Add possibility to handle remote managed postgresql setup

This is to address another part of issue #6 (closed)

This has been only partly tested (on the new possibility of remote postgresql setup), on classic (remote) Ansible deployment, but not through the shell script + ansible mix installation.

The new keys have been set in order to match current expectations (i.e. a local install of postgresql).

I end up declaring funkwhale_database_url in playbook and modifying DATABASE_URL in .env (it feels redundant).

defaults/main.yml

@@ -8,10 +8,23 @@ funkwhale_config_path: /srv/funkwhale/config
 funkwhale_external_storage_enabled: false
 funkwhale_disable_django_admin: false
 funkwhale_username: funkwhale
-funkwhale_database_managed: true
 funkwhale_frontend_managed: true
+
+funkwhale_database_managed: true
+funkwhale_database_local: true
 funkwhale_database_name: funkwhale
 funkwhale_database_user: funkwhale
+# the DB host as per your ansible inventory
+funkwhale_database_host_ansible: localhost
+# the DB FQDN or IP for funkwhale connector configuration (ex: pg01.local)
+funkwhale_database_host_app: localhost
+funkwhale_database_port: 5432
+
+# ↓ Only needed if 'funkwhale_database_managed' == false
+# ↓ This is also assuming DB and user have already been set up, outside of the playbook.
+# ↓ Considering the playbook handles both local and remote PostGreSQL server types, this should typically not be required.
+#funkwhale_database_url: postgresql://{{ funkwhale_database_user }}[:{{ funkwhale_database_password }}]@[{{ funkwhale_database_host_app }}]:{{ funkwhale_database_port | default(5432) }}/{{ funkwhale_database_name }}
+
 funkwhale_nginx_managed: true
 funkwhale_nginx_max_body_size: 100M
 funkwhale_redis_managed: true