add InstanceGroup.get_by_instance_uuid

Add a new method to the InstanceGroup object that lets you get a group
by an instance UUID.  Right now Nova only lets you have an instance in
a single group, so that's why this is a method of InstanceGroup and
not InstanceGroupList.

Change-Id: Ic0181e241471ad817284209e6a1093a438962bf1
Related-bug: #1379451

nova/objects/instance_group.py

@@ -31,7 +31,8 @@ class InstanceGroup(base.NovaPersistentObject, base.NovaObject):
     # Version 1.6: Add get_by_name()
     # Version 1.7: Deprecate metadetails
     # Version 1.8: Add count_members_by_user()
-    VERSION = '1.8'
+    # Version 1.9: Add get_by_instance_uuid()
+    VERSION = '1.9'
 
     fields = {
         'id': fields.IntegerField(),
@@ -89,6 +90,11 @@ class InstanceGroup(base.NovaPersistentObject, base.NovaObject):
 
         raise exception.InstanceGroupNotFound(group_uuid=name)
 
+    @base.remotable_classmethod
+    def get_by_instance_uuid(cls, context, instance_uuid):
+        db_inst = db.instance_group_get_by_instance(context, instance_uuid)
+        return cls._from_db_object(context, cls(), db_inst)
+
     @classmethod
     def get_by_hint(cls, context, hint):
         if uuidutils.is_uuid_like(hint):
@@ -179,7 +185,8 @@ class InstanceGroupList(base.ObjectListBase, base.NovaObject):
     # Version 1.3: InstanceGroup <= version 1.6
     # Version 1.4: InstanceGroup <= version 1.7
     # Version 1.5: InstanceGroup <= version 1.8
-    VERSION = '1.5'
+    # Version 1.6: InstanceGroup <= version 1.9
+    VERSION = '1.6'
 
     fields = {
         'objects': fields.ListOfObjectsField('InstanceGroup'),
@@ -192,6 +199,7 @@ class InstanceGroupList(base.ObjectListBase, base.NovaObject):
         '1.3': '1.6',
         '1.4': '1.7',
         '1.5': '1.8',
+        '1.6': '1.9',
         }
 
     @base.remotable_classmethod

nova/tests/objects/test_instance_group.py

@@ -54,6 +54,17 @@ class _TestInstanceGroupObjects(test.TestCase):
         self.assertEqual(obj_result.members, members)
         self.assertEqual(obj_result.policies, policies)
 
+    def test_get_by_instance_uuid(self):
+        values = self._get_default_values()
+        policies = ['policy1', 'policy2']
+        members = ['instance_id1', 'instance_id2']
+        db_result = self._create_instance_group(self.context, values,
+                                                policies=policies,
+                                                members=members)
+        obj_result = instance_group.InstanceGroup.get_by_instance_uuid(
+                self.context, 'instance_id1')
+        self.assertEqual(obj_result.uuid, db_result.uuid)
+
     def test_refresh(self):
         values = self._get_default_values()
         db_result = self._create_instance_group(self.context, values)

nova/tests/objects/test_objects.py

@@ -958,8 +958,8 @@ object_data = {
     'InstanceExternalEvent': '1.0-f1134523654407a875fd59b80f759ee7',
     'InstanceFault': '1.2-313438e37e9d358f3566c85f6ddb2d3e',
     'InstanceFaultList': '1.1-aeb598ffd0cd6aa61fca7adf0f5e900d',
-    'InstanceGroup': '1.8-9f3ef6ee21e424f817f76a63d35eb803',
-    'InstanceGroupList': '1.5-b507229896d60fad117cb3223dbaa0cc',
+    'InstanceGroup': '1.9-95ece99f092e8f4f88327cdbb44162c9',
+    'InstanceGroupList': '1.6-c6b78f3c9d9080d33c08667e80589817',
     'InstanceInfoCache': '1.5-ef64b604498bfa505a8c93747a9d8b2f',
     'InstanceList': '1.9-6f290799b0ac19eb9e72ed580520b883',
     'InstancePCIRequest': '1.1-e082d174f4643e5756ba098c47c1510f',