Don't expect meta attributes in object_compat that aren't in the db obj

The object_compat decorator expects to get the Instance object with
'metadata' and 'system_metadata' attributes but if those aren't in the
db instance dict object, Instance._from_db_object will fail with a
KeyError.

In Kilo this happens per refresh_instance_security_rules because in the
compute API code, the instance passed to refresh_instance_security_rules
comes from the call to get the security group(s) which joins on the
instances column, but that doesn't join on the metadata/system_metadata
fields for the instances.  So when the instances get to object_compat in
the compute manager and the db instance dict is converted to the
Instance object, it expects fields that aren't in the dict and we get
the KeyError.

The refresh_instance_security_rules case is fixed in Liberty per commit
12fbe6f082 - in that case the compute API
passes Instance objects to the compute manager so object_compat doesn't
have anything to do, _load_instance just sees instance_or_dict isn't a
dict and ignores it.

We're making this change since (1) it's an obviously wrong assumption in
object_compat and should be fixed and (2) we need to backport this fix
to stable/kilo since it's an upgrade impact for users there.

Closes-Bug: #1484738

Conflicts:
        nova/tests/unit/compute/test_compute.py

NOTE(mriedem): The conflict is due to the unit tests being moved in
kilo, otherwise this is unchanged.

Change-Id: I36a954c095a9aa35879200784dc18e35edf689e6
(cherry picked from commit 9369aab04e)
(cherry picked from commit 08d1153d3b)
This commit is contained in:
Matt Riedemann 2015-09-09 20:29:09 -07:00
parent 3dd5bb32bb
commit dc5ced25c6
2 changed files with 26 additions and 1 deletions

View File

@ -407,6 +407,11 @@ def object_compat(function):
def decorated_function(self, context, *args, **kwargs):
def _load_instance(instance_or_dict):
if isinstance(instance_or_dict, dict):
# try to get metadata and system_metadata for most cases but
# only attempt to load those if the db instance already has
# those fields joined
metas = [meta for meta in ('metadata', 'system_metadata')
if meta in instance_or_dict]
instance = objects.Instance._from_db_object(
context, objects.Instance(), instance_or_dict,
expected_attrs=metas)
@ -414,7 +419,6 @@ def object_compat(function):
return instance
return instance_or_dict
metas = ['metadata', 'system_metadata']
try:
kwargs['instance'] = _load_instance(kwargs['instance'])
except KeyError:

View File

@ -1352,6 +1352,24 @@ class ComputeTestCase(BaseTestCase):
def test_fn(_self, context, instance):
self.assertIsInstance(instance, objects.Instance)
self.assertEqual(instance.uuid, db_inst['uuid'])
self.assertEqual(instance.metadata, db_inst['metadata'])
self.assertEqual(instance.system_metadata,
db_inst['system_metadata'])
test_fn(None, self.context, instance=db_inst)
def test_object_compat_no_metas(self):
# Tests that we don't try to set metadata/system_metadata on the
# instance object using fields that aren't in the db object.
db_inst = fake_instance.fake_db_instance()
db_inst.pop('metadata', None)
db_inst.pop('system_metadata', None)
@compute_manager.object_compat
def test_fn(_self, context, instance):
self.assertIsInstance(instance, objects.Instance)
self.assertEqual(instance.uuid, db_inst['uuid'])
self.assertNotIn('metadata', instance)
self.assertNotIn('system_metadata', instance)
test_fn(None, self.context, instance=db_inst)
def test_object_compat_more_positional_args(self):
@ -1361,6 +1379,9 @@ class ComputeTestCase(BaseTestCase):
def test_fn(_self, context, instance, pos_arg_1, pos_arg_2):
self.assertIsInstance(instance, objects.Instance)
self.assertEqual(instance.uuid, db_inst['uuid'])
self.assertEqual(instance.metadata, db_inst['metadata'])
self.assertEqual(instance.system_metadata,
db_inst['system_metadata'])
self.assertEqual(pos_arg_1, 'fake_pos_arg1')
self.assertEqual(pos_arg_2, 'fake_pos_arg2')