Return BadRequest instead of UnprocessableEntity for volumes API

Changes exception from UnprocessableEntity to BadRequest when
input validation fails. Also raise BadRequest instead of a nova
exception InvalidParameterValue within the SnapshotController
create method. This is some preparation work to make sharing
unittests between V2.1 and V2 easier.

Partially implements blueprint v2-on-v3-api

Change-Id: I5c5b6f9680378d51f7fea054b52b99cd6cbe54b0

nova/api/openstack/compute/contrib/volumes.py

@@ -221,7 +221,8 @@ def create(self, req, body):
         authorize(context)
 
         if not self.is_valid_body(body, 'volume'):
-            raise exc.HTTPUnprocessableEntity()
+            msg = _("volume not specified")
+            raise exc.HTTPBadRequest(explanation=msg)
 
         vol = body['volume']
 
@@ -392,7 +393,8 @@ def create(self, req, server_id, body):
         authorize_attach(context, action='create')
 
         if not self.is_valid_body(body, 'volumeAttachment'):
-            raise exc.HTTPUnprocessableEntity()
+            msg = _("volumeAttachment not specified")
+            raise exc.HTTPBadRequest(explanation=msg)
         try:
             volume_id = body['volumeAttachment']['volumeId']
         except KeyError:
@@ -449,7 +451,8 @@ def update(self, req, server_id, id, body):
         authorize_attach(context, action='update')
 
         if not self.is_valid_body(body, 'volumeAttachment'):
-            raise exc.HTTPUnprocessableEntity()
+            msg = _("volumeAttachment not specified")
+            raise exc.HTTPBadRequest(explanation=msg)
 
         old_volume_id = id
         old_volume = self.volume_api.get(context, old_volume_id)
@@ -681,7 +684,8 @@ def create(self, req, body):
         authorize(context)
 
         if not self.is_valid_body(body, 'snapshot'):
-            raise exc.HTTPUnprocessableEntity()
+            msg = _("snapshot not specified")
+            raise exc.HTTPBadRequest(explanation=msg)
 
         snapshot = body['snapshot']
         volume_id = snapshot['volume_id']
@@ -694,7 +698,7 @@ def create(self, req, body):
             force = strutils.bool_from_string(force, strict=True)
         except ValueError:
             msg = _("Invalid value '%s' for force.") % force
-            raise exception.InvalidParameterValue(err=msg)
+            raise exc.HTTPBadRequest(explanation=msg)
 
         if force:
             create_func = self.volume_api.create_snapshot_force

nova/tests/api/openstack/compute/contrib/test_volumes.py

@@ -843,60 +843,60 @@ def test_full_volume(self):
         self.assertEqual(request['body'], expected)
 
 
-class CommonUnprocessableEntityTestCase(object):
+class CommonBadRequestTestCase(object):
 
     resource = None
     entity_name = None
     controller_cls = None
     kwargs = {}
 
     """
-    Tests of places we throw 422 Unprocessable Entity from
+    Tests of places we throw 400 Bad Request from
     """
 
     def setUp(self):
-        super(CommonUnprocessableEntityTestCase, self).setUp()
+        super(CommonBadRequestTestCase, self).setUp()
         self.controller = self.controller_cls()
 
-    def _unprocessable_create(self, body):
+    def _bad_request_create(self, body):
         req = fakes.HTTPRequest.blank('/v2/fake/' + self.resource)
         req.method = 'POST'
 
         kwargs = self.kwargs.copy()
         kwargs['body'] = body
-        self.assertRaises(webob.exc.HTTPUnprocessableEntity,
+        self.assertRaises(webob.exc.HTTPBadRequest,
                           self.controller.create, req, **kwargs)
 
     def test_create_no_body(self):
-        self._unprocessable_create(body=None)
+        self._bad_request_create(body=None)
 
     def test_create_missing_volume(self):
         body = {'foo': {'a': 'b'}}
-        self._unprocessable_create(body=body)
+        self._bad_request_create(body=body)
 
     def test_create_malformed_entity(self):
         body = {self.entity_name: 'string'}
-        self._unprocessable_create(body=body)
+        self._bad_request_create(body=body)
 
 
-class UnprocessableVolumeTestCase(CommonUnprocessableEntityTestCase,
-                                  test.TestCase):
+class BadRequestVolumeTestCase(CommonBadRequestTestCase,
+                               test.TestCase):
 
     resource = 'os-volumes'
     entity_name = 'volume'
     controller_cls = volumes.VolumeController
 
 
-class UnprocessableAttachmentTestCase(CommonUnprocessableEntityTestCase,
-                                      test.TestCase):
+class BadRequestAttachmentTestCase(CommonBadRequestTestCase,
+                                   test.TestCase):
 
     resource = 'servers/' + FAKE_UUID + '/os-volume_attachments'
     entity_name = 'volumeAttachment'
     controller_cls = volumes.VolumeAttachmentController
     kwargs = {'server_id': FAKE_UUID}
 
 
-class UnprocessableSnapshotTestCase(CommonUnprocessableEntityTestCase,
+class BadRequestSnapshotTestCase(CommonBadRequestTestCase,
                                     test.TestCase):
 
     resource = 'os-snapshots'
@@ -941,7 +941,7 @@ def test_force_false(self):
 
     def test_force_invalid(self):
         self.body['snapshot']['force'] = 'foo'
-        self.assertRaises(exception.InvalidParameterValue,
+        self.assertRaises(exc.HTTPBadRequest,
                           self.controller.create, self.req, body=self.body)