Use Docker images to build Linux versions to provide compatibility for older glibc versions

[andygruber]

This should prevent unplanned increasing of the supported glibc version. Ubuntu 22.04 is used here which uses glibc 2.35. That also gives support for Debian Bookworm.

This addresses partly #1176 . To fully address this a change to Ubuntu 20.04 images would be required, but this also needs to manually install cmake instead of using it from the distro repo.

Full build is available here:
https://github.com/andygruber/uWebSockets.js/actions/runs/29865474294

[uNetworkingAB]

ubuntu-22.04 is already supported natively by GitHub, you can just downgrade without any changes. The problem is that Node.js 26 raises compiler requirements very liberally, so a simple bump to 24.04 solved that. Any ancient Debian based distro will always have this problem of being, well ancient. It's a problem as old as time itself.

[andygruber]

I totally agree with you on that.

Still, some projects, run on older base OS. And e.g. Bookworm is not that ancient, it is just 3 years old and will be supported for another 2. RHEL9 is supported for another 5 years with its regular support plan.

The Docker variant provides a stable interface and makes sure to be flexible enough concerning tooling. I saw the issue you mentioned and installed llvm16, which is the first sufficient compiler version.

RHEL9 support would also be possible by switiching to Ubuntu 20.04. Then I would need to install a custom cmake too, but that is also no problem, if you like that.

I really hope this could be integrated into upstream. But of course that is your decision.