openstack
/
neutron
Code Issues Proposed changes

Ensure no GARPs are sent for Load Balancer VIPs on tenant networks 

When a loadbalancer is created in tenant network (VIP and members),
and that tenant network is connected to a router, which is connected
to the provider network, the ovn loadbalancer gets
associated to the ovn logical router. If the "router" option is used for
"nat-addresses" (as currently done), ovn-controller will send GARPs for
that VIP.

As there is nothing blocking different tenants in openstack to create a
subnet with the same CIDR and then a loadbalancer with the same VIP,
there may be several ovn-controllers generating GARPs on the provider
network for the same IP, each one with the MAC of the logical router
port belonging to each tenant.
This could be a problem for the physical network infrastructure.

This patch fixes it by setting a new option added in OVN[1], named
"exclude-lb-vips-from-garp", on the router gateway port, ensuring
no GARPs are sent for the load balancer VIPs.

[1] 183edfc446.1645793899.git.lorenzo.bianconi@redhat.com/

Closes-Bug: #1964901

Change-Id: Ifc2e5b2cc64c0b3beafd0a2e6eb9b9f248970cc5
(cherry picked from commit 9d4e6edd5b)
This commit is contained in:
Luis Tomas Bolivar 2022-03-08 13:04:58 +01:00
parent c6d3f90bee
commit 391af6c158
3 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
neutron/common/ovn/constants.py
View File

@ -50,10 +50,12 @@ OVN_PORT_BINDING_PROFILE_PARAMS = [{'parent_name': str,
{'vtep-physical-switch': str,
'vtep-logical-switch': str}]
MIGRATING_ATTR = 'migrating_to'
OVN_ROUTER_PORT_OPTION_KEYS = ['router-port', 'nat-addresses']
OVN_ROUTER_PORT_OPTION_KEYS = ['router-port', 'nat-addresses',
'exclude-lb-vips-from-garp']
OVN_GATEWAY_CHASSIS_KEY = 'redirect-chassis'
OVN_CHASSIS_REDIRECT = 'chassisredirect'
OVN_GATEWAY_NAT_ADDRESSES_KEY = 'nat-addresses'
OVN_ROUTER_PORT_EXCLUDE_LB_VIPS_GARP = 'exclude-lb-vips-from-garp'
OVN_DROP_PORT_GROUP_NAME = 'neutron_pg_drop'
OVN_ROUTER_PORT_GW_MTU_OPTION = 'gateway_mtu'

1
neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/commands.py
View File

@ -406,6 +406,7 @@ class SetLRouterPortInLSwitchPortCommand(command.BaseCommand):
options = {'router-port': self.lrouter_port}
if self.is_gw_port:
options[ovn_const.OVN_GATEWAY_NAT_ADDRESSES_KEY] = 'router'
options[ovn_const.OVN_ROUTER_PORT_EXCLUDE_LB_VIPS_GARP] = 'true'
setattr(port, 'options', options)
setattr(port, 'type', 'router')
setattr(port, 'addresses', self.lsp_address)

4
neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/ovsdb/test_commands.py
View File

@ -677,7 +677,9 @@ class TestSetLRouterPortInLSwitchPortCommand(TestBaseCommand):
self.ovn_api, fake_lsp.name, lrp_name, True, True, 'router')
cmd.run_idl(self.transaction)
self.assertEqual({'router-port': lrp_name,
'nat-addresses': 'router'}, fake_lsp.options)
'nat-addresses': 'router',
'exclude-lb-vips-from-garp': 'true'},
fake_lsp.options)
self.assertEqual('router', fake_lsp.type)
self.assertEqual('router', fake_lsp.addresses)