Add get_backdoor_port to scheduler.

This adds a get_backdoor_port function to the scheduler
service which enables returning the eventlet_backdoor port
from rpc for the service.

Change-Id: Ib88e2a9e709d5240722027c94e6762b4a3bd918c

nova/scheduler/rpcapi.py

@@ -49,6 +49,7 @@ class SchedulerAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         2.3 - Remove create_volume()
         2.4 - Change update_service_capabilities()
                 - accepts a list of capabilities
+        2.5 - Add get_backdoor_port()
     '''
 
     #
@@ -106,3 +107,7 @@ class SchedulerAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 service_name=service_name, host=host,
                 capabilities=capabilities),
                 version='2.4')
+
+    def get_backdoor_port(self, context, host):
+        return self.call(context, self.make_msg('get_backdoor_port'),
+                         version='2.5')

nova/tests/scheduler/test_rpcapi.py

@@ -37,6 +37,9 @@ class SchedulerRpcAPITestCase(test.TestCase):
         expected_msg = rpcapi.make_msg(method, **kwargs)
         expected_msg['version'] = expected_version
 
+        if method == 'get_backdoor_port':
+            del expected_msg['args']['host']
+
         self.fake_args = None
         self.fake_kwargs = None
 
@@ -84,3 +87,7 @@ class SchedulerRpcAPITestCase(test.TestCase):
                 rpc_method='fanout_cast', service_name='fake_name',
                 host='fake_host', capabilities='fake_capabilities',
                 version='2.4')
+
+    def test_get_backdoor_port(self):
+        self._test_scheduler_api('get_backdoor_port', rpc_method='call',
+                                 host='fake_host', version='2.5')