Use service fixture in DB servicegroup tests.

It was possible that the services created by the DB servicegroup tests
hung around and conflicted with other tests. Move the services used by
these tests into a fixture so that they can be cleaned up properly.

To ensure cleanup happens call Service.kill() on the service.

Change-Id: I38aafc6b6d3a17f104db9d8f13b1ab3b4632d470

nova/tests/servicegroup/test_db_servicegroup.py

@@ -15,6 +15,7 @@
 import datetime
 
 import eventlet
+import fixtures
 import mox
 
 from nova import context
@@ -25,6 +26,25 @@ from nova import servicegroup
 from nova import test
 
 
+class ServiceFixture(fixtures.Fixture):
+
+    def __init__(self, host, binary, topic):
+        super(ServiceFixture, self).__init__()
+        self.host = host
+        self.binary = binary
+        self.topic = topic
+        self.serv = None
+
+    def setUp(self):
+        super(ServiceFixture, self).setUp()
+        self.serv = service.Service(self.host,
+                                    self.binary,
+                                    self.topic,
+                                    'nova.tests.test_service.FakeManager',
+                                    1, 1)
+        self.addCleanup(self.serv.kill)
+
+
 class DBServiceGroupTestCase(test.TestCase):
 
     def setUp(self):
@@ -41,11 +61,8 @@ class DBServiceGroupTestCase(test.TestCase):
         self._ctx = context.get_admin_context()
 
     def test_DB_driver(self):
-        serv = service.Service(self._host,
-                                     self._binary,
-                                     self._topic,
-                                     'nova.tests.test_service.FakeManager',
-                                     1, 1)
+        serv = self.useFixture(
+            ServiceFixture(self._host, self._binary, self._topic)).serv
         serv.start()
         service_ref = db.service_get_by_args(self._ctx,
                                              self._host,
@@ -69,18 +86,12 @@ class DBServiceGroupTestCase(test.TestCase):
         host1 = self._host + '_1'
         host2 = self._host + '_2'
 
-        serv1 = service.Service(host1,
-                                self._binary,
-                                self._topic,
-                                'nova.tests.test_service.FakeManager',
-                                1, 1)
+        serv1 = self.useFixture(
+            ServiceFixture(host1, self._binary, self._topic)).serv
         serv1.start()
 
-        serv2 = service.Service(host2,
-                                self._binary,
-                                self._topic,
-                                'nova.tests.test_service.FakeManager',
-                                1, 1)
+        serv2 = self.useFixture(
+            ServiceFixture(host2, self._binary, self._topic)).serv
         serv2.start()
 
         service_ref1 = db.service_get_by_args(self._ctx,