From eec39762cf5343b354e2ac06a6682a7c3b4230c2 Mon Sep 17 00:00:00 2001 From: Matthew Booth Date: Fri, 22 Mar 2019 11:47:32 +0000 Subject: [PATCH] Fix incomplete instance data returned after build failure This change fixes a race in _cleanup_build_artifacts. We were updating the instance mapping to point at the cell in which the instance was created before the instance record was complete, i.e. before the related BDMs and tags were created in the cell DB. Updating the instance mapping exposes the cell's version of the instance to the API. If the API happened to fetch it before it was finished being created it would return incomplete data. Co-Authored-By: Matt Riedemann Closes-Bug: #1820337 Change-Id: If966eb1161c842ff49aa530e4482dbca87b61a3e (cherry picked from commit 64f6cbc9120e3c288f312eddc59452dee4998f93) --- nova/conductor/manager.py | 19 +++++--- nova/tests/unit/conductor/test_conductor.py | 54 +++++++++++++++++++++ 2 files changed, 66 insertions(+), 7 deletions(-) diff --git a/nova/conductor/manager.py b/nova/conductor/manager.py index 854e147ab5ce..10354a5f1576 100644 --- a/nova/conductor/manager.py +++ b/nova/conductor/manager.py @@ -1514,13 +1514,6 @@ class ComputeTaskManager(base.Base): 'build_instances', updates, exc, request_spec) - # TODO(mnaser): The cell mapping should already be populated by - # this point to avoid setting it below here. - inst_mapping = objects.InstanceMapping.get_by_instance_uuid( - context, instance.uuid) - inst_mapping.cell_mapping = cell - inst_mapping.save() - # In order to properly clean-up volumes when deleting a server in # ERROR status with no host, we need to store BDMs in the same # cell. @@ -1536,6 +1529,18 @@ class ComputeTaskManager(base.Base): with nova_context.target_cell(context, cell) as cctxt: self._create_tags(cctxt, instance.uuid, tags) + # NOTE(mdbooth): To avoid an incomplete instance record being + # returned by the API, the instance mapping must be + # created after the instance record is complete in + # the cell, and before the build request is + # destroyed. + # TODO(mnaser): The cell mapping should already be populated by + # this point to avoid setting it below here. + inst_mapping = objects.InstanceMapping.get_by_instance_uuid( + context, instance.uuid) + inst_mapping.cell_mapping = cell + inst_mapping.save() + # Be paranoid about artifacts being deleted underneath us. try: build_request.destroy() diff --git a/nova/tests/unit/conductor/test_conductor.py b/nova/tests/unit/conductor/test_conductor.py index b3d786ec7ac2..99dde54c251c 100644 --- a/nova/tests/unit/conductor/test_conductor.py +++ b/nova/tests/unit/conductor/test_conductor.py @@ -2179,6 +2179,60 @@ class ConductorTaskTestCase(_BaseTaskTestCase, test_compute.BaseTestCase): self.params['request_specs'][0].requested_resources = [] self._do_schedule_and_build_instances_test(self.params) + @mock.patch('nova.objects.InstanceMapping.get_by_instance_uuid') + def test_cleanup_build_artifacts(self, inst_map_get): + """Simple test to ensure the order of operations in the cleanup method + is enforced. + """ + req_spec = fake_request_spec.fake_spec_obj() + build_req = fake_build_request.fake_req_obj(self.context) + instance = build_req.instance + bdms = objects.BlockDeviceMappingList(objects=[ + objects.BlockDeviceMapping(instance_uuid=instance.uuid)]) + tags = objects.TagList(objects=[objects.Tag(tag='test')]) + cell1 = self.cell_mappings['cell1'] + cell_mapping_cache = {instance.uuid: cell1} + err = exc.TooManyInstances('test') + + # We need to assert that BDMs and tags are created in the cell DB + # before the instance mapping is updated. + def fake_create_block_device_mapping(*args, **kwargs): + inst_map_get.return_value.save.assert_not_called() + + def fake_create_tags(*args, **kwargs): + inst_map_get.return_value.save.assert_not_called() + + with test.nested( + mock.patch.object(self.conductor_manager, + '_set_vm_state_and_notify'), + mock.patch.object(self.conductor_manager, + '_create_block_device_mapping', + side_effect=fake_create_block_device_mapping), + mock.patch.object(self.conductor_manager, '_create_tags', + side_effect=fake_create_tags), + mock.patch.object(build_req, 'destroy'), + mock.patch.object(req_spec, 'destroy'), + ) as ( + _set_vm_state_and_notify, _create_block_device_mapping, + _create_tags, build_req_destroy, req_spec_destroy, + ): + self.conductor_manager._cleanup_build_artifacts( + self.context, err, [instance], [build_req], [req_spec], bdms, + tags, cell_mapping_cache) + # Assert the various mock calls. + _set_vm_state_and_notify.assert_called_once_with( + test.MatchType(context.RequestContext), instance.uuid, + 'build_instances', + {'vm_state': vm_states.ERROR, 'task_state': None}, err, req_spec) + _create_block_device_mapping.assert_called_once_with( + cell1, instance.flavor, instance.uuid, bdms) + _create_tags.assert_called_once_with( + test.MatchType(context.RequestContext), instance.uuid, tags) + inst_map_get.return_value.save.assert_called_once_with() + self.assertEqual(cell1, inst_map_get.return_value.cell_mapping) + build_req_destroy.assert_called_once_with() + req_spec_destroy.assert_called_once_with() + @mock.patch('nova.objects.CellMapping.get_by_uuid') def test_bury_in_cell0_no_cell0(self, mock_cm_get): mock_cm_get.side_effect = exc.CellMappingNotFound(uuid='0')