CompressLog: Add zstd compression

[SuperSandro2000]

Basically #1219 rebased on master

• hydra: 2024-08-20 -> 2024-08-21; nixos/hydra: use configured compression in hydra-compress-logs service nixpkgs#333212

[Mindavi]

See my comments @ nixpkgs.

[Mindavi]

Looks good to me, but haven't tested. Would really love it if a small test is added, but maybe that's a big ask. Would definitely improve my confidence, at least of the case where CompressLog is called. The fallback is probably a bit more annoying to test.

[SuperSandro2000]

Would really love it if a small test is added, but maybe that's a big ask.

I have tested this on my hydra and from what I can tell, it seems to work minus the bit that the original logs where not removed. I don't have time to write a test especially with the current test infrastructure.

[SuperSandro2000]

I did some more testing and the logs where not displayed in the web ui. That is now also fixed. I think I have now tested this change end to end and hopefully found all the misses along the way.

[Mindavi]

Diff now looks good to me, unfortunately I cannot test it this week. Maybe next week.

Out of curiosity, what happens if you fill in something else than bz2 or zstd? It'll just fail somewhere in the compression routines?

[SuperSandro2000]

Out of curiosity, what happens if you fill in something else than bz2 or zstd? It'll just fail somewhere in the compression routines?

I hope so. 😅 I didn't test this explicitly.