bgpd: Ignore routes from evpn if VRF is unknown

[piotrsuchy]

Fix for a bug, where FRR fails to install route received for an unknown but later-created VRF - detailed description can be found here:

#13708

This is our internal bug fix we introduced that fixed this issue for us shortly after submitting the issue report.

[donaldsharp]

@ton31337 -> opinions here on needing a new test case in topotests?

[ton31337]

I'm curious how it pass this test is_route_matching_for_vrf() in bgp_evpn_route_entry_install_if_vrf_match(). Something weird to me.

@piotrsuchy are you able to reproduce this deterministically?

[riw777]

it seems like this would be a good time to add a topo test here

[riw777]

code looks good, waiting on @ton31337 's question about reproducing this

[piotrsuchy]

I'm curious how it pass this test is_route_matching_for_vrf() in bgp_evpn_route_entry_install_if_vrf_match(). Something weird to me.

@piotrsuchy are you able to reproduce this deterministically?

Hello, sorry for the late response. Unfortunately I don't have a minimal deterministic reproduction - back when this issue appeared, we had a test suite on a pretty complex containerlab-like environment with our propriety software and configuration that was able to reproduce this issue, that came down to the reproduction steps mentioned in the linked issue above. The patch in this PR has made it so the issue wasn't reproducible and currently we have this patch running on production. Sadly I don't have a way to mimic this environment easily to reproduce this bug only. In the future when I have more cycles I might get back to this and try to have a minimal reproduction.

[ton31337]

Ok, I see I was most likely hooked on bgp_evpn_route_entry_install_if_vrf_match(), but there is install_uninstall_route_in_vrfs() also, that does not have VRF check. Could you at least add a logging to be able to check once we hit it?

[piotrsuchy]

Sure! I added the additional log if this condition is hit.
One of the tests in the CI failed, but it's not connected to this change and I can see it is the most common one failing recently, so probably a CI issue. Could you rerun? Thanks!

[riw777]

looks good, just waiting on other comments/etc.

[ton31337]

@Mergifyio backport dev/10.1

[mergify]

backport dev/10.1

✅ Backports have been created

• #16306 bgpd: Ignore routes from evpn if VRF is unknown (backport #16068) has been created for branch dev/10.1