services/_ansible/inventory/group_vars/all/compose_defaults.yml

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