Update ptf-ebpf CI test to Ubuntu 22.04

[jafingerhut]

No description provided.

[jafingerhut]

I have seen that the PSATernaryTest fails when trying to run the ptf-ebpf CI test on Ubuntu 22.04. It passes fine on Ubuntu 20.04. I have done a little bit of debugging, enough to determine that the table entries added, and the packet sent in, are the same on Ubuntu 20.04 and 22.04 tests, but the packet out is different on 22.04, for reasons that I do not understand.

By 2025-Apr-01, we should choose among one of the following courses of action:
(a) disable this CI test
(b) modify the test so it passes on Ubuntu 22.04 (or 24.04)
(c) modify the test so it runs in Ubuntu 20.04 in a container or something similar.

(b) seems preferable, if we can figure out how.

[fruffy]

I have seen that the PSATernaryTest fails when trying to run the ptf-ebpf CI test on Ubuntu 22.04. It passes fine on Ubuntu 20.04. I have done a little bit of debugging, enough to determine that the table entries added, and the packet sent in, are the same on Ubuntu 20.04 and 22.04 tests, but the packet out is different on 22.04, for reasons that I do not understand.

By 2025-Apr-01, we should choose among one of the following courses of action: (a) disable this CI test (b) modify the test so it passes on Ubuntu 22.04 (or 24.04) (c) modify the test so it runs in Ubuntu 20.04 in a container or something similar.

(b) seems preferable, if we can figure out how.

Iirc there are two reasons: Different kernel version and different clang version. The combination causes the produce program to be rejected by the verifier. I can take a look at this.

[jafingerhut]

@fruffy This PR is one possible way forward -- i.e. comment out the one test that fails on Ubuntu 22.04 in the EBPF back end, named PSATernaryTest, but keep all of the other passing ones uncommented. If you approve of merging this, I will create a p4c issue to track if/when someone fixes the PSATernaryTest on Ubuntu 22.04.

[fruffy]

@fruffy This PR is one possible way forward -- i.e. comment out the one test that fails on Ubuntu 22.04 in the EBPF back end, named PSATernaryTest, but keep all of the other passing ones uncommented. If you approve of merging this, I will create a p4c issue to track if/when someone fixes the PSATernaryTest on Ubuntu 22.04.

I have some changes ready which I would like to try out before disabling this test. But might take a little longer until I can create a PR.

[jafingerhut]

@fruffy This PR is one possible way forward -- i.e. comment out the one test that fails on Ubuntu 22.04 in the EBPF back end, named PSATernaryTest, but keep all of the other passing ones uncommented. If you approve of merging this, I will create a p4c issue to track if/when someone fixes the PSATernaryTest on Ubuntu 22.04.

I have some changes ready which I would like to try out before disabling this test. But might take a little longer until I can create a PR.

Great. I will leave this PR open in case it turns out we want it by April 1, but also happy to close this one if a bug fix for the failing test case on Ubuntu 22.04 is implemented.

[fruffy]

@tatry Any idea why this test could fail? Related to the clang version?

[tatry]

@fruffy

Any idea why this test could fail? Related to the clang version?

I'm not sure, probably related to clang version. As far as I remember, some time ago I tried to install the same same kernel (at least version of kernel from repo) on both Ubuntu versions, 20.04 and 22.04 but different clang (10 vs 12). On older tests passed fine but on 22.04 some failed.

[jafingerhut]

Just a reminder: starting April 1, all Github Actions that use Ubuntu 20.04 "directly" (i.e. not inside of a container), as the ci-ptf.yml CI test on this repo currently does, will fail every single time, forevermore. This will block merging future PRs, unless we merge in a PR like this one.

[fruffy]

We can go ahead with this PR for now. I sadly lost the changes I made in #5183 so it might take me a bit longer to debug this.