Merge "Raise RetryRequest on policy parent not found" into stable/liberty

neutron/policy.py

@@ -21,6 +21,7 @@ import collections
 import re
 
 from oslo_config import cfg
+from oslo_db import exception as db_exc
 from oslo_log import log as logging
 from oslo_policy import policy
 from oslo_utils import excutils
@@ -261,6 +262,13 @@ class OwnerCheck(policy.Check):
                          target[parent_foreign_key],
                          fields=[parent_field])
                 target[self.target_field] = data[parent_field]
+            except exceptions.NotFound as e:
+                # NOTE(kevinbenton): a NotFound exception can occur if a
+                # list operation is happening at the same time as one of
+                # the parents and its children being deleted. So we issue
+                # a RetryRequest so the API will redo the lookup and the
+                # problem items will be gone.
+                raise db_exc.RetryRequest(e)
             except Exception:
                 with excutils.save_and_reraise_exception():
                     LOG.exception(_LE('Policy check error while calling %s!'),

neutron/tests/unit/test_policy.py

@@ -16,6 +16,7 @@
 """Test of Policy Engine For Neutron"""
 
 import mock
+from oslo_db import exception as db_exc
 from oslo_policy import policy as oslo_policy
 from oslo_serialization import jsonutils
 from oslo_utils import importutils
@@ -538,6 +539,18 @@ class NeutronPolicyTestCase(base.BaseTestCase):
                               action,
                               target)
 
+    def test_retryrequest_on_notfound(self):
+        failure = exceptions.NetworkNotFound(net_id='whatever')
+        action = "create_port:mac"
+        with mock.patch.object(manager.NeutronManager.get_instance().plugin,
+                               'get_network', side_effect=failure):
+            target = {'network_id': 'whatever'}
+            try:
+                policy.enforce(self.context, action, target)
+                self.fail("Did not raise RetryRequest")
+            except db_exc.RetryRequest as e:
+                self.assertEqual(failure, e.inner_exc)
+
     def test_enforce_tenant_id_check_parent_resource_bw_compatibility(self):
 
         def fakegetnetwork(*args, **kwargs):