openstack/ironic-python-agent
Code Issues Proposed changes

Fix issue with double mocking of utils.execute functions

Browse Source 
An issue was discovered if we mock an already mock-ed function. This
was happening in our execute() detection code. Change it to not use a
mock and instead a function.

Add unit tests to show it works as intended.

Change-Id: Ia116b355e7adb3cbfb8ae34f4d59bf527f2889bb
This commit is contained in:
John L. Villalovos 2017-11-30 10:16:51 -08:00
parent 831576c906
commit fc3de87469
2 changed files with 110 additions and 21 deletions
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43
ironic_python_agent/tests/unit/base.py
View File

@ -18,7 +18,6 @@
import subprocess
import ironic_lib
import mock
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_config import fixture as config_fixture
@ -37,32 +36,27 @@ class IronicAgentTest(test_base.BaseTestCase):
def setUp(self):
super(IronicAgentTest, self).setUp()
"""Ban running external processes via 'execute' like functions
`self` will grow a property called _exec_patch which is the Mock
that replaces all the 'execute' related functions.
If the mock is called, an exception is raised to warn the tester.
"""
self._set_config()
# NOTE(bigjools): Not using a decorator on tests because I don't
# want to force every test method to accept a new arg. Instead, they
# can override or examine this self._exec_patch Mock as needed.
if self.block_execute:
self._exec_patch = mock.Mock()
self._exec_patch.side_effect = Exception(
"Don't call ironic_lib.utils.execute() / "
"processutils.execute() or similar functions in tests!")
# Ban running external processes via 'execute' like functions. If the
# patched function is called, an exception is raised to warn the
# tester.
if self.block_execute:
# NOTE(jlvillal): pyudev.Context() calls ctypes.find_library()
# which calls subprocess.Popen(). So not blocking
# subprocess.Popen()
self.patch(ironic_lib.utils, 'execute', self._exec_patch)
self.patch(processutils, 'execute', self._exec_patch)
self.patch(subprocess, 'call', self._exec_patch)
self.patch(subprocess, 'check_call', self._exec_patch)
self.patch(subprocess, 'check_output', self._exec_patch)
self.patch(utils, 'execute', self._exec_patch)
# NOTE(jlvillal): Intentionally not using mock as if you mock a
# mock it causes things to not work correctly. As doing an
# autospec=True causes strangeness. By using a simple function we
# can then mock it without issue.
self.patch(ironic_lib.utils, 'execute', do_not_call)
self.patch(processutils, 'execute', do_not_call)
self.patch(subprocess, 'call', do_not_call)
self.patch(subprocess, 'check_call', do_not_call)
self.patch(subprocess, 'check_output', do_not_call)
self.patch(utils, 'execute', do_not_call)
def _set_config(self):
self.cfg_fixture = self.useFixture(config_fixture.Config(CONF))
@ -76,3 +70,10 @@ class IronicAgentTest(test_base.BaseTestCase):
group = kw.pop('group', None)
for o, v in kw.items():
self.cfg_fixture.set_default(o, v, group=group)
def do_not_call(*args, **kwargs):
"""Helper function to raise an exception if it is called"""
raise Exception(
"Don't call ironic_lib.utils.execute() / "
"processutils.execute() or similar functions in tests!")

88
ironic_python_agent/tests/unit/test_base.py Normal file
View File

@ -0,0 +1,88 @@
# 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 subprocess
import ironic_lib
import mock
from oslo_concurrency import processutils
from ironic_python_agent.tests.unit import base as ironic_agent_base
from ironic_python_agent import utils
class BlockExecuteTestCase(ironic_agent_base.IronicAgentTest):
"""Test to ensure we block access to the 'execute' type functions"""
def test_exception_raised_for_execute(self):
execute_functions = (ironic_lib.utils.execute, processutils.execute,
subprocess.call, subprocess.check_call,
subprocess.check_output, utils.execute)
for function_name in execute_functions:
exc = self.assertRaises(
Exception,
function_name,
["echo", "%s" % function_name]) # noqa
# Have to use 'noqa' as we are raising plain Exception and we will
# get H202 error in 'pep8' check.
self.assertEqual(
"Don't call ironic_lib.utils.execute() / "
"processutils.execute() or similar functions in tests!",
"%s" % exc)
@mock.patch.object(utils, "execute", autospec=True)
def test_can_mock_execute(self, mock_exec):
# NOTE(jlvillal): We had discovered an issue where mocking wasn't
# working because we had used a mock to block access to the execute
# functions. This caused us to "mock a mock" and didn't work correctly.
# We want to make sure that we can mock our execute functions even with
# our "block execute" code.
utils.execute("ls")
utils.execute("echo")
self.assertEqual(2, mock_exec.call_count)
@mock.patch.object(ironic_lib.utils, "execute", autospec=True)
def test_exception_raised_for_execute_parent_mocked(self, mock_exec):
# Make sure that even if we mock the parent execute function, that we
# still get an exception for a child. So in this case utils.execute()
# calls ironic_lib.utils.execute(). Make sure an exception is raised
# even though we mocked ironic_lib.utils.execute()
exc = self.assertRaises(
Exception,
utils.execute,
"ls") # noqa
# Have to use 'noqa' as we are raising plain Exception and we will get
# H202 error in 'pep8' check.
self.assertEqual(
"Don't call ironic_lib.utils.execute() / "
"processutils.execute() or similar functions in tests!",
"%s" % exc)
class DontBlockExecuteTestCase(ironic_agent_base.IronicAgentTest):
"""Ensure we can turn off blocking access to 'execute' type functions"""
# Don't block the execute function
block_execute = False
@mock.patch.object(ironic_lib.utils, "execute", autospec=True)
def test_no_exception_raised_for_execute(self, mock_exec):
# Make sure we can call utils.execute() even though we didn't mock it.
# We do mock ironic_lib.utils.execute() so we don't actually execute
# anything.
utils.execute("ls")
utils.execute("echo")
self.assertEqual(2, mock_exec.call_count)