Merge with parent

13 files changed, 216 insertions, 137 deletions

diff --git a/nova/api/ec2/apirequest.py b/nova/api/ec2/apirequest.py
index 6672e60bb..7d78c5cfa 100644
--- a/nova/api/ec2/apirequest.py
+++ b/nova/api/ec2/apirequest.py
@@ -21,22 +21,15 @@ APIRequest class
 """
 
 import datetime
-import re
 # TODO(termie): replace minidom with etree
 from xml.dom import minidom
 
 from nova import log as logging
+from nova.api.ec2 import ec2utils
 
 LOG = logging.getLogger("nova.api.request")
 
 
-_c2u = re.compile('(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|$)))')
-
-
-def _camelcase_to_underscore(str):
-    return _c2u.sub(r'_\1', str).lower().strip('_')
-
-
 def _underscore_to_camelcase(str):
     return ''.join([x[:1].upper() + x[1:] for x in str.split('_')])
 
@@ -51,59 +44,6 @@ def _database_to_isoformat(datetimeobj):
     return datetimeobj.strftime("%Y-%m-%dT%H:%M:%SZ")
 
 
-def _try_convert(value):
-    """Return a non-string from a string or unicode, if possible.
-
-    ============= =====================================================
-    When value is returns
-    ============= =====================================================
-    zero-length   ''
-    'None'        None
-    'True'        True
-    'False'       False
-    '0', '-0'     0
-    0xN, -0xN     int from hex (postitive) (N is any number)
-    0bN, -0bN     int from binary (positive) (N is any number)
-    *             try conversion to int, float, complex, fallback value
-
-    """
-    if len(value) == 0:
-        return ''
-    if value == 'None':
-        return None
-    if value == 'True':
-        return True
-    if value == 'False':
-        return False
-    valueneg = value[1:] if value[0] == '-' else value
-    if valueneg == '0':
-        return 0
-    if valueneg == '':
-        return value
-    if valueneg[0] == '0':
-        if valueneg[1] in 'xX':
-            return int(value, 16)
-        elif valueneg[1] in 'bB':
-            return int(value, 2)
-        else:
-            try:
-                return int(value, 8)
-            except ValueError:
-                pass
-    try:
-        return int(value)
-    except ValueError:
-        pass
-    try:
-        return float(value)
-    except ValueError:
-        pass
-    try:
-        return complex(value)
-    except ValueError:
-        return value
-
-
 class APIRequest(object):
     def __init__(self, controller, action, version, args):
         self.controller = controller
@@ -114,7 +54,7 @@ class APIRequest(object):
     def invoke(self, context):
         try:
             method = getattr(self.controller,
-                             _camelcase_to_underscore(self.action))
+                             ec2utils.camelcase_to_underscore(self.action))
         except AttributeError:
             controller = self.controller
             action = self.action
@@ -125,19 +65,7 @@ class APIRequest(object):
             #       and reraise as 400 error.
             raise Exception(_error)
 
-        args = {}
-        for key, value in self.args.items():
-            parts = key.split(".")
-            key = _camelcase_to_underscore(parts[0])
-            if isinstance(value, str) or isinstance(value, unicode):
-                # NOTE(vish): Automatically convert strings back
-                #             into their respective values
-                value = _try_convert(value)
-            if len(parts) > 1:
-                d = args.get(key, {})
-                d[parts[1]] = value
-                value = d
-            args[key] = value
+        args = ec2utils.dict_from_dotted_str(self.args.items())
 
         for key in args.keys():
             # NOTE(vish): Turn numeric dict keys into lists
diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index e1c65ae40..97875f1f5 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -909,6 +909,25 @@ class CloudController(object):
         if kwargs.get('ramdisk_id'):
             ramdisk = self._get_image(context, kwargs['ramdisk_id'])
             kwargs['ramdisk_id'] = ramdisk['id']
+        for bdm in kwargs.get('block_device_mapping', []):
+            # NOTE(yamahata)
+            # BlockDevicedMapping.<N>.DeviceName
+            # BlockDevicedMapping.<N>.Ebs.SnapshotId
+            # BlockDevicedMapping.<N>.Ebs.VolumeSize
+            # BlockDevicedMapping.<N>.Ebs.DeleteOnTermination
+            # BlockDevicedMapping.<N>.VirtualName
+            # => remove .Ebs and allow volume id in SnapshotId
+            ebs = bdm.pop('ebs', None)
+            if ebs:
+                ec2_id = ebs.pop('snapshot_id')
+                id = ec2utils.ec2_id_to_id(ec2_id)
+                if ec2_id.startswith('snap-'):
+                    bdm['snapshot_id'] = id
+                elif ec2_id.startswith('vol-'):
+                    bdm['volume_id'] = id
+                ebs.setdefault('delete_on_termination', True)
+                bdm.update(ebs)
+
         image = self._get_image(context, kwargs['image_id'])
 
         if image:
@@ -933,37 +952,54 @@ class CloudController(object):
             user_data=kwargs.get('user_data'),
             security_group=kwargs.get('security_group'),
             availability_zone=kwargs.get('placement', {}).get(
-                                  'AvailabilityZone'))
+                                  'AvailabilityZone'),
+            block_device_mapping=kwargs.get('block_device_mapping', {}))
         return self._format_run_instances(context,
                                           instances[0]['reservation_id'])
 
+    def _do_instance(self, action, context, ec2_id):
+        instance_id = ec2utils.ec2_id_to_id(ec2_id)
+        action(context, instance_id=instance_id)
+
+    def _do_instances(self, action, context, instance_id):
+        for ec2_id in instance_id:
+            self._do_instance(action, context, ec2_id)
+
     def terminate_instances(self, context, instance_id, **kwargs):
         """Terminate each instance in instance_id, which is a list of ec2 ids.
         instance_id is a kwarg so its name cannot be modified."""
         LOG.debug(_("Going to start terminating instances"))
-        for ec2_id in instance_id:
-            instance_id = ec2utils.ec2_id_to_id(ec2_id)
-            self.compute_api.delete(context, instance_id=instance_id)
+        self._do_instances(self.compute_api.delete, context, instance_id)
         return True
 
     def reboot_instances(self, context, instance_id, **kwargs):
         """instance_id is a list of instance ids"""
         LOG.audit(_("Reboot instance %r"), instance_id, context=context)
-        for ec2_id in instance_id:
-            instance_id = ec2utils.ec2_id_to_id(ec2_id)
-            self.compute_api.reboot(context, instance_id=instance_id)
+        self._do_instances(self.compute_api.reboot, context, instance_id)
+        return True
+
+    def stop_instances(self, context, instance_id, **kwargs):
+        """Stop each instances in instance_id.
+        Here instance_id is a list of instance ids"""
+        LOG.debug(_("Going to stop instances"))
+        self._do_instances(self.compute_api.stop, context, instance_id)
+        return True
+
+    def start_instances(self, context, instance_id, **kwargs):
+        """Start each instances in instance_id.
+        Here instance_id is a list of instance ids"""
+        LOG.debug(_("Going to start instances"))
+        self._do_instances(self.compute_api.start, context, instance_id)
         return True
 
     def rescue_instance(self, context, instance_id, **kwargs):
         """This is an extension to the normal ec2_api"""
-        instance_id = ec2utils.ec2_id_to_id(instance_id)
-        self.compute_api.rescue(context, instance_id=instance_id)
+        self._do_instance(self.compute_api.rescue, contect, instnace_id)
         return True
 
     def unrescue_instance(self, context, instance_id, **kwargs):
         """This is an extension to the normal ec2_api"""
-        instance_id = ec2utils.ec2_id_to_id(instance_id)
-        self.compute_api.unrescue(context, instance_id=instance_id)
+        self._do_instance(self.compute_api.unrescue, context, instance_id)
         return True
 
     def update_instance(self, context, instance_id, **kwargs):
@@ -974,7 +1010,8 @@ class CloudController(object):
                 changes[field] = kwargs[field]
         if changes:
             instance_id = ec2utils.ec2_id_to_id(instance_id)
-            self.compute_api.update(context, instance_id=instance_id, **kwargs)
+            self.compute_api.update(context, instance_id=instance_id,
+                                    **changes)
         return True
 
     @staticmethod
diff --git a/nova/api/ec2/ec2utils.py b/nova/api/ec2/ec2utils.py
index 163aa4ed2..222e1de1e 100644
--- a/nova/api/ec2/ec2utils.py
+++ b/nova/api/ec2/ec2utils.py
@@ -16,6 +16,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import re
+
 from nova import exception
 
 
@@ -30,3 +32,95 @@ def ec2_id_to_id(ec2_id):
 def id_to_ec2_id(instance_id, template='i-%08x'):
     """Convert an instance ID (int) to an ec2 ID (i-[base 16 number])"""
     return template % instance_id
+
+
+_c2u = re.compile('(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|$)))')
+
+
+def camelcase_to_underscore(str):
+    return _c2u.sub(r'_\1', str).lower().strip('_')
+
+
+def _try_convert(value):
+    """Return a non-string from a string or unicode, if possible.
+
+    ============= =====================================================
+    When value is returns
+    ============= =====================================================
+    zero-length   ''
+    'None'        None
+    'True'        True case insensitive
+    'False'       False case insensitive
+    '0', '-0'     0
+    0xN, -0xN     int from hex (postitive) (N is any number)
+    0bN, -0bN     int from binary (positive) (N is any number)
+    *             try conversion to int, float, complex, fallback value
+
+    """
+    if len(value) == 0:
+        return ''
+    if value == 'None':
+        return None
+    lowered_value = value.lower()
+    if lowered_value == 'true':
+        return True
+    if lowered_value == 'false':
+        return False
+    valueneg = value[1:] if value[0] == '-' else value
+    if valueneg == '0':
+        return 0
+    if valueneg == '':
+        return value
+    if valueneg[0] == '0':
+        if valueneg[1] in 'xX':
+            return int(value, 16)
+        elif valueneg[1] in 'bB':
+            return int(value, 2)
+        else:
+            try:
+                return int(value, 8)
+            except ValueError:
+                pass
+    try:
+        return int(value)
+    except ValueError:
+        pass
+    try:
+        return float(value)
+    except ValueError:
+        pass
+    try:
+        return complex(value)
+    except ValueError:
+        return value
+
+
+def dict_from_dotted_str(items):
+    """parse multi dot-separated argument into dict.
+    EBS boot uses multi dot-separeted arguments like
+    BlockDeviceMapping.1.DeviceName=snap-id
+    Convert the above into
+    {'block_device_mapping': {'1': {'device_name': snap-id}}}
+    """
+    args = {}
+    for key, value in items:
+        parts = key.split(".")
+        key = camelcase_to_underscore(parts[0])
+        if isinstance(value, str) or isinstance(value, unicode):
+            # NOTE(vish): Automatically convert strings back
+            #             into their respective values
+            value = _try_convert(value)
+
+            if len(parts) > 1:
+                d = args.get(key, {})
+                args[key] = d
+                for k in parts[1:-1]:
+                    k = camelcase_to_underscore(k)
+                    v = d.get(k, {})
+                    d[k] = v
+                    d = v
+                d[camelcase_to_underscore(parts[-1])] = value
+            else:
+                args[key] = value
+
+    return args
diff --git a/nova/api/openstack/__init__.py b/nova/api/openstack/__init__.py
index ddd9580d7..f24017df0 100644
--- a/nova/api/openstack/__init__.py
+++ b/nova/api/openstack/__init__.py
@@ -113,8 +113,7 @@ class APIRouter(base_wsgi.Router):
                         collection={'detail': 'GET',
                                     'info': 'GET',
                                     'select': 'POST',
-                                    'boot': 'POST'
-                                   })
+                                    'boot': 'POST'})
 
         mapper.resource("console", "consoles",
                     controller=consoles.create_resource(),
diff --git a/nova/api/openstack/contrib/volumes.py b/nova/api/openstack/contrib/volumes.py
index feabdce89..e5e2c5b50 100644
--- a/nova/api/openstack/contrib/volumes.py
+++ b/nova/api/openstack/contrib/volumes.py
@@ -301,7 +301,7 @@ class Volumes(extensions.ExtensionDescriptor):
         return "Volumes"
 
     def get_alias(self):
-        return "VOLUMES"
+        return "os-volumes"
 
     def get_description(self):
         return "Volumes support"
@@ -317,12 +317,12 @@ class Volumes(extensions.ExtensionDescriptor):
 
         # NOTE(justinsb): No way to provide singular name ('volume')
         # Does this matter?
-        res = extensions.ResourceExtension('volumes',
+        res = extensions.ResourceExtension('os-volumes',
                                         VolumeController(),
                                         collection_actions={'detail': 'GET'})
         resources.append(res)
 
-        res = extensions.ResourceExtension('volume_attachments',
+        res = extensions.ResourceExtension('os-volume_attachments',
                                            VolumeAttachmentController(),
                                            parent=dict(
                                                 member_name='server',
diff --git a/nova/api/openstack/create_instance_helper.py b/nova/api/openstack/create_instance_helper.py
index fbc6318ef..436e524c1 100644
--- a/nova/api/openstack/create_instance_helper.py
+++ b/nova/api/openstack/create_instance_helper.py
@@ -94,7 +94,7 @@ class CreateInstanceHelper(object):
         except Exception, e:
             msg = _("Cannot find requested image %(image_href)s: %(e)s" %
                                                                     locals())
-            raise faults.Fault(exc.HTTPBadRequest(msg))
+            raise faults.Fault(exc.HTTPBadRequest(explanation=msg))
 
         personality = body['server'].get('personality')
 
@@ -106,7 +106,7 @@ class CreateInstanceHelper(object):
 
         if not 'name' in body['server']:
             msg = _("Server name is not defined")
-            raise exc.HTTPBadRequest(msg)
+            raise exc.HTTPBadRequest(explanation=msg)
 
         zone_blob = body['server'].get('blob')
         name = body['server']['name']
@@ -121,8 +121,7 @@ class CreateInstanceHelper(object):
             extra_values = {
                 'instance_type': inst_type,
                 'image_ref': image_href,
-                'password': password
-            }
+                'password': password}
 
             return (extra_values,
                     create_method(context,
@@ -138,14 +137,12 @@ class CreateInstanceHelper(object):
                                   injected_files=injected_files,
                                   admin_password=password,
                                   zone_blob=zone_blob,
-                                  reservation_id=reservation_id
-                    )
-                )
+                                  reservation_id=reservation_id))
         except quota.QuotaError as error:
             self._handle_quota_error(error)
         except exception.ImageNotFound as error:
             msg = _("Can not find requested image")
-            raise faults.Fault(exc.HTTPBadRequest(msg))
+            raise faults.Fault(exc.HTTPBadRequest(explanation=msg))
 
         # Let the caller deal with unhandled exceptions.
 
@@ -180,11 +177,11 @@ class CreateInstanceHelper(object):
     def _validate_server_name(self, value):
         if not isinstance(value, basestring):
             msg = _("Server name is not a string or unicode")
-            raise exc.HTTPBadRequest(msg)
+            raise exc.HTTPBadRequest(explanation=msg)
 
         if value.strip() == '':
             msg = _("Server name is an empty string")
-            raise exc.HTTPBadRequest(msg)
+            raise exc.HTTPBadRequest(explanation=msg)
 
     def _get_kernel_ramdisk_from_image(self, req, image_id):
         """Fetch an image from the ImageService, then if present, return the
@@ -265,7 +262,7 @@ class CreateInstanceHelper(object):
             return utils.generate_password(16)
         if not isinstance(password, basestring) or password == '':
             msg = _("Invalid adminPass")
-            raise exc.HTTPBadRequest(msg)
+            raise exc.HTTPBadRequest(explanation=msg)
         return password
 
 
diff --git a/nova/api/openstack/extensions.py b/nova/api/openstack/extensions.py
index 54e17e23d..da06ecd15 100644
--- a/nova/api/openstack/extensions.py
+++ b/nova/api/openstack/extensions.py
@@ -374,6 +374,8 @@ class ExtensionManager(object):
             LOG.debug(_('Ext updated: %s'), extension.get_updated())
         except AttributeError as ex:
             LOG.exception(_("Exception loading extension: %s"), unicode(ex))
+            return False
+        return True
 
     def _load_all_extensions(self):
         """Load extensions from the configured path.
@@ -412,15 +414,16 @@ class ExtensionManager(object):
                               'file': ext_path})
                     continue
                 new_ext = new_ext_class()
-                self._check_extension(new_ext)
-                self._add_extension(new_ext)
+                self.add_extension(new_ext)
+
+    def add_extension(self, ext):
+        # Do nothing if the extension doesn't check out
+        if not self._check_extension(ext):
+            return
 
-    def _add_extension(self, ext):
         alias = ext.get_alias()
         LOG.audit(_('Loaded extension: %s'), alias)
 
-        self._check_extension(ext)
-
         if alias in self.extensions:
             raise exception.Error("Found duplicate extension: %s" % alias)
         self.extensions[alias] = ext
diff --git a/nova/api/openstack/ips.py b/nova/api/openstack/ips.py
index abea71830..71646b6d3 100644
--- a/nova/api/openstack/ips.py
+++ b/nova/api/openstack/ips.py
@@ -32,25 +32,24 @@ class Controller(object):
         self.compute_api = nova.compute.API()
         self.builder = nova.api.openstack.views.addresses.ViewBuilderV10()
 
-    def index(self, req, server_id):
+    def _get_instance(self, req, server_id):
         try:
-            instance = self.compute_api.get(req.environ['nova.context'], id)
+            instance = self.compute_api.get(
+                req.environ['nova.context'], server_id)
         except nova.exception.NotFound:
             return faults.Fault(exc.HTTPNotFound())
+        return instance
+
+    def index(self, req, server_id):
+        instance = self._get_instance(req, server_id)
         return {'addresses': self.builder.build(instance)}
 
     def public(self, req, server_id):
-        try:
-            instance = self.compute_api.get(req.environ['nova.context'], id)
-        except nova.exception.NotFound:
-            return faults.Fault(exc.HTTPNotFound())
+        instance = self._get_instance(req, server_id)
         return {'public': self.builder.build_public_parts(instance)}
 
     def private(self, req, server_id):
-        try:
-            instance = self.compute_api.get(req.environ['nova.context'], id)
-        except nova.exception.NotFound:
-            return faults.Fault(exc.HTTPNotFound())
+        instance = self._get_instance(req, server_id)
         return {'private': self.builder.build_private_parts(instance)}
 
     def show(self, req, server_id, id):
diff --git a/nova/api/openstack/notes.txt b/nova/api/openstack/notes.txt
index 2330f1002..4e95bffc8 100644
--- a/nova/api/openstack/notes.txt
+++ b/nova/api/openstack/notes.txt
@@ -7,9 +7,6 @@ image ids.
 GlanceImageService(ImageService):
 image ids are URIs.
 
-LocalImageService(ImageService):
-image ids are random strings.
-
 OpenstackAPITranslationStore:
 translates RS server/images/flavor/etc ids into formats required
 by a given ImageService strategy.
diff --git a/nova/api/openstack/server_metadata.py b/nova/api/openstack/server_metadata.py
index 57666f6b7..8a314de22 100644
--- a/nova/api/openstack/server_metadata.py
+++ b/nova/api/openstack/server_metadata.py
@@ -18,9 +18,10 @@
 from webob import exc
 
 from nova import compute
-from nova import quota
 from nova.api.openstack import faults
 from nova.api.openstack import wsgi
+from nova import exception
+from nova import quota
 
 
 class Controller(object):
@@ -45,7 +46,11 @@ class Controller(object):
     def index(self, req, server_id):
         """ Returns the list of metadata for a given instance """
         context = req.environ['nova.context']
-        return self._get_metadata(context, server_id)
+        try:
+            return self._get_metadata(context, server_id)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
 
     def create(self, req, server_id, body):
         self._check_body(body)
@@ -55,8 +60,13 @@ class Controller(object):
             self.compute_api.update_or_create_instance_metadata(context,
                                                                 server_id,
                                                                 metadata)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
+
         except quota.QuotaError as error:
             self._handle_quota_error(error)
+
         return body
 
     def update(self, req, server_id, id, body):
@@ -72,6 +82,10 @@ class Controller(object):
             self.compute_api.update_or_create_instance_metadata(context,
                                                                 server_id,
                                                                 body)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
+
         except quota.QuotaError as error:
             self._handle_quota_error(error)
 
@@ -80,16 +94,26 @@ class Controller(object):
     def show(self, req, server_id, id):
         """ Return a single metadata item """
         context = req.environ['nova.context']
-        data = self._get_metadata(context, server_id)
-        if id in data['metadata']:
+        try:
+            data = self._get_metadata(context, server_id)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
+
+        try:
             return {id: data['metadata'][id]}
-        else:
-            return faults.Fault(exc.HTTPNotFound())
+        except KeyError:
+            msg = _("metadata item %s was not found" % (id))
+            raise exc.HTTPNotFound(explanation=msg)
 
     def delete(self, req, server_id, id):
         """ Deletes an existing metadata """
         context = req.environ['nova.context']
-        self.compute_api.delete_instance_metadata(context, server_id, id)
+        try:
+            self.compute_api.delete_instance_metadata(context, server_id, id)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
 
     def _handle_quota_error(self, error):
         """Reraise quota errors as api-specific http exceptions."""
diff --git a/nova/api/openstack/servers.py b/nova/api/openstack/servers.py
index 798fdd7f7..b82a6de19 100644
--- a/nova/api/openstack/servers.py
+++ b/nova/api/openstack/servers.py
@@ -51,7 +51,7 @@ class Controller(object):
         try:
             servers = self._items(req, is_detail=False)
         except exception.Invalid as err:
-            return exc.HTTPBadRequest(str(err))
+            return exc.HTTPBadRequest(explanation=str(err))
         return servers
 
     def detail(self, req):
@@ -59,7 +59,7 @@ class Controller(object):
         try:
             servers = self._items(req, is_detail=True)
         except exception.Invalid as err:
-            return exc.HTTPBadRequest(str(err))
+            return exc.HTTPBadRequest(explanation=str(err))
         return servers
 
     def _get_view_builder(self, req):
@@ -488,11 +488,11 @@ class ControllerV11(Controller):
         if (not 'changePassword' in input_dict
             or not 'adminPass' in input_dict['changePassword']):
             msg = _("No adminPass was specified")
-            return exc.HTTPBadRequest(msg)
+            return exc.HTTPBadRequest(explanation=msg)
         password = input_dict['changePassword']['adminPass']
         if not isinstance(password, basestring) or password == '':
             msg = _("Invalid adminPass")
-            return exc.HTTPBadRequest(msg)
+            return exc.HTTPBadRequest(explanation=msg)
         self.compute_api.set_admin_password(context, id, password)
         return exc.HTTPAccepted()
 
diff --git a/nova/api/openstack/views/servers.py b/nova/api/openstack/views/servers.py
index 245d0e3fa..cbfa5aae7 100644
--- a/nova/api/openstack/views/servers.py
+++ b/nova/api/openstack/views/servers.py
@@ -75,7 +75,7 @@ class ViewBuilder(object):
         }
 
         inst_dict = {
-            'id': int(inst['id']),
+            'id': inst['id'],
             'name': inst['display_name'],
             'addresses': self.addresses_builder.build(inst),
             'status': power_mapping[inst.get('state')]}
@@ -99,6 +99,7 @@ class ViewBuilder(object):
         self._build_image(inst_dict, inst)
         self._build_flavor(inst_dict, inst)
 
+        inst_dict['uuid'] = inst['uuid']
         return dict(server=inst_dict)
 
     def _build_image(self, response, inst):
diff --git a/nova/api/openstack/wsgi.py b/nova/api/openstack/wsgi.py
index 3f8acf339..a57b7f72b 100644
--- a/nova/api/openstack/wsgi.py
+++ b/nova/api/openstack/wsgi.py
@@ -363,11 +363,11 @@ class Resource(wsgi.Application):
             action, action_args, accept = self.deserializer.deserialize(
                                                                       request)
         except exception.InvalidContentType:
-            return webob.exc.HTTPBadRequest(_("Unsupported Content-Type"))
+            msg = _("Unsupported Content-Type")
+            return webob.exc.HTTPBadRequest(explanation=msg)
         except exception.MalformedRequestBody:
-            explanation = _("Malformed request body")
-            return faults.Fault(webob.exc.HTTPBadRequest(
-                                            explanation=explanation))
+            msg = _("Malformed request body")
+            return faults.Fault(webob.exc.HTTPBadRequest(explanation=msg))
 
         action_result = self.dispatch(request, action, action_args)