Clean up the changes of os.environ in functional tests

Use fixtures to restore the API version changes of os.environ
in each functional tests, aims to avoid the following test cases
failing in unexpected context.

And make sure setUpClass/tearDownClass call super class's
corresponding methods first.

Change-Id: Ie248fe9d3a9e25f1b076c9f2c363200f29a83817
Closes-Bug: #1696080

2 files changed, 35 insertions, 10 deletions

diff --git a/openstackclient/tests/functional/image/v1/test_image.py b/openstackclient/tests/functional/image/v1/test_image.py
index 901f4337..fa073f99 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 a93fa8cb..278ba5b9 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(