diff --git a/heat/engine/clients/os/nova.py b/heat/engine/clients/os/nova.py
index ca56d4c4ad..08afc26474 100644
--- a/heat/engine/clients/os/nova.py
+++ b/heat/engine/clients/os/nova.py
@@ -20,6 +20,7 @@ import pkgutil
 import string
 
 from neutronclient.common import exceptions as q_exceptions
+from novaclient import api_versions
 from novaclient import client as nc
 from novaclient import exceptions
 from oslo_config import cfg
@@ -34,6 +35,7 @@ from heat.common import exception
 from heat.common.i18n import _
 from heat.engine.clients import client_exception
 from heat.engine.clients import client_plugin
+from heat.engine.clients import microversion_mixin
 from heat.engine.clients import os as os_client
 from heat.engine import constraints
 
@@ -43,7 +45,8 @@ LOG = logging.getLogger(__name__)
 CLIENT_NAME = 'nova'
 
 
-class NovaClientPlugin(client_plugin.ClientPlugin):
+class NovaClientPlugin(microversion_mixin.MicroversionMixin,
+                       client_plugin.ClientPlugin):
 
     deferred_server_statuses = ['BUILD',
                                 'HARD_REBOOT',
@@ -60,13 +63,14 @@ class NovaClientPlugin(client_plugin.ClientPlugin):
 
     NOVA_API_VERSION = '2.1'
 
+    # TODO(ramishra) Remove these constants
     validate_versions = [
         V2_2, V2_8, V2_10, V2_15, V2_26, V2_37, V2_42
     ] = [
         '2.2', '2.8', '2.10', '2.15', '2.26', '2.37', '2.42'
     ]
 
-    supported_versions = [NOVA_API_VERSION] + validate_versions
+    max_microversion = None
 
     service_types = [COMPUTE] = ['compute']
 
@@ -78,10 +82,16 @@ class NovaClientPlugin(client_plugin.ClientPlugin):
             # TODO(prazumovsky): remove all unexpected calls from tests and
             # add default_version after that.
             version = self.NOVA_API_VERSION
+        args = self._get_args(version)
+
+        client = nc.Client(version, **args)
+        return client
+
+    def _get_args(self, version):
         endpoint_type = self._get_client_option(CLIENT_NAME, 'endpoint_type')
         extensions = nc.discover_extensions(version)
 
-        args = {
+        return {
             'session': self.context.keystone_session,
             'extensions': extensions,
             'endpoint_type': endpoint_type,
@@ -89,18 +99,19 @@ class NovaClientPlugin(client_plugin.ClientPlugin):
             'region_name': self._get_region_name(),
             'http_log_debug': self._get_client_option(CLIENT_NAME,
                                                       'http_log_debug')
-        }
+            }
 
-        client = nc.Client(version, **args)
-        # NOTE: check for microversion availability
-        if version in self.validate_versions:
-            try:
-                client.versions.get_current()
-            except exceptions.NotAcceptable:
-                raise exception.InvalidServiceVersion(service=self.COMPUTE,
-                                                      version=version)
+    def get_max_microversion(self):
+        if not self.max_microversion:
+            client = self._create()
+            self.max_microversion = client.versions.get_current().version
+        return self.max_microversion
 
-        return client
+    def is_version_supported(self, version):
+        api_ver = api_versions.get_api_version(version)
+        max_api_ver = api_versions.get_api_version(
+            self.get_max_microversion())
+        return max_api_ver >= api_ver
 
     def is_not_found(self, ex):
         return isinstance(ex, (exceptions.NotFound,
diff --git a/heat/tests/aws/test_eip.py b/heat/tests/aws/test_eip.py
index 3338244641..7bebed736c 100644
--- a/heat/tests/aws/test_eip.py
+++ b/heat/tests/aws/test_eip.py
@@ -172,7 +172,7 @@ class EIPTest(common.HeatTestCase):
         # force Nova, will test Neutron below
         super(EIPTest, self).setUp()
         self.fc = fakes_nova.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self.mock_list_net = self.patchobject(neutronclient.Client,
                                               'list_networks')
@@ -406,7 +406,7 @@ class AllocTest(common.HeatTestCase):
     def setUp(self):
         super(AllocTest, self).setUp()
         self.fc = fakes_nova.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self.mock_list_net = self.patchobject(neutronclient.Client,
                                               'list_networks')
diff --git a/heat/tests/aws/test_instance_network.py b/heat/tests/aws/test_instance_network.py
index 14a894f3c1..3d5b5dd9ed 100644
--- a/heat/tests/aws/test_instance_network.py
+++ b/heat/tests/aws/test_instance_network.py
@@ -210,7 +210,7 @@ class instancesTest(common.HeatTestCase):
                                       resource_defns['WebServer'], self.stack)
         metadata = instance.metadata_get()
 
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
 
         self._mock_get_image_id_success(image_id, 1)
@@ -244,7 +244,7 @@ class instancesTest(common.HeatTestCase):
             instance.properties['UserData'],
             'ec2-user')
         neutron.NeutronClientPlugin._create.assert_called_once_with()
-        nova.NovaClientPlugin._create.assert_called_once_with()
+        nova.NovaClientPlugin.client.assert_called_with()
         glance.GlanceClientPlugin.find_image_by_name_or_id.assert_called_with(
             image_id)
         return instance
@@ -278,7 +278,7 @@ class instancesTest(common.HeatTestCase):
         self.patchobject(neutron.NeutronClientPlugin, '_create',
                          return_value=FakeNeutron())
 
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
 
         # need to resolve the template functions
@@ -310,7 +310,7 @@ class instancesTest(common.HeatTestCase):
             instance.properties['UserData'],
             'ec2-user')
         neutron.NeutronClientPlugin._create.assert_called_once_with()
-        nova.NovaClientPlugin._create.assert_called_once_with()
+        nova.NovaClientPlugin.client.assert_called_with()
         glance.GlanceClientPlugin.find_image_by_name_or_id.assert_called_with(
             image_id)
         return instance
diff --git a/heat/tests/aws/test_loadbalancer.py b/heat/tests/aws/test_loadbalancer.py
index 71b7516524..07417d1305 100644
--- a/heat/tests/aws/test_loadbalancer.py
+++ b/heat/tests/aws/test_loadbalancer.py
@@ -89,9 +89,8 @@ class LoadBalancerTest(common.HeatTestCase):
         lb_defn = s.t.resource_definitions(s)[resource_name]
         rsrc = lb.LoadBalancer(resource_name, lb_defn, s)
 
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
-
         initial_md = {'AWS::CloudFormation::Init':
                       {'config':
                        {'files':
diff --git a/heat/tests/clients/test_nova_client.py b/heat/tests/clients/test_nova_client.py
index ee356cd343..2c28016fe5 100644
--- a/heat/tests/clients/test_nova_client.py
+++ b/heat/tests/clients/test_nova_client.py
@@ -47,8 +47,9 @@ class NovaClientPluginTest(NovaClientPluginTestCase):
         context = utils.dummy_context()
         ext_mock = self.patchobject(nc, 'discover_extensions')
         plugin = context.clients.client_plugin('nova')
+        plugin.max_microversion = '2.53'
         client = plugin.client()
-        ext_mock.assert_called_once_with('2.1')
+        ext_mock.assert_called_once_with('2.53')
         self.assertIsNotNone(client.servers)
 
     def test_v2_26_create(self):
@@ -57,21 +58,21 @@ class NovaClientPluginTest(NovaClientPluginTestCase):
         self.patchobject(nc, 'Client', return_value=mock.Mock())
 
         plugin = ctxt.clients.client_plugin('nova')
-        plugin.client(version=plugin.V2_26)
+        plugin.max_microversion = '2.53'
+        plugin.client(version='2.26')
 
-        ext_mock.assert_called_once_with(plugin.V2_26)
+        ext_mock.assert_called_once_with('2.26')
 
     def test_v2_26_create_failed(self):
         ctxt = utils.dummy_context()
         self.patchobject(nc, 'discover_extensions')
         plugin = ctxt.clients.client_plugin('nova')
+        plugin.max_microversion = '2.23'
         client_stub = mock.Mock()
-        client_stub.versions.get_current.side_effect = [
-            nova_exceptions.NotAcceptable(406)]
         self.patchobject(nc, 'Client', return_value=client_stub)
 
-        self.assertRaises(exception.InvalidServiceVersion, plugin.client,
-                          plugin.V2_26)
+        self.assertRaises(exception.InvalidServiceVersion,
+                          plugin.client, '2.26')
 
     def test_get_ip(self):
         my_image = mock.MagicMock()
@@ -475,6 +476,8 @@ class FlavorConstraintTest(common.HeatTestCase):
     def test_validate(self):
         client = fakes_nova.FakeClient()
         self.stub_keystoneclient()
+        self.patchobject(nova.NovaClientPlugin, 'get_max_microversion',
+                         return_value='2.27')
         self.patchobject(nova.NovaClientPlugin, '_create', return_value=client)
         client.flavors = mock.MagicMock()
 
@@ -521,6 +524,8 @@ class KeypairConstraintTest(common.HeatTestCase):
 
     def test_validation(self):
         client = fakes_nova.FakeClient()
+        self.patchobject(nova.NovaClientPlugin, 'get_max_microversion',
+                         return_value='2.27')
         self.patchobject(nova.NovaClientPlugin, '_create', return_value=client)
         client.keypairs = mock.MagicMock()
 
@@ -534,7 +539,7 @@ class KeypairConstraintTest(common.HeatTestCase):
         self.assertFalse(constraint.validate("bar", ctx))
         self.assertTrue(constraint.validate("foo", ctx))
         self.assertTrue(constraint.validate("", ctx))
-        nova.NovaClientPlugin._create.assert_called_once_with()
+        nova.NovaClientPlugin._create.assert_called_once_with(version='2.27')
         calls = [mock.call('bar'),
                  mock.call(key.name)]
         client.keypairs.get.assert_has_calls(calls)
diff --git a/heat/tests/db/test_sqlalchemy_api.py b/heat/tests/db/test_sqlalchemy_api.py
index 84ec251ebd..b102371265 100644
--- a/heat/tests/db/test_sqlalchemy_api.py
+++ b/heat/tests/db/test_sqlalchemy_api.py
@@ -98,7 +98,7 @@ class SqlAlchemyTest(common.HeatTestCase):
         return (template, stack)
 
     def _mock_create(self):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self._mock_get_image_id_success('F17-x86_64-gold', 744)
 
diff --git a/heat/tests/engine/service/test_stack_create.py b/heat/tests/engine/service/test_stack_create.py
index a58aac27a4..88c5971bf9 100644
--- a/heat/tests/engine/service/test_stack_create.py
+++ b/heat/tests/engine/service/test_stack_create.py
@@ -311,7 +311,7 @@ class StackCreateTest(common.HeatTestCase):
         stk = tools.get_stack(stack_name, self.ctx)
 
         fc = fakes_nova.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create', return_value=fc)
+        self.patchobject(nova.NovaClientPlugin, 'client', return_value=fc)
         self.patchobject(glance.GlanceClientPlugin, 'find_image_by_name_or_id',
                          return_value=744)
 
diff --git a/heat/tests/engine/tools.py b/heat/tests/engine/tools.py
index fdf5c39166..5192134dc3 100644
--- a/heat/tests/engine/tools.py
+++ b/heat/tests/engine/tools.py
@@ -217,7 +217,7 @@ def setup_mocks_with_mock(testcase, stack, mock_image_constraint=True,
                           mock_keystone=True):
     fc = fakes_nova.FakeClient()
     testcase.patchobject(instances.Instance, 'client', return_value=fc)
-    testcase.patchobject(nova.NovaClientPlugin, '_create', return_value=fc)
+    testcase.patchobject(nova.NovaClientPlugin, 'client', return_value=fc)
     instance = stack['WebServer']
     metadata = instance.metadata_get()
     if mock_image_constraint:
diff --git a/heat/tests/openstack/cinder/test_volume_utils.py b/heat/tests/openstack/cinder/test_volume_utils.py
index db3f178263..5e3bb05b9e 100644
--- a/heat/tests/openstack/cinder/test_volume_utils.py
+++ b/heat/tests/openstack/cinder/test_volume_utils.py
@@ -34,7 +34,7 @@ class VolumeTestCase(common.HeatTestCase):
         self.cinder_fc.volume_api_version = 2
         self.patchobject(cinder.CinderClientPlugin, '_create',
                          return_value=self.cinder_fc)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self.cinder_fc.volumes = mock.Mock(spec=self.cinder_fc.volumes)
         self.fc.volumes = mock.Mock()
@@ -56,7 +56,7 @@ class VolumeTestCase(common.HeatTestCase):
                                           update=False,
                                           extra_create_server_volume_mocks=[]):
         if not update:
-            nova.NovaClientPlugin._create.return_value = self.fc
+            nova.NovaClientPlugin.client.return_value = self.fc
 
         result = [fva]
         for m in extra_create_server_volume_mocks:
diff --git a/heat/tests/openstack/neutron/test_neutron_loadbalancer.py b/heat/tests/openstack/neutron/test_neutron_loadbalancer.py
index 9d6d82cdd7..739c21b606 100644
--- a/heat/tests/openstack/neutron/test_neutron_loadbalancer.py
+++ b/heat/tests/openstack/neutron/test_neutron_loadbalancer.py
@@ -883,12 +883,12 @@ class LoadBalancerTest(common.HeatTestCase):
 
         self.mc = mock.Mock(spec=neutronclient.Client)
         self.patchobject(neutronclient, 'Client', return_value=self.mc)
-        self.patchobject(nova.NovaClientPlugin, '_create')
+        self.patchobject(nova.NovaClientPlugin, 'client')
         self.patchobject(neutron.NeutronClientPlugin, 'has_extension',
                          return_value=True)
 
     def create_load_balancer(self, extra_create_mocks=[]):
-        nova.NovaClientPlugin._create.return_value = self.fc
+        nova.NovaClientPlugin.client.return_value = self.fc
         results = [{'member': {'id': 'member5678'}}]
         for m in extra_create_mocks:
             results.append(m)
@@ -907,13 +907,16 @@ class LoadBalancerTest(common.HeatTestCase):
                     'pool_id': 'pool123', 'protocol_port': 8080,
                     'address': '4.5.6.7'}}
             )
+            nova.NovaClientPlugin.client.assert_called_with()
+            self.assertEqual(create_count,
+                             nova.NovaClientPlugin.client.call_count)
         else:
             self.mc.create_member.assert_called_once_with({
                 'member': {
                     'pool_id': 'pool123', 'protocol_port': 8080,
                     'address': '1.2.3.4'}}
             )
-        nova.NovaClientPlugin._create.assert_called_once_with()
+            nova.NovaClientPlugin.client.assert_called_once_with()
 
     def test_create(self):
         rsrc = self.create_load_balancer()
diff --git a/heat/tests/openstack/nova/test_floatingip.py b/heat/tests/openstack/nova/test_floatingip.py
index b0cecc4c7a..afbdde0242 100644
--- a/heat/tests/openstack/nova/test_floatingip.py
+++ b/heat/tests/openstack/nova/test_floatingip.py
@@ -64,7 +64,7 @@ class NovaFloatingIPTest(common.HeatTestCase):
     def setUp(self):
         super(NovaFloatingIPTest, self).setUp()
         self.novaclient = fakes_nova.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.novaclient)
         self.mock_create_fip = self.patchobject(neutronclient.Client,
                                                 'create_floatingip')
diff --git a/heat/tests/openstack/nova/test_keypair.py b/heat/tests/openstack/nova/test_keypair.py
index 36e7bf5997..5cd9565212 100644
--- a/heat/tests/openstack/nova/test_keypair.py
+++ b/heat/tests/openstack/nova/test_keypair.py
@@ -48,7 +48,7 @@ class NovaKeyPairTest(common.HeatTestCase):
         self.fake_nova.keypairs = self.fake_keypairs
         self.patchobject(nova.NovaClientPlugin, 'has_extension',
                          return_value=True)
-        self.cp_mock = self.patchobject(nova.NovaClientPlugin, '_create',
+        self.cp_mock = self.patchobject(nova.NovaClientPlugin, 'client',
                                         return_value=self.fake_nova)
 
     def _mock_key(self, name, pub=None, priv=None):
@@ -187,7 +187,7 @@ class NovaKeyPairTest(common.HeatTestCase):
         stack = utils.parse_stack(template)
         definition = stack.t.resource_definitions(stack)['kp']
         kp_res = keypair.KeyPair('kp', definition, stack)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          side_effect=exception.InvalidServiceVersion(
                              service='compute',
                              version=nc_version
diff --git a/heat/tests/openstack/nova/test_server.py b/heat/tests/openstack/nova/test_server.py
index 224379dde5..bf80c8a0e2 100644
--- a/heat/tests/openstack/nova/test_server.py
+++ b/heat/tests/openstack/nova/test_server.py
@@ -19,7 +19,6 @@ import mock
 from keystoneauth1 import exceptions as ks_exceptions
 from neutronclient.v2_0 import client as neutronclient
 from novaclient import exceptions as nova_exceptions
-from novaclient.v2 import client as novaclient
 from oslo_serialization import jsonutils
 from oslo_utils import uuidutils
 import requests
@@ -353,7 +352,7 @@ class ServersTest(common.HeatTestCase):
                                 self.stack)
 
         self.patchobject(server, 'store_external_ports')
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self.patchobject(glance.GlanceClientPlugin, 'get_image',
                          return_value=self.mock_image)
@@ -495,7 +494,7 @@ class ServersTest(common.HeatTestCase):
 
     def test_server_create_metadata(self):
         stack_name = 'create_metadata_test_stack'
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         (tmpl, stack) = self._setup_test_stack(stack_name)
@@ -515,7 +514,7 @@ class ServersTest(common.HeatTestCase):
 
     def test_server_create_with_subnet_security_group(self):
         stack_name = 'server_with_subnet_security_group'
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         (tmpl, stack) = self._setup_test_stack(
@@ -559,7 +558,7 @@ class ServersTest(common.HeatTestCase):
         stack_name = 'server_with_str_network'
         return_server = self.fc.servers.list()[1]
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        mock_nc = self.patchobject(nova.NovaClientPlugin, '_create',
+        mock_nc = self.patchobject(nova.NovaClientPlugin, 'client',
                                    return_value=self.fc)
         self.patchobject(glance.GlanceClientPlugin, 'get_image',
                          return_value=self.mock_image)
@@ -577,7 +576,10 @@ class ServersTest(common.HeatTestCase):
         create_mock = self.patchobject(self.fc.servers, 'create',
                                        return_value=return_server)
         scheduler.TaskRunner(server.create)()
-        mock_nc.assert_called_with(version='2.37')
+        mock_nc.assert_has_calls([mock.call(),
+                                  mock.call(version='2.37'),
+                                  mock.call()])
+        self.assertEqual(3, mock_nc.call_count)
         self.assertEqual('none', create_mock.call_args[1]['nics'])
 
     def test_server_create_with_image_id(self):
@@ -703,7 +705,7 @@ class ServersTest(common.HeatTestCase):
             six.text_type(e))
 
     def test_server_create_raw_userdata(self):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         stack_name = 'raw_userdata_s'
@@ -724,7 +726,7 @@ class ServersTest(common.HeatTestCase):
         self.assertEqual({}, kwargs['meta'])
 
     def test_server_create_raw_config_userdata(self):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         stack_name = 'raw_userdata_s'
@@ -752,7 +754,7 @@ class ServersTest(common.HeatTestCase):
         self.assertEqual({}, kwargs['meta'])
 
     def test_server_create_raw_config_userdata_None(self):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         stack_name = 'raw_userdata_s'
@@ -788,7 +790,7 @@ class ServersTest(common.HeatTestCase):
     def _server_create_software_config(self, md=None,
                                        stack_name='software_config_s',
                                        ret_tmpl=False):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         (tmpl, stack) = self._setup_test_stack(stack_name)
@@ -879,7 +881,7 @@ class ServersTest(common.HeatTestCase):
         }, server.metadata_get())
 
     def _server_create_software_config_poll_heat(self, md=None):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         stack_name = 'software_config_s'
@@ -946,7 +948,7 @@ class ServersTest(common.HeatTestCase):
         }, server.metadata_get())
 
     def _server_create_software_config_poll_temp_url(self, md=None):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         stack_name = 'software_config_s'
@@ -1028,7 +1030,7 @@ class ServersTest(common.HeatTestCase):
         }, server.metadata_get())
 
     def _prepare_for_server_create(self, md=None):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         stack_name = 'software_config_s'
@@ -1146,7 +1148,7 @@ class ServersTest(common.HeatTestCase):
                                 resource_defns['WebServer'], stack)
         self.patchobject(server, 'store_external_ports')
 
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         mock_create = self.patchobject(self.fc.servers, 'create',
                                        return_value=return_server)
@@ -1166,7 +1168,7 @@ class ServersTest(common.HeatTestCase):
         server = servers.Server('WebServer',
                                 resource_defns['WebServer'], stack)
         self.patchobject(server, 'store_external_ports')
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         mock_create = self.patchobject(self.fc.servers, 'create',
                                        return_value=return_server)
@@ -1176,7 +1178,7 @@ class ServersTest(common.HeatTestCase):
         self.assertEqual({}, kwargs['meta'])
 
     def test_server_create_with_stack_scheduler_hints(self):
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         return_server = self.fc.servers.list()[1]
         return_server.id = '5678'
@@ -1227,7 +1229,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate(self):
         stack_name = 'srv_val'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_create_image',
@@ -1241,7 +1243,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_with_bootable_vol(self):
         stack_name = 'srv_val_bootvol'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self.stub_VolumeConstraint_validate()
         # create a server with bootable volume
@@ -1303,7 +1305,7 @@ class ServersTest(common.HeatTestCase):
                          return_value=True)
         t = template_format.parse(nova_keypair_template)
         templ = template.Template(t)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         stack = parser.Stack(utils.dummy_context(), stack_name, templ,
                              stack_id=uuidutils.generate_uuid())
@@ -1319,7 +1321,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_with_invalid_ssh_key(self):
         stack_name = 'srv_val_test'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         web_server = tmpl['Resources']['WebServer']
         # Make the ssh key have an invalid name
@@ -1342,7 +1344,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_software_config_invalid_meta(self):
         stack_name = 'srv_val_test'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         web_server = tmpl['Resources']['WebServer']
         web_server['Properties']['user_data_format'] = 'SOFTWARE_CONFIG'
@@ -1386,7 +1388,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_with_network_empty_ref(self):
         stack_name = 'srv_net'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         tmpl['Resources']['WebServer']['Properties']['networks'] = (
             [{'network': ''}])
@@ -1408,7 +1410,7 @@ class ServersTest(common.HeatTestCase):
         # create a server with 'uuid' and 'network' properties
         tmpl['Resources']['WebServer']['Properties']['networks'] = (
             [{'fixed_ip': '10.0.0.99'}])
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_validate_with_networks',
@@ -1434,7 +1436,7 @@ class ServersTest(common.HeatTestCase):
         tmpl['Resources']['WebServer']['Properties']['networks'] = (
             [{'floating_ip': '172.24.4.14',
               'network': '6b1688bb-18a0-4754-ab05-19daaedc5871'}])
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_validate_net_floating_ip',
@@ -1459,7 +1461,7 @@ class ServersTest(common.HeatTestCase):
         tmpl['Resources']['WebServer']['Properties']['networks'] = (
             [{'network': '6b1688bb-18a0-4754-ab05-19daaedc5871',
               'allocate_network': 'auto'}])
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_validate_net_list_str',
@@ -1517,7 +1519,7 @@ class ServersTest(common.HeatTestCase):
         tmpl['Resources']['WebServer']['Properties']['networks'] = (
             [{'uuid': 'aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa',
               'fixed_ip': '10.0.0.99'}])
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_validate_with_networks',
@@ -1536,7 +1538,7 @@ class ServersTest(common.HeatTestCase):
         tmpl['Resources']['WebServer']['Properties']['networks'] = (
             [{'network': 'public',
               'fixed_ip': '10.0.0.99'}])
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_validate_with_networks',
@@ -1559,7 +1561,7 @@ class ServersTest(common.HeatTestCase):
             {'port': ''}]
         tmpl['Resources']['WebServer']['Properties'][
             'security_groups'] = ['my_security_group']
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_validate_net_security_groups',
@@ -2176,7 +2178,7 @@ class ServersTest(common.HeatTestCase):
         self.assertRaises(resource.UpdateReplace, updater)
 
     @mock.patch.object(servers.Server, 'prepare_for_replace')
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_server_update_server_userdata_replace(self, mock_create,
                                                    mock_replace):
         stack_name = 'update_udatrep'
@@ -2192,7 +2194,7 @@ class ServersTest(common.HeatTestCase):
         updater = scheduler.TaskRunner(server.update, update_template)
         self.assertRaises(resource.UpdateReplace, updater)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_update_failed_server_not_replace(self, mock_create):
         stack_name = 'update_failed_server_not_replace'
         (tmpl, stack) = self._setup_test_stack(stack_name)
@@ -2213,7 +2215,7 @@ class ServersTest(common.HeatTestCase):
         self.assertEqual((server.UPDATE, server.COMPLETE), server.state)
 
     @mock.patch.object(servers.Server, 'prepare_for_replace')
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_server_update_server_userdata_ignore(self, mock_create,
                                                   mock_replace):
         stack_name = 'update_udatignore'
@@ -2682,7 +2684,7 @@ class ServersTest(common.HeatTestCase):
             }
         ]))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_block_device_mapping_volume_size_valid_int(self,
                                                                  mock_create):
         stack_name = 'val_vsize_valid'
@@ -2702,7 +2704,7 @@ class ServersTest(common.HeatTestCase):
         self.stub_VolumeConstraint_validate()
         self.assertIsNone(server.validate())
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_block_device_mapping_volume_size_valid_str(self,
                                                                  mock_create):
         stack_name = 'val_vsize_valid'
@@ -2721,7 +2723,7 @@ class ServersTest(common.HeatTestCase):
                          return_value=self.mock_flavor)
         self.assertIsNone(server.validate())
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_bd_mapping_volume_size_invalid_str(self, mock_create):
         stack_name = 'val_vsize_invalid'
         tmpl, stack = self._setup_test_stack(stack_name)
@@ -2737,7 +2739,7 @@ class ServersTest(common.HeatTestCase):
                                 server.validate)
         self.assertIn("Value '10a' is not an integer", six.text_type(exc))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_conflict_block_device_mapping_props(self, mock_create):
         stack_name = 'val_blkdev1'
         (tmpl, stack) = self._setup_test_stack(stack_name)
@@ -2752,7 +2754,7 @@ class ServersTest(common.HeatTestCase):
         self.stub_SnapshotConstraint_validate()
         self.assertRaises(exception.ResourcePropertyConflict, server.validate)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_insufficient_block_device_mapping_props(self,
                                                               mock_create):
         stack_name = 'val_blkdev2'
@@ -2770,7 +2772,7 @@ class ServersTest(common.HeatTestCase):
                "for device mapping vdb")
         self.assertEqual(msg, six.text_type(ex))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_block_device_mapping_with_empty_ref(self, mock_create):
         stack_name = 'val_blkdev2'
         (tmpl, stack) = self._setup_test_stack(stack_name)
@@ -2789,7 +2791,7 @@ class ServersTest(common.HeatTestCase):
         self.stub_VolumeConstraint_validate()
         self.assertIsNone(server.validate())
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_without_image_or_bootable_volume(self, mock_create):
         stack_name = 'val_imgvol'
         (tmpl, stack) = self._setup_test_stack(stack_name)
@@ -2808,7 +2810,7 @@ class ServersTest(common.HeatTestCase):
                'for instance %s' % server.name)
         self.assertEqual(msg, six.text_type(ex))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_invalid_image_status(self, mock_create):
         stack_name = 'test_stack'
         tmpl, stack = self._setup_test_stack(stack_name)
@@ -2826,7 +2828,7 @@ class ServersTest(common.HeatTestCase):
             'Image status is required to be active not sdfsdf.',
             six.text_type(error))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_insufficient_ram_flavor(self, mock_create):
         stack_name = 'test_stack'
         tmpl, stack = self._setup_test_stack(stack_name)
@@ -2847,7 +2849,7 @@ class ServersTest(common.HeatTestCase):
             'has only 4.',
             six.text_type(error))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_image_flavor_not_found(self, mock_create):
         stack_name = 'test_stack'
         tmpl, stack = self._setup_test_stack(stack_name)
@@ -2864,7 +2866,7 @@ class ServersTest(common.HeatTestCase):
         self.assertIsNone(server.validate())
         self.assertIsNone(server.validate())
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_insufficient_disk_flavor(self, mock_create):
         stack_name = 'test_stack'
         tmpl, stack = self._setup_test_stack(stack_name)
@@ -2961,7 +2963,7 @@ class ServersTest(common.HeatTestCase):
                                 server.validate)
         self.assertIn(msg, six.text_type(exc))
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_with_both_blk_dev_map_and_blk_dev_map_v2(self,
                                                                mock_create):
         stack_name = 'invalid_stack'
@@ -3005,7 +3007,7 @@ class ServersTest(common.HeatTestCase):
         else:
             self.assertIsNone(server.validate())
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_conflict_block_device_mapping_v2_props(self,
                                                              mock_create):
         stack_name = 'val_blkdev2'
@@ -3018,7 +3020,7 @@ class ServersTest(common.HeatTestCase):
             raise_exc=exception.ResourcePropertyConflict,
             error_msg=error_msg)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_bdm_v2_with_empty_mapping(self, mock_create):
         stack_name = 'val_blkdev2'
         bdm_v2 = [{}]
@@ -3028,20 +3030,20 @@ class ServersTest(common.HeatTestCase):
                                    raise_exc=exception.StackValidationFailed,
                                    error_msg=msg)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_bdm_v2_properties_success(self, mock_create):
         stack_name = 'bdm_v2_success'
         bdm_v2 = [{'volume_id': '1', 'boot_index': -1}]
         self._test_validate_bdm_v2(stack_name, bdm_v2)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_bdm_v2_with_unresolved_volume(self, mock_create):
         stack_name = 'bdm_v2_with_unresolved_vol'
         # empty string indicates that volume is unresolved
         bdm_v2 = [{'volume_id': ''}]
         self._test_validate_bdm_v2(stack_name, bdm_v2, with_image=False)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_bdm_v2_multiple_bootable_source(self, mock_create):
         stack_name = 'v2_multiple_bootable'
         # with two bootable sources: volume_id and image
@@ -3051,7 +3053,7 @@ class ServersTest(common.HeatTestCase):
                                    raise_exc=exception.StackValidationFailed,
                                    error_msg=msg)
 
-    @mock.patch.object(nova.NovaClientPlugin, '_create')
+    @mock.patch.object(nova.NovaClientPlugin, 'client')
     def test_validate_bdm_v2_properties_no_bootable_vol(self, mock_create):
         stack_name = 'bdm_v2_no_bootable'
         bdm_v2 = [{'swap_size': 10}]
@@ -3070,7 +3072,7 @@ class ServersTest(common.HeatTestCase):
                                                                       'b': 2,
                                                                       'c': 3,
                                                                       'd': 4}
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_create_image_err',
@@ -3091,7 +3093,7 @@ class ServersTest(common.HeatTestCase):
         tmpl.t['Resources']['WebServer']['Properties']['metadata'] = {'a': 1,
                                                                       'b': 2,
                                                                       'c': 3}
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_create_image_err',
@@ -3110,7 +3112,7 @@ class ServersTest(common.HeatTestCase):
         props['tags'] = ['a']
         # no need test with key_name
         props.pop('key_name')
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          side_effect=[
                              exception.InvalidServiceVersion(service='a',
                                                              version='2.26')])
@@ -3131,7 +3133,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_too_many_personality(self):
         stack_name = 'srv_val'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         tmpl.t['Resources']['WebServer']['Properties'][
             'personality'] = {"/fake/path1": "fake contents1",
@@ -3155,7 +3157,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_personality_okay(self):
         stack_name = 'srv_val'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         tmpl.t['Resources']['WebServer']['Properties'][
             'personality'] = {"/fake/path1": "fake contents1",
@@ -3175,7 +3177,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_personality_file_size_okay(self):
         stack_name = 'srv_val'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         tmpl.t['Resources']['WebServer']['Properties'][
             'personality'] = {"/fake/path1": "a" * 10240}
@@ -3190,7 +3192,7 @@ class ServersTest(common.HeatTestCase):
     def test_server_validate_personality_file_size_too_big(self):
         stack_name = 'srv_val'
         (tmpl, stack) = self._setup_test_stack(stack_name)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
 
         tmpl.t['Resources']['WebServer']['Properties'][
@@ -3212,7 +3214,7 @@ class ServersTest(common.HeatTestCase):
         stack_name = 'srv_val'
         (tmpl, stack) = self._setup_test_stack(
             stack_name, server_with_sw_config_personality)
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_create_image_err',
@@ -3235,7 +3237,7 @@ class ServersTest(common.HeatTestCase):
     def test_resolve_attribute_console_url(self):
         server = self.fc.servers.list()[0]
         tmpl, stack = self._setup_test_stack('console_url_stack')
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         ws = servers.Server(
             'WebServer', tmpl.resource_definitions(stack)['WebServer'], stack)
@@ -4193,7 +4195,7 @@ class ServersTest(common.HeatTestCase):
                          return_value=self.mock_image)
         mock_limits = self.patchobject(nova.NovaClientPlugin,
                                        'absolute_limits')
-        self.patchobject(nova.NovaClientPlugin, '_create')
+        self.patchobject(nova.NovaClientPlugin, 'client')
 
         # Assert here checks that server resource validates, but actually
         # this call is Act stage of this test. We calling server.validate()
@@ -4209,7 +4211,7 @@ class ServersTest(common.HeatTestCase):
         (tmpl, stack) = self._setup_test_stack(stack_name)
         tmpl.t['Resources']['WebServer']['Properties'][
             'personality'] = {"/fake/path1": "a" * 10}
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_create_image_err',
@@ -4226,7 +4228,7 @@ class ServersTest(common.HeatTestCase):
         (tmpl, stack) = self._setup_test_stack(stack_name)
         tmpl.t['Resources']['WebServer']['Properties'][
             'personality'] = {"/fake/path1": "a" * 10}
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         resource_defns = tmpl.resource_definitions(stack)
         server = servers.Server('server_create_image_err',
@@ -4244,7 +4246,7 @@ class ServersTest(common.HeatTestCase):
         tmpl = template.Template(t, files={'a_file': 'the content'})
         stack = parser.Stack(utils.dummy_context(), "server_restore", tmpl)
         stack.store()
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self.patchobject(glance.GlanceClientPlugin, 'get_image',
                          return_value=self.mock_image)
@@ -4285,7 +4287,7 @@ class ServersTest(common.HeatTestCase):
 
         self.patchobject(stack['WebServer'], 'store_external_ports')
 
-        mock_plugin = self.patchobject(nova.NovaClientPlugin, '_create')
+        mock_plugin = self.patchobject(nova.NovaClientPlugin, 'client')
         mock_plugin.return_value = self.fc
 
         return_server = self.fc.servers.list()[1]
@@ -4328,7 +4330,7 @@ class ServersTest(common.HeatTestCase):
 
         self.patchobject(stack['WebServer'], 'store_external_ports')
 
-        mock_plugin = self.patchobject(nova.NovaClientPlugin, '_create')
+        mock_plugin = self.patchobject(nova.NovaClientPlugin, 'client')
         mock_plugin.return_value = self.fc
         self.patchobject(glance.GlanceClientPlugin, 'get_image',
                          return_value=self.mock_image)
@@ -4379,7 +4381,7 @@ class ServersTest(common.HeatTestCase):
             utils.dummy_context(), 'snapshot_policy', tmpl)
         stack.store()
         rsrc = stack['WebServer']
-        mock_plugin = self.patchobject(nova.NovaClientPlugin, '_create')
+        mock_plugin = self.patchobject(nova.NovaClientPlugin, 'client')
         mock_plugin.return_value = self.fc
         delete_server = self.patchobject(self.fc.servers, 'delete')
         delete_server.side_effect = nova_exceptions.NotFound(404)
@@ -4454,10 +4456,6 @@ class ServerInternalPortTest(ServersTest):
         self.port_show = self.patchobject(neutronclient.Client,
                                           'show_port')
 
-        self.server_get = self.patchobject(novaclient.servers.ServerManager,
-                                           'get')
-        self.server_get.return_value = self.fc.servers.list()[1]
-
         def neutron_side_effect(*args):
             if args[0] == 'subnet':
                 return '1234'
@@ -4921,6 +4919,7 @@ class ServerInternalPortTest(ServersTest):
         port_ids = [{'id': 1122}]
 
         server._data = {"internal_ports": jsonutils.dumps(port_ids)}
+        self.patchobject(nova.NovaClientPlugin, 'client')
         self.patchobject(nova.NovaClientPlugin, 'interface_detach')
         self.patchobject(nova.NovaClientPlugin, 'fetch_server')
         self.patchobject(nova.NovaClientPlugin.check_interface_detach.retry,
@@ -4941,8 +4940,9 @@ class ServerInternalPortTest(ServersTest):
         external_port_ids = [{'id': '5566'}]
         server._data = {"internal_ports": jsonutils.dumps(port_ids),
                         "external_ports": jsonutils.dumps(external_port_ids)}
+
+        self.patchobject(nova.NovaClientPlugin, 'client')
         nova_server = self.fc.servers.list()[1]
-        server.client = mock.Mock()
         server.client().servers.get.return_value = nova_server
 
         self.patchobject(nova.NovaClientPlugin, 'interface_detach',
@@ -4966,13 +4966,16 @@ class ServerInternalPortTest(ServersTest):
         external_port_ids = [{'id': '5566'}]
         server._data = {"internal_ports": jsonutils.dumps(port_ids),
                         "external_ports": jsonutils.dumps(external_port_ids)}
+        self.patchobject(nova.NovaClientPlugin, 'client')
         self.patchobject(nova.NovaClientPlugin, 'fetch_server',
                          side_effect=nova_exceptions.NotFound(404))
         check_detach = self.patchobject(nova.NovaClientPlugin,
                                         'check_interface_detach')
+
+        self.patchobject(nova.NovaClientPlugin, 'client')
         nova_server = self.fc.servers.list()[1]
         nova_server.status = 'DELETED'
-        self.server_get.return_value = nova_server
+        server.client().servers.get.return_value = nova_server
 
         server.prepare_for_replace()
         check_detach.assert_not_called()
@@ -4987,9 +4990,10 @@ class ServerInternalPortTest(ServersTest):
         server._data = {"internal_ports": jsonutils.dumps(port_ids),
                         "external_ports": jsonutils.dumps(external_port_ids)}
 
+        self.patchobject(nova.NovaClientPlugin, 'client')
         nova_server = self.fc.servers.list()[1]
         nova_server.status = 'ERROR'
-        self.server_get.return_value = nova_server
+        server.client().servers.get.return_value = nova_server
 
         self.patchobject(nova.NovaClientPlugin, 'interface_detach',
                          return_value=True)
diff --git a/heat/tests/test_nokey.py b/heat/tests/test_nokey.py
index ea375fb18c..876fb4b8c6 100644
--- a/heat/tests/test_nokey.py
+++ b/heat/tests/test_nokey.py
@@ -50,7 +50,6 @@ class NoKeyTest(common.HeatTestCase):
         resource_defns = stack.t.resource_definitions(stack)
         instance = instances.Instance('create_instance_name',
                                       resource_defns['WebServer'], stack)
-
         # need to resolve the template functions
         metadata = instance.metadata_get()
         server_userdata = instance.client_plugin().build_userdata(
@@ -59,7 +58,7 @@ class NoKeyTest(common.HeatTestCase):
             'ec2-user')
 
         fc = fakes_nova.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=fc)
         self.patchobject(glance.GlanceClientPlugin, 'find_image_by_name_or_id',
                          return_value=1234)
diff --git a/heat/tests/test_server_tags.py b/heat/tests/test_server_tags.py
index e564112f4b..2d484b160d 100644
--- a/heat/tests/test_server_tags.py
+++ b/heat/tests/test_server_tags.py
@@ -77,7 +77,7 @@ class ServerTagsTest(common.HeatTestCase):
         instance = instances.Instance('WebServer',
                                       resource_defns['WebServer'], self.stack)
 
-        self.patchobject(nova.NovaClientPlugin, '_create',
+        self.patchobject(nova.NovaClientPlugin, 'client',
                          return_value=self.fc)
         self._mock_get_image_id_success('CentOS 5.2', 1)
         # need to resolve the template functions
diff --git a/heat/tests/test_stack.py b/heat/tests/test_stack.py
index ee368564a0..4a8caed9c0 100644
--- a/heat/tests/test_stack.py
+++ b/heat/tests/test_stack.py
@@ -1789,7 +1789,7 @@ class StackTest(common.HeatTestCase):
         # Mock objects so the query for flavors in server.FlavorConstraint
         # works for stack creation
         fc = fakes.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create', return_value=fc)
+        self.patchobject(nova.NovaClientPlugin, 'client', return_value=fc)
 
         fc.flavors = mock.Mock()
         flavor = collections.namedtuple("Flavor", ["id", "name"])
diff --git a/heat/tests/test_template.py b/heat/tests/test_template.py
index bf1498ef8e..34cc22a7bd 100644
--- a/heat/tests/test_template.py
+++ b/heat/tests/test_template.py
@@ -1227,7 +1227,7 @@ class TemplateTest(common.HeatTestCase):
         stk = stack.Stack(self.ctx, 'test_stack',
                           template.Template(empty_template))
         fc = fakes_nova.FakeClient()
-        self.patchobject(nova.NovaClientPlugin, '_create', return_value=fc)
+        self.patchobject(nova.NovaClientPlugin, 'client', return_value=fc)
         self.assertEqual(["nova1"], self.resolve(snippet, tmpl, stk))
 
     def test_replace_string_values(self):
diff --git a/heat/tests/test_validate.py b/heat/tests/test_validate.py
index d2f885abf1..927eba4661 100644
--- a/heat/tests/test_validate.py
+++ b/heat/tests/test_validate.py
@@ -1555,7 +1555,7 @@ class ValidateTest(common.HeatTestCase):
         self.assertRaises(exception.StackValidationFailed,
                           resource.validate)
 
-    @mock.patch('heat.engine.clients.os.nova.NovaClientPlugin._create')
+    @mock.patch('heat.engine.clients.os.nova.NovaClientPlugin.client')
     def test_invalid_security_groups_with_nics(self, mock_create):
         t = template_format.parse(test_template_invalid_secgroups)
         template = tmpl.Template(t,
@@ -1571,7 +1571,7 @@ class ValidateTest(common.HeatTestCase):
         self.assertRaises(exception.ResourcePropertyConflict,
                           resource.validate)
 
-    @mock.patch('heat.engine.clients.os.nova.NovaClientPlugin._create')
+    @mock.patch('heat.engine.clients.os.nova.NovaClientPlugin.client')
     def test_invalid_security_group_ids_with_nics(self, mock_create):
         t = template_format.parse(test_template_invalid_secgroupids)
         template = tmpl.Template(