Apply network MTU changes to l3 ports

This patch makes L3 agent to update its ports' MTU when it's changed on
core plugin side.

Related-Bug: #1671634
Change-Id: I4444da6358e8b8420a3a365e1107b02f5bb1161d

doc/source/admin/config-mtu.rst

@@ -34,9 +34,6 @@ architectures should avoid cases 2 and 3.
    networks that need a new MTU. (Network MTU update is available for all core
    plugins that implement the ``net-mtu-writable`` API extension.)
 
-   When using the Open vSwitch or Linux bridge drivers, new MTU calculations
-   will be propogated automatically after restarting the ``l3-agent`` service.
-
 Case 1
 ------
 

neutron/agent/l3/agent.py

@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+import itertools
+
 import eventlet
 import netaddr
 from neutron_lib.callbacks import events
@@ -29,6 +31,7 @@ from oslo_service import loopingcall
 from oslo_service import periodic_task
 from oslo_utils import excutils
 from oslo_utils import timeutils
+from osprofiler import profiler
 
 from neutron._i18n import _, _LE, _LI, _LW
 from neutron.agent.common import utils as common_utils
@@ -167,6 +170,7 @@ class L3PluginApi(object):
                           host=self.host, network_id=fip_net)
 
 
+@profiler.trace_cls("l3-agent")
 class L3NATAgent(ha.AgentMixin,
                  dvr.AgentMixin,
                  manager.Manager):
@@ -185,8 +189,9 @@ class L3NATAgent(ha.AgentMixin,
         1.3 - fipnamespace_delete_on_ext_net - to delete fipnamespace
               after the external network is removed
               Needed by the L3 service when dealing with DVR
+        1.4 - support network_update to get MTU updates
     """
-    target = oslo_messaging.Target(version='1.3')
+    target = oslo_messaging.Target(version='1.4')
 
     def __init__(self, host, conf=None):
         if conf:
@@ -256,6 +261,10 @@ class L3NATAgent(ha.AgentMixin,
                                       self.create_pd_router_update,
                                       self.conf)
 
+        # Consume network updates to trigger router resync
+        consumers = [[topics.NETWORK, topics.UPDATE]]
+        agent_rpc.create_consumers([self], topics.AGENT, consumers)
+
     def _check_config_params(self):
         """Check items in configuration files.
 
@@ -429,6 +438,16 @@ class L3NATAgent(ha.AgentMixin,
         LOG.debug('Got router added to agent :%r', payload)
         self.routers_updated(context, payload)
 
+    def network_update(self, context, **kwargs):
+        network_id = kwargs['network']['id']
+        for ri in self.router_info.values():
+            ports = itertools.chain(ri.internal_ports, [ri.ex_gw_port])
+            port_belongs = lambda p: p['network_id'] == network_id
+            if any(port_belongs(p) for p in ports):
+                update = queue.RouterUpdate(
+                    ri.router_id, queue.PRIORITY_SYNC_ROUTERS_TASK)
+                self._resync_router(update)
+
     def _process_router_if_compatible(self, router):
         if (self.conf.external_network_bridge and
             not ip_lib.device_exists(self.conf.external_network_bridge)):

neutron/agent/l3/ha_router.py

@@ -297,7 +297,9 @@ class HaRouter(router.RouterInfo):
         if device.addr.list(to=ip_cidr):
             super(HaRouter, self).remove_floating_ip(device, ip_cidr)
 
-    def internal_network_updated(self, interface_name, ip_cidrs):
+    def internal_network_updated(self, interface_name, ip_cidrs, mtu):
+        self.driver.set_mtu(interface_name, mtu, namespace=self.ns_name,
+                            prefix=router.INTERNAL_DEV_PREFIX)
         self._clear_vips(interface_name)
         self._disable_ipv6_addressing_on_interface(interface_name)
         for ip_cidr in ip_cidrs:

neutron/agent/l3/router_info.py

@@ -476,10 +476,13 @@ class RouterInfo(object):
         for existing_port in existing_ports:
             current_port = current_ports_dict.get(existing_port['id'])
             if current_port:
-                if (sorted(existing_port['fixed_ips'],
+                fixed_ips_changed = (
+                    sorted(existing_port['fixed_ips'],
                            key=helpers.safe_sort_key) !=
-                        sorted(current_port['fixed_ips'],
+                    sorted(current_port['fixed_ips'],
-                               key=helpers.safe_sort_key)):
+                           key=helpers.safe_sort_key))
+                mtu_changed = existing_port['mtu'] != current_port['mtu']
+                if fixed_ips_changed or mtu_changed:
                     updated_ports[current_port['id']] = current_port
         return updated_ports
 
@@ -502,7 +505,9 @@ class RouterInfo(object):
                   self.router_id)
         self.radvd.disable()
 
-    def internal_network_updated(self, interface_name, ip_cidrs):
+    def internal_network_updated(self, interface_name, ip_cidrs, mtu):
+        self.driver.set_mtu(interface_name, mtu, namespace=self.ns_name,
+                            prefix=INTERNAL_DEV_PREFIX)
         self.driver.init_router_port(
             interface_name,
             ip_cidrs=ip_cidrs,
@@ -562,7 +567,8 @@ class RouterInfo(object):
                 ip_cidrs = common_utils.fixed_ip_cidrs(p['fixed_ips'])
                 LOG.debug("updating internal network for port %s", p)
                 updated_cidrs += ip_cidrs
-                self.internal_network_updated(interface_name, ip_cidrs)
+                self.internal_network_updated(
+                    interface_name, ip_cidrs, p['mtu'])
                 enable_ra = enable_ra or self._port_has_ipv6_subnet(p)
 
         # Check if there is any pd prefix update

neutron/plugins/ml2/plugin.py

@@ -858,6 +858,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
     def update_network(self, context, id, network):
         net_data = network[net_def.RESOURCE_NAME]
         provider._raise_if_updates_provider_attributes(net_data)
+        need_network_update_notify = False
 
         with db_api.context_manager.writer.using(context):
             original_network = super(Ml2Plugin, self).get_network(context, id)
@@ -883,6 +884,8 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                 db_network.mtu is None):
                 db_network.mtu = self._get_network_mtu(db_network,
                                                        validate=False)
+                # agents should now update all ports to reflect new MTU
+                need_network_update_notify = True
 
             updated_network = self._make_network_dict(
                 db_network, context=context)
@@ -896,7 +899,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                 resources.NETWORK, events.PRECOMMIT_UPDATE, self, **kwargs)
 
             # TODO(QoS): Move out to the extension framework somehow.
-            need_network_update_notify = (
+            need_network_update_notify |= (
                 qos_consts.QOS_POLICY_ID in net_data and
                 original_network[qos_consts.QOS_POLICY_ID] !=
                 updated_network[qos_consts.QOS_POLICY_ID])

neutron/tests/common/l3_test_common.py

@@ -41,6 +41,7 @@ def get_ha_interface(ip='169.254.192.1', mac='12:34:56:78:2b:5d'):
             'id': _uuid(),
             'mac_address': mac,
             'name': u'L3 HA Admin port 0',
+            'mtu': 1500,
             'network_id': _uuid(),
             'status': u'ACTIVE',
             'subnets': [{'cidr': '169.254.192.0/18',
@@ -92,6 +93,7 @@ def prepare_router_data(ip_version=4, enable_snat=None, num_internal_ports=1,
     if enable_gw:
         ex_gw_port = {'id': _uuid(),
                       'mac_address': gateway_mac,
+                      'mtu': 1500,
                       'network_id': _uuid(),
                       'fixed_ips': fixed_ips,
                       'subnets': subnets,
@@ -182,6 +184,7 @@ def router_append_interface(router, count=1, ip_version=4, ra_mode=None,
 
         interfaces.append(
             {'id': _uuid(),
+             'mtu': 1500,
              'network_id': _uuid(),
              'admin_state_up': True,
              'fixed_ips': fixed_ips,
@@ -274,6 +277,7 @@ def router_append_pd_enabled_subnet(router, count=1):
     for i in range(current, current + count):
         subnet_id = _uuid()
         intf = {'id': _uuid(),
+                'mtu': 1500,
                 'network_id': _uuid(),
                 'admin_state_up': True,
                 'fixed_ips': [{'ip_address': '::1',
@@ -331,6 +335,7 @@ def prepare_ext_gw_test(context, ri, dual_stack=False):
                   'subnets': subnets,
                   'extra_subnets': [{'cidr': '172.16.0.0/24'}],
                   'id': _uuid(),
+                  'mtu': 1500,
                   'network_id': _uuid(),
                   'mac_address': 'ca:fe:de:ad:be:ef'}
     interface_name = ri.get_external_device_name(ex_gw_port['id'])

neutron/tests/fullstack/resources/client.py

@@ -50,6 +50,13 @@ class ClientFixture(fixtures.Fixture):
         self.addCleanup(_safe_method(delete), data['id'])
         return data
 
+    def _update_resource(self, resource_type, id, spec):
+        update = getattr(self.client, 'update_%s' % resource_type)
+
+        body = {resource_type: spec}
+        resp = update(id, body=body)
+        return resp[resource_type]
+
     def create_router(self, tenant_id, name=None, ha=False,
                       external_network=None):
         resource_type = 'router'
@@ -79,6 +86,9 @@ class ClientFixture(fixtures.Fixture):
 
         return self._create_resource(resource_type, spec)
 
+    def update_network(self, id, **kwargs):
+        return self._update_resource('network', id, kwargs)
+
     def create_subnet(self, tenant_id, network_id,
                       cidr, gateway_ip=None, name=None, enable_dhcp=True,
                       ipv6_address_mode='slaac', ipv6_ra_mode='slaac'):

neutron/tests/fullstack/test_l3_agent.py

@@ -110,6 +110,34 @@ class TestLegacyL3Agent(TestL3Agent):
             self.environment.hosts[0].l3_agent.get_namespace_suffix(), )
         self._assert_namespace_exists(namespace)
 
+    def test_mtu_update(self):
+        tenant_id = uuidutils.generate_uuid()
+
+        router = self.safe_client.create_router(tenant_id)
+        network = self.safe_client.create_network(tenant_id)
+        subnet = self.safe_client.create_subnet(
+            tenant_id, network['id'], '20.0.0.0/24', gateway_ip='20.0.0.1')
+        self.safe_client.add_router_interface(router['id'], subnet['id'])
+
+        namespace = "%s@%s" % (
+            self._get_namespace(router['id']),
+            self.environment.hosts[0].l3_agent.get_namespace_suffix(), )
+        self._assert_namespace_exists(namespace)
+
+        ip = ip_lib.IPWrapper(namespace)
+        common_utils.wait_until_true(lambda: ip.get_devices())
+
+        devices = ip.get_devices()
+        self.assertEqual(1, len(devices))
+
+        ri_dev = devices[0]
+        mtu = ri_dev.link.mtu
+        self.assertEqual(1500, mtu)
+
+        mtu -= 1
+        network = self.safe_client.update_network(network['id'], mtu=mtu)
+        common_utils.wait_until_true(lambda: ri_dev.link.mtu == mtu)
+
     def test_east_west_traffic(self):
         tenant_id = uuidutils.generate_uuid()
         router = self.safe_client.create_router(tenant_id)

neutron/tests/unit/agent/l3/test_agent.py

@@ -149,6 +149,7 @@ class BasicRouterOperationsFramework(base.BaseTestCase):
         self.snat_ports = [{'subnets': [{'cidr': '152.2.0.0/16',
                                          'gateway_ip': '152.2.0.1',
                                          'id': subnet_id_1}],
+                            'mtu': 1500,
                             'network_id': _uuid(),
                             'device_owner':
                             lib_constants.DEVICE_OWNER_ROUTER_SNAT,
@@ -160,6 +161,7 @@ class BasicRouterOperationsFramework(base.BaseTestCase):
                            {'subnets': [{'cidr': '152.10.0.0/16',
                                          'gateway_ip': '152.10.0.1',
                                          'id': subnet_id_2}],
+                            'mtu': 1450,
                             'network_id': _uuid(),
                             'device_owner':
                             lib_constants.DEVICE_OWNER_ROUTER_SNAT,
@@ -425,6 +427,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
         port = {'network_id': _uuid(),
                 'id': _uuid(),
                 'mac_address': 'ca:fe:de:ad:be:ef',
+                'mtu': 1500,
                 'fixed_ips': [{'subnet_id': _uuid(),
                                'ip_address': '99.0.1.9',
                                'prefixlen': 24}]}
@@ -459,6 +462,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
         port = {'network_id': _uuid(),
                 'id': _uuid(),
                 'mac_address': 'ca:fe:de:ad:be:ef',
+                'mtu': 1500,
                 'fixed_ips': [{'subnet_id': subnet_id,
                                'ip_address': '99.0.1.9',
                                'prefixlen': 24}],
@@ -473,6 +477,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                    'extra_subnets': [{'cidr': '172.16.0.0/24'}],
                    'id': _uuid(),
                    'network_id': _uuid(),
+                   'mtu': 1500,
                    'mac_address': 'ca:fe:de:ad:be:ef'}
         ex_gw_port = {'fixed_ips': [{'ip_address': '20.0.0.30',
                                      'prefixlen': 24,
@@ -482,6 +487,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                       'id': _uuid(),
                       portbindings.HOST_ID: HOSTNAME,
                       'network_id': _uuid(),
+                      'mtu': 1500,
                       'mac_address': 'ca:fe:de:ad:be:ef'}
         ri.snat_ports = sn_port
         ri.ex_gw_port = ex_gw_port
@@ -513,7 +519,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                 sn_port['mac_address'],
                 ri._get_snat_int_device_name(sn_port['id']),
                 lib_constants.SNAT_INT_DEV_PREFIX,
-                mtu=None)
+                mtu=1500)
             self.assertTrue(ri._check_if_address_scopes_match.called)
             if scope_match:
                 self.assertTrue(
@@ -667,10 +673,12 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                       'extra_subnets': [{'cidr': '172.16.0.0/24'}],
                       'id': _uuid(),
                       'network_id': ex_net_id,
+                      'mtu': 1500,
                       'mac_address': 'ca:fe:de:ad:be:ef'}
         ex_gw_port_no_sub = {'fixed_ips': [],
                              'id': _uuid(),
                              'network_id': ex_net_id,
+                             'mtu': 1500,
                              'mac_address': 'ca:fe:de:ad:be:ef'}
         interface_name = ri.get_external_device_name(ex_gw_port['id'])
 
@@ -1159,6 +1167,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                    'gateway_ip': '20.0.0.1'}],
               'id': _uuid(),
               'network_id': fake_network_id,
+              'mtu': 1500,
               'mac_address': 'ca:fe:de:ad:be:ef'}]
         )
 
@@ -1290,6 +1299,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                   'gateway_ip': '20.0.0.1'}],
              'id': _uuid(),
              'network_id': fake_network_id,
+             'mtu': 1500,
              'mac_address': 'ca:fe:de:ad:be:ef'}
         )
 
@@ -1336,6 +1346,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                    'gateway_ip': '20.0.0.1'}],
               'id': _uuid(),
               'network_id': fake_network_id,
+              'mtu': 1500,
               'mac_address': 'ca:fe:de:ad:be:ef'}]
         )
 
@@ -1388,6 +1399,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                    'gateway_ip': '20.0.0.1'}],
               'id': _uuid(),
               'network_id': 'fake_network_id',
+              'mtu': 1500,
               'mac_address': 'ca:fe:de:ad:be:ef'}]
         )
 
@@ -2588,6 +2600,7 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
                                     'gateway_ip': '20.0.0.1'}],
                        'id': port_id,
                        'network_id': _uuid(),
+                       'mtu': 1500,
                        'mac_address': 'ca:fe:de:ad:be:ef'}
 
         interface_name = ri._get_snat_int_device_name(port_id)