Enable automatic (SQLite -> Postgres) migration for matrix-appservice-discord

roles/matrix-bridge-appservice-discord/tasks/setup_install.yml

@@ -1,23 +1,29 @@
 ---
 
+- set_fact:
+    matrix_appservice_discord_requires_restart: false
+
 - block:
     - name: Check if an SQLite database already exists
       stat:
         path: "{{ matrix_appservice_discord_sqlite_database_path_local }}"
       register: matrix_appservice_discord_sqlite_database_path_local_stat_result
 
-  - name: Fail if an SQLite database already exists when using Postgres
-    fail:
-      msg: >-
-        matrix_appservice_discord_database_engine has been set to `postgres` (which is our new default now).
-        However, we've discovered an existing SQLite database in {{ matrix_appservice_discord_sqlite_database_path_local }}.
-        It appears that you've been using this bridge with the SQLite engine until now.
-        To continue using SQLite, opt into it explicitly: add `matrix_appservice_discord_database_engine: sqlite` to your vars.yml file and re-run this same command.
-        Alternatively, to migrate your existing SQLite database to Postgres:
-        1. Stop all services (`ansible-playbook -i inventory/hosts setup.yml --tags=stop`)
-        2. Import the SQLite database into Postgres (`ansible-playbook -v -i inventory/hosts setup.yml --tags=import-generic-sqlite-db --extra-vars='sqlite_database_path={{ matrix_appservice_discord_sqlite_database_path_local }} postgres_connection_string_variable_name=matrix_appservice_discord_database_connString'`)
-        3. Re-run the playbook (`ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,start`)
-    when: "matrix_appservice_discord_sqlite_database_path_local_stat_result.stat.exists"
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_appservice_discord_sqlite_database_path_local }}"
+              dst: "{{ matrix_appservice_discord_database_connString }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_appservice_discord_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-appservice-discord.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_appservice_discord_requires_restart: true
+      when: "matrix_appservice_discord_sqlite_database_path_local_stat_result.stat.exists|bool"
   when: "matrix_appservice_discord_database_engine == 'postgres'"
 
 - name: Ensure Appservice Discord image is pulled
@@ -100,3 +106,9 @@
   service:
     daemon_reload: yes
   when: "matrix_appservice_discord_systemd_service_result.changed"
+
+- name: Ensure matrix-appservice-discord.service restarted, if necessary
+  service:
+    name: "matrix-appservice-discord.service"
+    state: restarted
+  when: "matrix_appservice_discord_requires_restart|bool"