ansible-role-elasticsearch/tasks/checkParameters.yml

# Check for mandatory parameters

- fail: msg="Parameter 'es_http_port' must be defined when multicast is disabled"
  when: es_config['multicast_enabled'] == false and es_config['http_port'] is not defined

- fail: msg="Parameter 'es_transport_tcp_port' must be defined when multicast is disabled"
  when: es_config['multicast_enabled'] == false and es_config['transport_tcp_port'] is not defined

- fail: msg="Parameter 'es_unicast_hosts' must be defined when multicast is disabled"
  when: es_config['multicast_enabled'] == false and es_config['unicast_hosts'] is not defined