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>

4 files changed, 51 insertions, 0 deletions

diff --git a/yardstick/tests/functional/common/__init__.py b/yardstick/tests/functional/common/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/yardstick/tests/functional/common/__init__.py
diff --git a/yardstick/tests/functional/common/fake_module/__init__.py b/yardstick/tests/functional/common/fake_module/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/yardstick/tests/functional/common/fake_module/__init__.py
diff --git a/yardstick/tests/functional/common/fake_module/fake_library.py b/yardstick/tests/functional/common/fake_module/fake_library.py
new file mode 100644
index 000000000..28c7dc694
--- /dev/null
+++ b/yardstick/tests/functional/common/fake_module/fake_library.py
@@ -0,0 +1,17 @@
+# Copyright (c) 2018 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+class FakeClassToBeImported(object):
+    pass
diff --git a/yardstick/tests/functional/common/test_utils.py b/yardstick/tests/functional/common/test_utils.py
new file mode 100644
index 000000000..b5333bbde
--- /dev/null
+++ b/yardstick/tests/functional/common/test_utils.py
@@ -0,0 +1,34 @@
+# Copyright (c) 2018 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+import sys
+
+from yardstick.common import utils
+
+
+class ImportModulesFromPackageTestCase(unittest.TestCase):
+
+    def test_import_package(self):
+        module_name = 'yardstick.tests.functional.common.fake_module'
+        library_name = 'fake_library'
+        class_name = 'FakeClassToBeImported'
+        self.assertNotIn(module_name, sys.modules)
+
+        utils.import_modules_from_package(module_name)
+        self.assertIn(module_name, sys.modules)
+        module_obj = sys.modules[module_name]
+        library_obj = getattr(module_obj, library_name)
+        class_obj = getattr(library_obj, class_name)
+        self.assertEqual(class_name, class_obj().__class__.__name__)