Fix uses of service_get_all_compute_by_host

There should never be more than 1 service entry for the same topic and
host, however this method returns a list of services.  All callers of
this method except for 1 already account for there being only 1 service
entry for a particular 'compute' host and only use the first entry in the
return list.

This patch renames the DB API call to be 'service_get_by_compute_host'
and returns a single entry.  All uses of the old method are adjusted
accordingly.

Change-Id: I0e0ef62f5d2e71efe756940d9fdd98aa02fef216

1 files changed, 5 insertions, 6 deletions

diff --git a/nova/scheduler/driver.py b/nova/scheduler/driver.py
index dc494af8f..d1ae1cd6e 100644
--- a/nova/scheduler/driver.py
+++ b/nova/scheduler/driver.py
@@ -192,12 +192,12 @@ class Scheduler(object):
         # Checking src host exists and compute node
         src = instance_ref['host']
         try:
-            services = db.service_get_all_compute_by_host(context, src)
+            service = db.service_get_by_compute_host(context, src)
         except exception.NotFound:
             raise exception.ComputeServiceUnavailable(host=src)
 
         # Checking src host is alive.
-        if not self.servicegroup_api.service_is_up(services[0]):
+        if not self.servicegroup_api.service_is_up(service):
             raise exception.ComputeServiceUnavailable(host=src)
 
     def _live_migration_dest_check(self, context, instance_ref, dest):
@@ -209,8 +209,7 @@ class Scheduler(object):
         """
 
         # Checking dest exists and compute node.
-        dservice_refs = db.service_get_all_compute_by_host(context, dest)
-        dservice_ref = dservice_refs[0]
+        dservice_ref = db.service_get_by_compute_host(context, dest)
 
         # Checking dest host is alive.
         if not self.servicegroup_api.service_is_up(dservice_ref):
@@ -290,5 +289,5 @@ class Scheduler(object):
         :return: value specified by key
 
         """
-        compute_node_ref = db.service_get_all_compute_by_host(context, host)
-        return compute_node_ref[0]['compute_node'][0]
+        service_ref = db.service_get_by_compute_host(context, host)
+        return service_ref['compute_node'][0]