conf: Deprecate all topic options

There is no need to let users choose the RPC topic for all services.
It's best to deprecate and remove these options as it's really easy to
break nova by using these options, and there is little gain for
deployers in changing this option.

Change-Id: I3e6d3c29dd05e509e97646ff663209ae7201be58
Implements: blueprint centralize-config-options-ocata

nova/conf/cells.py

@@ -48,6 +48,12 @@ Related options:
 """),
     cfg.StrOpt('topic',
                 default='cells',
+                deprecated_for_removal=True,
+                deprecated_since='15.0.0',
+                deprecated_reason="""
+Configurable RPC topics provide little value and can result in a wide variety
+of errors. They should not be used.
+""",
                 help="""
 Topic
 

nova/conf/compute.py

@@ -605,6 +605,13 @@ instance_cleaning_opts = [
 rpcapi_opts = [
     cfg.StrOpt("compute_topic",
             default="compute",
+            deprecated_for_removal=True,
+            deprecated_since="15.0.0",
+            deprecated_reason="""
+There is no need to let users choose the RPC topic for all services - there
+is little gain from this. Furthermore, it makes it really easy to break Nova
+by using this option.
+""",
             help="""
 This is the message queue topic that the compute service 'listens' on. It is
 used when the compute service is started up to configure the queue, and

nova/conf/conductor.py

@@ -1,6 +1,3 @@
-# needs:check_deprecation_status
-
-
 # Copyright (c) 2010 OpenStack Foundation
 # All Rights Reserved.
 #
@@ -41,10 +38,16 @@ It no longer represents a reasonable alternative for deployers.
 
 Removal may be as early as 14.0.
 """),
-    # TODO(macsz) deprecate this option
     cfg.StrOpt(
         'topic',
         default='conductor',
+        deprecated_for_removal=True,
+        deprecated_since='15.0.0',
+        deprecated_reason="""
+There is no need to let users choose the RPC topic for all services - there
+is little gain from this. Furthermore, it makes it really easy to break Nova
+by using this option.
+""",
         help="""
 Topic exchange name on which conductor nodes listen.
 """),

nova/conf/console.py

@@ -33,9 +33,15 @@ Possible values
   * An empty list (default) or list of allowed origin hostnames.
 """),
 
-# TODO(pumaranikar): We can deprecate this option.
     cfg.StrOpt('console_topic',
                 default='console',
+                deprecated_for_removal=True,
+                deprecated_since='15.0.0',
+                deprecated_reason="""
+There is no need to let users choose the RPC topic for all services - there
+is little gain from this. Furthermore, it makes it really easy to break Nova
+by using this option.
+""",
                 help="""
 Represents the message queue topic name used by nova-console
 service when communicating via the AMQP server. The Nova API uses a message

nova/conf/consoleauth.py

@@ -18,9 +18,16 @@ from oslo_config import cfg
 
 
 consoleauth_opts = [
-    # TODO(aunnam): This option needs to be deprecated
+
     cfg.StrOpt('consoleauth_topic',
         default='consoleauth',
+        deprecated_for_removal=True,
+        deprecated_since='15.0.0',
+        deprecated_reason="""
+There is no need to let users choose the RPC topic for all services - there
+is little gain from this. Furthermore, it makes it really easy to break Nova
+by using this option.
+""",
         help="""
 This option allows you to change the message topic used by nova-consoleauth
 service when communicating via the AMQP server. Nova Console Authentication

nova/conf/network.py

@@ -752,6 +752,13 @@ driver_opts = [
 rpcapi_opts = [
     cfg.StrOpt('network_topic',
                default='network',
+               deprecated_for_removal=True,
+               deprecated_since='15.0.0',
+               deprecated_reason="""
+There is no need to let users choose the RPC topic for all services - there
+is little gain from this. Furthermore, it makes it really easy to break Nova
+by using this option.
+""",
                help='The topic network nodes listen on'),
     cfg.BoolOpt('multi_host',
                 default=False,

nova/conf/scheduler.py

@@ -18,9 +18,15 @@
 from oslo_config import cfg
 
 scheduler_opts = [
-    # TODO(sfinucan): Deprecate this option
     cfg.StrOpt("scheduler_topic",
         default="scheduler",
+        deprecated_for_removal=True,
+        deprecated_since="15.0.0",
+        deprecated_reason="""
+There is no need to let users choose the RPC topic for all services - there
+is little gain from this. Furthermore, it makes it really easy to break Nova
+by using this option.
+""",
         help="""
 Scheduler message queue topic.
 

releasenotes/notes/deprecate-topic-opts-68b1a752dba1eb24.yaml

@@ -0,0 +1,13 @@
+---
+deprecations:
+  - |
+    The ``topic`` config options are now deprecated and will be removed
+    in the next release. The deprecated options are as below:
+
+    * cells.topic
+    * compute_topic
+    * conductor.topic
+    * console_topic
+    * consoleauth_topic
+    * network_topic
+    * scheduler_topic