List all forbidden attributes in the request body.

When request content is validated by applying
cls.check_immutable_params() and an exception is
raised all forbidden parameters should be listed
in one response.

Change-Id: I15b3fa979bdb33bd341b0b99c1802af46273f358

keystone/common/controller.py

@@ -636,7 +636,7 @@ class V3Controller(wsgi.Application):
             return
 
         exception_args = {'target': cls.__name__,
-                          'attribute': blocked_keys.pop()}
+                          'attributes': ', '.join(blocked_keys)}
         raise exception.ImmutableAttributeError(**exception_args)
 
     @classmethod

keystone/exception.py

@@ -176,8 +176,8 @@ class ForbiddenAction(Forbidden):
 
 
 class ImmutableAttributeError(Forbidden):
-    message_format = _("Could not change immutable attribute %(attribute)s"
-                       " in target %(target)s")
+    message_format = _("Could not change immutable attribute(s) "
+                       "'%(attributes)s' in target %(target)s")
 
 
 class NotFound(Error):

keystone/tests/test_v3_controller.py

@@ -0,0 +1,51 @@
+# Copyright 2014 CERN.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import uuid
+
+from testtools import matchers
+
+from keystone.common import controller
+from keystone import exception
+from keystone import tests
+
+
+class V3ControllerTestCase(tests.TestCase):
+    """Tests for the V3Controller class."""
+    def setUp(self):
+        super(V3ControllerTestCase, self).setUp()
+
+        class ControllerUnderTest(controller.V3Controller):
+            _mutable_parameters = frozenset(['hello', 'world'])
+
+        self.api = ControllerUnderTest()
+
+    def test_check_immutable_params(self):
+        """Pass valid parameters to the method and expect no failure."""
+        ref = {
+            'hello': uuid.uuid4().hex,
+            'world': uuid.uuid4().hex
+        }
+        self.api.check_immutable_params(ref)
+
+    def test_check_immutable_params_fail(self):
+        """Pass invalid parameter to the method and expect failure."""
+        ref = dict([(uuid.uuid4().hex, uuid.uuid4().hex) for _ in range(3)])
+
+        ex = self.assertRaises(exception.ImmutableAttributeError,
+                               self.api.check_immutable_params, ref)
+        ex_msg = unicode(ex)
+        self.assertThat(ex_msg, matchers.Contains(self.api.__class__.__name__))
+        for key in ref.keys():
+            self.assertThat(ex_msg, matchers.Contains(key))