openstack
/
neutron
Code Issues Proposed changes

Improve performance of ensure_namespace 

The ensure_namespace method calls IpNetnsCommand.exists to
determine if the specified namespace exists or not.  This is
accomplished by listing all namespaces with "ip netns list"
and then looping through the output to determine if the specified
namespace was included in the output.

Research of various Linux operating systems has indicated that
namespaces are represented as files in /var/run/netns and root
authority is "typically" not required in order to look at the
files in this subdirectory.

The existing configuration option "use_helper_for_ns_read"
will be used to determine if the root-helper should be used to
to retrieve the list of namespaces.  If this configuraton option
is set to False, the native python os.listdir(/var/run/netns)
will be used.

Related-Bug: #1311804
Closes-Bug: #1497396
Change-Id: I9da627d07d6cbb6e5ef1a921a5f22963317a04e2
This commit is contained in:
John Kasperski 2015-09-24 18:16:18 -05:00 committed by John Kasperski
parent badb221bb0
commit 81823e8632
3 changed files with 32 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
neutron/agent/linux/ip_lib.py
View File

@ -38,6 +38,7 @@ OPTS = [
LOOPBACK_DEVNAME = 'lo'
IP_NETNS_PATH = '/var/run/netns'
SYS_NET_PATH = '/sys/class/net'
DEFAULT_GW_PATTERN = re.compile(r"via (\S+)")
METRIC_PATTERN = re.compile(r"metric (\S+)")
@ -210,7 +211,10 @@ class IPWrapper(SubProcessBase):
@classmethod
def get_namespaces(cls):
output = cls._execute([], 'netns', ('list',))
if not cfg.CONF.AGENT.use_helper_for_ns_read:
return os.listdir(IP_NETNS_PATH)
output = cls._execute([], 'netns', ['list'], run_as_root=True)
return [l.split()[0] for l in output.splitlines()]
@ -833,9 +837,11 @@ class IpNetnsCommand(IpCommandBase):
extra_ok_codes=extra_ok_codes, **kwargs)
def exists(self, name):
if not cfg.CONF.AGENT.use_helper_for_ns_read:
return name in os.listdir(IP_NETNS_PATH)
output = self._parent._execute(
['o'], 'netns', ['list'],
run_as_root=cfg.CONF.AGENT.use_helper_for_ns_read)
['o'], 'netns', ['list'], run_as_root=True)
for line in [l.split()[0] for l in output.splitlines()]:
if name == line:
return True

6
neutron/tests/functional/agent/linux/test_ip_lib.py
View File

@ -86,6 +86,12 @@ class IpLibTestFramework(functional_base.BaseSudoTestCase):
class IpLibTestCase(IpLibTestFramework):
def test_namespace_exists(self):
namespace = self.useFixture(net_helpers.NamespaceFixture())
self.assertTrue(namespace.ip_wrapper.netns.exists(namespace.name))
namespace.destroy()
self.assertFalse(namespace.ip_wrapper.netns.exists(namespace.name))
def test_device_exists(self):
attr = self.generate_device_details()

45
neutron/tests/unit/agent/linux/test_ip_lib.py
View File

@ -15,6 +15,7 @@
import mock
import netaddr
from oslo_config import cfg
import testtools
from neutron.agent.common import utils # noqa
@ -276,23 +277,37 @@ class TestIpWrapper(base.BaseTestCase):
def test_get_namespaces(self):
self.execute.return_value = '\n'.join(NETNS_SAMPLE)
cfg.CONF.AGENT.use_helper_for_ns_read = True
retval = ip_lib.IPWrapper.get_namespaces()
self.assertEqual(retval,
['12345678-1234-5678-abcd-1234567890ab',
'bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb',
'cccccccc-cccc-cccc-cccc-cccccccccccc'])
self.execute.assert_called_once_with([], 'netns', ('list',))
self.execute.assert_called_once_with([], 'netns', ['list'],
run_as_root=True)
def test_get_namespaces_iproute2_4(self):
self.execute.return_value = '\n'.join(NETNS_SAMPLE_IPROUTE2_4)
cfg.CONF.AGENT.use_helper_for_ns_read = True
retval = ip_lib.IPWrapper.get_namespaces()
self.assertEqual(retval,
['12345678-1234-5678-abcd-1234567890ab',
'bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb',
'cccccccc-cccc-cccc-cccc-cccccccccccc'])
self.execute.assert_called_once_with([], 'netns', ('list',))
self.execute.assert_called_once_with([], 'netns', ['list'],
run_as_root=True)
@mock.patch('os.listdir', return_value=NETNS_SAMPLE)
def test_get_namespaces_listdir(self, mocked_listdir):
cfg.CONF.AGENT.use_helper_for_ns_read = False
retval = ip_lib.IPWrapper.get_namespaces()
self.assertEqual(retval,
['12345678-1234-5678-abcd-1234567890ab',
'bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb',
'cccccccc-cccc-cccc-cccc-cccccccccccc'])
mocked_listdir.assert_called_once_with(ip_lib.IP_NETNS_PATH)
def test_add_tuntap(self):
ip_lib.IPWrapper().add_tuntap('tap0')
@ -1173,32 +1188,6 @@ class TestIpNetnsCommand(TestIPCmdBase):
self.netns_cmd.delete('ns')
self._assert_sudo([], ('delete', 'ns'), use_root_namespace=True)
def test_namespace_exists_use_helper(self):
self.config(group='AGENT', use_helper_for_ns_read=True)
retval = '\n'.join(NETNS_SAMPLE)
# need another instance to avoid mocking
netns_cmd = ip_lib.IpNetnsCommand(ip_lib.SubProcessBase())
with mock.patch('neutron.agent.common.utils.execute') as execute:
execute.return_value = retval
self.assertTrue(
netns_cmd.exists('bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb'))
execute.assert_called_once_with(['ip', '-o', 'netns', 'list'],
run_as_root=True,
log_fail_as_error=True)
def test_namespace_doest_not_exist_no_helper(self):
self.config(group='AGENT', use_helper_for_ns_read=False)
retval = '\n'.join(NETNS_SAMPLE)
# need another instance to avoid mocking
netns_cmd = ip_lib.IpNetnsCommand(ip_lib.SubProcessBase())
with mock.patch('neutron.agent.common.utils.execute') as execute:
execute.return_value = retval
self.assertFalse(
netns_cmd.exists('bbbbbbbb-1111-2222-3333-bbbbbbbbbbbb'))
execute.assert_called_once_with(['ip', '-o', 'netns', 'list'],
run_as_root=False,
log_fail_as_error=True)
def test_execute(self):
self.parent.namespace = 'ns'
with mock.patch('neutron.agent.common.utils.execute') as execute: