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

5 files changed, 98 insertions, 93 deletions

diff --git a/nova/tests/compute/test_host_api.py b/nova/tests/compute/test_host_api.py
index f00245d1e..0af1d6766 100644
--- a/nova/tests/compute/test_host_api.py
+++ b/nova/tests/compute/test_host_api.py
@@ -57,19 +57,19 @@ class HostApiTestCase(test.TestCase):
         given our fake input.
         """
         ctx = context.get_admin_context()
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
         host_name = 'host_c1'
-        db.service_get_all_compute_by_host(ctx, host_name).AndReturn(
-            [{'host': 'fake_host',
-              'compute_node': [
-                {'vcpus': 4,
-                 'vcpus_used': 1,
-                 'memory_mb': 8192,
-                 'memory_mb_used': 2048,
-                 'local_gb': 1024,
-                 'local_gb_used': 648}
-              ]
-            }])
+        db.service_get_by_compute_host(ctx, host_name).AndReturn(
+            {'host': 'fake_host',
+             'compute_node': [
+               {'vcpus': 4,
+                'vcpus_used': 1,
+                'memory_mb': 8192,
+                'memory_mb_used': 2048,
+                'local_gb': 1024,
+                'local_gb_used': 648}
+             ]
+            })
         self.mox.StubOutWithMock(db, 'instance_get_all_by_host')
         db.instance_get_all_by_host(ctx, 'fake_host').AndReturn(
             [{'project_id': 42,
diff --git a/nova/tests/compute/test_resource_tracker.py b/nova/tests/compute/test_resource_tracker.py
index 3bfd51461..53d92a13f 100644
--- a/nova/tests/compute/test_resource_tracker.py
+++ b/nova/tests/compute/test_resource_tracker.py
@@ -297,8 +297,8 @@ class MissingComputeNodeTestCase(BaseTestCase):
         super(MissingComputeNodeTestCase, self).setUp()
         self.tracker = self._tracker()
 
-        self.stubs.Set(db, 'service_get_all_compute_by_host',
-                self._fake_service_get_all_compute_by_host)
+        self.stubs.Set(db, 'service_get_by_compute_host',
+                self._fake_service_get_by_compute_host)
         self.stubs.Set(db, 'compute_node_create',
                 self._fake_create_compute_node)
 
@@ -306,10 +306,10 @@ class MissingComputeNodeTestCase(BaseTestCase):
         self.created = True
         return self._create_compute_node()
 
-    def _fake_service_get_all_compute_by_host(self, ctx, host):
+    def _fake_service_get_by_compute_host(self, ctx, host):
         # return a service with no joined compute
         service = self._create_service()
-        return [service]
+        return service
 
     def test_create_compute_node(self):
         self.tracker.update_available_resource(self.context)
@@ -330,8 +330,8 @@ class BaseTrackerTestCase(BaseTestCase):
         self.tracker = self._tracker()
         self._migrations = {}
 
-        self.stubs.Set(db, 'service_get_all_compute_by_host',
-                self._fake_service_get_all_compute_by_host)
+        self.stubs.Set(db, 'service_get_by_compute_host',
+                self._fake_service_get_by_compute_host)
         self.stubs.Set(db, 'compute_node_update',
                 self._fake_compute_node_update)
         self.stubs.Set(db, 'migration_update',
@@ -342,10 +342,10 @@ class BaseTrackerTestCase(BaseTestCase):
         self.tracker.update_available_resource(self.context)
         self.limits = self._limits()
 
-    def _fake_service_get_all_compute_by_host(self, ctx, host):
+    def _fake_service_get_by_compute_host(self, ctx, host):
         self.compute = self._create_compute_node()
         self.service = self._create_service(host, compute=self.compute)
-        return [self.service]
+        return self.service
 
     def _fake_compute_node_update(self, ctx, compute_node_id, values,
             prune_stats=False):
diff --git a/nova/tests/conductor/test_conductor.py b/nova/tests/conductor/test_conductor.py
index 46fadf4f0..cc3dbfcc0 100644
--- a/nova/tests/conductor/test_conductor.py
+++ b/nova/tests/conductor/test_conductor.py
@@ -451,12 +451,16 @@ class ConductorTestCase(_BaseTestCase, test.TestCase):
         self.conductor.instance_get_all_by_filters(self.context, filters,
                                                    'fake-key', 'fake-sort')
 
-    def _test_stubbed(self, name, dbargs, condargs):
+    def _test_stubbed(self, name, dbargs, condargs,
+                      db_result_listified=False):
         self.mox.StubOutWithMock(db, name)
         getattr(db, name)(self.context, *dbargs).AndReturn('fake-result')
         self.mox.ReplayAll()
         result = self.conductor.service_get_all_by(self.context, **condargs)
-        self.assertEqual(result, 'fake-result')
+        if db_result_listified:
+            self.assertEqual(['fake-result'], result)
+        else:
+            self.assertEqual('fake-result', result)
 
     def test_service_get_all(self):
         self._test_stubbed('service_get_all', (), {})
@@ -476,10 +480,11 @@ class ConductorTestCase(_BaseTestCase, test.TestCase):
                            ('host',),
                            dict(host='host'))
 
-    def test_service_get_all_compute_by_host(self):
-        self._test_stubbed('service_get_all_compute_by_host',
+    def test_service_get_by_compute_host(self):
+        self._test_stubbed('service_get_by_compute_host',
                            ('host',),
-                           dict(topic='compute', host='host'))
+                           dict(topic='compute', host='host'),
+                           db_result_listified=True)
 
     def test_service_get_by_args(self):
         self._test_stubbed('service_get_by_args',
@@ -547,12 +552,16 @@ class ConductorRPCAPITestCase(_BaseTestCase, test.TestCase):
         self.conductor.instance_get_all_by_filters(self.context, filters,
                                                    'fake-key', 'fake-sort')
 
-    def _test_stubbed(self, name, dbargs, condargs):
+    def _test_stubbed(self, name, dbargs, condargs,
+                      db_result_listified=False):
         self.mox.StubOutWithMock(db, name)
         getattr(db, name)(self.context, *dbargs).AndReturn('fake-result')
         self.mox.ReplayAll()
         result = self.conductor.service_get_all_by(self.context, **condargs)
-        self.assertEqual(result, 'fake-result')
+        if db_result_listified:
+            self.assertEqual(['fake-result'], result)
+        else:
+            self.assertEqual('fake-result', result)
 
     def test_service_get_all(self):
         self._test_stubbed('service_get_all', (), {})
@@ -572,10 +581,11 @@ class ConductorRPCAPITestCase(_BaseTestCase, test.TestCase):
                            ('host',),
                            dict(host='host'))
 
-    def test_service_get_all_compute_by_host(self):
-        self._test_stubbed('service_get_all_compute_by_host',
+    def test_service_get_by_compute_host(self):
+        self._test_stubbed('service_get_by_compute_host',
                            ('host',),
-                           dict(topic='compute', host='host'))
+                           dict(topic='compute', host='host'),
+                           db_result_listified=True)
 
 
 class ConductorAPITestCase(_BaseTestCase, test.TestCase):
@@ -681,8 +691,8 @@ class ConductorAPITestCase(_BaseTestCase, test.TestCase):
     def test_service_get_all_by_host(self):
         self._test_stubbed('service_get_all_by_host', 'host')
 
-    def test_service_get_all_compute_by_host(self):
-        self._test_stubbed('service_get_all_compute_by_host', 'host')
+    def test_service_get_by_compute_host(self):
+        self._test_stubbed('service_get_by_compute_host', 'host')
 
     def test_service_create(self):
         self._test_stubbed('service_create', {})
diff --git a/nova/tests/integrated/test_api_samples.py b/nova/tests/integrated/test_api_samples.py
index 5bdaa977a..0fb0e9107 100644
--- a/nova/tests/integrated/test_api_samples.py
+++ b/nova/tests/integrated/test_api_samples.py
@@ -2091,8 +2091,8 @@ class AdminActionsSamplesJsonTest(ServersSampleBase):
                            hypervisor_type='bar',
                            hypervisor_version='1',
                            disabled=False)
-            return [{'compute_node': [service]}]
-        self.stubs.Set(db, "service_get_all_compute_by_host", fake_get_compute)
+            return {'compute_node': [service]}
+        self.stubs.Set(db, "service_get_by_compute_host", fake_get_compute)
 
         response = self._do_post('servers/%s/action' % self.uuid,
                                  'admin-actions-live-migrate',
diff --git a/nova/tests/scheduler/test_scheduler.py b/nova/tests/scheduler/test_scheduler.py
index ceea74e70..dd5b0ae32 100644
--- a/nova/tests/scheduler/test_scheduler.py
+++ b/nova/tests/scheduler/test_scheduler.py
@@ -111,13 +111,13 @@ class SchedulerManagerTestCase(test.TestCase):
     def test_show_host_resources(self):
         host = 'fake_host'
 
-        computes = [{'host': host,
-                     'compute_node': [{'vcpus': 4,
-                                      'vcpus_used': 2,
-                                      'memory_mb': 1024,
-                                      'memory_mb_used': 512,
-                                      'local_gb': 1024,
-                                      'local_gb_used': 512}]}]
+        compute_node = {'host': host,
+                        'compute_node': [{'vcpus': 4,
+                                          'vcpus_used': 2,
+                                          'memory_mb': 1024,
+                                          'memory_mb_used': 512,
+                                          'local_gb': 1024,
+                                          'local_gb_used': 512}]}
         instances = [{'project_id': 'project1',
                       'vcpus': 1,
                       'memory_mb': 128,
@@ -134,11 +134,11 @@ class SchedulerManagerTestCase(test.TestCase):
                       'root_gb': 256,
                       'ephemeral_gb': 0}]
 
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
         self.mox.StubOutWithMock(db, 'instance_get_all_by_host')
 
-        db.service_get_all_compute_by_host(self.context, host).AndReturn(
-                computes)
+        db.service_get_by_compute_host(self.context, host).AndReturn(
+                compute_node)
         db.instance_get_all_by_host(self.context, host).AndReturn(instances)
 
         self.mox.ReplayAll()
@@ -338,8 +338,6 @@ class SchedulerTestCase(test.TestCase):
         block_migration = False
         disk_over_commit = False
         instance = jsonutils.to_primitive(self._live_migration_instance())
-        instance_id = instance['id']
-        instance_uuid = instance['uuid']
 
         self.driver._live_migration_src_check(self.context, instance)
         self.driver._live_migration_dest_check(self.context, instance, dest)
@@ -362,7 +360,7 @@ class SchedulerTestCase(test.TestCase):
         # Test live migration when all checks pass.
 
         self.mox.StubOutWithMock(servicegroup.API, 'service_is_up')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
         self.mox.StubOutWithMock(db, 'instance_get_all_by_host')
         self.mox.StubOutWithMock(rpc, 'call')
         self.mox.StubOutWithMock(rpc, 'cast')
@@ -373,34 +371,32 @@ class SchedulerTestCase(test.TestCase):
         block_migration = True
         disk_over_commit = True
         instance = jsonutils.to_primitive(self._live_migration_instance())
-        instance_id = instance['id']
-        instance_uuid = instance['uuid']
 
         # Source checks
-        db.service_get_all_compute_by_host(self.context,
-                instance['host']).AndReturn(['fake_service2'])
+        db.service_get_by_compute_host(self.context,
+                instance['host']).AndReturn('fake_service2')
         self.servicegroup_api.service_is_up('fake_service2').AndReturn(True)
 
         # Destination checks (compute is up, enough memory, disk)
-        db.service_get_all_compute_by_host(self.context,
-                dest).AndReturn(['fake_service3'])
+        db.service_get_by_compute_host(self.context,
+                dest).AndReturn('fake_service3')
         self.servicegroup_api.service_is_up('fake_service3').AndReturn(True)
         # assert_compute_node_has_enough_memory()
-        db.service_get_all_compute_by_host(self.context, dest).AndReturn(
-                [{'compute_node': [{'memory_mb': 2048,
-                                    'hypervisor_version': 1}]}])
+        db.service_get_by_compute_host(self.context, dest).AndReturn(
+                {'compute_node': [{'memory_mb': 2048,
+                                   'hypervisor_version': 1}]})
         db.instance_get_all_by_host(self.context, dest).AndReturn(
                 [dict(memory_mb=256), dict(memory_mb=512)])
 
         # Common checks (same hypervisor, etc)
-        db.service_get_all_compute_by_host(self.context, dest).AndReturn(
-                [{'compute_node': [{'hypervisor_type': 'xen',
-                                    'hypervisor_version': 1}]}])
-        db.service_get_all_compute_by_host(self.context,
+        db.service_get_by_compute_host(self.context, dest).AndReturn(
+                {'compute_node': [{'hypervisor_type': 'xen',
+                                   'hypervisor_version': 1}]})
+        db.service_get_by_compute_host(self.context,
             instance['host']).AndReturn(
-                    [{'compute_node': [{'hypervisor_type': 'xen',
-                                        'hypervisor_version': 1,
-                                        'cpu_info': 'fake_cpu_info'}]}])
+                    {'compute_node': [{'hypervisor_type': 'xen',
+                                       'hypervisor_version': 1,
+                                       'cpu_info': 'fake_cpu_info'}]})
 
         rpc.call(self.context, "compute.fake_host2",
                    {"method": 'check_can_live_migrate_destination',
@@ -440,7 +436,7 @@ class SchedulerTestCase(test.TestCase):
         # Raise exception when src compute node is does not exist.
 
         self.mox.StubOutWithMock(servicegroup.API, 'service_is_up')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
 
         dest = 'fake_host2'
         block_migration = False
@@ -448,9 +444,9 @@ class SchedulerTestCase(test.TestCase):
         instance = self._live_migration_instance()
 
         # Compute down
-        db.service_get_all_compute_by_host(self.context,
+        db.service_get_by_compute_host(self.context,
                 instance['host']).AndRaise(
-                                       exception.NotFound())
+                        exception.ComputeHostNotFound(host='fake'))
 
         self.mox.ReplayAll()
         self.assertRaises(exception.ComputeServiceUnavailable,
@@ -463,7 +459,7 @@ class SchedulerTestCase(test.TestCase):
         # Raise exception when src compute node is not alive.
 
         self.mox.StubOutWithMock(servicegroup.API, 'service_is_up')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
 
         dest = 'fake_host2'
         block_migration = False
@@ -471,8 +467,8 @@ class SchedulerTestCase(test.TestCase):
         instance = self._live_migration_instance()
 
         # Compute down
-        db.service_get_all_compute_by_host(self.context,
-                instance['host']).AndReturn(['fake_service2'])
+        db.service_get_by_compute_host(self.context,
+                instance['host']).AndReturn('fake_service2')
         self.servicegroup_api.service_is_up('fake_service2').AndReturn(False)
 
         self.mox.ReplayAll()
@@ -486,7 +482,7 @@ class SchedulerTestCase(test.TestCase):
         # Raise exception when dest compute node is not alive.
 
         self.mox.StubOutWithMock(self.driver, '_live_migration_src_check')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
         self.mox.StubOutWithMock(servicegroup.API, 'service_is_up')
 
         dest = 'fake_host2'
@@ -495,8 +491,8 @@ class SchedulerTestCase(test.TestCase):
         instance = self._live_migration_instance()
 
         self.driver._live_migration_src_check(self.context, instance)
-        db.service_get_all_compute_by_host(self.context,
-                dest).AndReturn(['fake_service3'])
+        db.service_get_by_compute_host(self.context,
+                dest).AndReturn('fake_service3')
         # Compute is down
         self.servicegroup_api.service_is_up('fake_service3').AndReturn(False)
 
@@ -511,17 +507,16 @@ class SchedulerTestCase(test.TestCase):
         # Confirms exception raises in case dest and src is same host.
 
         self.mox.StubOutWithMock(self.driver, '_live_migration_src_check')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
         self.mox.StubOutWithMock(servicegroup.API, 'service_is_up')
         block_migration = False
-        disk_over_commit = False
         instance = self._live_migration_instance()
         # make dest same as src
         dest = instance['host']
 
         self.driver._live_migration_src_check(self.context, instance)
-        db.service_get_all_compute_by_host(self.context,
-                dest).AndReturn(['fake_service3'])
+        db.service_get_by_compute_host(self.context,
+                dest).AndReturn('fake_service3')
         self.servicegroup_api.service_is_up('fake_service3').AndReturn(True)
 
         self.mox.ReplayAll()
@@ -535,7 +530,7 @@ class SchedulerTestCase(test.TestCase):
         # Confirms exception raises when dest doesn't have enough memory.
 
         self.mox.StubOutWithMock(self.driver, '_live_migration_src_check')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
         self.mox.StubOutWithMock(servicegroup.API, 'service_is_up')
         self.mox.StubOutWithMock(self.driver, '_get_compute_info')
         self.mox.StubOutWithMock(db, 'instance_get_all_by_host')
@@ -546,8 +541,8 @@ class SchedulerTestCase(test.TestCase):
         instance = self._live_migration_instance()
 
         self.driver._live_migration_src_check(self.context, instance)
-        db.service_get_all_compute_by_host(self.context,
-                dest).AndReturn(['fake_service3'])
+        db.service_get_by_compute_host(self.context,
+                dest).AndReturn('fake_service3')
         self.servicegroup_api.service_is_up('fake_service3').AndReturn(True)
 
         self.driver._get_compute_info(self.context, dest).AndReturn(
@@ -569,7 +564,7 @@ class SchedulerTestCase(test.TestCase):
         self.mox.StubOutWithMock(rpc, 'queue_get_for')
         self.mox.StubOutWithMock(rpc, 'call')
         self.mox.StubOutWithMock(rpc, 'cast')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
 
         dest = 'fake_host2'
         block_migration = False
@@ -579,13 +574,13 @@ class SchedulerTestCase(test.TestCase):
         self.driver._live_migration_src_check(self.context, instance)
         self.driver._live_migration_dest_check(self.context, instance, dest)
 
-        db.service_get_all_compute_by_host(self.context, dest).AndReturn(
-                [{'compute_node': [{'hypervisor_type': 'xen',
-                                    'hypervisor_version': 1}]}])
-        db.service_get_all_compute_by_host(self.context,
+        db.service_get_by_compute_host(self.context, dest).AndReturn(
+                {'compute_node': [{'hypervisor_type': 'xen',
+                                   'hypervisor_version': 1}]})
+        db.service_get_by_compute_host(self.context,
             instance['host']).AndReturn(
-                    [{'compute_node': [{'hypervisor_type': 'not-xen',
-                                        'hypervisor_version': 1}]}])
+                    {'compute_node': [{'hypervisor_type': 'not-xen',
+                                       'hypervisor_version': 1}]})
 
         self.mox.ReplayAll()
         self.assertRaises(exception.InvalidHypervisorType,
@@ -601,7 +596,7 @@ class SchedulerTestCase(test.TestCase):
         self.mox.StubOutWithMock(rpc, 'queue_get_for')
         self.mox.StubOutWithMock(rpc, 'call')
         self.mox.StubOutWithMock(rpc, 'cast')
-        self.mox.StubOutWithMock(db, 'service_get_all_compute_by_host')
+        self.mox.StubOutWithMock(db, 'service_get_by_compute_host')
 
         dest = 'fake_host2'
         block_migration = False
@@ -611,13 +606,13 @@ class SchedulerTestCase(test.TestCase):
         self.driver._live_migration_src_check(self.context, instance)
         self.driver._live_migration_dest_check(self.context, instance, dest)
 
-        db.service_get_all_compute_by_host(self.context, dest).AndReturn(
-                [{'compute_node': [{'hypervisor_type': 'xen',
-                                    'hypervisor_version': 1}]}])
-        db.service_get_all_compute_by_host(self.context,
+        db.service_get_by_compute_host(self.context, dest).AndReturn(
+                {'compute_node': [{'hypervisor_type': 'xen',
+                                    'hypervisor_version': 1}]})
+        db.service_get_by_compute_host(self.context,
             instance['host']).AndReturn(
-                    [{'compute_node': [{'hypervisor_type': 'xen',
-                                        'hypervisor_version': 2}]}])
+                    {'compute_node': [{'hypervisor_type': 'xen',
+                                       'hypervisor_version': 2}]})
         self.mox.ReplayAll()
         self.assertRaises(exception.DestinationHypervisorTooOld,
                 self.driver.schedule_live_migration, self.context,