Add regression test for bug 1825034

The fill_virtual_interface_list online data migration creates a
fake mostly empty instance record to satisfy a foreign key constraint
in the virtual_interfaces table which is used as a marker when paging
across cells to fulfill the migration. The problem is if you list deleted
servers (as admin) with the all_tenants=1 and deleted=1 filters, the API
will fail with a 500 error trying to load the instance.flavor field.

This adds a functional regression test for the bug.

Change-Id: I2030412566dfc6ec23dbf37685f6e6d145f710dc
Related-Bug: #1825034
(cherry picked from commit 91056970b5)

nova/tests/functional/regressions/test_bug_1825034.py

@@ -0,0 +1,91 @@
+# 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 six
+
+from nova import context as nova_context
+from nova.db import api as db_api
+from nova.objects import virtual_interface
+from nova import test
+from nova.tests import fixtures as nova_fixtures
+from nova.tests.functional.api import client as api_client
+from nova.tests.functional import fixtures as func_fixtures
+from nova.tests.functional import integrated_helpers
+from nova.tests.unit.image import fake as fake_image
+
+
+class FillVirtualInterfaceListMigration(
+        test.TestCase, integrated_helpers.InstanceHelperMixin):
+    """Regression test for a bug 1825034 introduced in Stein.
+
+    The fill_virtual_interface_list online data migration creates a mostly
+    empty marker instance record and immediately (soft) deletes it just to
+    satisfy a foreign key constraint with the virtual_interfaces table.
+
+    The problem is since the fake instance marker record is mostly empty,
+    it can fail to load fields in the API when listing deleted servers.
+    """
+
+    def setUp(self):
+        super(FillVirtualInterfaceListMigration, self).setUp()
+        api_fixture = self.useFixture(nova_fixtures.OSAPIFixture(
+            api_version='v2.1'))
+        self.api = api_fixture.admin_api
+        self.useFixture(nova_fixtures.NeutronFixture(self))
+        self.useFixture(func_fixtures.PlacementFixture())
+        self.start_service('conductor')
+        self.start_service('scheduler')
+        self.start_service('compute')
+        # the image fake backend needed for image discovery
+        fake_image.stub_out_image_service(self)
+        self.addCleanup(fake_image.FakeImageService_reset)
+
+    def _create_server(self):
+        server = self.api.post_server({
+            'server': {
+                'flavorRef': '1',
+                'name': 'test_fill_vifs_migration',
+                'networks': [{
+                    'uuid': nova_fixtures.NeutronFixture.network_1['id']
+                }],
+                'imageRef': fake_image.get_valid_image_id()
+            }
+        })
+        return self._wait_for_state_change(self.api, server, 'ACTIVE')
+
+    def test_fill_vifs_migration(self):
+        # Create a test server.
+        self._create_server()
+        # Run the online data migration which will create a (soft-deleted)
+        # marker record.
+        ctxt = nova_context.get_admin_context()
+        virtual_interface.fill_virtual_interface_list(ctxt, max_count=50)
+        # Now archive the deleted instance record.
+        # The following (archive stuff) is used to prove that the migration
+        # created a "fake instance". It is not necessary to trigger the bug.
+        table_to_rows_archived, deleted_instance_uuids = (
+            db_api.archive_deleted_rows(max_rows=1000))
+        self.assertIn('instances', table_to_rows_archived)
+        self.assertEqual(1, table_to_rows_archived['instances'])
+        self.assertEqual(1, len(deleted_instance_uuids))
+        self.assertEqual(virtual_interface.FAKE_UUID,
+                         deleted_instance_uuids[0])
+        # Since the above (archive stuff) removed the fake instance, do the
+        # migration again to recreate it so we can exercise the code path.
+        virtual_interface.fill_virtual_interface_list(ctxt, max_count=50)
+        # Now list deleted servers.
+        # FIXME(mriedem): This blows up trying to load fields (flavor) on the
+        # deleted marker flavor (bug 1825034).
+        ex = self.assertRaises(api_client.OpenStackApiException,
+                               self.api.get_servers,
+                               search_opts={'all_tenants': 1, 'deleted': 1})
+        self.assertIn('OrphanedObjectError', six.text_type(ex))