Give a way to save why a service has been disabled.

Implements blueprint record-reason-for-disabling-service

We added a field to the service table to log a reason when a service has
been disabled.
We added a new API extension called os-extended-services. The new extension
will extend the os-services extension adding:
- A method for disabling a service and specify a reason for that.

PUT /v2/{tenant_id}/os-services/disable-log-reason

When the os-extended-extension is loaded the call:

GET /V2/{tenant_id}/os-services
will return the list of services with reason information it that exists.

DocImpact
Change-Id: I87a4affc45160796ff11c7b03e591e6aba73d62a

2 files changed, 37 insertions, 0 deletions

diff --git a/nova/db/sqlalchemy/migrate_repo/versions/188_add_reason_column_to_service.py b/nova/db/sqlalchemy/migrate_repo/versions/188_add_reason_column_to_service.py
new file mode 100644
index 000000000..ed87bcfeb
--- /dev/null
+++ b/nova/db/sqlalchemy/migrate_repo/versions/188_add_reason_column_to_service.py
@@ -0,0 +1,36 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 OpenStack Foundation.
+#
+#    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 Column, MetaData, String, Table
+
+
+def upgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    services = Table('services', meta, autoload=True)
+    reason = Column('disabled_reason', String(255))
+    services.create_column(reason)
+    shadow_services = Table('shadow_services', meta, autoload=True)
+    shadow_services.create_column(reason.copy())
+
+
+def downgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    services = Table('services', meta, autoload=True)
+    services.drop_column('disabled_reason')
+    shadow_services = Table('shadow_services', meta, autoload=True)
+    shadow_services.drop_column('disabled_reason')
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index 28fe36a0d..d12e47246 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -53,6 +53,7 @@ class Service(BASE, NovaBase):
     topic = Column(String(255), nullable=True)
     report_count = Column(Integer, nullable=False, default=0)
     disabled = Column(Boolean, default=False)
+    disabled_reason = Column(String(255))
 
 
 class ComputeNode(BASE, NovaBase):