:
+    msg:
+      - "The 'pgbackrest_repo_host' variable is set but the 'pgbackrest' group in your inventory is empty."
+      - "Please add the necessary host to the 'pgbackrest' group in your inventory."
+  when:
+    - pgbackrest_repo_host | length > 0
+    - groups['pgbackrest'] is undefined or groups['pgbackrest'] | length == 0
+
 - name: "pgBackRest | Ensure 'repo1-host' and 'repo1-host-user' are set correctly"
   ansible.builtin.set_fact:
     pgbackrest_conf: