Move create_tap_dev to the new utility module.

Move another generally useful utility method out of nova-net to
somewhere more generic.

Change-Id: I1bf7afecd2e8122492dcb2c21b26e5b72919e6b5
blueprint: remove-nova-network

nova/network/linux_net.py

@@ -1231,31 +1231,6 @@ def _ovs_vsctl(args):
         raise exception.OvsConfigurationFailure(inner_exception=e)
 
 
-def create_tap_dev(dev, mac_address=None, multiqueue=False):
-    if not linux_net_utils.device_exists(dev):
-        try:
-            # First, try with 'ip'
-            cmd = ('ip', 'tuntap', 'add', dev, 'mode', 'tap')
-            if multiqueue:
-                cmd = cmd + ('multi_queue', )
-            utils.execute(*cmd, run_as_root=True, check_exit_code=[0, 2, 254])
-        except processutils.ProcessExecutionError:
-            if multiqueue:
-                LOG.warning(
-                    'Failed to create a tap device with ip tuntap. '
-                    'tunctl does not support creation of multi-queue '
-                    'enabled devices, skipping fallback.')
-                raise
-
-            # Second option: tunctl
-            utils.execute('tunctl', '-b', '-t', dev, run_as_root=True)
-        if mac_address:
-            utils.execute('ip', 'link', 'set', dev, 'address', mac_address,
-                          run_as_root=True, check_exit_code=[0, 2, 254])
-        utils.execute('ip', 'link', 'set', dev, 'up', run_as_root=True,
-                      check_exit_code=[0, 2, 254])
-
-
 def create_fp_dev(dev, sockpath, sockmode):
     if not linux_net_utils.device_exists(dev):
         utils.execute('fp-vdev', 'add', dev, '--sockpath', sockpath,
@@ -1755,7 +1730,7 @@ class NeutronLinuxBridgeInterfaceDriver(LinuxNetInterfaceDriver):
             for rule in get_gateway_rules(bridge):
                 iptables_manager.ipv4['filter'].add_rule(*rule)
 
-        create_tap_dev(dev, mac_address)
+        linux_net_utils.create_tap_dev(dev, mac_address)
 
         if not linux_net_utils.device_exists(bridge):
             LOG.debug("Starting bridge %s ", bridge)

nova/network/linux_utils.py

@@ -68,3 +68,28 @@ def create_veth_pair(dev1_name, dev2_name, mtu=None):
         utils.execute('ip', 'link', 'set', dev, 'promisc', 'on',
                       run_as_root=True)
         set_device_mtu(dev, mtu)
+
+
+def create_tap_dev(dev, mac_address=None, multiqueue=False):
+    if not device_exists(dev):
+        try:
+            # First, try with 'ip'
+            cmd = ('ip', 'tuntap', 'add', dev, 'mode', 'tap')
+            if multiqueue:
+                cmd = cmd + ('multi_queue', )
+            utils.execute(*cmd, run_as_root=True, check_exit_code=[0, 2, 254])
+        except processutils.ProcessExecutionError:
+            if multiqueue:
+                LOG.warning(
+                    'Failed to create a tap device with ip tuntap. '
+                    'tunctl does not support creation of multi-queue '
+                    'enabled devices, skipping fallback.')
+                raise
+
+            # Second option: tunctl
+            utils.execute('tunctl', '-b', '-t', dev, run_as_root=True)
+        if mac_address:
+            utils.execute('ip', 'link', 'set', dev, 'address', mac_address,
+                          run_as_root=True, check_exit_code=[0, 2, 254])
+        utils.execute('ip', 'link', 'set', dev, 'up', run_as_root=True,
+                      check_exit_code=[0, 2, 254])

nova/tests/unit/network/test_linux_net.py

@@ -1340,77 +1340,6 @@ class LinuxNetworkTestCase(test.NoDBTestCase):
                           linux_net.LinuxBridgeInterfaceDriver.remove_bridge,
                           'fake-bridge')
 
-    @mock.patch('nova.utils.execute')
-    def test_create_tap_dev(self, mock_execute):
-        linux_net.create_tap_dev('tap42')
-
-        mock_execute.assert_has_calls([
-            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
-                      run_as_root=True, check_exit_code=[0, 2, 254]),
-            mock.call('ip', 'link', 'set', 'tap42', 'up',
-                      run_as_root=True, check_exit_code=[0, 2, 254])
-        ])
-
-    @mock.patch('os.path.exists', return_value=True)
-    @mock.patch('nova.utils.execute')
-    def test_create_tap_skipped_when_exists(self, mock_execute, mock_exists):
-        linux_net.create_tap_dev('tap42')
-
-        mock_exists.assert_called_once_with('/sys/class/net/tap42')
-        mock_execute.assert_not_called()
-
-    @mock.patch('nova.utils.execute')
-    def test_create_tap_dev_mac(self, mock_execute):
-        linux_net.create_tap_dev('tap42', '00:11:22:33:44:55')
-
-        mock_execute.assert_has_calls([
-            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
-                      run_as_root=True, check_exit_code=[0, 2, 254]),
-            mock.call('ip', 'link', 'set', 'tap42',
-                      'address', '00:11:22:33:44:55',
-                      run_as_root=True, check_exit_code=[0, 2, 254]),
-            mock.call('ip', 'link', 'set', 'tap42', 'up',
-                      run_as_root=True, check_exit_code=[0, 2, 254])
-        ])
-
-    @mock.patch('nova.utils.execute')
-    def test_create_tap_dev_fallback_to_tunctl(self, mock_execute):
-        # ip failed, fall back to tunctl
-        mock_execute.side_effect = [processutils.ProcessExecutionError, 0, 0]
-
-        linux_net.create_tap_dev('tap42')
-
-        mock_execute.assert_has_calls([
-            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
-                      run_as_root=True, check_exit_code=[0, 2, 254]),
-            mock.call('tunctl', '-b', '-t', 'tap42',
-                      run_as_root=True),
-            mock.call('ip', 'link', 'set', 'tap42', 'up',
-                      run_as_root=True, check_exit_code=[0, 2, 254])
-        ])
-
-    @mock.patch('nova.utils.execute')
-    def test_create_tap_dev_multiqueue(self, mock_execute):
-        linux_net.create_tap_dev('tap42', multiqueue=True)
-
-        mock_execute.assert_has_calls([
-            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
-                      'multi_queue',
-                      run_as_root=True, check_exit_code=[0, 2, 254]),
-            mock.call('ip', 'link', 'set', 'tap42', 'up',
-                      run_as_root=True, check_exit_code=[0, 2, 254])
-        ])
-
-    @mock.patch('nova.utils.execute')
-    def test_create_tap_dev_multiqueue_tunctl_raises(self, mock_execute):
-        # if creation of a tap by the means of ip command fails,
-        # create_tap_dev() will try to do that by the means of tunctl
-        mock_execute.side_effect = processutils.ProcessExecutionError
-        # but tunctl can't create multiqueue taps, so the failure is expected
-        self.assertRaises(processutils.ProcessExecutionError,
-                          linux_net.create_tap_dev,
-                          'tap42', multiqueue=True)
-
     @mock.patch('nova.pci.utils.get_vf_num_by_pci_address')
     @mock.patch('nova.pci.utils.get_ifname_by_pci_address')
     @mock.patch('nova.utils.execute')

nova/tests/unit/network/test_utils.py

@@ -0,0 +1,95 @@
+# Copyright 2011 NTT
+# All Rights Reserved.
+#
+# 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 mock
+
+from oslo_concurrency import processutils
+
+from nova.network import linux_utils as net_utils
+from nova import test
+
+
+class NetUtilsTestCase(test.NoDBTestCase):
+    @mock.patch('nova.utils.execute')
+    def test_create_tap_dev(self, mock_execute):
+        net_utils.create_tap_dev('tap42')
+
+        mock_execute.assert_has_calls([
+            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
+                      run_as_root=True, check_exit_code=[0, 2, 254]),
+            mock.call('ip', 'link', 'set', 'tap42', 'up',
+                      run_as_root=True, check_exit_code=[0, 2, 254])
+        ])
+
+    @mock.patch('os.path.exists', return_value=True)
+    @mock.patch('nova.utils.execute')
+    def test_create_tap_skipped_when_exists(self, mock_execute, mock_exists):
+        net_utils.create_tap_dev('tap42')
+
+        mock_exists.assert_called_once_with('/sys/class/net/tap42')
+        mock_execute.assert_not_called()
+
+    @mock.patch('nova.utils.execute')
+    def test_create_tap_dev_mac(self, mock_execute):
+        net_utils.create_tap_dev('tap42', '00:11:22:33:44:55')
+
+        mock_execute.assert_has_calls([
+            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
+                      run_as_root=True, check_exit_code=[0, 2, 254]),
+            mock.call('ip', 'link', 'set', 'tap42',
+                      'address', '00:11:22:33:44:55',
+                      run_as_root=True, check_exit_code=[0, 2, 254]),
+            mock.call('ip', 'link', 'set', 'tap42', 'up',
+                      run_as_root=True, check_exit_code=[0, 2, 254])
+        ])
+
+    @mock.patch('nova.utils.execute')
+    def test_create_tap_dev_fallback_to_tunctl(self, mock_execute):
+        # ip failed, fall back to tunctl
+        mock_execute.side_effect = [processutils.ProcessExecutionError, 0, 0]
+
+        net_utils.create_tap_dev('tap42')
+
+        mock_execute.assert_has_calls([
+            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
+                      run_as_root=True, check_exit_code=[0, 2, 254]),
+            mock.call('tunctl', '-b', '-t', 'tap42',
+                      run_as_root=True),
+            mock.call('ip', 'link', 'set', 'tap42', 'up',
+                      run_as_root=True, check_exit_code=[0, 2, 254])
+        ])
+
+    @mock.patch('nova.utils.execute')
+    def test_create_tap_dev_multiqueue(self, mock_execute):
+        net_utils.create_tap_dev('tap42', multiqueue=True)
+
+        mock_execute.assert_has_calls([
+            mock.call('ip', 'tuntap', 'add', 'tap42', 'mode', 'tap',
+                      'multi_queue',
+                      run_as_root=True, check_exit_code=[0, 2, 254]),
+            mock.call('ip', 'link', 'set', 'tap42', 'up',
+                      run_as_root=True, check_exit_code=[0, 2, 254])
+        ])
+
+    @mock.patch('nova.utils.execute')
+    def test_create_tap_dev_multiqueue_tunctl_raises(self, mock_execute):
+        # if creation of a tap by the means of ip command fails,
+        # create_tap_dev() will try to do that by the means of tunctl
+        mock_execute.side_effect = processutils.ProcessExecutionError
+        # but tunctl can't create multiqueue taps, so the failure is expected
+        self.assertRaises(processutils.ProcessExecutionError,
+                          net_utils.create_tap_dev,
+                          'tap42', multiqueue=True)

nova/tests/unit/virt/libvirt/test_vif.py

@@ -979,7 +979,7 @@ class LibvirtVifTestCase(test.NoDBTestCase):
                 'NovaVMPort', self.vif_vrouter['devname'],
                 self.vif_vrouter['address'], '0.0.0.0', None)
 
-    @mock.patch('nova.network.linux_net.create_tap_dev')
+    @mock.patch('nova.network.linux_utils.create_tap_dev')
     @mock.patch('nova.privsep.libvirt.plug_contrail_vif')
     def test_plug_vrouter_with_details_multiqueue(
             self, mock_plug_contrail, mock_create_tap_dev):

nova/virt/libvirt/vif.py

@@ -644,7 +644,7 @@ class LibvirtGenericVIFDriver(object):
         dev = self.get_vif_devname(vif)
         port_id = vif['id']
         try:
-            linux_net.create_tap_dev(dev)
+            linux_net_utils.create_tap_dev(dev)
             nova.privsep.libvirt.plug_midonet_vif(port_id, dev)
         except processutils.ProcessExecutionError:
             LOG.exception(_("Failed while plugging vif"), instance=instance)
@@ -657,7 +657,7 @@ class LibvirtGenericVIFDriver(object):
         """
         dev = self.get_vif_devname(vif)
         iface_id = vif['id']
-        linux_net.create_tap_dev(dev)
+        linux_net_utils.create_tap_dev(dev)
         net_id = vif['network']['id']
         tenant_id = instance.project_id
         try:
@@ -670,7 +670,7 @@ class LibvirtGenericVIFDriver(object):
         """Plug a VIF_TYPE_TAP virtual interface."""
         dev = self.get_vif_devname(vif)
         mac = vif['details'].get(network_model.VIF_DETAILS_TAP_MAC_ADDRESS)
-        linux_net.create_tap_dev(dev, mac)
+        linux_net_utils.create_tap_dev(dev, mac)
         network = vif.get('network')
         mtu = network.get_meta('mtu') if network else None
         linux_net_utils.set_device_mtu(dev, mtu)
@@ -707,7 +707,7 @@ class LibvirtGenericVIFDriver(object):
         try:
             multiqueue = self._is_multiqueue_enabled(instance.image_meta,
                                                      instance.flavor)
-            linux_net.create_tap_dev(dev, multiqueue=multiqueue)
+            linux_net_utils.create_tap_dev(dev, multiqueue=multiqueue)
             nova.privsep.libvirt.plug_contrail_vif(
                 instance.project_id,
                 instance.uuid,