neutron/neutron/tests/unit/agent/linux/test_interface.py

662 lines
27 KiB
Python

# Copyright 2012 OpenStack Foundation
# 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 neutron_lib import constants
from neutron_lib import exceptions
from oslo_utils import excutils
from neutron.agent.common import ovs_lib
from neutron.agent.linux import interface
from neutron.agent.linux import ip_lib
from neutron.common import utils
from neutron.conf.agent import common as config
from neutron.tests import base
class BaseChild(interface.LinuxInterfaceDriver):
def plug_new(*args):
pass
def unplug(*args):
pass
class FakeNetwork(object):
id = '12345678-1234-5678-90ab-ba0987654321'
class FakeSubnet(object):
cidr = '192.168.1.1/24'
class FakeAllocation(object):
subnet = FakeSubnet()
ip_address = '192.168.1.2'
ip_version = constants.IP_VERSION_4
class FakePort(object):
id = 'abcdef01-1234-5678-90ab-ba0987654321'
fixed_ips = [FakeAllocation]
device_id = 'cccccccc-cccc-cccc-cccc-cccccccccccc'
network = FakeNetwork()
network_id = network.id
class TestBase(base.BaseTestCase):
def setUp(self):
super(TestBase, self).setUp()
self.conf = config.setup_conf()
config.register_interface_opts(self.conf)
self.ip_dev_p = mock.patch.object(ip_lib, 'IPDevice')
self.ip_dev = self.ip_dev_p.start()
self.ip_p = mock.patch.object(ip_lib, 'IPWrapper')
self.ip = self.ip_p.start()
self.device_exists_p = mock.patch.object(ip_lib, 'device_exists')
self.device_exists = self.device_exists_p.start()
self.get_devices_with_ip_p = mock.patch.object(ip_lib,
'get_devices_with_ip')
self.get_devices_with_ip = self.get_devices_with_ip_p.start()
class TestABCDriver(TestBase):
def setUp(self):
super(TestABCDriver, self).setUp()
mock_link_addr = mock.PropertyMock(return_value='aa:bb:cc:dd:ee:ff')
type(self.ip_dev().link).address = mock_link_addr
def test_get_device_name(self):
bc = BaseChild(self.conf)
device_name = bc.get_device_name(FakePort())
self.assertEqual('tapabcdef01-12', device_name)
def test_init_router_port(self):
addresses = [dict(scope='global',
dynamic=False, cidr='172.16.77.240/24')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
self.ip_dev().route.list_onlink_routes.return_value = []
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_router_port('tap0', ['192.168.1.2/24'], namespace=ns,
extra_subnets=[{'cidr': '172.20.0.0/24'}])
self.ip_dev.assert_has_calls(
[mock.call('tap0', namespace=ns),
mock.call().addr.list(),
mock.call().addr.delete('172.16.77.240/24'),
mock.call().addr.add('192.168.1.2/24'),
mock.call('tap0', namespace=ns),
mock.call().route.list_onlink_routes(constants.IP_VERSION_4),
mock.call().route.list_onlink_routes(constants.IP_VERSION_6),
mock.call().route.add_onlink_route('172.20.0.0/24')])
def test_init_router_port_delete_onlink_routes(self):
addresses = [dict(scope='global',
dynamic=False, cidr='172.16.77.240/24')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
self.ip_dev().route.list_onlink_routes.return_value = [
{'cidr': '172.20.0.0/24'}]
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_router_port('tap0', ['192.168.1.2/24'], namespace=ns)
self.ip_dev.assert_has_calls(
[mock.call().route.list_onlink_routes(constants.IP_VERSION_4),
mock.call().route.list_onlink_routes(constants.IP_VERSION_6),
mock.call().route.delete_onlink_route('172.20.0.0/24')])
def test_l3_init_with_preserve(self):
addresses = [dict(scope='global',
dynamic=False, cidr='192.168.1.3/32')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_l3('tap0', ['192.168.1.2/24'], namespace=ns,
preserve_ips=['192.168.1.3/32'])
self.ip_dev.assert_has_calls(
[mock.call('tap0', namespace=ns),
mock.call().addr.list(),
mock.call().addr.add('192.168.1.2/24')])
self.assertFalse(self.ip_dev().addr.delete.called)
self.assertFalse(self.ip_dev().delete_addr_and_conntrack_state.called)
def _test_l3_init_clean_connections(self, clean_connections):
addresses = [
dict(scope='global', dynamic=False, cidr='10.0.0.1/24'),
dict(scope='global', dynamic=False, cidr='10.0.0.3/32')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_l3('tap0', ['10.0.0.1/24'], namespace=ns,
clean_connections=clean_connections)
delete = self.ip_dev().delete_addr_and_conntrack_state
if clean_connections:
delete.assert_called_once_with('10.0.0.3/32')
else:
self.assertFalse(delete.called)
def test_l3_init_with_clean_connections(self):
self._test_l3_init_clean_connections(True)
def test_l3_init_without_clean_connections(self):
self._test_l3_init_clean_connections(False)
def test_init_router_port_ipv6_with_gw_ip(self):
addresses = [dict(scope='global',
dynamic=False,
cidr='2001:db8:a::123/64')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
self.ip_dev().route.list_onlink_routes.return_value = []
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
new_cidr = '2001:db8:a::124/64'
kwargs = {'namespace': ns,
'extra_subnets': [{'cidr': '2001:db8:b::/64'}]}
bc.init_router_port('tap0', [new_cidr], **kwargs)
expected_calls = (
[mock.call('tap0', namespace=ns),
mock.call().addr.list(),
mock.call().addr.delete('2001:db8:a::123/64'),
mock.call().addr.add('2001:db8:a::124/64')])
expected_calls += (
[mock.call('tap0', namespace=ns),
mock.call().route.list_onlink_routes(constants.IP_VERSION_4),
mock.call().route.list_onlink_routes(constants.IP_VERSION_6),
mock.call().route.add_onlink_route('2001:db8:b::/64')])
self.ip_dev.assert_has_calls(expected_calls)
def test_init_router_port_ext_gw_with_dual_stack(self):
old_addrs = [dict(ip_version=constants.IP_VERSION_4, scope='global',
dynamic=False, cidr='172.16.77.240/24'),
dict(ip_version=constants.IP_VERSION_6, scope='global',
dynamic=False, cidr='2001:db8:a::123/64')]
self.ip_dev().addr.list = mock.Mock(return_value=old_addrs)
self.ip_dev().route.list_onlink_routes.return_value = []
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
new_cidrs = ['192.168.1.2/24', '2001:db8:a::124/64']
bc.init_router_port('tap0', new_cidrs, namespace=ns,
extra_subnets=[{'cidr': '172.20.0.0/24'}])
self.ip_dev.assert_has_calls(
[mock.call('tap0', namespace=ns),
mock.call().addr.list(),
mock.call().addr.add('192.168.1.2/24'),
mock.call().addr.add('2001:db8:a::124/64'),
mock.call().addr.delete('172.16.77.240/24'),
mock.call().addr.delete('2001:db8:a::123/64'),
mock.call().route.list_onlink_routes(constants.IP_VERSION_4),
mock.call().route.list_onlink_routes(constants.IP_VERSION_6),
mock.call().route.add_onlink_route('172.20.0.0/24')],
any_order=True)
def test_init_router_port_with_ipv6_delete_onlink_routes(self):
addresses = [dict(scope='global',
dynamic=False, cidr='2001:db8:a::123/64')]
route = '2001:db8:a::/64'
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
self.ip_dev().route.list_onlink_routes.return_value = [{'cidr': route}]
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_router_port('tap0', ['2001:db8:a::124/64'], namespace=ns)
self.ip_dev.assert_has_calls(
[mock.call().route.list_onlink_routes(constants.IP_VERSION_4),
mock.call().route.list_onlink_routes(constants.IP_VERSION_6),
mock.call().route.delete_onlink_route(route)])
def test_l3_init_with_duplicated_ipv6(self):
addresses = [dict(scope='global',
dynamic=False,
cidr='2001:db8:a::123/64')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_l3('tap0', ['2001:db8:a::123/64'], namespace=ns)
self.assertFalse(self.ip_dev().addr.add.called)
def test_l3_init_with_duplicated_ipv6_uncompact(self):
addresses = [dict(scope='global',
dynamic=False,
cidr='2001:db8:a::123/64')]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
bc = BaseChild(self.conf)
ns = '12345678-1234-5678-90ab-ba0987654321'
bc.init_l3('tap0',
['2001:db8:a:0000:0000:0000:0000:0123/64'],
namespace=ns)
self.assertFalse(self.ip_dev().addr.add.called)
def test_l3_init_with_duplicated_ipv6_dynamic(self):
device_name = 'tap0'
cidr = '2001:db8:a::123/64'
ns = '12345678-1234-5678-90ab-ba0987654321'
addresses = [dict(scope='global',
dynamic=True,
cidr=cidr)]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
bc = BaseChild(self.conf)
bc.init_l3(device_name, [cidr], namespace=ns)
self.ip_dev.assert_has_calls(
[mock.call(device_name, namespace=ns),
mock.call().addr.list(),
mock.call().addr.delete(cidr),
mock.call().addr.add(cidr)])
def test_l3_init_with_duplicated_ipv6_lla(self):
device_name = 'tap0'
cidr = 'fe80::a8bb:ccff:fedd:eeff/64'
ns = '12345678-1234-5678-90ab-ba0987654321'
addresses = [dict(scope='link',
dynamic=False,
cidr=cidr)]
self.ip_dev().addr.list = mock.Mock(return_value=addresses)
bc = BaseChild(self.conf)
bc.init_l3(device_name, [cidr], namespace=ns)
self.ip_dev.assert_has_calls(
[mock.call(device_name, namespace=ns),
mock.call().addr.list()])
# The above assert won't verify there were no extra calls right
# after list()
self.assertFalse(self.ip_dev().addr.add.called)
def test_l3_init_with_not_present_ipv6_lla(self):
device_name = 'tap0'
cidr = 'fe80::a8bb:ccff:fedd:eeff/64'
ns = '12345678-1234-5678-90ab-ba0987654321'
self.ip_dev().addr.list = mock.Mock(return_value=[])
bc = BaseChild(self.conf)
bc.init_l3(device_name, [cidr], namespace=ns)
self.ip_dev.assert_has_calls(
[mock.call(device_name, namespace=ns),
mock.call().addr.list(),
mock.call().addr.add(cidr)])
def test_add_ipv6_addr(self):
device_name = 'tap0'
cidr = '2001:db8::/64'
ns = '12345678-1234-5678-90ab-ba0987654321'
bc = BaseChild(self.conf)
bc.add_ipv6_addr(device_name, cidr, ns)
self.ip_dev.assert_has_calls(
[mock.call(device_name, namespace=ns),
mock.call().addr.add(cidr, 'global')])
def test_delete_ipv6_addr(self):
device_name = 'tap0'
cidr = '2001:db8::/64'
ns = '12345678-1234-5678-90ab-ba0987654321'
bc = BaseChild(self.conf)
bc.delete_ipv6_addr(device_name, cidr, ns)
self.ip_dev.assert_has_calls(
[mock.call(device_name, namespace=ns),
mock.call().delete_addr_and_conntrack_state(cidr)])
def test_delete_ipv6_addr_with_prefix(self):
device_name = 'tap0'
prefix = '2001:db8::/48'
in_cidr = '2001:db8::/64'
out_cidr = '2001:db7::/64'
ns = '12345678-1234-5678-90ab-ba0987654321'
in_addresses = [dict(scope='global',
dynamic=False,
cidr=in_cidr)]
out_addresses = [dict(scope='global',
dynamic=False,
cidr=out_cidr)]
# Initially set the address list to be empty
self.ip_dev().addr.list = mock.Mock(return_value=[])
bc = BaseChild(self.conf)
# Call delete_v6addr_with_prefix when the address list is empty
bc.delete_ipv6_addr_with_prefix(device_name, prefix, ns)
# Assert that delete isn't called
self.assertFalse(self.ip_dev().delete_addr_and_conntrack_state.called)
# Set the address list to contain only an address outside of the range
# of the given prefix
self.ip_dev().addr.list = mock.Mock(return_value=out_addresses)
bc.delete_ipv6_addr_with_prefix(device_name, prefix, ns)
# Assert that delete isn't called
self.assertFalse(self.ip_dev().delete_addr_and_conntrack_state.called)
# Set the address list to contain only an address inside of the range
# of the given prefix
self.ip_dev().addr.list = mock.Mock(return_value=in_addresses)
bc.delete_ipv6_addr_with_prefix(device_name, prefix, ns)
# Assert that delete is called
self.ip_dev.assert_has_calls(
[mock.call(device_name, namespace=ns),
mock.call().addr.list(scope='global', filters=['permanent']),
mock.call().delete_addr_and_conntrack_state(in_cidr)])
def test_get_ipv6_llas(self):
ns = '12345678-1234-5678-90ab-ba0987654321'
addresses = [dict(scope='link',
dynamic=False,
cidr='fe80:cafe::/64')]
self.get_devices_with_ip.return_value = addresses
device_name = self.ip_dev().name
bc = BaseChild(self.conf)
llas = bc.get_ipv6_llas(device_name, ns)
self.assertEqual(addresses, llas)
kwargs = {'family': utils.get_socket_address_family(
constants.IP_VERSION_6),
'scope': 'link'}
self.get_devices_with_ip.assert_called_with(
ns, name=device_name, **kwargs)
def test_set_mtu_logs_once(self):
bc = BaseChild(self.conf)
with mock.patch('neutron.agent.linux.interface.LOG.warning') as log:
bc.set_mtu('dev', 9999)
log.assert_called_once_with(mock.ANY)
class TestOVSInterfaceDriver(TestBase):
def test_get_device_name(self):
br = interface.OVSInterfaceDriver(self.conf)
device_name = br.get_device_name(FakePort())
self.assertEqual('tapabcdef01-12', device_name)
def test_plug_no_ns(self):
self._test_plug()
def test_plug_with_ns(self):
self._test_plug(namespace='01234567-1234-1234-99')
def test_plug_alt_bridge(self):
self._test_plug(bridge='br-foo')
def test_plug_configured_bridge(self):
br = 'br-v'
self.conf.set_override('ovs_use_veth', False)
self.conf.set_override('ovs_integration_bridge', br)
self.assertEqual(self.conf.ovs_integration_bridge, br)
def device_exists(dev, namespace=None):
return dev == br
ovs = interface.OVSInterfaceDriver(self.conf)
with mock.patch.object(ovs, '_ovs_add_port') as add_port:
self.device_exists.side_effect = device_exists
ovs.plug('01234567-1234-1234-99',
'port-1234',
'tap0',
'aa:bb:cc:dd:ee:ff',
bridge=None,
namespace=None)
add_port.assert_called_once_with('br-v',
'tap0',
'port-1234',
'aa:bb:cc:dd:ee:ff',
internal=True)
def _test_plug(self, bridge=None, namespace=None):
with mock.patch('neutron.agent.ovsdb.impl_idl._connection'):
if not bridge:
bridge = 'br-int'
def device_exists(dev, namespace=None):
return dev == bridge
with mock.patch.object(ovs_lib.OVSBridge,
'replace_port') as replace:
ovs = interface.OVSInterfaceDriver(self.conf)
self.device_exists.side_effect = device_exists
link = self.ip.return_value.device.return_value.link
link.set_address.side_effect = (RuntimeError, None)
ovs.plug('01234567-1234-1234-99',
'port-1234',
'tap0',
'aa:bb:cc:dd:ee:ff',
bridge=bridge,
namespace=namespace,
mtu=9000)
replace.assert_called_once_with(
'tap0',
('type', 'internal'),
('external_ids', {
'iface-id': 'port-1234',
'iface-status': 'active',
'attached-mac': 'aa:bb:cc:dd:ee:ff'}))
expected = [
mock.call(),
mock.call().device('tap0'),
mock.call().device().link.set_address('aa:bb:cc:dd:ee:ff'),
mock.call().device().link.set_address('aa:bb:cc:dd:ee:ff')]
if namespace:
expected.extend(
[mock.call().ensure_namespace(namespace),
mock.call().ensure_namespace().add_device_to_namespace(
mock.ANY)])
expected.extend([
mock.call(namespace=namespace),
mock.call().device('tap0'),
mock.call().device().link.set_mtu(9000),
mock.call().device().link.set_up(),
])
self.ip.assert_has_calls(expected)
def test_plug_new(self):
with mock.patch('neutron.agent.ovsdb.impl_idl._connection'):
bridge = 'br-int'
namespace = '01234567-1234-1234-99'
with mock.patch.object(ovs_lib.OVSBridge,
'delete_port') as delete_port:
with mock.patch.object(ovs_lib.OVSBridge, 'replace_port'):
ovs = interface.OVSInterfaceDriver(self.conf)
reraise = mock.patch.object(
excutils, 'save_and_reraise_exception')
reraise.start()
proEr = exceptions.ProcessExecutionError('', 2)
processExecutionError = mock.Mock(side_effect=proEr)
ip = self.ip.return_value
ip.ensure_namespace.side_effect = processExecutionError
ovs.plug_new(
'01234567-1234-1234-99',
'port-1234',
'tap0',
'aa:bb:cc:dd:ee:ff',
bridge=bridge,
namespace=namespace,
prefix='veth',
mtu=9000)
delete_port.assert_called_once_with('tap0')
def test_unplug(self, bridge=None):
if not bridge:
bridge = 'br-int'
with mock.patch('neutron.agent.common.ovs_lib.OVSBridge') as ovs_br:
ovs = interface.OVSInterfaceDriver(self.conf)
ovs.unplug('tap0')
ovs_br.assert_has_calls([mock.call(bridge),
mock.call().delete_port('tap0')])
class TestOVSInterfaceDriverWithVeth(TestOVSInterfaceDriver):
def setUp(self):
super(TestOVSInterfaceDriverWithVeth, self).setUp()
self.conf.set_override('ovs_use_veth', True)
def test_get_device_name(self):
br = interface.OVSInterfaceDriver(self.conf)
device_name = br.get_device_name(FakePort())
self.assertEqual('ns-abcdef01-12', device_name)
def test_plug_with_prefix(self):
self._test_plug(devname='qr-0', prefix='qr-')
def _test_plug(self, devname=None, bridge=None, namespace=None,
prefix=None):
with mock.patch('neutron.agent.ovsdb.impl_idl._connection'):
if not devname:
devname = 'ns-0'
if not bridge:
bridge = 'br-int'
def device_exists(dev, namespace=None):
return dev == bridge
ovs = interface.OVSInterfaceDriver(self.conf)
self.device_exists.side_effect = device_exists
root_dev = mock.Mock()
ns_dev = mock.Mock()
self.ip().add_veth = mock.Mock(return_value=(root_dev, ns_dev))
mock.patch.object(
interface, '_get_veth',
return_value=(root_dev, ns_dev)).start()
expected = [mock.call(),
mock.call().add_veth('tap0', devname,
namespace2=namespace)]
with mock.patch.object(ovs_lib.OVSBridge,
'replace_port') as replace:
ovs.plug('01234567-1234-1234-99',
'port-1234',
devname,
'aa:bb:cc:dd:ee:ff',
bridge=bridge,
namespace=namespace,
prefix=prefix,
mtu=9000)
replace.assert_called_once_with(
'tap0',
('external_ids', {
'iface-id': 'port-1234',
'iface-status': 'active',
'attached-mac': 'aa:bb:cc:dd:ee:ff'}))
ns_dev.assert_has_calls(
[mock.call.link.set_address('aa:bb:cc:dd:ee:ff')])
ns_dev.assert_has_calls([mock.call.link.set_mtu(9000)])
root_dev.assert_has_calls([mock.call.link.set_mtu(9000)])
self.ip.assert_has_calls(expected)
root_dev.assert_has_calls([mock.call.link.set_up()])
ns_dev.assert_has_calls([mock.call.link.set_up()])
def test_plug_new(self, bridge=None, namespace=None):
# The purpose of test_plug_new in parent class(TestOVSInterfaceDriver)
# is to test exception(exceptions.ProcessExecutionError), method here
# would not go through that code, So just pass
pass
def test_unplug(self, bridge=None):
if not bridge:
bridge = 'br-int'
with mock.patch('neutron.agent.common.ovs_lib.OVSBridge') as ovs_br:
ovs = interface.OVSInterfaceDriver(self.conf)
ovs.unplug('ns-0', bridge=bridge)
ovs_br.assert_has_calls([mock.call(bridge),
mock.call().delete_port('tap0')])
self.ip_dev.assert_has_calls([mock.call('ns-0', namespace=None),
mock.call().link.delete()])
class TestBridgeInterfaceDriver(TestBase):
def test_get_device_name(self):
br = interface.BridgeInterfaceDriver(self.conf)
device_name = br.get_device_name(FakePort())
self.assertEqual('ns-abcdef01-12', device_name)
def test_plug_no_ns(self):
self._test_plug()
def test_plug_with_ns(self):
self._test_plug(namespace='01234567-1234-1234-99')
def _test_plug(self, namespace=None):
def device_exists(device, namespace=None):
return device.startswith('brq')
root_veth = mock.Mock()
ns_veth = mock.Mock()
self.ip().add_veth = mock.Mock(return_value=(root_veth, ns_veth))
mock.patch.object(
interface, '_get_veth',
return_value=(root_veth, ns_veth)).start()
self.device_exists.side_effect = device_exists
br = interface.BridgeInterfaceDriver(self.conf)
mac_address = 'aa:bb:cc:dd:ee:ff'
br.plug('01234567-1234-1234-99',
'port-1234',
'ns-0',
mac_address,
namespace=namespace,
mtu=9000)
ip_calls = [mock.call(),
mock.call().add_veth('tap0', 'ns-0', namespace2=namespace)]
ns_veth.assert_has_calls([mock.call.link.set_address(mac_address)])
ns_veth.assert_has_calls([mock.call.link.set_mtu(9000)])
root_veth.assert_has_calls([mock.call.link.set_mtu(9000)])
self.ip.assert_has_calls(ip_calls)
root_veth.assert_has_calls([mock.call.link.set_up()])
ns_veth.assert_has_calls([mock.call.link.set_up()])
def test_plug_dev_exists(self):
self.device_exists.return_value = True
with mock.patch('neutron.agent.linux.interface.LOG.info') as log:
br = interface.BridgeInterfaceDriver(self.conf)
br.plug('01234567-1234-1234-99',
'port-1234',
'tap0',
'aa:bb:cc:dd:ee:ff')
self.assertFalse(self.ip_dev.called)
self.assertEqual(log.call_count, 1)
def test_unplug_no_device(self):
self.device_exists.return_value = False
self.ip_dev().link.delete.side_effect = RuntimeError
with mock.patch('neutron.agent.linux.interface.LOG') as log:
br = interface.BridgeInterfaceDriver(self.conf)
br.unplug('tap0')
[mock.call(), mock.call('tap0'), mock.call().link.delete()]
self.assertEqual(log.error.call_count, 1)
def test_unplug(self):
self.device_exists.return_value = True
with mock.patch('neutron.agent.linux.interface.LOG.debug') as log:
br = interface.BridgeInterfaceDriver(self.conf)
br.unplug('tap0')
self.assertEqual(log.call_count, 1)
self.ip_dev.assert_has_calls([mock.call('tap0', namespace=None),
mock.call().link.delete()])