Release bdm constraint source and dest type

https://bugs.launchpad.net/nova/+bug/1377958 fixed a problem
that source_type: image, destination_type: local is not
supported for boot instance, exception should be raised to
reject the param otherwise it will lead to instance become
ERROR state.

However the fix introduced a problem on nova client
https://bugs.launchpad.net/python-novaclient/+bug/1418484
The fix of the bug leads to following command become invalid

nova boot test-vm --flavor m1.medium --image centos-vm-32
--nic net-id=c3f40e33-d535-4217-916b-1450b8cd3987 --block-device
id=26b7b917-2794-452a-95e5-2efb2ca6e32d,bus=sata,source=volume,bootindex=1

So we need to release the original constraint to allow
the above special case pass the validation check then
we can revert the nova client exception
(https://review.openstack.org/#/c/165932/)

This patch checks the boot_index and whether image param is
given after we found the bdm has source_type: image,
destination_type: local, if this is the special case, then
no exception will be raised.

Closes-Bug: #1433609

Change-Id: If43faae95169bc3864449a8364975f5c887aac14
(cherry picked from commit cadbcc440a2fcfb8532f38111999a06557fbafc2)

4 files changed, 45 insertions, 10 deletions

diff --git a/nova/api/openstack/compute/plugins/v3/block_device_mapping.py b/nova/api/openstack/compute/plugins/v3/block_device_mapping.py
index c28851e265..4a6f667688 100644
--- a/nova/api/openstack/compute/plugins/v3/block_device_mapping.py
+++ b/nova/api/openstack/compute/plugins/v3/block_device_mapping.py
@@ -47,6 +47,11 @@ class BlockDeviceMapping(extensions.V3APIExtensionBase):
     # NOTE(gmann): This function is not supposed to use 'body_deprecated_param'
     # parameter as this is placed to handle scheduler_hint extension for V2.1.
     def server_create(self, server_dict, create_kwargs, body_deprecated_param):
+
+        # Have to check whether --image is given, see bug 1433609
+        image_href = server_dict.get('imageRef')
+        image_uuid_specified = image_href is not None
+
         bdm = server_dict.get(ATTRIBUTE_NAME, [])
         legacy_bdm = server_dict.get(LEGACY_ATTRIBUTE_NAME, [])
 
@@ -57,7 +62,8 @@ class BlockDeviceMapping(extensions.V3APIExtensionBase):
 
         try:
             block_device_mapping = [
-                block_device.BlockDeviceDict.from_api(bdm_dict)
+                block_device.BlockDeviceDict.from_api(bdm_dict,
+                    image_uuid_specified)
                 for bdm_dict in bdm]
         except exception.InvalidBDMFormat as e:
             raise exc.HTTPBadRequest(explanation=e.format_message())
diff --git a/nova/api/openstack/compute/servers.py b/nova/api/openstack/compute/servers.py
index 999685ee46..d3d52aedd4 100644
--- a/nova/api/openstack/compute/servers.py
+++ b/nova/api/openstack/compute/servers.py
@@ -383,7 +383,7 @@ class Controller(wsgi.Controller):
             raise exc.HTTPBadRequest(explanation=expl)
         return user_data
 
-    def _extract_bdm(self, server_dict):
+    def _extract_bdm(self, server_dict, image_uuid_specified):
         legacy_bdm = True
         block_device_mapping = None
         block_device_mapping_v2 = None
@@ -424,7 +424,8 @@ class Controller(wsgi.Controller):
 
             try:
                 block_device_mapping_v2 = [
-                    block_device.BlockDeviceDict.from_api(bdm_dict)
+                    block_device.BlockDeviceDict.from_api(bdm_dict,
+                        image_uuid_specified)
                     for bdm_dict in block_device_mapping_v2]
             except exception.InvalidBDMFormat as e:
                 raise exc.HTTPBadRequest(explanation=e.format_message())
@@ -552,7 +553,9 @@ class Controller(wsgi.Controller):
         user_data = self._extract(server_dict, 'os-user-data', 'user_data')
         self._validate_user_data(user_data)
 
-        legacy_bdm, block_device_mapping = self._extract_bdm(server_dict)
+        image_uuid_specified = bool(image_uuid)
+        legacy_bdm, block_device_mapping = self._extract_bdm(server_dict,
+            image_uuid_specified)
 
         ret_resv_id = False
         # min_count and max_count are optional.  If they exist, they may come
diff --git a/nova/block_device.py b/nova/block_device.py
index 28b496c2c1..d8ae4a6b98 100644
--- a/nova/block_device.py
+++ b/nova/block_device.py
@@ -171,7 +171,7 @@ class BlockDeviceDict(dict):
         return cls(new_bdm, non_computable_fields)
 
     @classmethod
-    def from_api(cls, api_dict):
+    def from_api(cls, api_dict, image_uuid_specified):
         """Transform the API format of data to the internally used one.
 
         Only validate if the source_type field makes sense.
@@ -194,8 +194,13 @@ class BlockDeviceDict(dict):
                         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."))
+                boot_index = api_dict.get('boot_index', -1)
+
+                # if this bdm is generated from --image ,then
+                # source_type = image and destination_type = local is allowed
+                if not (image_uuid_specified and boot_index == 0):
+                    raise exception.InvalidBDMFormat(
+                        details=_("Mapping image to local is not supported."))
 
         api_dict.pop('uuid', None)
         return cls(api_dict)
diff --git a/nova/tests/unit/test_block_device.py b/nova/tests/unit/test_block_device.py
index 6abb58d6fd..7d1bee0bde 100644
--- a/nova/tests/unit/test_block_device.py
+++ b/nova/tests/unit/test_block_device.py
@@ -523,7 +523,7 @@ class TestBlockDeviceDict(test.NoDBTestCase):
             if new['snapshot_id']:
                 new['volume_id'] = None
             self.assertThat(
-                block_device.BlockDeviceDict.from_api(api),
+                block_device.BlockDeviceDict.from_api(api, False),
                 matchers.IsSubDictOf(new))
 
     def test_from_api_invalid_blank_id(self):
@@ -534,7 +534,8 @@ class TestBlockDeviceDict(test.NoDBTestCase):
                     'delete_on_termination': True,
                     'boot_index': -1}
         self.assertRaises(exception.InvalidBDMFormat,
-                          block_device.BlockDeviceDict.from_api, api_dict)
+                          block_device.BlockDeviceDict.from_api, api_dict,
+                          False)
 
     def test_from_api_invalid_source_to_local_mapping(self):
         api_dict = {'id': 1,
@@ -542,7 +543,27 @@ class TestBlockDeviceDict(test.NoDBTestCase):
                     'destination_type': 'local',
                     'uuid': 'fake-volume-id-1'}
         self.assertRaises(exception.InvalidBDMFormat,
-                          block_device.BlockDeviceDict.from_api, api_dict)
+                          block_device.BlockDeviceDict.from_api, api_dict,
+                          False)
+
+    def test_from_api_valid_source_to_local_mapping(self):
+        api_dict = {'id': 1,
+                    'source_type': 'image',
+                    'destination_type': 'local',
+                    'volume_id': 'fake-volume-id-1',
+                    'uuid': 1,
+                    'boot_index': 0}
+
+        retexp = block_device.BlockDeviceDict(
+            {'id': 1,
+             'source_type': 'image',
+             'image_id': 1,
+             'destination_type': 'local',
+             'volume_id': 'fake-volume-id-1',
+             'boot_index': 0})
+        self.assertEqual(
+            block_device.BlockDeviceDict.from_api(api_dict, True),
+            retexp)
 
     def test_legacy(self):
         for legacy, new in zip(self.legacy_mapping, self.new_mapping):