Reject unsupported image to local BDM

Specifying image to local BDM at nova boot is not supported.
This patch adds a validation to the API to reject this not supported
mapping.

Closes-bug: #1377958
Change-Id: I0c38134e2aacca83d98ed0b341f15c480afe14f1

nova/block_device.py

@@ -182,6 +182,7 @@ class BlockDeviceDict(dict):
 
             source_type = api_dict.get('source_type')
             device_uuid = api_dict.get('uuid')
+            destination_type = api_dict.get('destination_type')
 
             if source_type not in ('volume', 'image', 'snapshot', 'blank'):
                 raise exception.InvalidBDMFormat(
@@ -194,6 +195,9 @@ class BlockDeviceDict(dict):
                     raise exception.InvalidBDMFormat(
                         details=_("Missing device UUID."))
                 api_dict[source_type + '_id'] = device_uuid
+            if source_type == 'image' and destination_type == 'local':
+                raise exception.InvalidBDMFormat(
+                    details=_("Mapping image to local is not supported."))
 
         api_dict.pop('uuid', None)
         return cls(api_dict)

nova/tests/unit/test_block_device.py

@@ -534,6 +534,14 @@ class TestBlockDeviceDict(test.NoDBTestCase):
         self.assertRaises(exception.InvalidBDMFormat,
                           block_device.BlockDeviceDict.from_api, api_dict)
 
+    def test_from_api_invalid_source_to_local_mapping(self):
+        api_dict = {'id': 1,
+                    'source_type': 'image',
+                    'destination_type': 'local',
+                    'uuid': 'fake-volume-id-1'}
+        self.assertRaises(exception.InvalidBDMFormat,
+                          block_device.BlockDeviceDict.from_api, api_dict)
+
     def test_legacy(self):
         for legacy, new in zip(self.legacy_mapping, self.new_mapping):
             self.assertThat(