add postgres support for mx-puppet-* with fallback to sqlite in role and migration notice

roles/matrix-bridge-mx-puppet-slack/defaults/main.yml

@@ -57,6 +57,21 @@ matrix_mx_puppet_slack_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_slack_login_shared_secret: ''
 
+# Database configuration, role uses 'sqlite' per default but playbook sets up postgres by default
+matrix_mx_puppet_slack_database_engine: sqlite
+matrix_mx_puppet_slack_database_username: matrix_mx_puppet_slack
+matrix_mx_puppet_slack_database_password: ~
+matrix_mx_puppet_slack_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_slack_database_port: 5432
+matrix_mx_puppet_slack_database_name: matrix_mx_puppet_slack
+matrix_mx_puppet_slack_database_file: /data/database.db
+matrix_mx_puppet_slack_database_connString: >-2
+  {%- if matrix_mx_puppet_slack_database_engine == 'postgres' -%}
+  postgresql://{{ matrix_mx_puppet_slack_database_username }}:{{ matrix_mx_puppet_slack_database_password }}@{{ matrix_mx_puppet_slack_database_hostname }}:{{ matrix_mx_puppet_slack_database_port }}/{{ matrix_mx_puppet_slack_database_name }}?sslmode=disable
+  {%- else if matrix_mx_puppet_slack_database_engine == 'sqlite' -%}
+  {{ matrix_mx_puppet_slack_database_engine }}://{{ matrix_mx_puppet_slack_database_file }}
+  {%- endif -%}
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #

roles/matrix-bridge-mx-puppet-slack/tasks/validate_config.yml

@@ -8,3 +8,23 @@
   with_items:
     - "matrix_mx_puppet_slack_appservice_token"
     - "matrix_mx_puppet_slack_homeserver_token"
+
+- block:
+  - name: Check if sqlite database already exists
+    stat:
+      path: "{{ matrix_mx_puppet_slack_data_path }}/database.db"
+    register: matrix_mx_puppet_slack_sqlite_database_path_local_stat_result
+
+  - name: Fail if an SQLite database already exists when using Postgres
+    fail:
+      msg: >-
+        matrix_mx_puppet_slack_database_engine has been set to `postgres` (which is our new default now).
+        However, we've discovered an existing SQLite database in {{ matrix_mx_puppet_slack_data_path }}/database.db.
+        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_mx_puppet_slack_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_mx_puppet_slack_data_path }}/database.db postgres_connection_string_variable_name=matrix_mx_puppet_slack_database_connString'`)
+        3. Re-run the playbook (`ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,start`)
+    when: "matrix_mx_puppet_slack_sqlite_database_path_local_stat_result.stat.exists"
+  when: "matrix_mx_puppet_slack_database_engine == 'postgres'"

roles/matrix-bridge-mx-puppet-slack/templates/config.yaml.j2

@@ -58,15 +58,18 @@ provisioning:
   apiPrefix: /_matrix/provision
 
 database:
+{% if matrix_mx_puppet_slack_database_engine == 'postgres' %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  connString: "postgres://matrix_puppet_slack:{{ matrix_additional_databases | selectattr('name', 'equalto', 'matrix_puppet_slack') | map(attribute='pass') | first }}@{{ matrix_postgres_connection_hostname }}/matrix_puppet_slack?sslmode=disable"
+  connString: {{ matrix_mx_puppet_slack_database_connString | to_json }}
+{% else %}
   # Use SQLite3 as a database backend
   # The name of the database file
-  #filename: /data/database.db
+  filename: {{ matrix_mx_puppet_slack_database_file }}
+{% endif %}
 
 logging:
   # Log level of console output