remove use of contextlib and with nested

- The use of contextlib and "with nested" statements are deprecated.
- This change remove the deprecation warning by refactoring all
  unit test that used "with neted" statements to create mocks via
  with the decorator syntax.
- This chage removes all depencies on contexlib.

trivial_fix

Change-Id: I6d929e59306f9289f717fff3fb79542e804396b6

releasenotes/notes/contextlib-and-nested-with-statements-2747a9ebb9a5bfd7.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - The use of contextlib and  with nested statements is deprecated.
+    "with nested" statements are not python 3 compatible as with statement now directly
+    support context managers. The use of contextlib and "with nested" statements has
+    been removed from all unittests in favor of the @mock decorator syntax.

vif_plug_linux_bridge/tests/test_linux_net.py

@@ -10,10 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import contextlib
 import mock
 import os.path
-import six
 import testtools
 
 import fixtures
@@ -28,14 +26,6 @@ from vif_plug_linux_bridge import privsep
 
 CONF = cfg.CONF
 
-if six.PY2:
-    nested = contextlib.nested
-else:
-    @contextlib.contextmanager
-    def nested(*contexts):
-        with contextlib.ExitStack() as stack:
-            yield [stack.enter_context(c) for c in contexts]
-
 
 class LinuxNetTest(testtools.TestCase):
 

vif_plug_linux_bridge/tests/test_plugin.py

@@ -10,9 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import contextlib
 import mock
-import six
 import testtools
 
 from os_vif import objects
@@ -21,15 +19,6 @@ from vif_plug_linux_bridge import linux_bridge
 from vif_plug_linux_bridge import linux_net
 
 
-if six.PY2:
-    nested = contextlib.nested
-else:
-    @contextlib.contextmanager
-    def nested(*contexts):
-        with contextlib.ExitStack() as stack:
-            yield [stack.enter_context(c) for c in contexts]
-
-
 class PluginTest(testtools.TestCase):
 
     def __init__(self, *args, **kwargs):
@@ -41,7 +30,10 @@ class PluginTest(testtools.TestCase):
             name='demo',
             uuid='f0000000-0000-0000-0000-000000000001')
 
-    def test_plug_bridge(self):
+    @mock.patch.object(linux_net, 'ensure_vlan_bridge')
+    @mock.patch.object(linux_net, 'ensure_bridge')
+    def test_plug_bridge(self, mock_ensure_bridge,
+                         mock_ensure_vlan_bridge):
         network = objects.network.Network(
             id='437c6db5-4e6f-4b43-b64b-ed6a11ee5ba7',
             bridge='br0')
@@ -53,17 +45,16 @@ class PluginTest(testtools.TestCase):
             dev_name='tap-xxx-yyy-zzz',
             bridge_name="br0")
 
-        with nested(
-                mock.patch.object(linux_net, 'ensure_bridge'),
-                mock.patch.object(linux_net, 'ensure_vlan_bridge')
-        ) as (mock_ensure_bridge, mock_ensure_vlan_bridge):
         plugin = linux_bridge.LinuxBridgePlugin.load("linux_bridge")
         plugin.plug(vif, self.instance)
 
         self.assertEqual(len(mock_ensure_bridge.calls), 0)
         self.assertEqual(len(mock_ensure_vlan_bridge.calls), 0)
 
-    def test_plug_bridge_create_br(self):
+    @mock.patch.object(linux_net, 'ensure_vlan_bridge')
+    @mock.patch.object(linux_net, 'ensure_bridge')
+    def test_plug_bridge_create_br(self, mock_ensure_bridge,
+                                   mock_ensure_vlan_bridge):
         network = objects.network.Network(
             id='437c6db5-4e6f-4b43-b64b-ed6a11ee5ba7',
             bridge='br0',
@@ -77,10 +68,6 @@ class PluginTest(testtools.TestCase):
             dev_name='tap-xxx-yyy-zzz',
             bridge_name="br0")
 
-        with nested(
-                mock.patch.object(linux_net, 'ensure_bridge'),
-                mock.patch.object(linux_net, 'ensure_vlan_bridge')
-        ) as (mock_ensure_bridge, mock_ensure_vlan_bridge):
         plugin = linux_bridge.LinuxBridgePlugin.load("linux_bridge")
         plugin.plug(vif, self.instance)
 
@@ -93,7 +80,11 @@ class PluginTest(testtools.TestCase):
     def test_plug_bridge_create_br_vlan_mtu_from_config(self):
         self._test_plug_bridge_create_br_vlan()
 
-    def _test_plug_bridge_create_br_vlan(self, mtu=None):
+    @mock.patch.object(linux_net, 'ensure_vlan_bridge')
+    @mock.patch.object(linux_net, 'ensure_bridge')
+    def _test_plug_bridge_create_br_vlan(self, mock_ensure_bridge,
+                                         mock_ensure_vlan_bridge,
+                                         mtu=None):
         network = objects.network.Network(
             id='437c6db5-4e6f-4b43-b64b-ed6a11ee5ba7',
             bridge='br0',
@@ -110,10 +101,6 @@ class PluginTest(testtools.TestCase):
             dev_name='tap-xxx-yyy-zzz',
             bridge_name="br0")
 
-        with nested(
-                mock.patch.object(linux_net, 'ensure_bridge'),
-                mock.patch.object(linux_net, 'ensure_vlan_bridge')
-        ) as (mock_ensure_bridge, mock_ensure_vlan_bridge):
         plugin = linux_bridge.LinuxBridgePlugin.load("linux_bridge")
         plugin.plug(vif, self.instance)
 

vif_plug_ovs/tests/test_linux_net.py

@@ -10,10 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import contextlib
 import mock
 import os.path
-import six
 import testtools
 
 from oslo_concurrency import processutils
@@ -22,14 +20,6 @@ from vif_plug_ovs import constants
 from vif_plug_ovs import linux_net
 from vif_plug_ovs import privsep
 
-if six.PY2:
-    nested = contextlib.nested
-else:
-    @contextlib.contextmanager
-    def nested(*contexts):
-        with contextlib.ExitStack() as stack:
-            yield [stack.enter_context(c) for c in contexts]
-
 
 class LinuxNetTest(testtools.TestCase):
 

vif_plug_ovs/tests/test_plugin.py

@@ -10,9 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import contextlib
 import mock
-import six
 import testtools
 
 from os_vif import objects
@@ -22,15 +20,6 @@ from vif_plug_ovs import linux_net
 from vif_plug_ovs import ovs
 
 
-if six.PY2:
-    nested = contextlib.nested
-else:
-    @contextlib.contextmanager
-    def nested(*contexts):
-        with contextlib.ExitStack() as stack:
-            yield [stack.enter_context(c) for c in contexts]
-
-
 class PluginTest(testtools.TestCase):
 
     def __init__(self, *args, **kwargs):
@@ -124,11 +113,9 @@ class PluginTest(testtools.TestCase):
             timeout=plugin.config.ovs_vsctl_timeout,
             interface_type=constants.OVS_VHOSTUSER_INTERFACE_TYPE)
 
-    def test_plug_ovs(self):
+    @mock.patch.object(ovs, 'sys')
-        with nested(
+    @mock.patch.object(linux_net, 'ensure_ovs_bridge')
-                mock.patch.object(ovs, 'sys'),
+    def test_plug_ovs(self, ensure_ovs_bridge, mock_sys):
-                mock.patch.object(linux_net, 'ensure_ovs_bridge')
-        ) as (mock_sys, ensure_ovs_bridge):
         mock_sys.platform = 'linux'
         plug_bridge_mock = mock.Mock()
         plugin = ovs.OvsPlugin.load("ovs")
@@ -138,7 +125,17 @@ class PluginTest(testtools.TestCase):
         ensure_ovs_bridge.assert_called_once_with(
             self.vif_ovs.network.bridge, constants.OVS_DATAPATH_SYSTEM)
 
-    def test_plug_ovs_bridge(self):
+    @mock.patch.object(linux_net, 'ensure_ovs_bridge')
+    @mock.patch.object(ovs.OvsPlugin, '_create_vif_port')
+    @mock.patch.object(linux_net, 'add_bridge_port')
+    @mock.patch.object(linux_net, 'create_veth_pair')
+    @mock.patch.object(linux_net, 'device_exists', return_value=False)
+    @mock.patch.object(linux_net, 'ensure_bridge')
+    @mock.patch.object(ovs, 'sys')
+    def test_plug_ovs_bridge(self, mock_sys, ensure_bridge,
+                             device_exists, create_veth_pair,
+                             add_bridge_port, _create_vif_port,
+                             ensure_ovs_bridge):
         calls = {
             'device_exists': [mock.call('qvob679325f-ca')],
             'create_veth_pair': [mock.call('qvbb679325f-ca',
@@ -154,17 +151,6 @@ class PluginTest(testtools.TestCase):
                                             constants.OVS_DATAPATH_SYSTEM)]
         }
 
-        with nested(
-                mock.patch.object(ovs, 'sys'),
-                mock.patch.object(linux_net, 'ensure_bridge'),
-                mock.patch.object(linux_net, 'device_exists',
-                                  return_value=False),
-                mock.patch.object(linux_net, 'create_veth_pair'),
-                mock.patch.object(linux_net, 'add_bridge_port'),
-                mock.patch.object(ovs.OvsPlugin, '_create_vif_port'),
-                mock.patch.object(linux_net, 'ensure_ovs_bridge')
-        ) as (mock_sys, ensure_bridge, device_exists, create_veth_pair,
-              add_bridge_port, _create_vif_port, ensure_ovs_bridge):
         mock_sys.platform = 'linux'
         plugin = ovs.OvsPlugin.load("ovs")
         plugin.plug(self.vif_ovs_hybrid, self.instance)
@@ -175,7 +161,12 @@ class PluginTest(testtools.TestCase):
         _create_vif_port.assert_has_calls(calls['_create_vif_port'])
         ensure_ovs_bridge.assert_has_calls(calls['ensure_ovs_bridge'])
 
-    def _check_plug_ovs_windows(self, vif):
+    @mock.patch.object(linux_net, 'ensure_ovs_bridge')
+    @mock.patch.object(ovs.OvsPlugin, '_create_vif_port')
+    @mock.patch.object(linux_net, 'device_exists', return_value=False)
+    @mock.patch.object(ovs, 'sys')
+    def _check_plug_ovs_windows(self, vif, mock_sys, device_exists,
+                                _create_vif_port, ensure_ovs_bridge):
         calls = {
             'device_exists': [mock.call(vif.id)],
             '_create_vif_port': [mock.call(vif, vif.id, self.instance)],
@@ -183,13 +174,6 @@ class PluginTest(testtools.TestCase):
                                             constants.OVS_DATAPATH_SYSTEM)]
         }
 
-        with nested(
-                mock.patch.object(ovs, 'sys'),
-                mock.patch.object(linux_net, 'device_exists',
-                                  return_value=False),
-                mock.patch.object(ovs.OvsPlugin, '_create_vif_port'),
-                mock.patch.object(linux_net, 'ensure_ovs_bridge')
-        ) as (mock_sys, device_exists, _create_vif_port, ensure_ovs_bridge):
         mock_sys.platform = constants.PLATFORM_WIN32
         plugin = ovs.OvsPlugin.load("ovs")
         plugin.plug(vif, self.instance)
@@ -210,33 +194,29 @@ class PluginTest(testtools.TestCase):
         plugin.unplug(self.vif_ovs, self.instance)
         self.assertFalse(unplug_bridge_mock.called)
 
-    def test_unplug_ovs_bridge(self):
+    @mock.patch.object(linux_net, 'delete_ovs_vif_port')
+    @mock.patch.object(linux_net, 'delete_bridge')
+    @mock.patch.object(ovs, 'sys')
+    def test_unplug_ovs_bridge(self, mock_sys, delete_bridge,
+                               delete_ovs_vif_port):
         calls = {
             'delete_bridge': [mock.call('qbrvif-xxx-yyy', 'qvbb679325f-ca')],
             'delete_ovs_vif_port': [mock.call('br0', 'qvob679325f-ca',
                                     timeout=120)]
         }
-        with nested(
-                mock.patch.object(ovs, 'sys'),
-                mock.patch.object(linux_net, 'delete_bridge'),
-                mock.patch.object(linux_net, 'delete_ovs_vif_port')
-        ) as (mock_sys, delete_bridge, delete_ovs_vif_port):
         mock_sys.platform = 'linux'
         plugin = ovs.OvsPlugin.load("ovs")
         plugin.unplug(self.vif_ovs_hybrid, self.instance)
         delete_bridge.assert_has_calls(calls['delete_bridge'])
         delete_ovs_vif_port.assert_has_calls(calls['delete_ovs_vif_port'])
 
-    def _check_unplug_ovs_windows(self, vif):
+    @mock.patch.object(linux_net, 'delete_ovs_vif_port')
-        with nested(
+    @mock.patch.object(ovs, 'sys')
-                mock.patch.object(ovs, 'sys'),
+    def _check_unplug_ovs_windows(self, vif, mock_sys, delete_ovs_vif_port):
-                mock.patch.object(linux_net, 'delete_ovs_vif_port')
-        ) as (mock_sys, delete_ovs_vif_port):
         mock_sys.platform = constants.PLATFORM_WIN32
         plugin = ovs.OvsPlugin.load("ovs")
         plugin.unplug(vif, self.instance)
-            delete_ovs_vif_port.assert_called_once_with(
+        delete_ovs_vif_port.assert_called_once_with('br0', vif.id, timeout=120)
-                'br0', vif.id, timeout=120)
 
     def test_unplug_ovs_windows(self):
         self._check_unplug_ovs_windows(self.vif_ovs)
@@ -244,7 +224,9 @@ class PluginTest(testtools.TestCase):
     def test_unplug_ovs_bridge_windows(self):
         self._check_unplug_ovs_windows(self.vif_ovs_hybrid)
 
-    def test_plug_ovs_vhostuser(self):
+    @mock.patch.object(linux_net, 'ensure_ovs_bridge')
+    @mock.patch.object(ovs.OvsPlugin, '_create_vif_port')
+    def test_plug_ovs_vhostuser(self, _create_vif_port, ensure_ovs_bridge):
         calls = {
 
             '_create_vif_port': [mock.call(
@@ -255,22 +237,17 @@ class PluginTest(testtools.TestCase):
                                             constants.OVS_DATAPATH_NETDEV)]
         }
 
-        with nested(
-                mock.patch.object(ovs.OvsPlugin, '_create_vif_port'),
-                mock.patch.object(linux_net, 'ensure_ovs_bridge')
-        ) as (_create_vif_port, ensure_ovs_bridge):
         plugin = ovs.OvsPlugin.load("ovs")
         plugin.plug(self.vif_vhostuser, self.instance)
         _create_vif_port.assert_has_calls(calls['_create_vif_port'])
         ensure_ovs_bridge.assert_has_calls(calls['ensure_ovs_bridge'])
 
-    def test_unplug_ovs_vhostuser(self):
+    @mock.patch.object(linux_net, 'delete_ovs_vif_port')
+    def test_unplug_ovs_vhostuser(self, delete_ovs_vif_port):
         calls = {
             'delete_ovs_vif_port': [mock.call('br0', 'vhub679325f-ca',
                                     timeout=120)]
         }
-        with mock.patch.object(linux_net, 'delete_ovs_vif_port') \
-            as delete_ovs_vif_port:
         plugin = ovs.OvsPlugin.load("ovs")
         plugin.unplug(self.vif_vhostuser, self.instance)
         delete_ovs_vif_port.assert_has_calls(calls['delete_ovs_vif_port'])