r/nextcloud: Dynamically set version in config

Nextcloud thinks it needs to run the upgrade/migration tool if the
version number in its configuration file does not match the running
version.  It then updates the config file with the correct version. The
next time the configuration policy is applied, however, the version will
revert back to whatever is set in the template.  This will re-trigger
the upgrade notification.

To avoid this problem, we now set the version in the configuration file
dynamically.  Nextcloud writes its version number in a constant in
`version.php`.

roles/nextcloud/tasks/main.yml

@@ -12,6 +12,21 @@
   tags:
   - install
 
+- name: check nextcloud version
+  command: >-
+    php -r 'require "/usr/share/nextcloud/version.php";
+    echo join(".", $OC_Version);'
+  check_mode: false
+  changed_when: false
+  register: check_nc_version
+  tags:
+  - always
+- name: set nc_version fact
+  set_fact:
+    nc_version: '{{ check_nc_version.stdout }}'
+  tags:
+  - always
+
 - name: ensure nextcloud database user exists
   become: true
   become_user: postgres

roles/nextcloud/templates/config.php.j2

@@ -35,7 +35,7 @@ $CONFIG = array (
   ),
   'datadirectory' => '/var/lib/nextcloud/data',
   'dbtype' => 'pgsql',
-  'version' => '20.0.8.1',
+  'version' => '{{ nc_version }}',
   'overwrite.cli.url' => 'https://{{ nextcloud_server_name }}',
   'dbname' => 'nextcloud',
   'dbhost' => 'localhost',