Reviewed: https://review.opendev.org/c/openstack/neutron/+/865525 Committed: https://opendev.org/openstack/neutron/commit/c813b658d0e5e0c00093f90f849fcf67ddca16cf Submitter: "Zuul (22348)" Branch: master
commit c813b658d0e5e0c00093f90f849fcf67ddca16cf Author: Maximilian Stinsky <[email protected]> Date: Thu Nov 24 11:40:04 2022 +0100 Fix duplicated routes exceptions Since the train release neutron adds routes with protocol static. Keepalived also adds the same routes with different protocols depending on the keepalived version. This can result in duplicated routes inside network namespaces. On l3 agent restarts those duplicate routes then prevent the l3 agent from updating its router state because it runs into 'RTNETLINK answers: File exists expections' when it tries to execute 'ip route' commands. This patch adds the same protocol static to each virtual route of keepalived's configuration so network namespaces do not run into duplicated routes anymore. Closes-Bug: #1956846 Change-Id: Ic35b5d4b9110b832c10345c45ec62c0923237cfd ** Changed in: neutron Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1956846 Title: ha router duplicated routes Status in neutron: Fix Released Bug description: In our openstack stein installation (neutron 14.4.2) we upgraded keepalived from 1.3.9 to 2.2.4. After that when restarting the neutron-l3-agent we saw that the router state of routers with external gatways were not able to update anymore. So we ended up with only standby routers even though keepalived is working fine and we can see one keepalived in master state. After debugging a bit we found the following traceback: ``` Traceback (most recent call last): File "/usr/lib/python3/dist-packages/eventlet/hubs/hub.py", line 461, in fire_timers timer() File "/usr/lib/python3/dist-packages/eventlet/hubs/timer.py", line 59, in __call__ cb(*args, **kw) File "/usr/lib/python3/dist-packages/neutron/agent/l3/ha.py", line 166, in _enqueue_state_change ri.set_external_gw_port_link_status(link_up=True, set_gw=True) File "/usr/lib/python3/dist-packages/neutron/agent/l3/ha_router.py", line 547, in set_external_gw_port_link_status ns_name, preserve_ips) File "/usr/lib/python3/dist-packages/neutron/agent/l3/router_info.py", line 750, in _external_gateway_settings clean_connections=True) File "/usr/lib/python3/dist-packages/neutron/agent/linux/interface.py", line 179, in init_router_port preserve_ips) File "/usr/lib/python3/dist-packages/neutron/agent/linux/interface.py", line 203, in set_onlink_routes device.route.add_onlink_route(route) File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 662, in add_onlink_route self.add_route(cidr, scope='link') File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 712, in add_route self._run_as_root_detect_device_not_found([ip_version], args) File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 615, in _run_as_root_detect_device_not_found raise exceptions.DeviceNotFoundError(device_name=self.name) File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 220, in __exit__ self.force_reraise() File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise six.reraise(self.type_, self.value, self.tb) File "/usr/local/lib/python3.6/dist-packages/six.py", line 719, in reraise raise value File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 610, in _run_as_root_detect_device_not_found return self._as_root(options, tuple(args)) File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 407, in _as_root use_root_namespace=use_root_namespace) File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 121, in _as_root namespace=namespace) File "/usr/lib/python3/dist-packages/neutron/agent/linux/ip_lib.py", line 129, in _execute log_fail_as_error=self.log_fail_as_error) File "/usr/lib/python3/dist-packages/neutron/agent/linux/utils.py", line 147, in execute returncode=returncode) neutron_lib.exceptions.ProcessExecutionError: Exit code: 2; Stdin: ; Stdout: ; Stderr: RTNETLINK answers: File exists ``` This traceback is triggered because the routers got duplicated routes, here an example router: ``` ip netns exec qrouter-76f69b0d-c9ac-4a98-851a-f74b23b2de49 ip r default via x.x.244.67 dev qg-6c2ee5e0-ad proto 18 default via x.x.244.67 dev qg-6c2ee5e0-ad 10.0.0.0/24 dev qr-15d63a29-8e proto kernel scope link src 10.0.0.10 169.254.0.0/24 dev ha-f64d319f-ed proto kernel scope link src 169.254.0.13 169.254.192.0/18 dev ha-f64d319f-ed proto kernel scope link src 169.254.197.12 x.x.244.64/26 dev qg-6c2ee5e0-ad proto kernel scope link src x.x.244.116 x.x.244.128/25 dev qg-6c2ee5e0-ad proto 18 scope link x.x.244.128/25 dev qg-6c2ee5e0-ad scope link ``` First I thought that we hit a keepalived bug which I filed here: https://github.com/acassen/keepalived/issues/2076 What I got to understand from the communication with pqarmitage from the issue is that keepalived is setting `proto 18/keepalived` in newer versions and I think that this breaks with neutron. So what I assume is happening here is the following. On a "fresh" router or a failover the qg- interface of the router is down, therefore keepalived is not able to set the virtual routes. neutron then creates the gateway routes through the set_external_gw_port_link_status function (https://opendev.org/openstack/neutron/src/tag/14.4.2/neutron/agent/l3/ha_router.py#L528) after it brings up the qg- interface. When I now restart the neutron-l3-agent it reloads keepalived which triggers keepalived to recreate the virtual_routes which it was not able to create when the qg- interface was down and because of the new functionality it creates the same route but with the addition of `proto 18` and we end up with duplicated routes. After that neutron fails on the `ip route replace` command with the RTNETLINK answers: File exists error. Here is a router example of getting into this state: backup router: ``` ip netns exec qrouter-76f69b0d-c9ac-4a98-851a-f74b23b2de49 ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 1755: ha-f64d319f-ed: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether fa:16:3e:56:3f:59 brd ff:ff:ff:ff:ff:ff inet 169.254.197.12/18 brd 169.254.255.255 scope global ha-f64d319f-ed valid_lft forever preferred_lft forever inet6 fe80::f816:3eff:fe56:3f59/64 scope link valid_lft forever preferred_lft forever 1756: qr-15d63a29-8e: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether fa:16:3e:a9:cc:49 brd ff:ff:ff:ff:ff:ff 1757: qg-6c2ee5e0-ad: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether fa:16:3e:d2:6c:c7 brd ff:ff:ff:ff:ff:ff ip netns exec qrouter-76f69b0d-c9ac-4a98-851a-f74b23b2de49 ip r 169.254.192.0/18 dev ha-f64d319f-ed proto kernel scope link src 169.254.197.12 ``` After a failover to the backup node where I assume neutron is setting the gateway routes: ``` ip netns exec qrouter-76f69b0d-c9ac-4a98-851a-f74b23b2de49 ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 1755: ha-f64d319f-ed: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether fa:16:3e:56:3f:59 brd ff:ff:ff:ff:ff:ff inet 169.254.197.12/18 brd 169.254.255.255 scope global ha-f64d319f-ed valid_lft forever preferred_lft forever inet 169.254.0.13/24 scope global ha-f64d319f-ed valid_lft forever preferred_lft forever inet6 fe80::f816:3eff:fe56:3f59/64 scope link valid_lft forever preferred_lft forever 1756: qr-15d63a29-8e: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether fa:16:3e:a9:cc:49 brd ff:ff:ff:ff:ff:ff inet 10.0.0.10/24 scope global qr-15d63a29-8e valid_lft forever preferred_lft forever inet6 fe80::f816:3eff:fea9:cc49/64 scope link nodad valid_lft forever preferred_lft forever 1757: qg-6c2ee5e0-ad: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether fa:16:3e:d2:6c:c7 brd ff:ff:ff:ff:ff:ff inet x.x.244.116/26 scope global qg-6c2ee5e0-ad valid_lft forever preferred_lft forever inet6 x.x:1003::22b/64 scope global nodad valid_lft forever preferred_lft forever inet6 fe80::f816:3eff:fed2:6cc7/64 scope link nodad valid_lft forever preferred_lft forever ip netns exec qrouter-76f69b0d-c9ac-4a98-851a-f74b23b2de49 ip r default via x.x.244.67 dev qg-6c2ee5e0-ad 10.0.0.0/24 dev qr-15d63a29-8e proto kernel scope link src 10.0.0.10 169.254.0.0/24 dev ha-f64d319f-ed proto kernel scope link src 169.254.0.13 169.254.192.0/18 dev ha-f64d319f-ed proto kernel scope link src 169.254.197.12 x.x.244.64/26 dev qg-6c2ee5e0-ad proto kernel scope link src x.x.244.116 x.x.244.128/25 dev qg-6c2ee5e0-ad scope link ``` And then after a neutron-l3-agent restart which triggers a keepalived reload: ``` ip netns exec qrouter-76f69b0d-c9ac-4a98-851a-f74b23b2de49 ip r default via x.x.244.67 dev qg-6c2ee5e0-ad proto 18 default via x.x.244.67 dev qg-6c2ee5e0-ad 10.0.0.0/24 dev qr-15d63a29-8e proto kernel scope link src 10.0.0.10 169.254.0.0/24 dev ha-f64d319f-ed proto kernel scope link src 169.254.0.13 169.254.192.0/18 dev ha-f64d319f-ed proto kernel scope link src 169.254.197.12 x.x.244.64/26 dev qg-6c2ee5e0-ad proto kernel scope link src x.x.244.116 x.x.244.128/25 dev qg-6c2ee5e0-ad proto 18 scope link x.x.244.128/25 dev qg-6c2ee5e0-ad scope link ``` To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1956846/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
