matrix-docker-ansible-deploy/roles/custom/matrix-conduit/tasks/validate_config.yml

---

- name: Fail if required Conduit settings not defined
  ansible.builtin.fail:
    msg: >-
      You need to define a required configuration setting (`{{ item.name }}`).      
  when: "item.when | bool and vars[item.name] == ''"
  with_items:
    - {'name': 'matrix_conduit_hostname', when: true}
    - {'name': 'matrix_conduit_container_network', when: true}