Avoid lazy-loading projects during flavor notification

This makes the flavor notification not load the flavor's projects
if they are not already set. Even though we attempted to orphan the
instance-bound flavors in a recent change[1], there are other times
where we were loading projects purely for the notification. This
lazy-load physically will not work if we're in the cell, and is
never something we want to do when we're an instance-bound flavor.

This makes us check to see if projects are loaded, and if so, clone
the flavor to notify on, and set projects on that clone to an
empty list.

[1]: This effectively reverts I458f81931bad7874e951e1c0fd464d149f61b244
which solved the problem in some places, but not all.

Change-Id: I0f80f101a528ab9cda81d025cf316f2ac16bdcb7

nova/notifications/objects/flavor.py

@@ -75,6 +75,13 @@ class FlavorPayload(base.NotificationPayloadBase):
 
     def __init__(self, flavor, **kwargs):
         super(FlavorPayload, self).__init__(**kwargs)
+        if 'projects' not in flavor:
+            # NOTE(danms): If projects is not loaded in the flavor,
+            # don't attempt to load it. If we're in a child cell then
+            # we can't load the real flavor, and if we're a flavor on
+            # an instance then we don't want to anyway.
+            flavor = flavor.obj_clone()
+            flavor._context = None
         self.populate_schema(flavor=flavor)
 
     def obj_make_compatible(self, primitive, target_version):

nova/objects/flavor.py

@@ -610,6 +610,11 @@ def destroy(self):
             db.flavor_destroy(self._context, self.flavorid)
 
     def _send_notification(self, action):
+        # NOTE(danms): Instead of making the below notification
+        # lazy-load projects (which is a problem for instance-bound
+        # flavors and compute-cell operations), just load them here.
+        if 'projects' not in self:
+            self._load_projects()
         notification_type = flavor_notification.FlavorNotification
         payload_type = flavor_notification.FlavorPayload
 

nova/objects/instance.py

@@ -272,19 +272,6 @@ def _obj_from_primitive(cls, context, objver, primitive):
         self = super(Instance, cls)._obj_from_primitive(context, objver,
                                                         primitive)
         self._reset_metadata_tracking()
-
-        # Note(gibi): The flavors stored in the instance should not be used
-        # for lazy load data from the db as these objects aren't connected to
-        # real flavor objects in the db. However during RPC deserialization
-        # every object gets a valid context so we have to orphan the flavors
-        # again.
-        if self.obj_attr_is_set('flavor'):
-            self.flavor._context = None
-        if self.obj_attr_is_set('old_flavor') and self.old_flavor:
-            self.old_flavor._context = None
-        if self.obj_attr_is_set('new_flavor') and self.new_flavor:
-            self.new_flavor._context = None
-
         return self
 
     @property

nova/tests/unit/objects/test_instance.py

@@ -1518,30 +1518,6 @@ def test_obj_clone(self):
         inst1 = inst1.obj_clone()
         self.assertEqual(len(inst1.obj_what_changed()), 0)
 
-    def test_flavor_deserialization_orphans_flavor(self):
-        flavor = objects.Flavor(context=self.context,
-                                name='test-flavor',
-                                memory_mb=1024,
-                                root_gb=0,
-                                vcpus=1,
-                                flavorid="m1.test")
-        flavor.create()
-        inst = objects.Instance(context=self.context,
-                                user_id=self.context.user_id,
-                                project_id=self.context.project_id,
-                                flavor=flavor,
-                                old_flavor=flavor,
-                                new_flavor=flavor)
-        inst.create()
-
-        inst = objects.Instance.get_by_uuid(self.context,
-                                            uuid=inst.uuid,
-                                            expected_attrs=['flavor'])
-
-        self.assertIsNone(inst.flavor._context)
-        self.assertIsNone(inst.old_flavor._context)
-        self.assertIsNone(inst.new_flavor._context)
-
 
 class TestInstanceObject(test_objects._LocalTest,
                          _TestInstanceObject):