Stop using scheduler RPC API magic

If a scheduler RPC message isn't handled directly by a SchedulerManager
method, the __getattr__() fallback passes the message to a driver
method in the form of schedule_${method}() and, if that doesn't exist,
instead calls the schedule() method supplying the topic and method
args.

This is pretty bizarre stuff and we appear to only use it in two cases:

  1) live_migration - this is how the schedule_live_migration()
     method in the driver gets called, but the side-effect is that
     we require the client to pass a topic argument which is never
     used. This would be much more sanely handled with an explicit
     SchedulerManager.live_migration() method.

  2) create_volume - the volume API asks the scheduler to pick a
     target host for create_volume() using this method. This would
     be easily handled with an SchedulerManager.create_volume()
     method.

Change-Id: I1047489d85ac51d8d36fea1c4eb858df638ce349

2 files changed, 9 insertions, 6 deletions

diff --git a/nova/tests/scheduler/test_multi_scheduler.py b/nova/tests/scheduler/test_multi_scheduler.py
index fd79fffb3..6fce5bc35 100644
--- a/nova/tests/scheduler/test_multi_scheduler.py
+++ b/nova/tests/scheduler/test_multi_scheduler.py
@@ -46,9 +46,6 @@ class FakeVolumeScheduler(driver.Scheduler):
         super(FakeVolumeScheduler, self).__init__()
         self.is_update_caps_called = False
 
-    def schedule_create_volume(self, *args, **kwargs):
-        pass
-
     def schedule_create_volumes(self, *args, **kwargs):
         pass
 
@@ -97,7 +94,7 @@ class MultiDriverTestCase(test_scheduler.SchedulerTestCase):
 
         #no compute methods are proxied at this time
         test_methods = {compute_driver: [],
-                        volume_driver: ['create_volume', 'create_volumes']}
+                        volume_driver: ['create_volumes']}
 
         for driver, methods in test_methods.iteritems():
             for method in methods:
diff --git a/nova/tests/scheduler/test_rpcapi.py b/nova/tests/scheduler/test_rpcapi.py
index a2fee64b2..95133622b 100644
--- a/nova/tests/scheduler/test_rpcapi.py
+++ b/nova/tests/scheduler/test_rpcapi.py
@@ -86,10 +86,16 @@ class SchedulerRpcAPITestCase(test.TestCase):
         self._test_scheduler_api('live_migration', rpc_method='call',
                 block_migration='fake_block_migration',
                 disk_over_commit='fake_disk_over_commit',
-                instance='fake_instance', dest='fake_dest', topic='fake_topic',
-                version='1.3')
+                instance='fake_instance', dest='fake_dest',
+                version='1.7')
 
     def test_update_service_capabilities(self):
         self._test_scheduler_api('update_service_capabilities',
                 rpc_method='fanout_cast', service_name='fake_name',
                 host='fake_host', capabilities='fake_capabilities')
+
+    def test_create_volume(self):
+        self._test_scheduler_api('create_volume',
+                rpc_method='cast', volume_id="fake_volume",
+                snapshot_id="fake_snapshots", reservations=list('fake_res'),
+                version='1.7')