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

---
- name: Fail if required matrix-alertmanager-receiver 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_alertmanager_receiver_hostname', when: true}
    - {'name': 'matrix_alertmanager_receiver_path_prefix', when: true}
    - {'name': 'matrix_alertmanager_receiver_config_matrix_homeserver_url', when: true}
    - {'name': 'matrix_alertmanager_receiver_config_matrix_access_token', when: true}
    - {'name': 'matrix_alertmanager_receiver_container_network', when: true}
    - {'name': 'matrix_alertmanager_receiver_metrics_proxying_hostname', when: "{{ matrix_alertmanager_receiver_metrics_proxying_enabled }}"}
    - {'name': 'matrix_alertmanager_receiver_metrics_proxying_path_prefix', when: "{{ matrix_alertmanager_receiver_metrics_proxying_enabled }}"}