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

1 files changed, 7 insertions, 7 deletions

diff --git a/nova/volume/api.py b/nova/volume/api.py
index bbb3149b0..3b8c62e11 100644
--- a/nova/volume/api.py
+++ b/nova/volume/api.py
@@ -31,6 +31,7 @@ from nova.openstack.common import rpc
 from nova.openstack.common import timeutils
 import nova.policy
 from nova import quota
+from nova.scheduler import rpcapi as scheduler_rpcapi
 
 volume_host_opt = cfg.BoolOpt('snapshot_same_host',
         default=True,
@@ -72,6 +73,10 @@ def check_policy(context, action, target_obj=None):
 class API(base.Base):
     """API for interacting with the volume manager."""
 
+    def __init__(self, **kwargs):
+        self.scheduler_rpcapi = scheduler_rpcapi.SchedulerAPI()
+        super(API, self).__init__(**kwargs)
+
     def create(self, context, size, name, description, snapshot=None,
                      volume_type=None, metadata=None, availability_zone=None):
         check_policy(context, 'create')
@@ -172,13 +177,8 @@ class API(base.Base):
                       "args": {"volume_id": volume_id,
                                "snapshot_id": snapshot_id}})
         else:
-            rpc.cast(context,
-                     FLAGS.scheduler_topic,
-                     {"method": "create_volume",
-                      "args": {"topic": FLAGS.volume_topic,
-                               "volume_id": volume_id,
-                               "snapshot_id": snapshot_id,
-                               "reservations": reservations}})
+            self.scheduler_rpcapi.create_volume(
+                context, volume_id, snapshot_id, reservations)
 
     @wrap_check_policy
     def delete(self, context, volume):