Add migration 021 set_engine_mysql_innodb

Change: I1536c9276bc807aac26849e37556b465e8b5c9eb which added
migration 018 neglected to set the mysql engine to InnoDB
when it added the image_locations table. This commit adds a
new migration to set the image_locations table to the InnoDB
engine.

Change-Id: I935065d8e1929d5df075cc5c7de81793b1dd73a1

glance/db/sqlalchemy/migrate_repo/versions/021_set_engine_mysql_innodb.py

@@ -0,0 +1,37 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 OpenStack Foundation
+# All Rights Reserved.
+# Copyright 2013 IBM Corp.
+#
+#    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 sqlalchemy import MetaData
+
+tables = ['image_locations']
+
+
+def upgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    if migrate_engine.name == "mysql":
+        d = migrate_engine.execute("SHOW TABLE STATUS WHERE Engine!='InnoDB';")
+        for row in d.fetchall():
+            table_name = row[0]
+            if table_name in tables:
+                migrate_engine.execute("ALTER TABLE %s Engine=InnoDB" %
+                                       table_name)
+
+
+def downgrade(migrate_engine):
+    pass