If you are using the Identity v3 API with Metacloud version 4.0 (Liberty) or later, you must specify the domain for any
openstack user commands. Otherwise, these commands return an error such as the following:
The request you have made requires authentication. (HTTP 401) (Request-ID:<ID>)
To specify the domain, insert the --domain option with the domain name into the command:
openstack user list --domain <DOMAIN_NAME>
For more information about domains in the context of the Identity API, see Understanding Identity.