Clean up setting of control_exchange default

The RPC code from Oslo now registers the control_exchange option but
provides us with an API for changing the default.

blueprint: scope-config-opts
Change-Id: Ie7950daaddb53f38eb72d2a113e1f26252dd6903

2 files changed, 9 insertions, 12 deletions

diff --git a/nova/openstack/common/rpc/__init__.py b/nova/openstack/common/rpc/__init__.py
index a223e8fde..cfdac03bd 100644
--- a/nova/openstack/common/rpc/__init__.py
+++ b/nova/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/nova/openstack/common/rpc/amqp.py b/nova/openstack/common/rpc/amqp.py
index a5a79cc30..6464914db 100644
--- a/nova/openstack/common/rpc/amqp.py
+++ b/nova/openstack/common/rpc/amqp.py
@@ -428,7 +428,4 @@ def cleanup(connection_pool):
 
 
 def get_control_exchange(conf):
-    try:
-        return conf.control_exchange
-    except cfg.NoSuchOptError:
-        return 'openstack'
+    return conf.control_exchange