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

1 files changed, 22 insertions, 7 deletions

diff --git a/openstackclient/tests/functional/identity/v2/common.py b/openstackclient/tests/functional/identity/v2/common.py
index 69ef728b..f4bc10bd 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')