matrix-docker-ansible-deploy/roles/matrix-client-element/tasks/validate_config.yml

---

- name: Fail if required Element settings not defined
  fail:
    msg: >
      You need to define a required configuration setting (`{{ item }}`) for using Element.      
  when: "vars[item] == ''"
  with_items:
    - "matrix_client_element_default_hs_url"

- name: (Deprecation) Catch and report riot-web variables
  fail:
    msg: >-
      Riot has been renamed to Element (https://element.io/blog/welcome-to-element/).
      The playbook will migrate your existing configuration and data automatically, but you need to adjust variable names.
      Please change your configuration (vars.yml) to rename all riot-web variables (`{{ item.old }}` -> `{{ item.new }}`).
      Also note that DNS configuration changes may be necessary.      
  when: "vars | dict2items | selectattr('key', 'match', item.old) | list | items2dict"
  with_items:
    - {'old': 'matrix_riot_web_.*', 'new': 'matrix_client_element_.*'}