You are not authorized to perform the requested action:

amurleopard

$ curl -s -H X-Auth-Token:$OS_AUTH_TOKEN -H "Content-type: application/json" http://localhost:35357/v3/domains 

{"error": {"message": "You are not authorized to perform the requested 
action: identity:list_domains.", "code": 403, "title": "Forbidden"}}

The authentication token is supplied but make sure is it the right one, in later versions of Openstack, the Identity Service (keystone) has the concept of multiple domains and tokens can be for different scope levels project or domain.

In this instance the error was due to using the token generated for project, after changing to a domain token, it worked.