Add missing unique constraint

There is missing unique constraint in chassis table.
This patch adds missing UC in separate migration.

Change-Id: If4640d09a19bbd1548375fa6817e9d926c805c7c

ironic/db/sqlalchemy/migrate_repo/versions/011_add_chassis_uc.py

@@ -0,0 +1,30 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+# -*- encoding: utf-8 -*-
+#
+#    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 migrate.changeset import UniqueConstraint
+from sqlalchemy import MetaData, Table
+
+
+def upgrade(migrate_engine):
+    meta = MetaData(bind=migrate_engine)
+    t = Table('chassis', meta, autoload=True)
+
+    # NOTE: new name convention for UC
+    uc = UniqueConstraint('uuid', table=t, name='uniq_chassis0uuid')
+    uc.create()
+
+
+def downgrade(migrate_engine):
+    raise NotImplementedError('Downgrade from version 011 is unsupported.')

ironic/db/sqlalchemy/models.py

@@ -84,6 +84,9 @@ class Chassis(Base):
     """Represents a hardware chassis."""
 
     __tablename__ = 'chassis'
+    __table_args__ = (
+        schema.UniqueConstraint('uuid', name='uniq_chassis0uuid'),
+        )
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36))
     extra = Column(JSONEncodedDict)

ironic/tests/db/sqlalchemy/test_migrations.py

@@ -680,3 +680,11 @@ class TestMigrations(BaseMigrationTestCase, WalkVersionsMixin):
         self.assertEqual(f_key['referred_table'], 'chassis')
         self.assertEqual(f_key['referred_columns'], ['id'])
         self.assertEqual(f_key['constrained_columns'], ['chassis_id'])
+
+    def _check_011(self, engine, data):
+        chassis = db_utils.get_table(engine, 'chassis')
+        chassis_data = {'uuid': 'uuu-111-222', 'extra': 'extra1'}
+        chassis.insert().values(chassis_data).execute()
+        self.assertRaises(sqlalchemy.exc.IntegrityError,
+                          chassis.insert().execute,
+                          {'uuid': 'uuu-111-222', 'extra': 'extra2'})