Follow up to I5b9d41ef34385689d8da9b3962a1eac759eddf6a

This addresses the TODO based on the review comment here [1].

[1] https://review.opendev.org/#/c/637070/56/nova/conductor/tasks/cross_cell_migrate.py@970

Part of blueprint cross-cell-resize

Change-Id: Ic48a73cc7e25a8f639aaec3e7ca59224184c495b

nova/conductor/tasks/cross_cell_migrate.py

@@ -24,6 +24,7 @@ from nova.compute import task_states
 from nova.compute import utils as compute_utils
 from nova.compute import vm_states
 from nova.conductor.tasks import base
+from nova import conf
 from nova import context as nova_context
 from nova import exception
 from nova.i18n import _
@@ -36,6 +37,7 @@ from nova.scheduler import utils as scheduler_utils
 from nova.volume import cinder
 
 LOG = logging.getLogger(__name__)
+CONF = conf.CONF
 
 
 def clone_creatable_object(ctxt, obj, delete_fields=None):
@@ -967,7 +969,7 @@ class ConfirmResizeTask(base.TaskBase):
             self.legacy_notifier, ctxt, instance, 'resize.confirm.%s' % phase)
         # Send the versioned notification.
         compute_utils.notify_about_instance_action(
-            ctxt, instance, instance.host,  # TODO(mriedem): Use CONF.host?
+            ctxt, instance, CONF.host,
             action=fields.NotificationAction.RESIZE_CONFIRM,
             phase=phase)
 

nova/tests/unit/conductor/tasks/test_cross_cell_migrate.py

@@ -1203,13 +1203,14 @@ class ConfirmResizeTaskTestCase(test.NoDBTestCase):
     @mock.patch('nova.compute.utils.notify_about_instance_action')
     def test_send_resize_confirm_notification(self, mock_versioned_notify,
                                               mock_legacy_notify):
+        self.flags(host='fake-conductor-host')
         instance = self.task.instance
         self.task._send_resize_confirm_notification(instance, 'fake-phase')
         mock_legacy_notify.assert_called_once_with(
             self.task.legacy_notifier, instance._context, instance,
             'resize.confirm.fake-phase')
         mock_versioned_notify.assert_called_once_with(
-            instance._context, instance, instance.host,
+            instance._context, instance, 'fake-conductor-host',
             action=fields.NotificationAction.RESIZE_CONFIRM,
             phase='fake-phase')