Change alarm_history.detail to text type

The existing alarm_history.detail column size is 255 chars,
which is not enough for some large JSON payloads.

Change to Text column to make sure we store all detail.

Change-Id: I1b4ebee33954acc1f41a4cf0d0b991055b7d4fe9
Closes-Bug: #1236861
Signed-off-by: Stephen Gran <stephen.gran@guardian.co.uk>

ceilometer/storage/sqlalchemy/migrate_repo/versions/019_alarm_history_detail_is_text.py

@@ -0,0 +1,38 @@
+# -*- encoding: utf-8 -*-
+
+# 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 String
+from sqlalchemy import Text
+from sqlalchemy import MetaData
+from sqlalchemy import Table
+
+
+meta = MetaData()
+
+
+def upgrade(migrate_engine):
+    meta.bind = migrate_engine
+    alm_hist = Table('alarm_history', meta, autoload=True)
+    alm_hist.c.detail.alter(type=Text)
+
+
+def downgrade(migrate_engine):
+    meta.bind = migrate_engine
+    alm_hist = Table('alarm_history', meta, autoload=True)
+    alm_hist.c.detail.alter(type=String(255))

ceilometer/storage/sqlalchemy/models.py

@@ -237,7 +237,7 @@ class AlarmChange(Base):
     project_id = Column(String(255), ForeignKey('project.id'))
     user_id = Column(String(255), ForeignKey('user.id'))
     type = Column(String(20))
-    detail = Column(String(255))
+    detail = Column(Text)
     timestamp = Column(DateTime, default=timeutils.utcnow)