Rolling Upgrades: Fix Group OVO

On commit 325f99a64a we bumped group
version to 1.1 when we added 3 new fields but we didn't add backward
compatibility code to version 1.0, which means that we'll break rolling
upgrades if this information is passed between services.

TrivialFix

Change-Id: I855f63073950bd9a6f1e847666cae1d444ee0067

cinder/objects/group.py

@@ -12,13 +12,15 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_utils import versionutils
+from oslo_versionedobjects import fields
+
 from cinder import db
 from cinder import exception
 from cinder.i18n import _
 from cinder import objects
 from cinder.objects import base
 from cinder.objects import fields as c_fields
-from oslo_versionedobjects import fields
 
 
 @base.CinderObjectRegistry.register
@@ -52,6 +54,15 @@ class Group(base.CinderPersistentObject, base.CinderObject,
                                               nullable=True),
     }
 
+    def obj_make_compatible(self, primitive, target_version):
+        """Make an object representation compatible with target version."""
+        super(Group, self).obj_make_compatible(primitive, target_version)
+        target_version = versionutils.convert_version_to_tuple(target_version)
+        if target_version < (1, 1):
+            for key in ('group_snapshot_id', 'source_group_id',
+                        'group_snapshots'):
+                primitive.pop(key, None)
+
     @staticmethod
     def _from_db_object(context, group, db_group,
                         expected_attrs=None):

cinder/tests/unit/objects/test_group.py

@@ -12,11 +12,13 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import ddt
 import mock
 import six
 
 from cinder import exception
 from cinder import objects
+from cinder.objects import base as ovo_base
 from cinder.objects import fields
 from cinder.tests.unit import fake_constants as fake
 from cinder.tests.unit import fake_volume
@@ -35,6 +37,7 @@ fake_group = {
 }
 
 
+@ddt.ddt
 class TestGroup(test_objects.BaseObjectsTestCase):
 
     @mock.patch('cinder.db.sqlalchemy.api.group_get',
@@ -160,6 +163,22 @@ class TestGroup(test_objects.BaseObjectsTestCase):
         self.assertEqual(len(db_volumes), len(group.volumes))
         self._compare(self, db_volumes[0], group.volumes[0])
 
+    @ddt.data('1.10', '1.11')
+    def test_obj_make_compatible(self, version):
+        extra_data = {'group_snapshot_id': fake.GROUP_SNAPSHOT_ID,
+                      'source_group_id': fake.GROUP_ID,
+                      'group_snapshots': objects.GroupSnapshotList()}
+        group = objects.Group(self.context, name='name', **extra_data)
+
+        serializer = ovo_base.CinderObjectSerializer(version)
+        primitive = serializer.serialize_entity(self.context, group)
+
+        converted_group = objects.Group.obj_from_primitive(primitive)
+        is_set = version == '1.11'
+        for key in extra_data:
+            self.assertEqual(is_set, converted_group.obj_attr_is_set(key))
+        self.assertEqual('name', converted_group.name)
+
 
 class TestGroupList(test_objects.BaseObjectsTestCase):
     @mock.patch('cinder.db.group_get_all',