Drop foreign key contraints of alarm in sqlalchemy

This patch drops the foreign key constraints of alarms to user_id and
project_id in sqlalchemy.

Closes-Bug: 1260176
Change-Id: I7336ee1e3f885421db5aae3a30af0e918b79450b

ceilometer/storage/impl_sqlalchemy.py

@@ -312,8 +312,6 @@ class Connection(base.Connection):
             query = session.query(models.User).filter(
                 ~models.User.id.in_(session.query(models.Meter.user_id)
                                     .group_by(models.Meter.user_id)),
-                ~models.User.id.in_(session.query(models.Alarm.user_id)
-                                    .group_by(models.Alarm.user_id)),
                 ~models.User.id.in_(session.query(models.AlarmChange.user_id)
                                     .group_by(models.AlarmChange.user_id))
             )
@@ -324,9 +322,6 @@ class Connection(base.Connection):
                 .filter(~models.Project.id.in_(
                     session.query(models.Meter.project_id)
                         .group_by(models.Meter.project_id)),
-                        ~models.Project.id.in_(
-                            session.query(models.Alarm.project_id)
-                            .group_by(models.Alarm.project_id)),
                         ~models.Project.id.in_(
                             session.query(models.AlarmChange.project_id)
                             .group_by(models.AlarmChange.project_id)),
@@ -729,10 +724,6 @@ class Connection(base.Connection):
         """
         session = sqlalchemy_session.get_session()
         with session.begin():
-            Connection._create_or_update(session, models.User,
-                                         alarm.user_id)
-            Connection._create_or_update(session, models.Project,
-                                         alarm.project_id)
             alarm_row = models.Alarm(id=alarm.alarm_id)
             alarm_row.update(alarm.as_dict())
             session.add(alarm_row)

ceilometer/storage/sqlalchemy/migrate_repo/versions/027_remove_alarm_fk_constraints.py

@@ -0,0 +1,78 @@
+# -*- encoding: utf-8 -*-
+#
+# Copyright © 2014 Intel Crop.
+#
+# Author: Lianhao Lu <lianhao.lu@intel.com>
+#
+# 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 import ForeignKeyConstraint
+from sqlalchemy import MetaData, Table
+from sqlalchemy.sql.expression import select
+
+from ceilometer.openstack.common.db.sqlalchemy import utils
+
+TABLES = ['user', 'project', 'alarm']
+
+INDEXES = {
+    "alarm": (('user_id', 'user', 'id'),
+              ('project_id', 'project', 'id')),
+}
+
+
+def upgrade(migrate_engine):
+    if migrate_engine.name == 'sqlite':
+        return
+    meta = MetaData(bind=migrate_engine)
+    load_tables = dict((table_name, Table(table_name, meta, autoload=True))
+                       for table_name in TABLES)
+    for table_name, indexes in INDEXES.items():
+        table = load_tables[table_name]
+        for column, ref_table_name, ref_column_name in indexes:
+            ref_table = load_tables[ref_table_name]
+            params = {'columns': [table.c[column]],
+                      'refcolumns': [ref_table.c[ref_column_name]]}
+            if migrate_engine.name == 'mysql':
+                params['name'] = "_".join(('fk', table_name, column))
+            fkey = ForeignKeyConstraint(**params)
+            fkey.drop()
+
+
+def downgrade(migrate_engine):
+    if migrate_engine.name == 'sqlite':
+        return
+    meta = MetaData(bind=migrate_engine)
+    load_tables = dict((table_name, Table(table_name, meta, autoload=True))
+                       for table_name in TABLES)
+    for table_name, indexes in INDEXES.items():
+        table = load_tables[table_name]
+        # Save data that conflicted with FK.
+        columns = [column.copy() for column in table.columns]
+        table_dump = Table('dump027_' + table_name, meta, *columns)
+        table_dump.create()
+        for column, ref_table_name, ref_column_name in indexes:
+            ref_table = load_tables[ref_table_name]
+            subq = select([getattr(ref_table.c, ref_column_name)])
+            sql = utils.InsertFromSelect(table_dump, table.select().where(
+                ~ getattr(table.c, column).in_(subq)))
+            sql_del = table.delete().where(
+                ~ getattr(table.c, column).in_(subq))
+            migrate_engine.execute(sql)
+            migrate_engine.execute(sql_del)
+
+            params = {'columns': [table.c[column]],
+                      'refcolumns': [ref_table.c[ref_column_name]]}
+            if migrate_engine.name == 'mysql':
+                params['name'] = "_".join(('fk', table_name, column))
+            fkey = ForeignKeyConstraint(**params)
+            fkey.create()

ceilometer/storage/sqlalchemy/models.py

@@ -267,8 +267,8 @@ class Alarm(Base):
     description = Column(Text)
     timestamp = Column(PreciseTimestamp, default=timeutils.utcnow)
 
-    user_id = Column(String(255), ForeignKey('user.id'))
-    project_id = Column(String(255), ForeignKey('project.id'))
+    user_id = Column(String(255))
+    project_id = Column(String(255))
 
     state = Column(String(255))
     state_timestamp = Column(PreciseTimestamp, default=timeutils.utcnow)

ceilometer/tests/storage/test_storage_scenarios.py

@@ -695,16 +695,15 @@ class RawSampleTest(DBTestBase,
         self.conn.create_alarm(alarm)
         timeutils.utcnow.override_time = datetime.datetime(2012, 7, 2, 10, 45)
         self.conn.clear_expired_metering_data(5)
-        # user and project with Alarms associated with it aren't deleted.
         f = storage.SampleFilter(meter='instance')
         results = list(self.conn.get_samples(f))
         self.assertEqual(len(results), 2)
         results = list(self.conn.get_users())
-        self.assertEqual(len(results), 3)
-        self.assertIn('user-id', results)
+        self.assertEqual(len(results), 2)
+        self.assertNotIn('user-id', results)
         results = list(self.conn.get_projects())
-        self.assertEqual(len(results), 3)
-        self.assertIn('project-id', results)
+        self.assertEqual(len(results), 2)
+        self.assertNotIn('project-id', results)
         results = list(self.conn.get_resources())
         self.assertEqual(len(results), 2)