Fix leaked mocks in the 'guestagent/test_api' module

Make all test suites in the module extend
'trove_testtools.TestCase' to enable dangling mock detector.

There was also a need to add a mocked entry to
upgrade/test_models.py. Previous implementation was
working because of leaked mock from guestagent/test_api.py

Needed an update to guestagent/test_vertica_api.py which was
earlier passing because of leaked mock from guestagent/test_api.py.

Change-Id: If8d654c3a6d2f47d2a4ffa70bab72201dd053226
Partial-Bug: 1448273

trove/tests/unittests/guestagent/test_api.py

@@ -15,7 +15,6 @@ from eventlet import Timeout
 import mock
 from oslo_messaging.rpc.client import RemoteError
 import oslo_messaging as messaging
-import testtools
 from testtools.matchers import Is
 
 import trove.common.context as context
@@ -23,6 +22,7 @@ from trove.common import exception
 from trove.common.remote import guest_client
 from trove.guestagent import api
 from trove import rpc
+from trove.tests.unittests import trove_testtools
 
 REPLICATION_SNAPSHOT = {'master': {'id': '123', 'host': '192.168.0.1',
                                    'port': 3306},
@@ -48,11 +48,11 @@ def _mock_call(cmd, timeout, version=None, username=None, hostname=None,
         raise BaseException("Test Failed")
 
 
-class ApiTest(testtools.TestCase):
-    def setUp(self):
+class ApiTest(trove_testtools.TestCase):
+    @mock.patch.object(rpc, 'get_client')
+    def setUp(self, *args):
         super(ApiTest, self).setUp()
         self.context = context.TroveContext()
-        rpc.get_client = mock.Mock()
         self.guest = api.API(self.context, 0)
         self.guest._cast = _mock_call_pwd_change
         self.guest._call = _mock_call
@@ -456,7 +456,7 @@ class ApiTest(testtools.TestCase):
         self.call_context.cast = mock.Mock()
 
 
-class ApiStrategyTest(testtools.TestCase):
+class ApiStrategyTest(trove_testtools.TestCase):
 
     @mock.patch('trove.guestagent.api.API.__init__',
                 mock.Mock(return_value=None))

trove/tests/unittests/guestagent/test_vertica_api.py

@@ -20,6 +20,7 @@ from trove.common import exception
 from trove.common.rpc.version import RPC_API_VERSION
 from trove.common.strategies.cluster.experimental.vertica.guestagent import (
     VerticaGuestAgentAPI)
+from trove import rpc
 from trove.tests.unittests import trove_testtools
 
 
@@ -35,7 +36,8 @@ def _mock_call(cmd, timeout, version=None, user=None,
 
 
 class ApiTest(trove_testtools.TestCase):
-    def setUp(self):
+    @mock.patch.object(rpc, 'get_client')
+    def setUp(self, *args):
         super(ApiTest, self).setUp()
         self.context = context.TroveContext()
         self.guest = VerticaGuestAgentAPI(self.context, 0)

trove/tests/unittests/upgrade/test_models.py

@@ -15,6 +15,7 @@
 #
 from mock import Mock, patch
 from trove.extensions.mgmt.upgrade.models import UpgradeMessageSender
+from trove import rpc
 from trove.tests.unittests import trove_testtools
 
 
@@ -64,7 +65,9 @@ class TestUpgradeModel(trove_testtools.TestCase):
                       "config_location": "http://swift/trove-guestagent.conf"})
 
     @patch('trove.guestagent.api.API.upgrade')
-    def _assert_create_with_metadata(self, api_upgrade_mock, metadata=None):
+    @patch.object(rpc, 'get_client')
+    def _assert_create_with_metadata(self, mock_client, api_upgrade_mock,
+                                     metadata=None):
         """Excercise UpgradeMessageSender.create() call.
         """
         context = Mock()