Add basic ansible stuff for management

acme-dns is fully handled by ansible already. All services should be
created by ansible in the end.

_ansible/inventory/group_vars/all/compose_defaults.yml

@@ -0,0 +1,14 @@
+compose_default_file:
+  services:
+    app:
+      image: "{{ compose.image }}"
+      restart: always
+      labels:
+        com.centurylinklabs.watchtower.enable: "{{ compose.watchtower | default(false) }}"
+      networks:
+        apps:
+          aliases:
+            - "{{ service.name }}"
+  networks:
+    apps:
+      external: true

_ansible/inventory/group_vars/all/main.yml

@@ -0,0 +1,8 @@
+admin_email: tobias@msrg.cc
+
+postgres:
+  host: db.serguzim.me
+  port: 5432
+
+services_path: /opt/services/
+caddy_config_path: "{{ (services_path, 'caddy', 'config', 'conf.d') | path_join }}"