diff --git a/openstackclient/tests/functional/common/test_extension.py b/openstackclient/tests/functional/common/test_extension.py
index d7dc398b5..e3a91fe65 100644
--- a/openstackclient/tests/functional/common/test_extension.py
+++ b/openstackclient/tests/functional/common/test_extension.py
@@ -25,6 +25,7 @@ class ExtensionTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        super(ExtensionTests, cls).setUpClass()
         cls.haz_network = base.is_service_enabled('network')
 
     def test_extension_list_compute(self):
diff --git a/openstackclient/tests/functional/common/test_help.py b/openstackclient/tests/functional/common/test_help.py
index e31d3b869..7f2740995 100644
--- a/openstackclient/tests/functional/common/test_help.py
+++ b/openstackclient/tests/functional/common/test_help.py
@@ -12,6 +12,8 @@
 
 import os
 
+import fixtures
+
 from openstackclient.tests.functional import base
 
 
@@ -76,10 +78,11 @@ class HelpTests(base.TestCase):
 
     def test_commands_help_no_auth(self):
         """Check help commands without auth info."""
-        # Pop all auth info
-        auth_info = {key: os.environ.pop(key)
-                     for key in os.environ.keys()
-                     if key.startswith('OS_')}
+        # Pop all auth info. os.environ will be changed in loop, so do not
+        # replace os.environ.keys() to os.environ
+        for key in os.environ.keys():
+            if key.startswith('OS_'):
+                self.useFixture(fixtures.EnvironmentVariable(key, None))
 
         raw_output = self.openstack('help')
         self.assertIn('usage: openstack', raw_output)
@@ -115,6 +118,3 @@ class HelpTests(base.TestCase):
         self.assertIn('List containers', raw_output)
         raw_output = self.openstack('container list --help')
         self.assertIn('List containers', raw_output)
-
-        # Restore auth info
-        os.environ.update(auth_info)
diff --git a/openstackclient/tests/functional/common/test_quota.py b/openstackclient/tests/functional/common/test_quota.py
index 1b13e95ed..76c69a4d0 100644
--- a/openstackclient/tests/functional/common/test_quota.py
+++ b/openstackclient/tests/functional/common/test_quota.py
@@ -26,6 +26,7 @@ class QuotaTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        super(QuotaTests, cls).setUpClass()
         cls.haz_network = base.is_service_enabled('network')
         cls.PROJECT_NAME =\
             cls.get_openstack_configuration_value('auth.project_name')
diff --git a/openstackclient/tests/functional/compute/v2/test_flavor.py b/openstackclient/tests/functional/compute/v2/test_flavor.py
index 0b01da517..eefd3fabd 100644
--- a/openstackclient/tests/functional/compute/v2/test_flavor.py
+++ b/openstackclient/tests/functional/compute/v2/test_flavor.py
@@ -23,6 +23,7 @@ class FlavorTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        super(FlavorTests, cls).setUpClass()
         # Make a project
         cmd_output = json.loads(cls.openstack(
             "project create -f json --enable " + cls.PROJECT_NAME
@@ -31,8 +32,11 @@ class FlavorTests(base.TestCase):
 
     @classmethod
     def tearDownClass(cls):
-        raw_output = cls.openstack("project delete " + cls.PROJECT_NAME)
-        cls.assertOutput('', raw_output)
+        try:
+            raw_output = cls.openstack("project delete " + cls.PROJECT_NAME)
+            cls.assertOutput('', raw_output)
+        finally:
+            super(FlavorTests, cls).tearDownClass()
 
     def test_flavor_delete(self):
         """Test create w/project, delete multiple"""
diff --git a/openstackclient/tests/functional/compute/v2/test_server.py b/openstackclient/tests/functional/compute/v2/test_server.py
index c9f4d62c8..b7a259967 100644
--- a/openstackclient/tests/functional/compute/v2/test_server.py
+++ b/openstackclient/tests/functional/compute/v2/test_server.py
@@ -25,6 +25,7 @@ class ServerTests(common.ComputeTestCase):
 
     @classmethod
     def setUpClass(cls):
+        super(ServerTests, cls).setUpClass()
         cls.haz_network = base.is_service_enabled('network')
 
     def test_server_list(self):
diff --git a/openstackclient/tests/functional/identity/v2/common.py b/openstackclient/tests/functional/identity/v2/common.py
index 69ef728b1..f4bc10bdd 100644
--- a/openstackclient/tests/functional/identity/v2/common.py
+++ b/openstackclient/tests/functional/identity/v2/common.py
@@ -12,6 +12,7 @@
 
 import os
 
+import fixtures
 from tempest.lib.common.utils import data_utils
 from tempest.lib import exceptions as tempest_exceptions
 
@@ -41,17 +42,13 @@ class IdentityTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        # prepare v2 env
-        os.environ['OS_IDENTITY_API_VERSION'] = '2.0'
-        auth_url = os.environ.get('OS_AUTH_URL')
-        if auth_url:
-            os.environ['OS_AUTH_URL'] = auth_url.replace('v3', 'v2.0')
-
+        super(IdentityTests, cls).setUpClass()
         # create dummy project
         cls.project_name = data_utils.rand_name('TestProject')
         cls.project_description = data_utils.rand_name('description')
         try:
             cls.openstack(
+                '--os-identity-api-version 2 '
                 'project create '
                 '--description %(description)s '
                 '--enable '
@@ -69,7 +66,25 @@ class IdentityTests(base.TestCase):
 
     @classmethod
     def tearDownClass(cls):
-        cls.openstack('project delete %s' % cls.project_name)
+        try:
+            cls.openstack(
+                '--os-identity-api-version 2 '
+                'project delete %s' % cls.project_name)
+        finally:
+            super(IdentityTests, cls).tearDownClass()
+
+    def setUp(self):
+        super(IdentityTests, self).setUp()
+        # prepare v2 env
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_IDENTITY_API_VERSION', '2.0')
+        self.useFixture(ver_fixture)
+        auth_url = os.environ.get('OS_AUTH_URL')
+        if auth_url:
+            auth_url_fixture = fixtures.EnvironmentVariable(
+                'OS_AUTH_URL', auth_url.replace('v3', 'v2.0')
+            )
+            self.useFixture(auth_url_fixture)
 
     def _create_dummy_project(self, add_clean_up=True):
         project_name = data_utils.rand_name('TestProject')
diff --git a/openstackclient/tests/functional/identity/v3/common.py b/openstackclient/tests/functional/identity/v3/common.py
index 1ec3ac928..6d7896d8f 100644
--- a/openstackclient/tests/functional/identity/v3/common.py
+++ b/openstackclient/tests/functional/identity/v3/common.py
@@ -12,6 +12,7 @@
 
 import os
 
+import fixtures
 from tempest.lib.common.utils import data_utils
 
 from openstackclient.tests.functional import base
@@ -53,16 +54,12 @@ class IdentityTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        # prepare v3 env
-        os.environ['OS_IDENTITY_API_VERSION'] = '3'
-        auth_url = os.environ.get('OS_AUTH_URL')
-        if auth_url:
-            os.environ['OS_AUTH_URL'] = auth_url.replace('v2.0', 'v3')
-
+        super(IdentityTests, cls).setUpClass()
         # create dummy domain
         cls.domain_name = data_utils.rand_name('TestDomain')
         cls.domain_description = data_utils.rand_name('description')
         cls.openstack(
+            '--os-identity-api-version 3 '
             'domain create '
             '--description %(description)s '
             '--enable '
@@ -73,6 +70,7 @@ class IdentityTests(base.TestCase):
         cls.project_name = data_utils.rand_name('TestProject')
         cls.project_description = data_utils.rand_name('description')
         cls.openstack(
+            '--os-identity-api-version 3 '
             'project create '
             '--domain %(domain)s '
             '--description %(description)s '
@@ -83,11 +81,30 @@ class IdentityTests(base.TestCase):
 
     @classmethod
     def tearDownClass(cls):
-        # delete dummy project
-        cls.openstack('project delete %s' % cls.project_name)
-        # disable and delete dummy domain
-        cls.openstack('domain set --disable %s' % cls.domain_name)
-        cls.openstack('domain delete %s' % cls.domain_name)
+        try:
+            # delete dummy project
+            cls.openstack('--os-identity-api-version 3 '
+                          'project delete %s' % cls.project_name)
+            # disable and delete dummy domain
+            cls.openstack('--os-identity-api-version 3 '
+                          'domain set --disable %s' % cls.domain_name)
+            cls.openstack('--os-identity-api-version 3 '
+                          'domain delete %s' % cls.domain_name)
+        finally:
+            super(IdentityTests, cls).tearDownClass()
+
+    def setUp(self):
+        super(IdentityTests, self).setUp()
+        # prepare v3 env
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_IDENTITY_API_VERSION', '3')
+        self.useFixture(ver_fixture)
+        auth_url = os.environ.get('OS_AUTH_URL')
+        if auth_url:
+            auth_url_fixture = fixtures.EnvironmentVariable(
+                'OS_AUTH_URL', auth_url.replace('v2.0', 'v3')
+            )
+            self.useFixture(auth_url_fixture)
 
     def _create_dummy_user(self, add_clean_up=True):
         username = data_utils.rand_name('TestUser')
diff --git a/openstackclient/tests/functional/image/v1/test_image.py b/openstackclient/tests/functional/image/v1/test_image.py
index 901f4337a..fa073f99a 100644
--- a/openstackclient/tests/functional/image/v1/test_image.py
+++ b/openstackclient/tests/functional/image/v1/test_image.py
@@ -11,9 +11,10 @@
 #    under the License.
 
 import json
-import os
 import uuid
 
+import fixtures
+
 from openstackclient.tests.functional import base
 
 
@@ -25,8 +26,9 @@ class ImageTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        os.environ['OS_IMAGE_API_VERSION'] = '1'
+        super(ImageTests, cls).setUpClass()
         json_output = json.loads(cls.openstack(
+            '--os-image-api-version 1 '
             'image create -f json ' +
             cls.NAME
         ))
@@ -35,10 +37,21 @@ class ImageTests(base.TestCase):
 
     @classmethod
     def tearDownClass(cls):
-        cls.openstack(
-            'image delete ' +
-            cls.image_id
+        try:
+            cls.openstack(
+                '--os-image-api-version 1 '
+                'image delete ' +
+                cls.image_id
+            )
+        finally:
+            super(ImageTests, cls).tearDownClass()
+
+    def setUp(self):
+        super(ImageTests, self).setUp()
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_IMAGE_API_VERSION', '1'
         )
+        self.useFixture(ver_fixture)
 
     def test_image_list(self):
         json_output = json.loads(self.openstack(
diff --git a/openstackclient/tests/functional/image/v2/test_image.py b/openstackclient/tests/functional/image/v2/test_image.py
index a93fa8cbe..278ba5b94 100644
--- a/openstackclient/tests/functional/image/v2/test_image.py
+++ b/openstackclient/tests/functional/image/v2/test_image.py
@@ -11,9 +11,9 @@
 #    under the License.
 
 import json
-import os
 import uuid
 
+import fixtures
 # from glanceclient import exc as image_exceptions
 
 from openstackclient.tests.functional import base
@@ -27,8 +27,9 @@ class ImageTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        os.environ['OS_IMAGE_API_VERSION'] = '2'
+        super(ImageTests, cls).setUpClass()
         json_output = json.loads(cls.openstack(
+            '--os-image-api-version 2 '
             'image create -f json ' +
             cls.NAME
         ))
@@ -37,10 +38,21 @@ class ImageTests(base.TestCase):
 
     @classmethod
     def tearDownClass(cls):
-        cls.openstack(
-            'image delete ' +
-            cls.image_id
+        try:
+            cls.openstack(
+                '--os-image-api-version 2 '
+                'image delete ' +
+                cls.image_id
+            )
+        finally:
+            super(ImageTests, cls).tearDownClass()
+
+    def setUp(self):
+        super(ImageTests, self).setUp()
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_IMAGE_API_VERSION', '2'
         )
+        self.useFixture(ver_fixture)
 
     def test_image_list(self):
         json_output = json.loads(self.openstack(
diff --git a/openstackclient/tests/functional/network/v2/common.py b/openstackclient/tests/functional/network/v2/common.py
index bed07878f..e3835abf5 100644
--- a/openstackclient/tests/functional/network/v2/common.py
+++ b/openstackclient/tests/functional/network/v2/common.py
@@ -18,5 +18,5 @@ class NetworkTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        # super(NetworkTests, cls).setUp()
+        super(NetworkTests, cls).setUpClass()
         cls.haz_network = base.is_service_enabled('network')
diff --git a/openstackclient/tests/functional/network/v2/test_floating_ip.py b/openstackclient/tests/functional/network/v2/test_floating_ip.py
index 9e34622cf..1d11fc5d2 100644
--- a/openstackclient/tests/functional/network/v2/test_floating_ip.py
+++ b/openstackclient/tests/functional/network/v2/test_floating_ip.py
@@ -88,19 +88,22 @@ class FloatingIpTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            del_output = cls.openstack(
-                'subnet delete ' +
-                cls.EXTERNAL_SUBNET_NAME + ' ' +
-                cls.PRIVATE_SUBNET_NAME
-            )
-            cls.assertOutput('', del_output)
-            del_output = cls.openstack(
-                'network delete ' +
-                cls.EXTERNAL_NETWORK_NAME + ' ' +
-                cls.PRIVATE_NETWORK_NAME
-            )
-            cls.assertOutput('', del_output)
+        try:
+            if cls.haz_network:
+                del_output = cls.openstack(
+                    'subnet delete ' +
+                    cls.EXTERNAL_SUBNET_NAME + ' ' +
+                    cls.PRIVATE_SUBNET_NAME
+                )
+                cls.assertOutput('', del_output)
+                del_output = cls.openstack(
+                    'network delete ' +
+                    cls.EXTERNAL_NETWORK_NAME + ' ' +
+                    cls.PRIVATE_NETWORK_NAME
+                )
+                cls.assertOutput('', del_output)
+        finally:
+            super(FloatingIpTests, cls).tearDownClass()
 
     def setUp(self):
         super(FloatingIpTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_ip_availability.py b/openstackclient/tests/functional/network/v2/test_ip_availability.py
index cb4b8150a..86a53c0ce 100644
--- a/openstackclient/tests/functional/network/v2/test_ip_availability.py
+++ b/openstackclient/tests/functional/network/v2/test_ip_availability.py
@@ -41,17 +41,20 @@ class IPAvailabilityTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_subnet = cls.openstack(
-                'subnet delete ' +
-                cls.NAME
-            )
-            raw_network = cls.openstack(
-                'network delete ' +
-                cls.NETWORK_NAME
-            )
-            cls.assertOutput('', raw_subnet)
-            cls.assertOutput('', raw_network)
+        try:
+            if cls.haz_network:
+                raw_subnet = cls.openstack(
+                    'subnet delete ' +
+                    cls.NAME
+                )
+                raw_network = cls.openstack(
+                    'network delete ' +
+                    cls.NETWORK_NAME
+                )
+                cls.assertOutput('', raw_subnet)
+                cls.assertOutput('', raw_network)
+        finally:
+            super(IPAvailabilityTests, cls).tearDownClass()
 
     def setUp(self):
         super(IPAvailabilityTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_network.py b/openstackclient/tests/functional/network/v2/test_network.py
index b23323a00..91939703d 100644
--- a/openstackclient/tests/functional/network/v2/test_network.py
+++ b/openstackclient/tests/functional/network/v2/test_network.py
@@ -361,7 +361,7 @@ class NetworkTests(common.NetworkTests):
             self.assertNotIn(name2, col_name)
 
     def test_network_dhcp_agent(self):
-        if self.haz_network:
+        if not self.haz_network:
             self.skipTest("No Network service present")
 
         name1 = uuid.uuid4().hex
@@ -408,7 +408,7 @@ class NetworkTests(common.NetworkTests):
 
     def test_network_set(self):
         """Tests create options, set, show, delete"""
-        if self.haz_network:
+        if not self.haz_network:
             self.skipTest("No Network service present")
 
         name = uuid.uuid4().hex
diff --git a/openstackclient/tests/functional/network/v2/test_network_meter_rule.py b/openstackclient/tests/functional/network/v2/test_network_meter_rule.py
index 71b406b46..31bc08453 100644
--- a/openstackclient/tests/functional/network/v2/test_network_meter_rule.py
+++ b/openstackclient/tests/functional/network/v2/test_network_meter_rule.py
@@ -39,13 +39,15 @@ class TestMeterRule(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        common.NetworkTests.tearDownClass()
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network meter delete ' +
-                cls.METER_ID
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network meter delete ' +
+                    cls.METER_ID
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            common.NetworkTests.tearDownClass()
 
     def setUp(self):
         super(TestMeterRule, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_network_qos_policy.py b/openstackclient/tests/functional/network/v2/test_network_qos_policy.py
index ccbf437c3..53c15ecf6 100644
--- a/openstackclient/tests/functional/network/v2/test_network_qos_policy.py
+++ b/openstackclient/tests/functional/network/v2/test_network_qos_policy.py
@@ -39,12 +39,15 @@ class NetworkQosPolicyTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network qos policy delete ' +
-                cls.NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network qos policy delete ' +
+                    cls.NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(NetworkQosPolicyTests, cls).tearDownClass()
 
     def setUp(self):
         super(NetworkQosPolicyTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_network_qos_rule.py b/openstackclient/tests/functional/network/v2/test_network_qos_rule.py
index 6e40d8e0d..8b34422fb 100644
--- a/openstackclient/tests/functional/network/v2/test_network_qos_rule.py
+++ b/openstackclient/tests/functional/network/v2/test_network_qos_rule.py
@@ -51,17 +51,20 @@ class NetworkQosRuleTestsMinimumBandwidth(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network qos rule delete ' +
-                cls.QOS_POLICY_NAME + ' ' +
-                cls.RULE_ID
-            )
-            cls.openstack(
-                'network qos policy delete ' +
-                cls.QOS_POLICY_NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network qos rule delete ' +
+                    cls.QOS_POLICY_NAME + ' ' +
+                    cls.RULE_ID
+                )
+                cls.openstack(
+                    'network qos policy delete ' +
+                    cls.QOS_POLICY_NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(NetworkQosRuleTestsMinimumBandwidth, cls).tearDownClass()
 
     def setUp(self):
         super(NetworkQosRuleTestsMinimumBandwidth, self).setUp()
@@ -123,14 +126,18 @@ class NetworkQosRuleTestsDSCPMarking(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network qos rule delete ' +
-                cls.QOS_POLICY_NAME + ' ' +
-                cls.RULE_ID
-            )
-            cls.openstack('network qos policy delete ' + cls.QOS_POLICY_NAME)
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network qos rule delete ' +
+                    cls.QOS_POLICY_NAME + ' ' +
+                    cls.RULE_ID
+                )
+                cls.openstack(
+                    'network qos policy delete ' + cls.QOS_POLICY_NAME)
+                cls.assertOutput('', raw_output)
+        finally:
+            super(NetworkQosRuleTestsDSCPMarking, cls).tearDownClass()
 
     def setUp(self):
         super(NetworkQosRuleTestsDSCPMarking, self).setUp()
@@ -198,14 +205,18 @@ class NetworkQosRuleTestsBandwidthLimit(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network qos rule delete ' +
-                cls.QOS_POLICY_NAME + ' ' +
-                cls.RULE_ID
-            )
-            cls.openstack('network qos policy delete ' + cls.QOS_POLICY_NAME)
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network qos rule delete ' +
+                    cls.QOS_POLICY_NAME + ' ' +
+                    cls.RULE_ID
+                )
+                cls.openstack(
+                    'network qos policy delete ' + cls.QOS_POLICY_NAME)
+                cls.assertOutput('', raw_output)
+        finally:
+            super(NetworkQosRuleTestsBandwidthLimit, cls).tearDownClass()
 
     def setUp(self):
         super(NetworkQosRuleTestsBandwidthLimit, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_network_rbac.py b/openstackclient/tests/functional/network/v2/test_network_rbac.py
index 893f19939..2206761f0 100644
--- a/openstackclient/tests/functional/network/v2/test_network_rbac.py
+++ b/openstackclient/tests/functional/network/v2/test_network_rbac.py
@@ -47,15 +47,18 @@ class NetworkRBACTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output_rbac = cls.openstack(
-                'network rbac delete ' + cls.ID
-            )
-            raw_output_network = cls.openstack(
-                'network delete ' + cls.OBJECT_ID
-            )
-            cls.assertOutput('', raw_output_rbac)
-            cls.assertOutput('', raw_output_network)
+        try:
+            if cls.haz_network:
+                raw_output_rbac = cls.openstack(
+                    'network rbac delete ' + cls.ID
+                )
+                raw_output_network = cls.openstack(
+                    'network delete ' + cls.OBJECT_ID
+                )
+                cls.assertOutput('', raw_output_rbac)
+                cls.assertOutput('', raw_output_network)
+        finally:
+            super(NetworkRBACTests, cls).tearDownClass()
 
     def setUp(self):
         super(NetworkRBACTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_network_segment.py b/openstackclient/tests/functional/network/v2/test_network_segment.py
index 6dec82d9e..b34515fa4 100644
--- a/openstackclient/tests/functional/network/v2/test_network_segment.py
+++ b/openstackclient/tests/functional/network/v2/test_network_segment.py
@@ -55,11 +55,14 @@ class NetworkSegmentTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network delete ' + cls.NETWORK_NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network delete ' + cls.NETWORK_NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(NetworkSegmentTests, cls).tearDownClass()
 
     def setUp(self):
         super(NetworkSegmentTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_port.py b/openstackclient/tests/functional/network/v2/test_port.py
index 14454454e..09ac3566e 100644
--- a/openstackclient/tests/functional/network/v2/test_port.py
+++ b/openstackclient/tests/functional/network/v2/test_port.py
@@ -33,11 +33,14 @@ class PortTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network delete ' + cls.NETWORK_NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network delete ' + cls.NETWORK_NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(PortTests, cls).tearDownClass()
 
     def setUp(self):
         super(PortTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_security_group.py b/openstackclient/tests/functional/network/v2/test_security_group.py
index 6da7e204d..b601c913f 100644
--- a/openstackclient/tests/functional/network/v2/test_security_group.py
+++ b/openstackclient/tests/functional/network/v2/test_security_group.py
@@ -38,20 +38,23 @@ class SecurityGroupTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            # Rename test
-            raw_output = cls.openstack(
-                'security group set --name ' +
-                cls.OTHER_NAME + ' ' +
-                cls.NAME
-            )
-            cls.assertOutput('', raw_output)
-            # Delete test
-            raw_output = cls.openstack(
-                'security group delete ' +
-                cls.OTHER_NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                # Rename test
+                raw_output = cls.openstack(
+                    'security group set --name ' +
+                    cls.OTHER_NAME + ' ' +
+                    cls.NAME
+                )
+                cls.assertOutput('', raw_output)
+                # Delete test
+                raw_output = cls.openstack(
+                    'security group delete ' +
+                    cls.OTHER_NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(SecurityGroupTests, cls).tearDownClass()
 
     def setUp(self):
         super(SecurityGroupTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_security_group_rule.py b/openstackclient/tests/functional/network/v2/test_security_group_rule.py
index e153116b1..40951a011 100644
--- a/openstackclient/tests/functional/network/v2/test_security_group_rule.py
+++ b/openstackclient/tests/functional/network/v2/test_security_group_rule.py
@@ -51,18 +51,20 @@ class SecurityGroupRuleTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'security group rule delete ' +
-                cls.SECURITY_GROUP_RULE_ID
-            )
-            cls.assertOutput('', raw_output)
-
-            raw_output = cls.openstack(
-                'security group delete ' +
-                cls.SECURITY_GROUP_NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'security group rule delete ' +
+                    cls.SECURITY_GROUP_RULE_ID
+                )
+                cls.assertOutput('', raw_output)
+                raw_output = cls.openstack(
+                    'security group delete ' +
+                    cls.SECURITY_GROUP_NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(SecurityGroupRuleTests, cls).tearDownClass()
 
     def setUp(self):
         super(SecurityGroupRuleTests, self).setUp()
diff --git a/openstackclient/tests/functional/network/v2/test_subnet.py b/openstackclient/tests/functional/network/v2/test_subnet.py
index 413754157..040b645b1 100644
--- a/openstackclient/tests/functional/network/v2/test_subnet.py
+++ b/openstackclient/tests/functional/network/v2/test_subnet.py
@@ -36,12 +36,15 @@ class SubnetTests(common.NetworkTests):
 
     @classmethod
     def tearDownClass(cls):
-        if cls.haz_network:
-            raw_output = cls.openstack(
-                'network delete ' +
-                cls.NETWORK_NAME
-            )
-            cls.assertOutput('', raw_output)
+        try:
+            if cls.haz_network:
+                raw_output = cls.openstack(
+                    'network delete ' +
+                    cls.NETWORK_NAME
+                )
+                cls.assertOutput('', raw_output)
+        finally:
+            super(SubnetTests, cls).tearDownClass()
 
     def setUp(self):
         super(SubnetTests, self).setUp()
diff --git a/openstackclient/tests/functional/object/v1/test_container.py b/openstackclient/tests/functional/object/v1/test_container.py
index af76efd96..acfbab11d 100644
--- a/openstackclient/tests/functional/object/v1/test_container.py
+++ b/openstackclient/tests/functional/object/v1/test_container.py
@@ -21,14 +21,18 @@ class ContainerTests(base.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        super(ContainerTests, cls).setUpClass()
         opts = cls.get_opts(['container'])
         raw_output = cls.openstack('container create ' + cls.NAME + opts)
         cls.assertOutput(cls.NAME + '\n', raw_output)
 
     @classmethod
     def tearDownClass(cls):
-        raw_output = cls.openstack('container delete ' + cls.NAME)
-        cls.assertOutput('', raw_output)
+        try:
+            raw_output = cls.openstack('container delete ' + cls.NAME)
+            cls.assertOutput('', raw_output)
+        finally:
+            super(ContainerTests, cls).tearDownClass()
 
     def test_container_list(self):
         opts = self.get_opts(['Name'])
diff --git a/openstackclient/tests/functional/volume/v1/common.py b/openstackclient/tests/functional/volume/v1/common.py
index f9d96bbb6..4978cea31 100644
--- a/openstackclient/tests/functional/volume/v1/common.py
+++ b/openstackclient/tests/functional/volume/v1/common.py
@@ -10,7 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import os
+import fixtures
 
 from openstackclient.tests.functional.volume import base
 
@@ -18,6 +18,9 @@ from openstackclient.tests.functional.volume import base
 class BaseVolumeTests(base.BaseVolumeTests):
     """Base class for Volume functional tests. """
 
-    @classmethod
-    def setUpClass(cls):
-        os.environ['OS_VOLUME_API_VERSION'] = '1'
+    def setUp(self):
+        super(BaseVolumeTests, self).setUp()
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_VOLUME_API_VERSION', '1'
+        )
+        self.useFixture(ver_fixture)
diff --git a/openstackclient/tests/functional/volume/v1/test_snapshot.py b/openstackclient/tests/functional/volume/v1/test_snapshot.py
index 28726762d..c60472c55 100644
--- a/openstackclient/tests/functional/volume/v1/test_snapshot.py
+++ b/openstackclient/tests/functional/volume/v1/test_snapshot.py
@@ -35,9 +35,12 @@ class VolumeSnapshotTests(common.BaseVolumeTests):
 
     @classmethod
     def tearDownClass(cls):
-        cls.wait_for_status('volume', cls.VOLLY, 'available')
-        raw_output = cls.openstack('volume delete --force ' + cls.VOLLY)
-        cls.assertOutput('', raw_output)
+        try:
+            cls.wait_for_status('volume', cls.VOLLY, 'available')
+            raw_output = cls.openstack('volume delete --force ' + cls.VOLLY)
+            cls.assertOutput('', raw_output)
+        finally:
+            super(VolumeSnapshotTests, cls).tearDownClass()
 
     def test_volume_snapshot__delete(self):
         """Test create, delete multiple"""
diff --git a/openstackclient/tests/functional/volume/v1/test_transfer_request.py b/openstackclient/tests/functional/volume/v1/test_transfer_request.py
index bd6128295..73191fc9d 100644
--- a/openstackclient/tests/functional/volume/v1/test_transfer_request.py
+++ b/openstackclient/tests/functional/volume/v1/test_transfer_request.py
@@ -37,12 +37,15 @@ class TransferRequestTests(common.BaseVolumeTests):
 
     @classmethod
     def tearDownClass(cls):
-        raw_output_transfer = cls.openstack(
-            'volume transfer request delete ' + cls.NAME)
-        raw_output_volume = cls.openstack(
-            'volume delete ' + cls.VOLUME_NAME)
-        cls.assertOutput('', raw_output_transfer)
-        cls.assertOutput('', raw_output_volume)
+        try:
+            raw_output_transfer = cls.openstack(
+                'volume transfer request delete ' + cls.NAME)
+            raw_output_volume = cls.openstack(
+                'volume delete ' + cls.VOLUME_NAME)
+            cls.assertOutput('', raw_output_transfer)
+            cls.assertOutput('', raw_output_volume)
+        finally:
+            super(TransferRequestTests, cls).tearDownClass()
 
     def test_volume_transfer_request_accept(self):
         volume_name = uuid.uuid4().hex
diff --git a/openstackclient/tests/functional/volume/v1/test_volume_type.py b/openstackclient/tests/functional/volume/v1/test_volume_type.py
index acad34add..74e140700 100644
--- a/openstackclient/tests/functional/volume/v1/test_volume_type.py
+++ b/openstackclient/tests/functional/volume/v1/test_volume_type.py
@@ -31,8 +31,11 @@ class VolumeTypeTests(common.BaseVolumeTests):
 
     @classmethod
     def tearDownClass(cls):
-        raw_output = cls.openstack('volume type delete ' + cls.NAME)
-        cls.assertOutput('', raw_output)
+        try:
+            raw_output = cls.openstack('volume type delete ' + cls.NAME)
+            cls.assertOutput('', raw_output)
+        finally:
+            super(VolumeTypeTests, cls).tearDownClass()
 
     def test_volume_type_list(self):
         cmd_output = json.loads(self.openstack('volume type list -f json'))
diff --git a/openstackclient/tests/functional/volume/v2/common.py b/openstackclient/tests/functional/volume/v2/common.py
index 1d14719fc..381767142 100644
--- a/openstackclient/tests/functional/volume/v2/common.py
+++ b/openstackclient/tests/functional/volume/v2/common.py
@@ -10,7 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import os
+import fixtures
 
 from openstackclient.tests.functional.volume import base
 
@@ -18,6 +18,9 @@ from openstackclient.tests.functional.volume import base
 class BaseVolumeTests(base.BaseVolumeTests):
     """Base class for Volume functional tests. """
 
-    @classmethod
-    def setUpClass(cls):
-        os.environ['OS_VOLUME_API_VERSION'] = '2'
+    def setUp(self):
+        super(BaseVolumeTests, self).setUp()
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_VOLUME_API_VERSION', '2'
+        )
+        self.useFixture(ver_fixture)
diff --git a/openstackclient/tests/functional/volume/v2/test_snapshot.py b/openstackclient/tests/functional/volume/v2/test_snapshot.py
index 2fff43c82..ba6b2c283 100644
--- a/openstackclient/tests/functional/volume/v2/test_snapshot.py
+++ b/openstackclient/tests/functional/volume/v2/test_snapshot.py
@@ -35,10 +35,13 @@ class VolumeSnapshotTests(common.BaseVolumeTests):
 
     @classmethod
     def tearDownClass(cls):
-        cls.wait_for_status('volume', cls.VOLLY, 'available')
-        raw_output = cls.openstack(
-            'volume delete --force ' + cls.VOLLY)
-        cls.assertOutput('', raw_output)
+        try:
+            cls.wait_for_status('volume', cls.VOLLY, 'available')
+            raw_output = cls.openstack(
+                'volume delete --force ' + cls.VOLLY)
+            cls.assertOutput('', raw_output)
+        finally:
+            super(VolumeSnapshotTests, cls).tearDownClass()
 
     def test_volume_snapshot__delete(self):
         """Test create, delete multiple"""
diff --git a/openstackclient/tests/functional/volume/v2/test_transfer_request.py b/openstackclient/tests/functional/volume/v2/test_transfer_request.py
index e9c2236b7..33495af63 100644
--- a/openstackclient/tests/functional/volume/v2/test_transfer_request.py
+++ b/openstackclient/tests/functional/volume/v2/test_transfer_request.py
@@ -38,12 +38,15 @@ class TransferRequestTests(common.BaseVolumeTests):
 
     @classmethod
     def tearDownClass(cls):
-        raw_output_transfer = cls.openstack(
-            'volume transfer request delete ' + cls.NAME)
-        raw_output_volume = cls.openstack(
-            'volume delete ' + cls.VOLUME_NAME)
-        cls.assertOutput('', raw_output_transfer)
-        cls.assertOutput('', raw_output_volume)
+        try:
+            raw_output_transfer = cls.openstack(
+                'volume transfer request delete ' + cls.NAME)
+            raw_output_volume = cls.openstack(
+                'volume delete ' + cls.VOLUME_NAME)
+            cls.assertOutput('', raw_output_transfer)
+            cls.assertOutput('', raw_output_volume)
+        finally:
+            super(TransferRequestTests, cls).tearDownClass()
 
     def test_volume_transfer_request_accept(self):
         volume_name = uuid.uuid4().hex
diff --git a/openstackclient/tests/functional/volume/v2/test_volume_type.py b/openstackclient/tests/functional/volume/v2/test_volume_type.py
index 11acf2f8a..99630e6b0 100644
--- a/openstackclient/tests/functional/volume/v2/test_volume_type.py
+++ b/openstackclient/tests/functional/volume/v2/test_volume_type.py
@@ -31,8 +31,11 @@ class VolumeTypeTests(common.BaseVolumeTests):
 
     @classmethod
     def tearDownClass(cls):
-        raw_output = cls.openstack('volume type delete ' + cls.NAME)
-        cls.assertOutput('', raw_output)
+        try:
+            raw_output = cls.openstack('volume type delete ' + cls.NAME)
+            cls.assertOutput('', raw_output)
+        finally:
+            super(VolumeTypeTests, cls).tearDownClass()
 
     def test_volume_type_list(self):
         cmd_output = json.loads(self.openstack('volume type list -f json'))
diff --git a/openstackclient/tests/functional/volume/v3/common.py b/openstackclient/tests/functional/volume/v3/common.py
index bc8befa67..a710a6835 100644
--- a/openstackclient/tests/functional/volume/v3/common.py
+++ b/openstackclient/tests/functional/volume/v3/common.py
@@ -10,7 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import os
+import fixtures
 
 from openstackclient.tests.functional.volume import base
 
@@ -18,6 +18,9 @@ from openstackclient.tests.functional.volume import base
 class BaseVolumeTests(base.BaseVolumeTests):
     """Base class for Volume functional tests. """
 
-    @classmethod
-    def setUpClass(cls):
-        os.environ['OS_VOLUME_API_VERSION'] = '3'
+    def setUp(self):
+        super(BaseVolumeTests, self).setUp()
+        ver_fixture = fixtures.EnvironmentVariable(
+            'OS_VOLUME_API_VERSION', '3'
+        )
+        self.useFixture(ver_fixture)
diff --git a/openstackclient/tests/functional/volume/v3/test_qos.py b/openstackclient/tests/functional/volume/v3/test_qos.py
index a7af3c5b9..a6290fc53 100644
--- a/openstackclient/tests/functional/volume/v3/test_qos.py
+++ b/openstackclient/tests/functional/volume/v3/test_qos.py
@@ -10,15 +10,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import os
-
 from openstackclient.tests.functional.volume.v2 import test_qos as v2
+from openstackclient.tests.functional.volume.v3 import common
 
 
-class QosTests(v2.QosTests):
+class QosTests(common.BaseVolumeTests, v2.QosTests):
     """Functional tests for volume qos. """
-
-    @classmethod
-    def setUpClass(cls):
-        super(QosTests, cls).setUpClass()
-        os.environ['OS_VOLUME_API_VERSION'] = '3'
diff --git a/openstackclient/tests/functional/volume/v3/test_snapshot.py b/openstackclient/tests/functional/volume/v3/test_snapshot.py
index bf05b9de9..38e0563a7 100644
--- a/openstackclient/tests/functional/volume/v3/test_snapshot.py
+++ b/openstackclient/tests/functional/volume/v3/test_snapshot.py
@@ -11,13 +11,8 @@
 #    under the License.
 
 from openstackclient.tests.functional.volume.v2 import test_snapshot as v2
-import os
+from openstackclient.tests.functional.volume.v3 import common
 
 
-class VolumeSnapshotTests(v2.VolumeSnapshotTests):
+class VolumeSnapshotTests(common.BaseVolumeTests, v2.VolumeSnapshotTests):
     """Functional tests for volume snapshot. """
-
-    @classmethod
-    def setUpClass(cls):
-        super(VolumeSnapshotTests, cls).setUpClass()
-        os.environ['OS_VOLUME_API_VERSION'] = '3'
diff --git a/openstackclient/tests/functional/volume/v3/test_transfer_request.py b/openstackclient/tests/functional/volume/v3/test_transfer_request.py
index 7b54dd20f..b32532375 100644
--- a/openstackclient/tests/functional/volume/v3/test_transfer_request.py
+++ b/openstackclient/tests/functional/volume/v3/test_transfer_request.py
@@ -12,13 +12,8 @@
 
 from openstackclient.tests.functional.volume.v2 import test_transfer_request \
     as v2
-import os
+from openstackclient.tests.functional.volume.v3 import common
 
 
-class TransferRequestTests(v2.TransferRequestTests):
+class TransferRequestTests(common.BaseVolumeTests, v2.TransferRequestTests):
     """Functional tests for transfer request. """
-
-    @classmethod
-    def setUpClass(cls):
-        super(TransferRequestTests, cls).setUpClass()
-        os.environ['OS_VOLUME_API_VERSION'] = '3'
diff --git a/openstackclient/tests/functional/volume/v3/test_volume.py b/openstackclient/tests/functional/volume/v3/test_volume.py
index 333826d83..283b830f6 100644
--- a/openstackclient/tests/functional/volume/v3/test_volume.py
+++ b/openstackclient/tests/functional/volume/v3/test_volume.py
@@ -11,13 +11,8 @@
 #    under the License.
 
 from openstackclient.tests.functional.volume.v2 import test_volume as v2
-import os
+from openstackclient.tests.functional.volume.v3 import common
 
 
-class VolumeTests(v2.VolumeTests):
+class VolumeTests(common.BaseVolumeTests, v2.VolumeTests):
     """Functional tests for volume. """
-
-    @classmethod
-    def setUpClass(cls):
-        super(VolumeTests, cls).setUpClass()
-        os.environ['OS_VOLUME_API_VERSION'] = '3'
diff --git a/openstackclient/tests/functional/volume/v3/test_volume_type.py b/openstackclient/tests/functional/volume/v3/test_volume_type.py
index f10e64b42..eb66515ed 100644
--- a/openstackclient/tests/functional/volume/v3/test_volume_type.py
+++ b/openstackclient/tests/functional/volume/v3/test_volume_type.py
@@ -11,13 +11,8 @@
 #    under the License.
 
 from openstackclient.tests.functional.volume.v2 import test_volume_type as v2
-import os
+from openstackclient.tests.functional.volume.v3 import common
 
 
-class VolumeTypeTests(v2.VolumeTypeTests):
+class VolumeTypeTests(common.BaseVolumeTests, v2.VolumeTypeTests):
     """Functional tests for volume type. """
-
-    @classmethod
-    def setUpClass(cls):
-        super(VolumeTypeTests, cls).setUpClass()
-        os.environ['OS_VOLUME_API_VERSION'] = '3'