Merge "compute: Ensure updates to bdms during pre_live_migration are saved" into stable/wallaby

Author: Zuul

nova/compute/manager.py

@@ -8214,6 +8214,14 @@ def pre_live_migration(self, context, instance, disk, migrate_data):
             self.network_api.setup_networks_on_host(context, instance,
                                                              self.host)
 
+            # NOTE(lyarwood): The above call to driver.pre_live_migration
+            # can result in the virt drivers attempting to stash additional
+            # metadata into the connection_info of the underlying bdm.
+            # Ensure this is saved to the database by calling .save() against
+            # the driver BDMs we passed down via block_device_info.
+            for driver_bdm in block_device_info['block_device_mapping']:
+                driver_bdm.save()
+
         except Exception:
             # If we raise, migrate_data with the updated attachment ids
             # will not be returned to the source host for rollback.

nova/tests/functional/regressions/test_bug_1939545.py

@@ -103,9 +103,9 @@ def test_live_migrate_update_device_path(
         # Live migrate the instance to another host
         self._live_migrate(self.server)
 
-        # FIXME(lyarwood): This is bug #1939545, again get the volume bdm and
-        # assert that the saved connection_info doesn't contain device_path.
+        # Again get the volume bdm and assert that the saved connection_info
+        # contains device_path.
         bdm = objects.BlockDeviceMapping.get_by_volume_and_instance(
             ctxt, volume_id, self.server['id'])
         connection_info = jsonutils.loads(bdm.connection_info)
-        self.assertNotIn('device_path', connection_info.get('data'))
+        self.assertIn('device_path', connection_info.get('data'))

nova/tests/unit/compute/test_compute_mgr.py

@@ -9220,6 +9220,10 @@ def _test(mock_attach, mock_get_bdms, mock_ivbi,
                   mock_gibdi, mock_plm, mock_nwapi, mock_notify,
                   mock_bdm_save, mock_attach_complete, mock_notify_about_inst):
 
+            mock_driver_bdm = mock.Mock(spec=driver_bdm_volume)
+            mock_gibdi.return_value = {
+                'block_device_mapping': [mock_driver_bdm]}
+
             mock_get_bdms.return_value = [vol_bdm, image_bdm]
             mock_attach.return_value = {'id': new_attachment_id}
             mock_plm.return_value = migrate_data
@@ -9244,7 +9248,10 @@ def _test(mock_attach, mock_get_bdms, mock_ivbi,
             self.assertEqual(vol_bdm.attachment_id, new_attachment_id)
             self.assertEqual(migrate_data.old_vol_attachment_ids[volume_id],
                              orig_attachment_id)
+            # Initially save of the attachment_id
             mock_bdm_save.assert_called_once_with()
+            # Later save via the driver bdm for connection_info updates etc.
+            mock_driver_bdm.save.assert_called_once_with()
             mock_attach_complete.assert_called_once_with(self.context,
                                                          new_attachment_id)