Avoid error 500 on shelve task_state race

When shelving a server and saving its new SHELVING task state, we
expect the current task state to be None and do not handle any
UnexpectedTaskStateError exceptions that the database layer may throw
at us. In those cases, we return an error 500 to the user, when in
actuality an error 409 conflict would be more appropriate. This
patch makes the API layer handle UnexpectedTaskStateError exceptions
and return a 409 to the user.

Closes-bug: 1850694
Change-Id: Ie0b421cd5d3a5781c1dd09fab4ed013ece0f939d
(cherry picked from commit a423d8b277)
This commit is contained in:
Artom Lifshitz 2019-10-30 14:03:49 -04:00
parent 0bc14aa427
commit 32dbd2f585
2 changed files with 19 additions and 1 deletions

View File

@ -48,7 +48,8 @@ class ShelveController(wsgi.Controller):
'project_id': instance.project_id})
try:
self.compute_api.shelve(context, instance)
except exception.InstanceIsLocked as e:
except (exception.InstanceIsLocked,
exception.UnexpectedTaskStateError) as e:
raise exc.HTTPConflict(explanation=e.format_message())
except exception.InstanceInvalidState as state_error:
common.raise_http_conflict_for_instance_invalid_state(state_error,

View File

@ -21,6 +21,7 @@ import webob
from nova.api.openstack import api_version_request
from nova.api.openstack.compute import shelve as shelve_v21
from nova.compute import task_states
from nova.compute import vm_states
from nova import exception
from nova import policy
@ -46,6 +47,22 @@ class ShelvePolicyTestV21(test.NoDBTestCase):
self.assertRaises(webob.exc.HTTPConflict, self.controller._shelve,
self.req, uuidsentinel.fake, {})
@mock.patch('nova.api.openstack.common.get_instance')
@mock.patch('nova.objects.instance.Instance.save')
def test_shelve_task_state_race(self, mock_save, get_instance_mock):
instance = fake_instance.fake_instance_obj(
self.req.environ['nova.context'],
vm_state=vm_states.ACTIVE, task_state=None)
instance.launched_at = instance.created_at
get_instance_mock.return_value = instance
mock_save.side_effect = exception.UnexpectedTaskStateError(
instance_uuid=instance.uuid, expected=None,
actual=task_states.SHELVING)
ex = self.assertRaises(webob.exc.HTTPConflict, self.controller._shelve,
self.req, uuidsentinel.fake, body={'shelve': {}})
self.assertIn('Conflict updating instance', six.text_type(ex))
mock_save.assert_called_once_with(expected_task_state=[None])
@mock.patch('nova.api.openstack.common.get_instance')
def test_unshelve_locked_server(self, get_instance_mock):
get_instance_mock.return_value = (