make api error messages more readable

nova/endpoint/api.py

@@ -304,7 +304,10 @@ class APIRequestHandler(tornado.web.RequestHandler):
         try:
             failure.raiseException()
         except exception.ApiError as ex:
-            self._error(type(ex).__name__ + "." + ex.code, ex.message)
+            if ex.code:
+                self._error(ex.code, ex.message)
+            else:
+                self._error(type(ex).__name__, ex.message)
         # TODO(vish): do something more useful with unknown exceptions
         except Exception as ex:
             self._error(type(ex).__name__, str(ex))

nova/endpoint/cloud.py

@@ -529,7 +529,7 @@ class CloudController(object):
                          context.project.id, min_instances)
             raise QuotaError("Instance quota exceeded. You can only "
                              "run %s more instances of this type." %
-                             num_instances)
+                             num_instances, "InstanceLimitExceeded")
         # make sure user can access the image
         # vpn image is private so it doesn't show up on lists
         vpn = kwargs['image_id'] == FLAGS.vpn_image_id