In devstack, there is an error:
Not Found (HTTP 404) (Request-ID: req-c5b74593-ecd6-4c06-9db1-b1fa9c124fc1).
This is a keystone authentication failure.
Use keystoneauth1.load.get_plugin_loader to load and discovery dynamically
without explicitly specifying V2 or V3 of keystone.
Change-Id: Ic43d7c194387a4063b38a11e1a1c850aaaf713c0
60aa9ec5dd