Move calls to ovs-vsctl to privsep.

The exception handling isn't perfect, but it keeps the interface
unchanged. Its quite hard to include the command in the exception
like we did before, so I am hoping we can just not do that thing.

Change-Id: I9d46e0dc228ed2df9f681c1a2f4dca3c018c7822

nova/network/linux_net.py

@@ -1178,16 +1178,6 @@ def _ra_pid_for(dev):
             return int(f.read())
 
 
-def _ovs_vsctl(args):
-    full_args = ['ovs-vsctl', '--timeout=%s' % CONF.ovs_vsctl_timeout] + args
-    try:
-        return utils.execute(*full_args, run_as_root=True)
-    except Exception as e:
-        LOG.error("Unable to execute %(cmd)s. Exception: %(exception)s",
-                  {'cmd': full_args, 'exception': e})
-        raise exception.OvsConfigurationFailure(inner_exception=e)
-
-
 def delete_bridge_dev(dev):
     """Delete a network bridge."""
     if nova.privsep.linux_net.device_exists(dev):
@@ -1596,14 +1586,16 @@ class LinuxOVSInterfaceDriver(LinuxNetInterfaceDriver):
         dev = self.get_dev(network)
         if not nova.privsep.linux_net.device_exists(dev):
             bridge = CONF.linuxnet_ovs_integration_bridge
-            _ovs_vsctl(['--', '--may-exist', 'add-port', bridge, dev,
-                        '--', 'set', 'Interface', dev, 'type=internal',
-                        '--', 'set', 'Interface', dev,
-                        'external-ids:iface-id=%s' % dev,
-                        '--', 'set', 'Interface', dev,
-                        'external-ids:iface-status=active',
-                        '--', 'set', 'Interface', dev,
-                        'external-ids:attached-mac=%s' % mac_address])
+
+            try:
+                nova.privsep.linux_net.ovs_plug(CONF.ovs_vsctl_timeout,
+                                                bridge, dev, mac_address)
+            except Exception as e:
+                LOG.error('Unable to execute ovs-plug. Exception: '
+                          '%(exception)s',
+                          {'exception': e})
+                raise exception.OvsConfigurationFailure(inner_exception=e)
+
             nova.privsep.linux_net.set_device_macaddr(
                 dev, mac_address)
             nova.privsep.linux_net.set_device_mtu(dev, network.get('mtu'))
@@ -1633,7 +1625,14 @@ class LinuxOVSInterfaceDriver(LinuxNetInterfaceDriver):
     def unplug(self, network):
         dev = self.get_dev(network)
         bridge = CONF.linuxnet_ovs_integration_bridge
-        _ovs_vsctl(['--', '--if-exists', 'del-port', bridge, dev])
+        try:
+            nova.privsep.linux_net.ovs_unplug(CONF.ovs_vsctl_timeout,
+                                              bridge, dev)
+        except Exception as e:
+            LOG.error('Unable to execute ovs-unplug. Exception: %(exception)s',
+                      {'exception': e})
+            raise exception.OvsConfigurationFailure(inner_exception=e)
+
         return dev
 
     def get_dev(self, network):

nova/privsep/linux_net.py

@@ -348,3 +348,22 @@ def start_ra(conf_path, pid_path):
            '-C', '%s' % conf_path,
            '-p', '%s' % pid_path]
     processutils.execute(*cmd)
+
+
+@nova.privsep.sys_admin_pctxt.entrypoint
+def ovs_plug(timeout, bridge, dev, mac_address):
+    processutils.execute('ovs-vsctl', '--timeout=%s' % timeout,
+                         '--', '--may-exist', 'add-port', bridge, dev,
+                         '--', 'set', 'Interface', dev, 'type=internal',
+                         '--', 'set', 'Interface', dev,
+                         'external-ids:iface-id=%s' % dev,
+                         '--', 'set', 'Interface', dev,
+                         'external-ids:iface-status=active',
+                         '--', 'set', 'Interface', dev,
+                         'external-ids:attached-mac=%s' % mac_address)
+
+
+@nova.privsep.sys_admin_pctxt.entrypoint
+def ovs_unplug(timeout, bridge, dev):
+    processutils.execute('ovs-vsctl', '--timeout=%s' % timeout,
+                         '--', '--if-exists', 'del-port', bridge, dev)

nova/tests/unit/network/test_linux_net.py

@@ -34,7 +34,6 @@ from nova.network import driver
 from nova.network import linux_net
 from nova import objects
 from nova import test
-from nova import utils
 
 
 CONF = nova.conf.CONF
@@ -642,21 +641,15 @@ class LinuxNetworkTestCase(test.NoDBTestCase):
                      "share_address": False}, "fakemac")
         self.assertEqual(2, mock_add_rule.call_count)
 
-    @mock.patch('nova.privsep.linux_net.device_exists')
-    @mock.patch.object(utils, 'execute')
-    def test_linux_ovs_driver_plug_exception(self, mock_execute,
+    @mock.patch('nova.privsep.linux_net.device_exists',
+                return_value=False)
+    @mock.patch(
+        'nova.privsep.linux_net.ovs_plug',
+        side_effect=processutils.ProcessExecutionError('specific_error'))
+    def test_linux_ovs_driver_plug_exception(self, mock_plug,
                                              mock_device_exists):
         self.flags(fake_network=False)
 
-        def fake_execute(*args, **kwargs):
-            raise processutils.ProcessExecutionError('specific_error')
-
-        def fake_device_exists(*args, **kwargs):
-            return False
-
-        mock_execute.side_effect = fake_execute
-        mock_device_exists.side_effect = fake_device_exists
-
         driver = linux_net.LinuxOVSInterfaceDriver()
 
         exc = self.assertRaises(exception.OvsConfigurationFailure,
@@ -668,7 +661,7 @@ class LinuxNetworkTestCase(test.NoDBTestCase):
                        re.DOTALL))
         self.assertIsInstance(exc.kwargs['inner_exception'],
                               processutils.ProcessExecutionError)
-        mock_execute.assert_called_once()
+        mock_plug.assert_called_once()
         mock_device_exists.assert_called_once()
 
     @mock.patch.object(linux_net.LinuxBridgeInterfaceDriver,