Prevent tests' unmocked access to utils.execute()

This change introduces a new base test class that mocks out
utils.execute and forces an exception if it gets called.
This has rooted out many tests that were doing this as a side effect of
calling other functions, doing things like modprobe and running iscsi
on the host's actual machine.

The tests are all now appropriately patched in places where this was
happening, and the new base class permanently prevents this from
accidentally happening again.

If you really want to call utils.execute() then you need to re-mock it
in your unit test.

Change-Id: Idf87d09a9c01a6bfe2767f8becabe65c02983518

12 files changed, 113 insertions, 47 deletions

diff --git a/ironic_python_agent/tests/unit/base.py b/ironic_python_agent/tests/unit/base.py
new file mode 100644
index 00000000..11fff16b
--- /dev/null
+++ b/ironic_python_agent/tests/unit/base.py
@@ -0,0 +1,43 @@
+# Copyright 2017 Cisco Systems, Inc
+#
+# 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.
+
+"""Common utilities and classes across all unit tests."""
+
+import mock
+
+from oslotest import base as test_base
+
+from ironic_python_agent import utils
+
+
+class IronicAgentTest(test_base.BaseTestCase):
+    """Extends the base test to provide common features across agent tests."""
+
+    def setUp(self):
+        super(IronicAgentTest, self).setUp()
+        """Add a blanket ban on running external processes via utils.execute().
+
+        `self` will grow a property  called _exec_patch which is the Mock
+        that replaces utils.execute.
+
+        If the mock is called, an exception is raised to warn the tester.
+        """
+        # 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.
+        self._exec_patch = mock.Mock()
+        self._exec_patch.side_effect = Exception(
+            "Don't call utils.execute in tests!")
+        self.patch(utils, 'execute', self._exec_patch)
diff --git a/ironic_python_agent/tests/unit/test_agent.py b/ironic_python_agent/tests/unit/test_agent.py
index 45dd9ee1..f2ede91c 100644
--- a/ironic_python_agent/tests/unit/test_agent.py
+++ b/ironic_python_agent/tests/unit/test_agent.py
@@ -20,7 +20,6 @@ import mock
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_serialization import jsonutils
-from oslotest import base as test_base
 import pkg_resources
 from stevedore import extension
 
@@ -31,6 +30,7 @@ from ironic_python_agent.extensions import base
 from ironic_python_agent import hardware
 from ironic_python_agent import inspector
 from ironic_python_agent import netutils
+from ironic_python_agent.tests.unit import base as ironic_agent_base
 from ironic_python_agent import utils
 
 EXPECTED_ERROR = RuntimeError('command execution failed')
@@ -49,7 +49,7 @@ class FakeExtension(base.BaseAgentExtension):
     pass
 
 
-class TestHeartbeater(test_base.BaseTestCase):
+class TestHeartbeater(ironic_agent_base.IronicAgentTest):
     def setUp(self):
         super(TestHeartbeater, self).setUp()
         self.mock_agent = mock.Mock()
@@ -129,7 +129,7 @@ class TestHeartbeater(test_base.BaseTestCase):
 
 @mock.patch.object(hardware.GenericHardwareManager, '_wait_for_disks',
                    lambda self: None)
-class TestBaseAgent(test_base.BaseTestCase):
+class TestBaseAgent(ironic_agent_base.IronicAgentTest):
 
     def setUp(self):
         super(TestBaseAgent, self).setUp()
@@ -171,6 +171,10 @@ class TestBaseAgent(test_base.BaseTestCase):
         self.assertEqual(pkg_resources.get_distribution('ironic-python-agent')
                          .version, status.version)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
+    @mock.patch(
+        'ironic_python_agent.hardware_managers.cna._detect_cna_card',
+        mock.Mock())
     @mock.patch.object(agent.IronicPythonAgent,
                        '_wait_for_interface', autospec=True)
     @mock.patch.object(hardware, 'dispatch_to_managers', autospec=True)
@@ -203,6 +207,9 @@ class TestBaseAgent(test_base.BaseTestCase):
         mock_dispatch.assert_called_once_with("list_hardware_info")
         self.agent.heartbeater.start.assert_called_once_with()
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
+    @mock.patch('ironic_python_agent.hardware_managers.cna._detect_cna_card',
+                mock.Mock())
     @mock.patch.object(agent.IronicPythonAgent,
                        '_wait_for_interface', autospec=True)
     @mock.patch.object(inspector, 'inspect', autospec=True)
@@ -249,6 +256,10 @@ class TestBaseAgent(test_base.BaseTestCase):
         mock_dispatch.assert_called_once_with("list_hardware_info")
         self.agent.heartbeater.start.assert_called_once_with()
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
+    @mock.patch(
+        'ironic_python_agent.hardware_managers.cna._detect_cna_card',
+        mock.Mock())
     @mock.patch.object(agent.IronicPythonAgent,
                        '_wait_for_interface', autospec=True)
     @mock.patch.object(inspector, 'inspect', autospec=True)
@@ -298,6 +309,10 @@ class TestBaseAgent(test_base.BaseTestCase):
         self.assertFalse(mock_wait.called)
         self.assertFalse(mock_dispatch.called)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
+    @mock.patch(
+        'ironic_python_agent.hardware_managers.cna._detect_cna_card',
+        mock.Mock())
     @mock.patch.object(agent.IronicPythonAgent,
                        '_wait_for_interface', autospec=True)
     @mock.patch.object(inspector, 'inspect', autospec=True)
@@ -497,7 +512,7 @@ class TestBaseAgent(test_base.BaseTestCase):
 
 @mock.patch.object(hardware.GenericHardwareManager, '_wait_for_disks',
                    lambda self: None)
-class TestAgentStandalone(test_base.BaseTestCase):
+class TestAgentStandalone(ironic_agent_base.IronicAgentTest):
 
     def setUp(self):
         super(TestAgentStandalone, self).setUp()
@@ -515,6 +530,10 @@ class TestAgentStandalone(test_base.BaseTestCase):
                                              'agent_ipmitool',
                                              True)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
+    @mock.patch(
+        'ironic_python_agent.hardware_managers.cna._detect_cna_card',
+        mock.Mock())
     @mock.patch('wsgiref.simple_server.make_server', autospec=True)
     @mock.patch.object(hardware.HardwareManager, 'list_hardware_info',
                        autospec=True)
@@ -551,7 +570,7 @@ class TestAgentStandalone(test_base.BaseTestCase):
                    lambda self: None)
 @mock.patch.object(socket, 'gethostbyname', autospec=True)
 @mock.patch.object(utils, 'execute', autospec=True)
-class TestAdvertiseAddress(test_base.BaseTestCase):
+class TestAdvertiseAddress(ironic_agent_base.IronicAgentTest):
     def setUp(self):
         super(TestAdvertiseAddress, self).setUp()
 
diff --git a/ironic_python_agent/tests/unit/test_api.py b/ironic_python_agent/tests/unit/test_api.py
index 4ffbc166..ce8def0d 100644
--- a/ironic_python_agent/tests/unit/test_api.py
+++ b/ironic_python_agent/tests/unit/test_api.py
@@ -15,18 +15,18 @@
 import time
 
 import mock
-from oslotest import base as test_base
 import pecan
 import pecan.testing
 
 from ironic_python_agent import agent
 from ironic_python_agent.extensions import base
+from ironic_python_agent.tests.unit import base as ironic_agent_base
 
 
 PATH_PREFIX = '/v1'
 
 
-class TestIronicAPI(test_base.BaseTestCase):
+class TestIronicAPI(ironic_agent_base.IronicAgentTest):
 
     def setUp(self):
         super(TestIronicAPI, self).setUp()
diff --git a/ironic_python_agent/tests/unit/test_encoding.py b/ironic_python_agent/tests/unit/test_encoding.py
index a54dc6ef..64cd9b63 100644
--- a/ironic_python_agent/tests/unit/test_encoding.py
+++ b/ironic_python_agent/tests/unit/test_encoding.py
@@ -12,9 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from oslotest import base as test_base
-
 from ironic_python_agent import encoding
+from ironic_python_agent.tests.unit import base
 
 
 class SerializableTesting(encoding.Serializable):
@@ -33,7 +32,7 @@ class SerializableComparableTesting(encoding.SerializableComparable):
         self.jill = jill
 
 
-class TestSerializable(test_base.BaseTestCase):
+class TestSerializable(base.IronicAgentTest):
     def test_baseclass_serialize(self):
         obj = encoding.Serializable()
         self.assertEqual({}, obj.serialize())
@@ -44,7 +43,7 @@ class TestSerializable(test_base.BaseTestCase):
         self.assertEqual(expected, obj.serialize())
 
 
-class TestSerializableComparable(test_base.BaseTestCase):
+class TestSerializableComparable(base.IronicAgentTest):
 
     def test_childclass_equal(self):
         obj1 = SerializableComparableTesting('hello', 'world')
diff --git a/ironic_python_agent/tests/unit/test_errors.py b/ironic_python_agent/tests/unit/test_errors.py
index 40aa9399..8ebcb8f8 100644
--- a/ironic_python_agent/tests/unit/test_errors.py
+++ b/ironic_python_agent/tests/unit/test_errors.py
@@ -12,9 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from oslotest import base as test_base
-
 from ironic_python_agent import errors
+from ironic_python_agent.tests.unit import base
 
 DETAILS = 'details'
 SAME_CL_DETAILS = 'same_as_class_details'
@@ -32,7 +31,7 @@ class TestError(errors.RESTError):
         super(TestError, self).__init__(details)
 
 
-class TestErrors(test_base.BaseTestCase):
+class TestErrors(base.IronicAgentTest):
 
     def test_RESTError(self):
         e = errors.RESTError()
diff --git a/ironic_python_agent/tests/unit/test_hardware.py b/ironic_python_agent/tests/unit/test_hardware.py
index f7b0de5c..b637cfae 100644
--- a/ironic_python_agent/tests/unit/test_hardware.py
+++ b/ironic_python_agent/tests/unit/test_hardware.py
@@ -22,12 +22,12 @@ import netifaces
 from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_utils import units
-from oslotest import base as test_base
 import pyudev
 from stevedore import extension
 
 from ironic_python_agent import errors
 from ironic_python_agent import hardware
+from ironic_python_agent.tests.unit import base
 from ironic_python_agent import utils
 
 CONF = cfg.CONF
@@ -257,7 +257,7 @@ class FakeHardwareManager(hardware.GenericHardwareManager):
         return self._hardware_support
 
 
-class TestHardwareManagerLoading(test_base.BaseTestCase):
+class TestHardwareManagerLoading(base.IronicAgentTest):
     def setUp(self):
         super(TestHardwareManagerLoading, self).setUp()
         # In order to use ExtensionManager.make_test_instance() without
@@ -286,7 +286,7 @@ class TestHardwareManagerLoading(test_base.BaseTestCase):
 
 
 @mock.patch.object(hardware, '_udev_settle', lambda *_: None)
-class TestGenericHardwareManager(test_base.BaseTestCase):
+class TestGenericHardwareManager(base.IronicAgentTest):
     def setUp(self):
         super(TestGenericHardwareManager, self).setUp()
         self.hardware = hardware.GenericHardwareManager()
@@ -784,6 +784,9 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
         self.hardware.get_boot_info.return_value = hardware.BootInfo(
             current_boot_mode='bios', pxe_interface='boot:if')
 
+        self.hardware.get_bmc_address = mock.Mock()
+        self.hardware.get_system_vendor_info = mock.Mock()
+
         hardware_info = self.hardware.list_hardware_info()
         self.assertEqual(self.hardware.get_memory(), hardware_info['memory'])
         self.assertEqual(self.hardware.get_cpus(), hardware_info['cpu'])
@@ -1490,6 +1493,7 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
         self.assertEqual(2, mocked_root_dev.call_count)
         mocked_sleep.assert_called_once_with(CONF.disk_wait_delay)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
     @mock.patch.object(hardware.GenericHardwareManager, 'list_block_devices',
                        autospec=True)
     @mock.patch.object(time, 'sleep', autospec=True)
@@ -1517,6 +1521,7 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
         mocked_root_dev.assert_called_with(mocked_block_dev.return_value)
         self.assertEqual(10, mocked_root_dev.call_count)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
     @mock.patch.object(hardware.GenericHardwareManager, 'list_block_devices',
                        autospec=True)
     @mock.patch.object(time, 'sleep', autospec=True)
@@ -1539,6 +1544,7 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
         mocked_root_dev.assert_called_with(mocked_block_dev.return_value)
         self.assertEqual(2, mocked_root_dev.call_count)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
     @mock.patch.object(hardware.GenericHardwareManager, 'list_block_devices',
                        autospec=True)
     @mock.patch.object(time, 'sleep', autospec=True)
@@ -1552,6 +1558,7 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
 
         mocked_sleep.assert_called_with(3)
 
+    @mock.patch.object(hardware, '_check_for_iscsi', mock.Mock())
     @mock.patch.object(hardware.GenericHardwareManager, 'list_block_devices',
                        autospec=True)
     @mock.patch.object(time, 'sleep', autospec=True)
@@ -1611,7 +1618,7 @@ class TestGenericHardwareManager(test_base.BaseTestCase):
 
 @mock.patch.object(os, 'listdir', lambda *_: [])
 @mock.patch.object(utils, 'execute', autospec=True)
-class TestModuleFunctions(test_base.BaseTestCase):
+class TestModuleFunctions(base.IronicAgentTest):
 
     @mock.patch.object(hardware, '_get_device_info',
                        lambda x, y, z: 'FooTastic')
diff --git a/ironic_python_agent/tests/unit/test_inspector.py b/ironic_python_agent/tests/unit/test_inspector.py
index 0847e581..63401b98 100644
--- a/ironic_python_agent/tests/unit/test_inspector.py
+++ b/ironic_python_agent/tests/unit/test_inspector.py
@@ -21,13 +21,13 @@ import time
 import mock
 from oslo_concurrency import processutils
 from oslo_config import cfg
-from oslotest import base as test_base
 import requests
 import stevedore
 
 from ironic_python_agent import errors
 from ironic_python_agent import hardware
 from ironic_python_agent import inspector
+from ironic_python_agent.tests.unit import base
 from ironic_python_agent import utils
 
 
@@ -46,7 +46,7 @@ class AcceptingFailure(mock.Mock):
             failure, expect_error)
 
 
-class TestMisc(test_base.BaseTestCase):
+class TestMisc(base.IronicAgentTest):
     def test_default_collector_loadable(self):
         ext = inspector.extension_manager([inspector.DEFAULT_COLLECTOR])
         self.assertIs(ext[inspector.DEFAULT_COLLECTOR].plugin,
@@ -62,7 +62,7 @@ class TestMisc(test_base.BaseTestCase):
 @mock.patch.object(inspector, 'setup_ipmi_credentials', autospec=True)
 @mock.patch.object(inspector, 'call_inspector', new_callable=AcceptingFailure)
 @mock.patch.object(stevedore, 'NamedExtensionManager', autospec=True)
-class TestInspect(test_base.BaseTestCase):
+class TestInspect(base.IronicAgentTest):
     def setUp(self):
         super(TestInspect, self).setUp()
         CONF.set_override('inspection_callback_url', 'http://foo/bar',
@@ -131,7 +131,7 @@ class TestInspect(test_base.BaseTestCase):
 
 
 @mock.patch.object(requests, 'post', autospec=True)
-class TestCallInspector(test_base.BaseTestCase):
+class TestCallInspector(base.IronicAgentTest):
     def setUp(self):
         super(TestCallInspector, self).setUp()
         CONF.set_override('inspection_callback_url', 'url',
@@ -176,7 +176,7 @@ class TestCallInspector(test_base.BaseTestCase):
 
 
 @mock.patch.object(utils, 'execute', autospec=True)
-class TestSetupIpmiCredentials(test_base.BaseTestCase):
+class TestSetupIpmiCredentials(base.IronicAgentTest):
     def setUp(self):
         super(TestSetupIpmiCredentials, self).setUp()
         self.resp = {'ipmi_username': 'user',
@@ -227,7 +227,7 @@ class TestSetupIpmiCredentials(test_base.BaseTestCase):
         self.assertEqual(expected, mock_call.call_args_list)
 
 
-class BaseDiscoverTest(test_base.BaseTestCase):
+class BaseDiscoverTest(base.IronicAgentTest):
     def setUp(self):
         super(BaseDiscoverTest, self).setUp()
         self.inventory = {
@@ -302,7 +302,7 @@ class TestCollectDefault(BaseDiscoverTest):
 
 
 @mock.patch.object(utils, 'collect_system_logs', autospec=True)
-class TestCollectLogs(test_base.BaseTestCase):
+class TestCollectLogs(base.IronicAgentTest):
 
     def test(self, mock_collect):
         data = {}
@@ -320,7 +320,7 @@ class TestCollectLogs(test_base.BaseTestCase):
 
 
 @mock.patch.object(utils, 'execute', autospec=True)
-class TestCollectExtraHardware(test_base.BaseTestCase):
+class TestCollectExtraHardware(base.IronicAgentTest):
     def setUp(self):
         super(TestCollectExtraHardware, self).setUp()
         self.data = {}
@@ -366,7 +366,7 @@ class TestCollectExtraHardware(test_base.BaseTestCase):
 
 
 @mock.patch.object(os, 'listdir', autospec=True)
-class TestCollectPciDevicesInfo(test_base.BaseTestCase):
+class TestCollectPciDevicesInfo(base.IronicAgentTest):
     def setUp(self):
         super(TestCollectPciDevicesInfo, self).setUp()
         self.data = {}
@@ -421,7 +421,7 @@ class TestCollectPciDevicesInfo(test_base.BaseTestCase):
 
 @mock.patch.object(utils, 'get_agent_params', lambda: {'BOOTIF': '01-cdef'})
 @mock.patch.object(hardware, 'dispatch_to_managers', autospec=True)
-class TestWaitForDhcp(test_base.BaseTestCase):
+class TestWaitForDhcp(base.IronicAgentTest):
     def setUp(self):
         super(TestWaitForDhcp, self).setUp()
         CONF.set_override('inspection_dhcp_wait_timeout',
@@ -507,7 +507,7 @@ class TestWaitForDhcp(test_base.BaseTestCase):
         self.assertFalse(mocked_dispatch.called)
 
 
-class TestNormalizeMac(test_base.BaseTestCase):
+class TestNormalizeMac(base.IronicAgentTest):
     def test_correct_mac(self):
         self.assertEqual('11:22:33:aa:bb:cc',
                          inspector._normalize_mac('11:22:33:aa:BB:cc'))
diff --git a/ironic_python_agent/tests/unit/test_ironic_api_client.py b/ironic_python_agent/tests/unit/test_ironic_api_client.py
index abcdbfa5..6d7c2a47 100644
--- a/ironic_python_agent/tests/unit/test_ironic_api_client.py
+++ b/ironic_python_agent/tests/unit/test_ironic_api_client.py
@@ -15,11 +15,11 @@
 import mock
 from oslo_serialization import jsonutils
 from oslo_service import loopingcall
-from oslotest import base as test_base
 
 from ironic_python_agent import errors
 from ironic_python_agent import hardware
 from ironic_python_agent import ironic_api_client
+from ironic_python_agent.tests.unit import base
 
 API_URL = 'http://agent-api.ironic.example.org/'
 
@@ -32,7 +32,7 @@ class FakeResponse(object):
         self.headers = headers or {}
 
 
-class TestBaseIronicPythonAgent(test_base.BaseTestCase):
+class TestBaseIronicPythonAgent(base.IronicAgentTest):
     def setUp(self):
         super(TestBaseIronicPythonAgent, self).setUp()
         self.api_client = ironic_api_client.APIClient(API_URL)
diff --git a/ironic_python_agent/tests/unit/test_multi_hardware.py b/ironic_python_agent/tests/unit/test_multi_hardware.py
index 9374707e..7849cf23 100644
--- a/ironic_python_agent/tests/unit/test_multi_hardware.py
+++ b/ironic_python_agent/tests/unit/test_multi_hardware.py
@@ -15,11 +15,11 @@
 import collections
 
 import mock
-from oslotest import base as test_base
 from stevedore import extension
 
 from ironic_python_agent import errors
 from ironic_python_agent import hardware
+from ironic_python_agent.tests.unit import base
 
 
 def counted(fn):
@@ -105,7 +105,7 @@ class FakeMainlineHardwareManager(hardware.HardwareManager):
         return hardware.HardwareSupport.MAINLINE
 
 
-class TestMultipleHardwareManagerLoading(test_base.BaseTestCase):
+class TestMultipleHardwareManagerLoading(base.IronicAgentTest):
     def setUp(self):
         super(TestMultipleHardwareManagerLoading, self).setUp()
         fake_ep = mock.Mock()
@@ -120,14 +120,11 @@ class TestMultipleHardwareManagerLoading(test_base.BaseTestCase):
 
         self.extension_mgr_patcher = mock.patch('stevedore.ExtensionManager',
                                                 autospec=True)
+        self.addCleanup(self.extension_mgr_patcher.stop)
         self.mocked_extension_mgr = self.extension_mgr_patcher.start()
         self.mocked_extension_mgr.return_value = self.fake_ext_mgr
         hardware._global_managers = None
 
-    def tearDown(self):
-        super(TestMultipleHardwareManagerLoading, self).tearDown()
-        self.extension_mgr_patcher.stop()
-
     def test_mainline_method_only(self):
         hardware.dispatch_to_managers('specific_only')
 
@@ -212,7 +209,7 @@ class TestMultipleHardwareManagerLoading(test_base.BaseTestCase):
                           'unexpected_fail')
 
 
-class TestNoHardwareManagerLoading(test_base.BaseTestCase):
+class TestNoHardwareManagerLoading(base.IronicAgentTest):
     def setUp(self):
         super(TestNoHardwareManagerLoading, self).setUp()
         self.empty_ext_mgr = extension.ExtensionManager.make_test_instance([])
diff --git a/ironic_python_agent/tests/unit/test_multi_hardware_clean_steps.py b/ironic_python_agent/tests/unit/test_multi_hardware_clean_steps.py
index 104bbbb5..ef47124e 100644
--- a/ironic_python_agent/tests/unit/test_multi_hardware_clean_steps.py
+++ b/ironic_python_agent/tests/unit/test_multi_hardware_clean_steps.py
@@ -13,11 +13,11 @@
 # limitations under the License.
 
 import mock
-from oslotest import base as test_base
 from stevedore import extension
 
 from ironic_python_agent.extensions import clean
 from ironic_python_agent import hardware
+from ironic_python_agent.tests.unit import base
 
 
 def _build_clean_step(name, priority, reboot=False, abort=False):
@@ -53,7 +53,7 @@ class ZFakeGenericHardwareManager(hardware.HardwareManager):
                 _build_clean_step('ZHigherPrio', 100)]
 
 
-class TestMultipleHardwareManagerCleanSteps(test_base.BaseTestCase):
+class TestMultipleHardwareManagerCleanSteps(base.IronicAgentTest):
     def setUp(self):
         super(TestMultipleHardwareManagerCleanSteps, self).setUp()
 
@@ -73,14 +73,11 @@ class TestMultipleHardwareManagerCleanSteps(test_base.BaseTestCase):
 
         self.extension_mgr_patcher = mock.patch('stevedore.ExtensionManager',
                                                 autospec=True)
+        self.addCleanup(self.extension_mgr_patcher.stop)
         self.mocked_extension_mgr = self.extension_mgr_patcher.start()
         self.mocked_extension_mgr.return_value = self.fake_ext_mgr
         hardware._global_managers = None
 
-    def tearDown(self):
-        super(TestMultipleHardwareManagerCleanSteps, self).tearDown()
-        self.extension_mgr_patcher.stop()
-
     def test_clean_step_ordering(self):
         as_results = self.agent_extension.get_clean_steps(node={}, ports=[])
         results = as_results.join().command_result
diff --git a/ironic_python_agent/tests/unit/test_netutils.py b/ironic_python_agent/tests/unit/test_netutils.py
index db9f8414..4237b155 100644
--- a/ironic_python_agent/tests/unit/test_netutils.py
+++ b/ironic_python_agent/tests/unit/test_netutils.py
@@ -16,9 +16,9 @@ import binascii
 
 import mock
 from oslo_config import cfg
-from oslotest import base as test_base
 
 from ironic_python_agent import netutils
+from ironic_python_agent.tests.unit import base
 
 # hexlify-ed output from LLDP packet
 FAKE_LLDP_PACKET = binascii.unhexlify(
@@ -37,7 +37,7 @@ def socket_socket_sig(family=None, type=None, proto=None):
     pass
 
 
-class TestNetutils(test_base.BaseTestCase):
+class TestNetutils(base.IronicAgentTest):
     def setUp(self):
         super(TestNetutils, self).setUp()
 
diff --git a/ironic_python_agent/tests/unit/test_utils.py b/ironic_python_agent/tests/unit/test_utils.py
index dab7c14a..31c9988b 100644
--- a/ironic_python_agent/tests/unit/test_utils.py
+++ b/ironic_python_agent/tests/unit/test_utils.py
@@ -31,9 +31,14 @@ import six
 import testtools
 
 from ironic_python_agent import errors
+from ironic_python_agent.tests.unit import base as ironic_agent_base
 from ironic_python_agent import utils
 
 
+# Normally we'd use the IronicAgentTest base class which mocks out
+# any use of utils.execute() to prevent accidental processes. However
+# this test is checking the upcall to ironic_lib's execute(), so that
+# is mocked out instead.
 class ExecuteTestCase(test_base.BaseTestCase):
 
     @mock.patch.object(ironic_utils, 'execute', autospec=True)
@@ -43,7 +48,7 @@ class ExecuteTestCase(test_base.BaseTestCase):
                                              check_exit_code=False)
 
 
-class GetAgentParamsTestCase(test_base.BaseTestCase):
+class GetAgentParamsTestCase(ironic_agent_base.IronicAgentTest):
 
     @mock.patch('oslo_log.log.getLogger', autospec=True)
     @mock.patch('six.moves.builtins.open', autospec=True)