[mailman3] We need admin access to database for migrations

We didn't need that on staging, but on production the permissions are more
granular.

Signed-off-by: Michal Konecny <mkonecny@redhat.com>

roles/mailman3/tasks/main.yml

@@ -147,8 +147,11 @@
 
 - name: Install the hyperkitty/postorius settings file
   ansible.builtin.template:
-    src: settings.py.j2
-    dest: "{{ mailman_webui_confdir }}/settings.py"
+    src: "{{ item }}.j2"
+    dest: "{{ mailman_webui_confdir }}/{{ item }}"
+  with_items:
+    - settings.py
+    - settings_admin.py
   tags:
     - config
     - mailman
@@ -334,6 +337,8 @@
     chdir: /etc/mailman3
   become_user: mailman
   become: true
+  environment:
+    DJANGO_SETTINGS_MODULE = "{{ mailman_webui_confdir }}/settings_admin.py"
   tags:
     - mailman
     - db

roles/mailman3/templates/settings_admin.py.j2

@@ -0,0 +1,23 @@
+#-*- coding: utf-8 -*-
+
+"""
+Copy of the Django settings file, but with database admin credentials (for
+schema modifications)
+"""
+
+from settings import *
+try:
+    from settings_local import *
+except ImportError:
+    pass
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.postgresql_psycopg2',
+        'NAME': 'hyperkitty',
+        'USER': 'hyperkittyadmin',
+        'PASSWORD': '{{ mailman_hyperkitty_admin_db_pass }}',
+        'HOST': '{{ mailman_db_server }}',
+        'PORT': '',
+    }
+}