Fix:

Postgres as supplying wrong env variable

postgres/playbook.yml

@@ -21,9 +21,9 @@
         state: started
         restart_policy: "unless-stopped"
         env:
-          POSTGRESQL_USER: "{{ pg_user }}"
-          POSTGRESQL_PASSWORD: "{{ pg_password }}"
-          POSTGRESQL_DATABASE: 'postgres'
+          POSTGRES_USER: "{{ pg_user }}"
+          POSTGRES_PASSWORD: "{{ pg_password }}"
+          POSTGRES_DB: 'postgres'
           PGDATA: '/var/lib/postgresql/data/pgdata'
         published_ports:
           - 5432:5432