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

---

- name: Fail if required variables are undefined
  ansible.builtin.fail:
    msg: "The `{{ item }}` variable must be defined and have a non-null value."
  with_items:
    - "matrix_pantalaimon_homeserver_url"
  when: "vars[item] == '' or vars[item] is none"