xgboost 2.0.1 is breaking on rootless docker.

[prafullat]

On rootless docker, path cgroup is readable only by root user.

As such, if any non-root users even tries to import xgboost, it fails with permission error.
Permission denied [/sys/fs/cgroup/cpu.max]

Can you please check and avoid this error is this path is not accessible?
We are not able to use xgboost in the rootless docker container.

[hcho3]

@prafullat Can you post the full stack trace for the permission error?

[trivialfis]

Will try to reproduce once I get back to work. At the moment my guess is this line to be blamed

xgboost/src/common/threading_utils.cc

Line 78 in 5e64276

auto has_v2 = fs::exists(bandwidth_path);

[trivialfis]

I have tried to launch an image with and without gosu, running in rootless mode of docker, but couldn't reproduce the issue. @hcho3 might have better insight here.

$ docker info | grep "Root"
WARNING: No cpuset support
WARNING: No io.weight support
WARNING: No io.weight (per device) support
WARNING: No io.max (rbps) support
WARNING: No io.max (wbps) support
 Docker Root Dir: /home/ubuntu/.local/share/docker
WARNING: No io.max (riops) support
WARNING: No io.max (wiops) support

[trivialfis]

Feel free to reopen if there is further information. Will try to fix it if there's a reproducer.

[zhangzzk]

I am having the exact issue with a non-root user importing the package:

>>> import xgboost terminate called after throwing an instance of 'std::filesystem::__cxx11::filesystem_error' what(): filesystem error: status: Permission denied [/sys/fs/cgroup/cpu.max] Aborted (core dumped)

[trivialfis]

Could you please share how you installed docker (or any other environment)?

[zhangzzk]

Thank you for the quick reply.
Sorry I am a very beginner at this. I am a non-root user on a shared computing cluster and I am not the one setting up the environment. Could you perhaps give more specific instructions on the information I can provide?

[trivialfis]

Could you perhaps give more specific instructions on the information I can provide?

Unfortunately, I want these instructions as well. ;-( Maybe you can share the result of docker info so that I can compare it with mine? @hcho3 might be able to provide more insights into the system setup.

[zhangzzk]

I think I am not running on a docker so docker info is not a valid command.

[trivialfis]

I will open a PR to catch all potential exceptions in that function.