Register the control_exchange RPC option

Fixes bug #1031725

Have the control_exchange option be registered by Oslo, but allow
projects to override the default of 'openstack' by doing e.g.:

  rpc.set_defaults(control_exchange='nova')

Change-Id: Ic6e534d9a70a1cfc94207b78caa57e897cf78f63

2 files changed, 9 insertions, 13 deletions

diff --git a/openstack/common/rpc/__init__.py b/openstack/common/rpc/__init__.py
index e11fa16..902cea2 100644
--- a/openstack/common/rpc/__init__.py
+++ b/openstack/common/rpc/__init__.py
@@ -57,19 +57,19 @@ rpc_opts = [
     cfg.BoolOpt('fake_rabbit',
                 default=False,
                 help='If passed, use a fake RabbitMQ provider'),
-    #
-    # The following options are not registered here, but are expected to be
-    # present. The project using this library must register these options with
-    # the configuration so that project-specific defaults may be defined.
-    #
-    #cfg.StrOpt('control_exchange',
-    #           default='nova',
-    #           help='AMQP exchange to connect to if using RabbitMQ or Qpid'),
+    cfg.StrOpt('control_exchange',
+               default='openstack',
+               help='AMQP exchange to connect to if using RabbitMQ or Qpid'),
 ]
 
 cfg.CONF.register_opts(rpc_opts)
 
 
+def set_defaults(control_exchange):
+    cfg.set_defaults(rpc_opts,
+                     control_exchange=control_exchange)
+
+
 def create_connection(new=True):
     """Create a connection to the message bus used for rpc.
 
diff --git a/openstack/common/rpc/amqp.py b/openstack/common/rpc/amqp.py
index 193b621..00b2f24 100644
--- a/openstack/common/rpc/amqp.py
+++ b/openstack/common/rpc/amqp.py
@@ -33,7 +33,6 @@ from eventlet import greenpool
 from eventlet import pools
 from eventlet import semaphore
 
-from openstack.common import cfg
 from openstack.common import excutils
 from openstack.common.gettextutils import _
 from openstack.common import local
@@ -428,7 +427,4 @@ def cleanup(connection_pool):
 
 
 def get_control_exchange(conf):
-    try:
-        return conf.control_exchange
-    except cfg.NoSuchOptError:
-        return 'openstack'
+    return conf.control_exchange