Test that new tables don't use soft deletes

Soft deletes were deprecated in Mitaka. Whitelist the existing
tables that use soft deletes, and add a test to make sure no new
ones are added.

Change-Id: Ibdf0f0e9944a8d3e71ef7411d14f0054ed17e7b6
Closes-Bug: #1533859

nova/tests/unit/db/test_models.py

@@ -0,0 +1,86 @@
+# Copyright 2016 OpenStack Foundation
+# All Rights Reserved.
+#
+#    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.
+
+from nova.db.sqlalchemy import api_models
+from nova.db.sqlalchemy import models
+from nova import test
+
+
+class TestSoftDeletesDeprecated(test.NoDBTestCase):
+
+    def test_no_new_soft_deletes(self):
+        whitelist = [
+            'agent_builds',
+            'aggregate_hosts',
+            'aggregate_metadata',
+            'aggregates',
+            'block_device_mapping',
+            'bw_usage_cache',
+            'cells',
+            'certificates',
+            'compute_nodes',
+            'console_pools',
+            'consoles',
+            'dns_domains',
+            'fixed_ips',
+            'floating_ips',
+            'instance_actions',
+            'instance_actions_events',
+            'instance_extra',
+            'instance_faults',
+            'instance_group_member',
+            'instance_group_policy',
+            'instance_groups',
+            'instance_id_mappings',
+            'instance_info_caches',
+            'instance_metadata',
+            'instance_system_metadata',
+            'instance_type_extra_specs',
+            'instance_type_projects',
+            'instance_types',
+            'instances',
+            'key_pairs',
+            'migrations',
+            'networks',
+            'pci_devices',
+            'project_user_quotas',
+            'provider_fw_rules',
+            'quota_classes',
+            'quota_usages',
+            'quotas',
+            'reservations',
+            's3_images',
+            'security_group_default_rules',
+            'security_group_instance_association',
+            'security_group_rules',
+            'security_groups',
+            'services',
+            'snapshot_id_mappings',
+            'snapshots',
+            'task_log',
+            'virtual_interfaces',
+            'volume_id_mappings',
+            'volume_usage_cache'
+         ]
+
+        # Soft deletes are deprecated. Whitelist the tables that currently
+        # allow soft deletes. No new tables should be added to this whitelist.
+        tables = []
+        for base in [models.BASE, api_models.API_BASE]:
+            for table_name, table in base.metadata.tables.items():
+                columns = [column.name for column in table.columns]
+                if 'deleted' in columns or 'deleted_at' in columns:
+                    tables.append(table_name)
+        self.assertEqual(whitelist, sorted(tables))