Add get_by_instance_uuids() to InstanceMappingList

This provides a bulk lookup for things that need it, such as the
server_groups api module.

Related to blueprint cells-aware-api

Change-Id: I8bd5c9611b7ba076116aac50f4c9bfea6fb41034

nova/objects/instance_mapping.py

@@ -136,7 +136,8 @@ class InstanceMapping(base.NovaTimestampObject, base.NovaObject):
 class InstanceMappingList(base.ObjectListBase, base.NovaObject):
     # Version 1.0: Initial version
     # Version 1.1: Added get_by_cell_id method.
-    VERSION = '1.1'
+    # Version 1.2: Added get_by_instance_uuids method
+    VERSION = '1.2'
 
     fields = {
         'objects': fields.ListOfObjectsField('InstanceMapping'),
@@ -169,3 +170,17 @@ class InstanceMappingList(base.ObjectListBase, base.NovaObject):
         db_mappings = cls._get_by_cell_id_from_db(context, cell_id)
         return base.obj_make_list(context, cls(), objects.InstanceMapping,
                 db_mappings)
+
+    @staticmethod
+    @db_api.api_context_manager.reader
+    def _get_by_instance_uuids_from_db(context, uuids):
+        return (context.session.query(api_models.InstanceMapping)
+                .options(joinedload('cell_mapping'))
+                .filter(api_models.InstanceMapping.instance_uuid.in_(uuids))
+                .all())
+
+    @base.remotable_classmethod
+    def get_by_instance_uuids(cls, context, uuids):
+        db_mappings = cls._get_by_instance_uuids_from_db(context, uuids)
+        return base.obj_make_list(context, cls(), objects.InstanceMapping,
+                db_mappings)

nova/tests/functional/db/test_instance_mapping.py

@@ -18,6 +18,7 @@ from nova.objects import cell_mapping
 from nova.objects import instance_mapping
 from nova import test
 from nova.tests import fixtures
+from nova.tests import uuidsentinel
 
 
 sample_mapping = {'instance_uuid': '',
@@ -170,3 +171,15 @@ class InstanceMappingListTestCase(test.NoDBTestCase):
         )
         self.assertEqual(1, len(inst_mapping_list))
         self.assertEqual(db_inst_mapping1['id'], inst_mapping_list[0].id)
+
+    def test_instance_mapping_get_by_instance_uuids(self):
+        db_inst_mapping1 = create_mapping()
+        db_inst_mapping2 = create_mapping(cell_id=None)
+        # Create a third that we won't include
+        create_mapping()
+        uuids = [db_inst_mapping1.instance_uuid,
+                 db_inst_mapping2.instance_uuid]
+        mappings = instance_mapping.InstanceMappingList.get_by_instance_uuids(
+            self.context, uuids + [uuidsentinel.deleted_instance])
+        self.assertEqual(sorted(uuids),
+                         sorted([m.instance_uuid for m in mappings]))

nova/tests/unit/objects/test_objects.py

@@ -1111,7 +1111,7 @@ object_data = {
     'InstanceInfoCache': '1.5-cd8b96fefe0fc8d4d337243ba0bf0e1e',
     'InstanceList': '2.2-ff71772c7bf6d72f6ef6eee0199fb1c9',
     'InstanceMapping': '1.0-65de80c491f54d19374703c0753c4d47',
-    'InstanceMappingList': '1.1-14d4a4296c3cbf51e660b657dc37b19e',
+    'InstanceMappingList': '1.2-ee638619aa3d8a82a59c0c83bfa64d78',
     'InstanceNUMACell': '1.4-7c1eb9a198dee076b4de0840e45f4f55',
     'InstanceNUMATopology': '1.3-ec0030cb0402a49c96da7051c037082a',
     'InstancePCIRequest': '1.1-b1d75ebc716cb12906d9d513890092bf',