Get endpoint if os_image_url is not set

If env['OS_IMAGE_URL'] is not set then None is returned. This is then
used ignoring the endpoint_type, service_type and region_name. This
patch will use those values if the endpoint is None.

Change-Id: I76cc527b05d2be75d3dbc33123a0d71be97fe25c
Closes-bug: #1579768

glanceclient/shell.py

@@ -442,7 +442,16 @@ class OpenStackImagesShell(object):
             }
         else:
             kwargs = self._get_kwargs_for_create_session(args)
-            kwargs = {'session': self._get_keystone_session(**kwargs)}
+            ks_session = self._get_keystone_session(**kwargs)
+            kwargs = {'session': ks_session}
+
+        if endpoint is None:
+            endpoint_type = args.os_endpoint_type or 'public'
+            service_type = args.os_service_type or 'image'
+            endpoint = ks_session.get_endpoint(
+                service_type=service_type,
+                interface=endpoint_type,
+                region_name=args.os_region_name)
 
         return glanceclient.Client(api_version, endpoint, **kwargs)