openstack/neutron
Code Issues Proposed changes

Make OVN driver validate Geneve max_header_size

Browse Source 
Also updates the docs to be clearer on OVN-Geneve relation topics.

Co-Authored-By: Elvira García Ruiz <egarciar@redhat.com>
Change-Id: Ia253cc4d85261ce1535f4d27b3da91275d879903
Closes-bug: #1868137
This commit is contained in:
Radosław Piliszek 2020-03-24 17:55:23 +01:00 committed by Elvira García Ruiz
parent 7e5e6d4929
commit dc4a57d966
10 changed files with 65 additions and 15 deletions
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9
doc/source/install/ovn/manual_install.rst
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@ -192,7 +192,14 @@ primary node. See the :doc:`/ovn/faq/index` for more information.
network segments. However, OVN ignores the actual values. Thus, the ID
range only determines the quantity of Geneve networks in the
environment. For example, a range of ``5001:6000`` defines a maximum
of 1000 Geneve networks.
of 1000 Geneve networks. On the other hand, these values are still
relevant in Neutron context so ``1:1000`` and ``5001:6000`` are *not*
simply interchangeable.
.. warning::
The default for ``max_header_size``, ``30``, is too low for OVN.
OVN requires at least ``38``.
* Optionally, enable support for VLAN provider and self-service
networks on one or more physical networks. If you specify only

17
neutron/conf/plugins/ml2/drivers/driver_type.py
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@ -41,15 +41,18 @@ geneve_opts = [
default=[],
help=_("Comma-separated list of <vni_min>:<vni_max> tuples "
"enumerating ranges of Geneve VNI IDs that are "
"available for tenant network allocation")),
"available for tenant network allocation. "
"Note OVN does not use the actual values.")),
cfg.IntOpt('max_header_size',
default=p_const.GENEVE_ENCAP_MIN_OVERHEAD,
help=_("Geneve encapsulation header size is dynamic, this "
"value is used to calculate the maximum MTU "
"for the driver. "
"The default size for this field is 30, which is the "
"size of the Geneve header without any additional "
"option headers.")),
help=_("The maximum allowed Geneve encapsulation header size "
"(in bytes). "
"Geneve header is extensible, this value is used to "
"calculate the maximum MTU for Geneve-based networks. "
"The default is 30, which is the size of the Geneve "
"header without any additional option headers. "
"Note the default is not enough for OVN which "
"requires at least 38.")),
]
vxlan_opts = [

8
neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py
View File

@ -65,6 +65,7 @@ import neutron.wsgi
LOG = log.getLogger(__name__)
OVN_MIN_GENEVE_MAX_HEADER_SIZE = 38
class OVNPortUpdateError(n_exc.BadRequest):
@ -117,6 +118,13 @@ class OVNMechanismDriver(api.MechanismDriver):
self._post_fork_event = threading.Event()
if cfg.CONF.SECURITYGROUP.firewall_driver:
LOG.warning('Firewall driver configuration is ignored')
if (cfg.CONF.ml2_type_geneve.max_header_size <
OVN_MIN_GENEVE_MAX_HEADER_SIZE):
LOG.critical('Geneve max_header_size set too low for OVN '
'(%d vs %d)',
cfg.CONF.ml2_type_geneve.max_header_size,
OVN_MIN_GENEVE_MAX_HEADER_SIZE)
raise SystemExit(1)
self._setup_vif_port_bindings()
if impl_idl_ovn.OvsdbSbOvnIdl.schema_has_table('Chassis_Private'):
self.agent_chassis_table = 'Chassis_Private'

3
neutron/tests/functional/base.py
View File

@ -177,6 +177,9 @@ class TestOVNFunctionalBase(test_plugin.Ml2PluginV2TestCase,
ml2_config.cfg.CONF.set_override('vni_ranges',
['1:65536'],
group='ml2_type_geneve')
# ensure viable minimum is set for OVN's Geneve
ml2_config.cfg.CONF.set_override('max_header_size', 38,
group='ml2_type_geneve')
ovn_conf.cfg.CONF.set_override('dns_servers',
['10.10.10.10'],
group='ovn')

6
neutron/tests/functional/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_ovn_db_resources.py
View File

@ -760,13 +760,14 @@ class TestNBDbResources(base.TestOVNFunctionalBase):
# is not configured as domain_name.
# Parameter taken from configuration
# should be set instead.
mtu = str(1480 - cfg.CONF.ml2_type_geneve.max_header_size)
expected_dhcp_options_rows = {
'cidr': '10.0.0.0/24',
'external_ids': {'subnet_id': subnet['id']},
'options': {'dns_server': '{10.10.10.10}',
'domain_name': '"%s"' % cfg.CONF.dns_domain,
'lease_time': '43200',
'mtu': '1450',
'mtu': mtu,
'router': '10.0.0.1',
'server_id': '10.0.0.1',
'server_mac': dhcp_mac}}
@ -781,13 +782,14 @@ class TestNBDbResources(base.TestOVNFunctionalBase):
p = self._make_port(self.fmt, n1['network']['id'],
fixed_ips=[{'subnet_id': subnet['id']}])
dhcp_mac = self._get_subnet_dhcp_mac(subnet)
mtu = str(1480 - cfg.CONF.ml2_type_geneve.max_header_size)
# Make sure that domain_name is not included.
expected_dhcp_options_rows = {
'cidr': '10.0.0.0/24',
'external_ids': {'subnet_id': subnet['id']},
'options': {'dns_server': '{10.10.10.10}',
'lease_time': '43200',
'mtu': '1450',
'mtu': mtu,
'router': '10.0.0.1',
'server_id': '10.0.0.1',
'server_mac': dhcp_mac}}

2
neutron/tests/functional/services/ovn_l3/test_plugin.py
View File

@ -448,7 +448,7 @@ class TestRouter(base.TestOVNFunctionalBase):
'address_mode': ovn_utils.get_ovn_ipv6_address_mode(
address_mode),
'send_periodic': 'true',
'mtu': '1450'}
'mtu': '1442'}
else:
expected_ra_configs = {}
self._validate_router_ipv6_ra_configs(lrp_name, expected_ra_configs)

21
neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py
View File

@ -92,6 +92,9 @@ class TestOVNMechanismDriverBase(MechDriverSetupBase,
cfg.CONF.set_override('vni_ranges',
['1:65536'],
group='ml2_type_geneve')
# ensure viable minimum is set for OVN's Geneve
cfg.CONF.set_override('max_header_size', 38,
group='ml2_type_geneve')
ovn_conf.cfg.CONF.set_override('ovn_metadata_enabled', False,
group='ovn')
ovn_conf.cfg.CONF.set_override('dns_servers', ['8.8.8.8'],
@ -2010,6 +2013,9 @@ class OVNMechanismDriverTestCase(MechDriverSetupBase,
cfg.CONF.set_override('vni_ranges',
['1:65536'],
group='ml2_type_geneve')
# ensure viable minimum is set for OVN's Geneve
cfg.CONF.set_override('max_header_size', 38,
group='ml2_type_geneve')
ovn_conf.cfg.CONF.set_override('dns_servers', ['8.8.8.8'], group='ovn')
mock.patch.object(impl_idl_ovn.Backend, 'schema_helper').start()
super(OVNMechanismDriverTestCase, self).setUp()
@ -2155,6 +2161,8 @@ class TestOVNMechanismDriverSegment(MechDriverSetupBase,
_mechanism_drivers = ['logger', 'ovn']
def setUp(self):
cfg.CONF.set_override('max_header_size', 38,
group='ml2_type_geneve')
mock.patch.object(impl_idl_ovn.Backend, 'schema_helper').start()
super(TestOVNMechanismDriverSegment, self).setUp()
p = mock.patch.object(ovn_utils, 'get_revision_number', return_value=1)
@ -2175,11 +2183,12 @@ class TestOVNMechanismDriverSegment(MechDriverSetupBase,
network_id=network['id'], physical_network='phys_net1',
segmentation_id=200, network_type='vlan')['segment']
# As geneve networks mtu shouldn't be more than 1450, update it
data = {'network': {'mtu': 1450}}
# As geneve networks mtu shouldn't be more than 1442 considering the
# Geneve max_header_size for OVN must be at least 38), update it
data = {'network': {'mtu': 1442}}
req = self.new_update_request('networks', data, network['id'])
res = self.deserialize(self.fmt, req.get_response(self.api))
self.assertEqual(1450, res['network']['mtu'])
self.assertEqual(1442, res['network']['mtu'])
self._test_create_segment(
network_id=network['id'],
@ -2949,6 +2958,9 @@ class TestOVNMechanismDriverSecurityGroup(MechDriverSetupBase,
cfg.CONF.set_override('mechanism_drivers',
['logger', 'ovn'],
'ml2')
# ensure viable minimum is set for OVN's Geneve
cfg.CONF.set_override('max_header_size', 38,
group='ml2_type_geneve')
cfg.CONF.set_override('dns_servers', ['8.8.8.8'], group='ovn')
mock.patch.object(impl_idl_ovn.Backend, 'schema_helper').start()
super(TestOVNMechanismDriverSecurityGroup, self).setUp()
@ -3258,10 +3270,13 @@ class TestOVNMechanismDriverMetadataPort(MechDriverSetupBase,
def setUp(self):
mock.patch.object(impl_idl_ovn.Backend, 'schema_helper').start()
cfg.CONF.set_override('max_header_size', 38,
group='ml2_type_geneve')
super(TestOVNMechanismDriverMetadataPort, self).setUp()
self.nb_ovn = self.mech_driver.nb_ovn
self.sb_ovn = self.mech_driver.sb_ovn
self.ctx = context.get_admin_context()
# ensure viable minimum is set for OVN's Geneve
ovn_conf.cfg.CONF.set_override('ovn_metadata_enabled', True,
group='ovn')
p = mock.patch.object(ovn_utils, 'get_revision_number', return_value=1)

3
neutron/tests/unit/plugins/ml2/test_ext_portsecurity.py
View File

@ -35,10 +35,13 @@ class PSExtDriverTestCase(test_plugin.Ml2PluginV2TestCase,
def test_create_net_port_security_default(self):
_core_plugin = directory.get_plugin()
admin_ctx = context.get_admin_context()
# Maximum MTU depends on the GENEVE max header size, which is variable.
mtu = 1530 - cfg.CONF.ml2_type_geneve.max_header_size
args = {'network':
{'name': 'test',
'tenant_id': '',
'shared': False,
'mtu': mtu,
'admin_state_up': True,
'status': 'ACTIVE'}}
network = None

5
neutron/tests/unit/services/ovn_l3/test_plugin.py
View File

@ -58,9 +58,12 @@ class TestOVNL3RouterPlugin(test_mech_driver.Ml2PluginV2TestCase):
def setUp(self):
mock.patch('neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb.'
'impl_idl_ovn.Backend.schema_helper').start()
cfg.CONF.set_override('max_header_size', 38, group='ml2_type_geneve')
super(TestOVNL3RouterPlugin, self).setUp()
revision_plugin.RevisionPlugin()
network_attrs = {external_net.EXTERNAL: True, 'mtu': 1500}
# MTU needs to be 1442 instead of 1500 because GENEVE headers size
# must be at least 38 when using OVN
network_attrs = {external_net.EXTERNAL: True, 'mtu': 1442}
self.fake_network = \
fake_resources.FakeNetwork.create_one_network(
attrs=network_attrs).info()

6
releasenotes/notes/bug-1868137-5bf3354d016c988b.yaml Normal file
View File

@ -0,0 +1,6 @@
---
fixes:
- |
Ensures that OVN's mechanism driver does not start when
``[ml2_type_geneve]/max_header_size`` is set below the required 38.
`LP#1868137 <https://launchpad.net/bugs/1868137>`__