etcd_key_file

raw details (from release v2.2.3):

{
  "name": "etcd_key_file",
  "long": "etcd-key-file",
  "required_if": "tower_storage\", \"etcd",
  "value_name": "FILE",
  "takes_value": "true",
  "help": "TLS key file to use when establishing a connection to the etcd endpoint"
}