openstack/neutron
Code Issues Proposed changes

Merge "Fix for race condition during netns creation"

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This commit is contained in:
Jenkins 2017-09-20 16:57:24 +00:00 committed by Gerrit Code Review
commit 1be2c27d96
4 changed files with 61 additions and 13 deletions
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22
neutron/agent/linux/ip_lib.py
View File

@ -29,6 +29,7 @@ import six
from neutron._i18n import _
from neutron.agent.common import utils
from neutron.agent.linux import utils as linux_utils
from neutron.common import exceptions as n_exc
from neutron.common import utils as common_utils
from neutron.privileged.agent.linux import ip_lib as privileged
@ -202,12 +203,23 @@ class IPWrapper(SubProcessBase):
return IPDevice(name, namespace=self.namespace)
def ensure_namespace(self, name):
if not self.netns.exists(name):
# we must save and restore this before returning
orig_log_fail_as_error = self.get_log_fail_as_error()
self.set_log_fail_as_error(False)
try:
ip = self.netns.add(name)
lo = ip.device(LOOPBACK_DEVNAME)
lo.link.set_up()
else:
ip = IPWrapper(namespace=name)
except linux_utils.ProcessExecutionError:
if self.netns.exists(name):
# NOTE(slaweq): error which was catched here might be actually
# because of namespace already exists, in such case it's not
# a real issue
return IPWrapper(namespace=name)
raise
finally:
self.set_log_fail_as_error(orig_log_fail_as_error)
lo = ip.device(LOOPBACK_DEVNAME)
lo.link.set_up()
return ip
def namespace_is_empty(self):

12
neutron/tests/functional/agent/linux/test_ip_lib.py
View File

@ -185,6 +185,18 @@ class IpLibTestCase(IpLibTestFramework):
device.link.delete()
def test_ensure_namespace(self):
attr = self.generate_device_details()
ip = ip_lib.IPWrapper()
# Try to create same namespace twice, should be no error in both cases
ns = ip.ensure_namespace(attr.namespace)
ns2 = ip.ensure_namespace(attr.namespace)
self.assertTrue(ip.netns.exists(attr.namespace))
self.assertEqual(attr.namespace, ns.namespace)
self.assertEqual(attr.namespace, ns2.namespace)
def test_get_routing_table(self):
attr = self.generate_device_details(
ip_cidrs=["%s/24" % TEST_IP, "fd00::1/64"]

7
neutron/tests/unit/agent/l3/test_dvr_fip_ns.py
View File

@ -24,6 +24,7 @@ from neutron.agent.l3 import link_local_allocator as lla
from neutron.agent.l3 import router_info
from neutron.agent.linux import ip_lib
from neutron.agent.linux import iptables_manager
from neutron.agent.linux import utils as linux_utils
from neutron.common import exceptions as n_exc
from neutron.tests import base
@ -189,8 +190,12 @@ class TestDvrFipNs(base.BaseTestCase):
@mock.patch.object(iptables_manager, 'IptablesManager')
@mock.patch.object(utils, 'execute')
@mock.patch.object(ip_lib.IpNetnsCommand, 'add')
@mock.patch.object(ip_lib.IpNetnsCommand, 'exists')
def _test_create(self, old_kernel, exists, execute, IPTables):
def _test_create(self, old_kernel, exists, add, execute, IPTables):
add.side_effect = linux_utils.ProcessExecutionError(
message="Cannot create namespace file ns: File exists",
returncode=1)
exists.return_value = True
# There are up to six sysctl calls - two to enable forwarding,
# two for arp_ignore and arp_announce, and two for ip_nonlocal_bind

33
neutron/tests/unit/agent/linux/test_ip_lib.py
View File

@ -26,6 +26,7 @@ import testtools
from neutron.agent.common import utils # noqa
from neutron.agent.linux import ip_lib
from neutron.agent.linux import utils as linux_utils
from neutron.common import exceptions as n_exc
from neutron import privileged
from neutron.privileged.agent.linux import ip_lib as priv_lib
@ -403,21 +404,39 @@ class TestIpWrapper(base.BaseTestCase):
ip = ip_lib.IPWrapper()
with mock.patch.object(ip.netns, 'exists') as ns_exists:
with mock.patch('neutron.agent.common.utils.execute'):
ns_exists.return_value = False
ip.ensure_namespace('ns')
self.execute.assert_has_calls(
[mock.call([], 'netns', ('add', 'ns'),
run_as_root=True, namespace=None,
log_fail_as_error=True)])
log_fail_as_error=False)])
ns_exists.assert_not_called()
ip_dev.assert_has_calls([mock.call('lo', namespace='ns'),
mock.call().link.set_up()])
def test_ensure_namespace_existing(self):
with mock.patch.object(ip_lib, 'IpNetnsCommand') as ip_ns_cmd:
ip_ns_cmd.exists.return_value = True
ns = ip_lib.IPWrapper().ensure_namespace('ns')
self.assertFalse(self.execute.called)
self.assertEqual(ns.namespace, 'ns')
with mock.patch.object(ip_lib, 'IPDevice') as ip_dev:
ip = ip_lib.IPWrapper()
with mock.patch.object(ip.netns, 'add') as ns_add_cmd, \
mock.patch.object(ip.netns, 'exists') as ns_exists_cmd:
ns_add_cmd.side_effect = linux_utils.ProcessExecutionError(
message=("Cannot create namespace file /var/run/netns/ns: "
"File exists"),
returncode=1)
ns_exists_cmd.return_value = True
ns = ip.ensure_namespace('ns')
self.assertEqual(ns.namespace, 'ns')
ip_dev.assert_not_called()
def test_ensure_namespace_error(self):
with mock.patch.object(ip_lib, 'IPDevice'):
ip = ip_lib.IPWrapper()
with mock.patch.object(ip.netns, 'add') as ns_add_cmd, \
mock.patch.object(ip.netns, 'exists') as ns_exists_cmd:
ns_add_cmd.side_effect = linux_utils.ProcessExecutionError(
message="Test add namespace failed", returncode=1)
ns_exists_cmd.return_value = False
self.assertRaises(linux_utils.ProcessExecutionError,
ip.ensure_namespace, 'ns')
def test_namespace_is_empty_no_devices(self):
ip = ip_lib.IPWrapper(namespace='ns')