From 8f6870b451fd0858f50146f52e50c7315527013a Mon Sep 17 00:00:00 2001
From: Dmitry Tantsur <divius.inside@gmail.com>
Date: Thu, 27 Sep 2018 12:52:31 +0200
Subject: [PATCH] Prevent configuration changes in unit tests from affecting
 each other

Currently some of our tests set overrides, but nothing restores them.
This changes adds a config fixture to the bass class and also switches
some tests to using set_override instead of direct assignment.

Change-Id: I178061608e407047fb87d547c277ea38db353c26
Story: #2003891
Task: #26758
---
 ironic_lib/tests/base.py       |  4 ++++
 ironic_lib/tests/test_utils.py | 19 +++++++------------
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/ironic_lib/tests/base.py b/ironic_lib/tests/base.py
index 6aaeacaa..06eba30d 100644
--- a/ironic_lib/tests/base.py
+++ b/ironic_lib/tests/base.py
@@ -18,6 +18,7 @@
 import subprocess
 
 from oslo_concurrency import processutils
+from oslo_config import fixture as config_fixture
 from oslotest import base as test_base
 
 from ironic_lib import utils
@@ -36,6 +37,9 @@ class IronicLibTestCase(test_base.BaseTestCase):
     def setUp(self):
         super(IronicLibTestCase, self).setUp()
 
+        # Make sure config overrides do not leak for test to test.
+        self.cfg_fixture = self.useFixture(config_fixture.Config())
+
         # Ban running external processes via 'execute' like functions. If the
         # patched function is called, an exception is raised to warn the
         # tester.
diff --git a/ironic_lib/tests/test_utils.py b/ironic_lib/tests/test_utils.py
index d95112ad..e8d49b4b 100644
--- a/ironic_lib/tests/test_utils.py
+++ b/ironic_lib/tests/test_utils.py
@@ -467,6 +467,13 @@ class MatchRootDeviceTestCase(base.IronicLibTestCase):
 
 class WaitForDisk(base.IronicLibTestCase):
 
+    def setUp(self):
+        super(WaitForDisk, self).setUp()
+        CONF.set_override('check_device_interval', .01,
+                          group='disk_partitioner')
+        CONF.set_override('check_device_max_retries', 2,
+                          group='disk_partitioner')
+
     @mock.patch.object(utils, 'execute', autospec=True)
     def test_wait_for_disk_to_become_available(self, mock_exc):
         mock_exc.return_value = ('', '')
@@ -481,8 +488,6 @@ class WaitForDisk(base.IronicLibTestCase):
                        side_effect=processutils.ProcessExecutionError(
                            stderr='fake'))
     def test_wait_for_disk_to_become_available_no_fuser(self, mock_exc):
-        CONF.disk_partitioner.check_device_interval = .01
-        CONF.disk_partitioner.check_device_max_retries = 2
         self.assertRaises(exception.IronicException,
                           utils.wait_for_disk_to_become_available,
                           'fake-dev')
@@ -500,8 +505,6 @@ class WaitForDisk(base.IronicLibTestCase):
         # NOTE(TheJulia): Looks like fuser returns the actual list of pids
         # in the stdout output, where as all other text is returned in
         # stderr.
-        CONF.disk_partitioner.check_device_interval = .01
-        CONF.disk_partitioner.check_device_max_retries = 2
         # The 'psmisc' version has a leading space character in stdout. The
         # filename is output to stderr
         mock_exc.side_effect = [(' 1234   ', 'fake-dev: '),
@@ -528,8 +531,6 @@ class WaitForDisk(base.IronicLibTestCase):
         # NOTE(TheJulia): Looks like fuser returns the actual list of pids
         # in the stdout output, where as all other text is returned in
         # stderr.
-        CONF.disk_partitioner.check_device_interval = .01
-        CONF.disk_partitioner.check_device_max_retries = 2
         # The 'busybox' version does not have a leading space character in
         # stdout. Also nothing is output to stderr.
         mock_exc.side_effect = [('1234', ''),
@@ -553,8 +554,6 @@ class WaitForDisk(base.IronicLibTestCase):
         # NOTE(TheJulia): Looks like fuser returns the actual list of pids
         # in the stdout output, where as all other text is returned in
         # stderr.
-        CONF.disk_partitioner.check_device_interval = .01
-        CONF.disk_partitioner.check_device_max_retries = 2
 
         mock_exc.return_value = ('', 'Specified filename /dev/fake '
                                      'does not exist.')
@@ -579,8 +578,6 @@ class WaitForDisk(base.IronicLibTestCase):
         # Test that initially device is not available but then becomes
         # available. This version has the 'psmisc' version of 'fuser' values
         # for stdout and stderr.
-        CONF.disk_partitioner.check_device_interval = .01
-        CONF.disk_partitioner.check_device_max_retries = 2
         # The 'psmisc' version has a leading space character in stdout. The
         # filename is output to stderr
         mock_exc.side_effect = [(' 1234   ', 'fake-dev: '),
@@ -598,8 +595,6 @@ class WaitForDisk(base.IronicLibTestCase):
         # Test that initially device is not available but then becomes
         # available. This version has the 'busybox' version of 'fuser' values
         # for stdout and stderr.
-        CONF.disk_partitioner.check_device_interval = .01
-        CONF.disk_partitioner.check_device_max_retries = 2
         # The 'busybox' version does not have a leading space character in
         # stdout. Also nothing is output to stderr.
         mock_exc.side_effect = [('1234 5895', ''),