Add helper functions for work with temp dirs and files

* Add function get_tempname required for create temporary filename
It has optional arguments: dir and prefix:
dir setup a directory where this file will be created
prefix setup a prefix value of the file

Usage:

    from octane.util import tempfile

    tmp_name = tempfile.get_tempname()

* Adding of contextmanager temp_dir is required for creating of tempdir
before code block and removing it upon completion of the block.

Usage:

    from octane.util import tempfile

    with tempfile.temp_dir() as my_tmp_dir:
        # code block
        ...

Change-Id: I20b8a0109a85ef41708fa8c9e7e050b391ed039e

octane/tests/test_util_tempfile.py

@@ -0,0 +1,53 @@
+# 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 mock
+import pytest
+
+from octane.util import tempfile
+
+
+@pytest.mark.parametrize("dir", ["dir_1", "dir_2", None])
+@pytest.mark.parametrize("prefix", ["prefix_1", "prefix_2", None])
+def test_get_tempname(mocker, dir, prefix):
+    fd = mock.Mock()
+    tmp_file_name = mock.Mock()
+    mock_mkstemp = mocker.patch(
+        "tempfile.mkstemp",
+        return_value=(fd, tmp_file_name))
+    os_close_mock = mocker.patch("os.close")
+    assert tmp_file_name == tempfile.get_tempname(dir, prefix)
+    if prefix:
+        mock_mkstemp.assert_called_once_with(dir=dir, prefix=prefix)
+    else:
+        mock_mkstemp.assert_called_once_with(dir=dir)
+    os_close_mock.assert_called_once_with(fd)
+
+
+@pytest.mark.parametrize("is_exception", [True, False])
+def test_temp_dir(mocker, is_exception):
+
+    class TestException(Exception):
+        pass
+
+    temp_dir_name = mock.Mock()
+    mkdtemp_mock = mocker.patch("tempfile.mkdtemp", return_value=temp_dir_name)
+    rm_tree_mock = mocker.patch("shutil.rmtree")
+    if is_exception:
+        with pytest.raises(TestException):
+            with tempfile.temp_dir():
+                raise TestException
+    else:
+        with tempfile.temp_dir():
+            pass
+    mkdtemp_mock.assert_called_once_with()
+    rm_tree_mock.assert_called_once_with(temp_dir_name)

octane/util/archivate.py

@@ -10,6 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from __future__ import absolute_import
+
 import contextlib
 import io
 import itertools

octane/util/auth.py

@@ -10,22 +10,19 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import os
 import shutil
-import tempfile
 import yaml
 
 import contextlib
 
 from octane.util import helpers
+from octane.util import tempfile
 
 
 @contextlib.contextmanager
 def set_astute_password(auth_context):
-    fd, tmp_file_name = tempfile.mkstemp(
-        dir="/etc/fuel",
-        prefix=".astute.yaml.octane")
-    os.close(fd)
+    tmp_file_name = tempfile.get_tempname(
+        dir="/etc/fuel", prefix=".astute.yaml.octane")
     shutil.copy2("/etc/fuel/astute.yaml", tmp_file_name)
     try:
         data = helpers.get_astute_dict()

octane/util/tempfile.py

@@ -0,0 +1,36 @@
+# 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.
+
+from __future__ import absolute_import
+
+import contextlib
+import os
+import shutil
+import tempfile
+
+
+def get_tempname(dir=None, prefix=None):
+    kwargs = {}
+    if prefix is not None:
+        kwargs["prefix"] = prefix
+    fd, tmp_file_name = tempfile.mkstemp(dir=dir, **kwargs)
+    os.close(fd)
+    return tmp_file_name
+
+
+@contextlib.contextmanager
+def temp_dir():
+    temp_dir = tempfile.mkdtemp()
+    try:
+        yield temp_dir
+    finally:
+        shutil.rmtree(temp_dir)