openstack/neutron
Code Issues Proposed changes

Add global_physnet_mtu and deprecate segment_mtu

Browse Source 
Introduce the neutron-wide 'global_physnet_mtu' option that
references the underlying physical network MTU. This also
introduces a method in plugin.common.utils that all plugins
should use to retrieve it. This value should be used to
calculate the proper MTU for virtual network components.

This patch also deprecate the 'segment_mtu' option specific
to the ML2 plug-in and makes ML2 reference this new option.

Closes-Bug: #1542475
Closes-Bug: #1542108
Change-Id: I6ffc8973c9b8f46cc19922ff04fdd2d23646b878
This commit is contained in:
Kevin Benton 2016-02-23 13:11:40 -08:00
parent 205e86a7f2
commit ae45cd5732
10 changed files with 52 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
neutron/common/config.py
View File

@ -175,7 +175,16 @@ core_opts = [
choices=('legacy', 'pecan'),
help=_("This will choose the web framework in which to run "
"the Neutron API server. 'pecan' is a new experiemental "
"rewrite of the API server."))
"rewrite of the API server.")),
cfg.IntOpt('global_physnet_mtu', default=1500,
deprecated_name='segment_mtu', deprecated_group='ml2',
help=_('MTU of the underlying physical network. Neutron uses '
'this value to calculate MTU for all virtual network '
'components. For flat and VLAN networks, neutron uses '
'this value without modification. For overlay networks '
'such as VXLAN, neutron automatically subtracts the '
'overlay protocol overhead from this value. Defaults '
'to 1500, the standard value for Ethernet.'))
]
core_cli_opts = [

12
neutron/plugins/common/utils.py
View File

@ -18,6 +18,7 @@ Common utilities and helper functions for OpenStack Networking Plugins.
import hashlib
from oslo_config import cfg
from oslo_log import log as logging
import six
import webob.exc
@ -32,6 +33,17 @@ INTERFACE_HASH_LEN = 6
LOG = logging.getLogger(__name__)
def get_deployment_physnet_mtu():
"""Retrieves global physical network MTU setting.
Plugins should use this function to retrieve the MTU set by the operator
that is equal to or less than the MTU of their nodes' physical interfaces.
Note that it is the responsibility of the plugin to deduct the value of
any encapsulation overhead required before advertising it to VMs.
"""
return cfg.CONF.global_physnet_mtu
def is_valid_vlan_tag(vlan):
return p_const.MIN_VLAN_TAG <= vlan <= p_const.MAX_VLAN_TAG

5
neutron/plugins/ml2/config.py
View File

@ -52,11 +52,6 @@ ml2_opts = [
'this feature and instances typically default to a '
'1500 MTU. Only impacts instances, not neutron network '
'components such as bridges and routers.')),
cfg.IntOpt('segment_mtu', default=1500,
help=_('The maximum permissible size of an unfragmented '
'packet travelling a L2 network segment. The default '
'value of 1500 is used as the segment MTU, to reflect '
'standard Ethernet.')),
cfg.ListOpt('physical_network_mtus',
default=[],
help=_("A list of mappings of physical networks to MTU "

3
neutron/plugins/ml2/drivers/helpers.py
View File

@ -21,6 +21,7 @@ from oslo_log import log
from neutron.common import exceptions as exc
from neutron.common import utils
from neutron.plugins.common import utils as p_utils
from neutron.plugins.ml2 import driver_api as api
@ -41,7 +42,7 @@ class BaseTypeDriver(api.TypeDriver):
self.physnet_mtus = []
def get_mtu(self, physical_network=None):
return cfg.CONF.ml2.segment_mtu
return p_utils.get_deployment_physnet_mtu()
class SegmentTypeDriver(BaseTypeDriver):

8
neutron/tests/unit/plugins/ml2/drivers/test_type_flat.py
View File

@ -122,22 +122,22 @@ class FlatTypeTest(testlib_api.SqlTestCase):
self.assertIsNone(observed)
def test_get_mtu(self):
config.cfg.CONF.set_override('segment_mtu', 1475, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1475)
config.cfg.CONF.set_override('path_mtu', 1400, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1450, self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 1375, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1375)
config.cfg.CONF.set_override('path_mtu', 1400, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1375, self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 1425, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1400, self.driver.get_mtu('physnet2'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 0, group='ml2')
self.driver.physnet_mtus = {}
self.assertEqual(0, self.driver.get_mtu('physnet1'))

8
neutron/tests/unit/plugins/ml2/drivers/test_type_gre.py
View File

@ -56,25 +56,25 @@ class GreTypeTest(base_type_tunnel.TunnelTypeTestMixin,
self.assertEqual(base_type_tunnel.HOST_TWO, endpoint['host'])
def test_get_mtu(self):
config.cfg.CONF.set_override('segment_mtu', 1500, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1500)
config.cfg.CONF.set_override('path_mtu', 1475, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1475 - p_const.GRE_ENCAP_OVERHEAD,
self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 1425, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1425)
config.cfg.CONF.set_override('path_mtu', 1475, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1400, 'physnet2': 1400}
self.assertEqual(1425 - p_const.GRE_ENCAP_OVERHEAD,
self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 1475, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1425}
self.assertEqual(1475 - p_const.GRE_ENCAP_OVERHEAD,
self.driver.get_mtu('physnet2'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 0, group='ml2')
self.driver.physnet_mtus = {}
self.assertEqual(0, self.driver.get_mtu('physnet1'))

8
neutron/tests/unit/plugins/ml2/drivers/test_type_vlan.py
View File

@ -205,22 +205,22 @@ class VlanTypeTest(testlib_api.SqlTestCase):
segment)
def test_get_mtu(self):
config.cfg.CONF.set_override('segment_mtu', 1475, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1475)
config.cfg.CONF.set_override('path_mtu', 1400, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1450, self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 1375, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1375)
config.cfg.CONF.set_override('path_mtu', 1400, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1375, self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 1400, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1450, self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 0, group='ml2')
self.driver.physnet_mtus = {}
self.assertEqual(0, self.driver.get_mtu('physnet1'))

8
neutron/tests/unit/plugins/ml2/drivers/test_type_vxlan.py
View File

@ -66,25 +66,25 @@ class VxlanTypeTest(base_type_tunnel.TunnelTypeTestMixin,
self.assertEqual(base_type_tunnel.HOST_TWO, endpoint['host'])
def test_get_mtu(self):
config.cfg.CONF.set_override('segment_mtu', 1500, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1500)
config.cfg.CONF.set_override('path_mtu', 1475, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1450, 'physnet2': 1400}
self.assertEqual(1475 - p_const.VXLAN_ENCAP_OVERHEAD,
self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 1450, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1450)
config.cfg.CONF.set_override('path_mtu', 1475, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1400, 'physnet2': 1425}
self.assertEqual(1450 - p_const.VXLAN_ENCAP_OVERHEAD,
self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 1450, group='ml2')
self.driver.physnet_mtus = {'physnet1': 1425, 'physnet2': 1400}
self.assertEqual(1450 - p_const.VXLAN_ENCAP_OVERHEAD,
self.driver.get_mtu('physnet1'))
config.cfg.CONF.set_override('segment_mtu', 0, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 0)
config.cfg.CONF.set_override('path_mtu', 0, group='ml2')
self.driver.physnet_mtus = {}
self.assertEqual(0, self.driver.get_mtu('physnet1'))

2
neutron/tests/unit/plugins/ml2/test_plugin.py
View File

@ -378,7 +378,7 @@ class TestExternalNetwork(Ml2PluginV2TestCase):
class TestMl2NetworksWithVlanTransparencyAndMTU(TestMl2NetworksV2):
def setUp(self, plugin=None):
config.cfg.CONF.set_override('path_mtu', 1000, group='ml2')
config.cfg.CONF.set_override('segment_mtu', 1000, group='ml2')
config.cfg.CONF.set_override('global_physnet_mtu', 1000)
config.cfg.CONF.set_override('advertise_mtu', True)
config.cfg.CONF.set_override('vlan_transparent', True)
super(TestMl2NetworksWithVlanTransparencyAndMTU, self).setUp(plugin)

11
releasenotes/notes/segment_mtu_to_global_physnet_mtu-9cee5ff09557edeb.yaml Normal file
View File

@ -0,0 +1,11 @@
---
deprecations:
- The 'segment_mtu' option of the ML2 configuration has been
deprecated and replaced with the 'global_physnet_mtu' option
in the main Neutron configuration. This option is meant to
be used by all plugins for an operator to reference their
physical network's MTU, regardless of the backend plugin.
Plugins should access this config option via the
'get_deployment_physnet_mtu' method added to
neutron.plugins.common.utils to avoid being broken on any
potential renames in the future.