Replace "oslo_utils.importutils" with standard library "importlib"

The current implementation of dynamic library importation is prone
to failure [1]:
- "sys.modules" is modified manually, which is something not
  recommended [2].
- When a module is imported is added to "sys.modules"; that means
  there is no need to manually create an entry in this object.
- "importlib" library is part of the standard library and is now
  available in PY3 and PY2 (backported). This library contains a
  function called "import_module" to import a module in runtime.

[1]https://github.com/opnfv/yardstick/blob/d2c7cc4e9768ed003257a95c92cdb278d516761b/yardstick/common/utils.py#L72-L93
[2]http://justus.science/blog/2015/04/19/sys.modules-is-dangerous.html

JIRA: YARDSTICK-949

Change-Id: Ide3b74f98858d06fa275fb6c9b78ceeaa64feed5
Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/yardstick/tests/unit/common/test_utils.py b/yardstick/tests/unit/common/test_utils.py
index 452b93a56..033bb0243 100644
--- a/yardstick/tests/unit/common/test_utils.py
+++ b/yardstick/tests/unit/common/test_utils.py
@@ -7,12 +7,9 @@
 # http://www.apache.org/licenses/LICENSE-2.0
 ##############################################################################
 
-# Unittest for yardstick.common.utils
-
-from __future__ import absolute_import
-
 from copy import deepcopy
 import errno
+import importlib
 import ipaddress
 from itertools import product, chain
 import mock
@@ -60,8 +57,8 @@ class ImportModulesFromPackageTestCase(unittest.TestCase):
         utils.import_modules_from_package('foo.bar')
 
     @mock.patch('yardstick.common.utils.os.walk')
-    @mock.patch('yardstick.common.utils.importutils')
-    def test_import_modules_from_package(self, mock_importutils, mock_walk):
+    @mock.patch.object(importlib, 'import_module')
+    def test_import_modules_from_package(self, mock_import_module, mock_walk):
 
         yardstick_root = os.path.dirname(os.path.dirname(yardstick.__file__))
         mock_walk.return_value = ([
@@ -69,7 +66,7 @@ class ImportModulesFromPackageTestCase(unittest.TestCase):
         ])
 
         utils.import_modules_from_package('foo.bar')
-        mock_importutils.import_module.assert_called_with('bar.baz')
+        mock_import_module.assert_called_once_with('bar.baz')
 
 
 class GetParaFromYaml(unittest.TestCase):