Set ondelete='CASCADE' on foreign key

This commit actually do the samething as this patch:
https://review.openstack.org/#/c/534225/ did. But this commit will
update db after the patch "Some DB version is missing":
https://review.openstack.org/#/c/536713/. In order to avoid the bug
https://bugs.launchpad.net/zun/+bug/1744881. This commit changes the
'ForeignKey' attribute with ondelete='CASCADE' in ContainerAction
and ContainerActionEvent model.

Change-Id: Ib91cc31569a7a3ccc324f36626b4c186ba0b060c

zun/db/sqlalchemy/alembic/versions/50829990c965_add_ondelete_to_container_actions_.py

@@ -0,0 +1,47 @@
+# 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.
+
+"""add ondelete to container_actions_events foreign key
+
+Revision ID: 50829990c965
+Revises: fb9ad4a050f8
+Create Date: 2018-02-02 03:58:14.384716
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '50829990c965'
+down_revision = 'fb9ad4a050f8'
+branch_labels = None
+depends_on = None
+
+from alembic import op
+from sqlalchemy.engine.reflection import Inspector as insp
+
+CONTAINER_ACTIONS_EVENTS = 'container_actions_events'
+CONTAINER_ACTIONS = 'container_actions'
+
+
+def upgrade():
+    bind = op.get_bind()
+
+    inspector = insp.from_engine(bind)
+    foreign_keys = inspector.get_foreign_keys(CONTAINER_ACTIONS_EVENTS)
+
+    for foreign_key in foreign_keys:
+        if foreign_key.get('referred_table') == CONTAINER_ACTIONS:
+            op.drop_constraint(foreign_key.get('name'),
+                               CONTAINER_ACTIONS_EVENTS,
+                               type_="foreignkey")
+            op.create_foreign_key(
+                None, CONTAINER_ACTIONS_EVENTS, CONTAINER_ACTIONS,
+                ['action_id'], ['id'], ondelete='CASCADE')

zun/db/sqlalchemy/alembic/versions/fb9ad4a050f8_drop_container_actions_foreign_key.py

@@ -0,0 +1,46 @@
+# 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.
+
+"""drop_container_actions_foreign_key
+
+Revision ID: fb9ad4a050f8
+Revises: 6ff4d35f4334
+Create Date: 2018-02-02 11:01:46.151429
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'fb9ad4a050f8'
+down_revision = '6ff4d35f4334'
+branch_labels = None
+depends_on = None
+
+from alembic import op
+from sqlalchemy.engine.reflection import Inspector as insp
+
+CONTAINER_ACTIONS = 'container_actions'
+CONTAINER = 'container'
+
+
+def upgrade():
+    bind = op.get_bind()
+
+    inspector = insp.from_engine(bind)
+    foreign_keys = inspector.get_foreign_keys(CONTAINER_ACTIONS)
+
+    for foreign_key in foreign_keys:
+        if foreign_key.get('referred_table') == CONTAINER:
+            op.drop_constraint(foreign_key.get('name'), CONTAINER_ACTIONS,
+                               type_="foreignkey")
+            op.create_foreign_key(
+                None, CONTAINER_ACTIONS, CONTAINER, ['container_uuid'],
+                ['uuid'], ondelete='CASCADE')

zun/db/sqlalchemy/models.py

@@ -422,7 +422,8 @@ class ContainerAction(Base):
 
     id = Column(Integer, primary_key=True, nullable=False)
     action = Column(String(255))
-    container_uuid = Column(String(36), ForeignKey('container.uuid'),
+    container_uuid = Column(String(36),
+                            ForeignKey('container.uuid', ondelete='CASCADE'),
                             nullable=False)
     request_id = Column(String(255))
     user_id = Column(String(255))
@@ -444,7 +445,8 @@ class ContainerActionEvent(Base):
 
     id = Column(Integer, primary_key=True, nullable=False)
     event = Column(String(255))
-    action_id = Column(Integer, ForeignKey('container_actions.id'),
+    action_id = Column(Integer,
+                       ForeignKey('container_actions.id', ondelete='CASCADE'),
                        nullable=False)
     start_time = Column(DateTime, default=timeutils.utcnow)
     finish_time = Column(DateTime)