Add functional regression test for bug 1778305

This tests the scenario where an operator has upgraded from Ocata =>
Pike but has old, deleted services that share the same hostname with
currently existing, running services. The current behavior is that
ServiceTooOld is raised when we try to generate a UUID for the old,
deleted service while querying for a list of instances. After the bug
is fixed, we should be able to successfully query for a list of
instances.

Related-Bug: #1778305

Change-Id: I1c62a0a5be6c44176b5714af00cc181eb5437585
(cherry picked from commit 1d9aaef)
(cherry picked from commit 06ae1ff)

Author: melwitt

nova/tests/functional/regressions/test_bug_1778305.py

@@ -0,0 +1,67 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import nova.context
+from nova.db import api as db
+from nova import objects
+from nova import test
+
+
+class InstanceListWithOldDeletedServiceTestCase(test.TestCase):
+
+    def setUp(self):
+        super(InstanceListWithOldDeletedServiceTestCase, self).setUp()
+        self.context = nova.context.RequestContext('fake-user', 'fake-project')
+
+    def test_instance_list_old_deleted_service_with_no_uuid(self):
+        # Create a nova-compute service record with a host that will match the
+        # instance's host, with no uuid. We can't do this through the
+        # Service object because it will automatically generate a uuid.
+        # Use service version 9, which is too old compared to the minimum
+        # version in the rest of the deployment.
+        service = db.service_create(self.context, {'host': 'fake-host',
+                                                   'binary': 'nova-compute',
+                                                   'version': 9})
+        self.assertIsNone(service['uuid'])
+
+        # Now delete it.
+        db.service_destroy(self.context, service['id'])
+
+        # Create a new service with the same host name that has a UUID and a
+        # current version.
+        new_service = objects.Service(context=self.context, host='fake-host',
+                                      binary='nova-compute')
+        new_service.create()
+
+        # Create an instance whose host will match both services, including the
+        # deleted one.
+        inst = objects.Instance(context=self.context,
+                                project_id=self.context.project_id,
+                                host='fake-host')
+        inst.create()
+
+        # TODO(melwitt): Remove this assert when the bug is fixed.
+        self.assertRaises(nova.exception.ServiceTooOld,
+                          objects.InstanceList.get_by_filters,
+                          self.context, {}, expected_attrs=['services'])
+
+        # TODO(melwitt): Uncomment these asserts when the bug is fixed.
+        # insts = objects.InstanceList.get_by_filters(
+        #    self.context, {}, expected_attrs=['services'])
+        # self.assertEqual(1, len(insts))
+        # self.assertEqual(2, len(insts[0].services))
+        # Deleted service should not have a UUID
+        # for service in insts[0].services:
+        #    if service.deleted:
+        #        self.assertNotIn('uuid', service)
+        #    else:
+        #        self.assertIsNotNone(service.uuid)