2 months ago
Title: Judge0 deployment failing with cgroup and sudo errors on Railway
Description:
I'm trying to deploy Judge0 (a code execution engine) on Railway, but it's failing during startup with these errors:
sudo: unable to send audit message: Operation not permitted
Failed to create control group /sys/fs/cgroup/memory/box-14/: No such file or directory
chown: cannot access '/box': No such file or directory
What I've tried:
- Removed pre-deploy commands that use
sudo - Attempted to create
/boxdirectory in pre-deploy - Used the official
judge0/judge0:latestDocker image
The issue: Judge0 appears to require:
sudoaccess to manage system resources- Direct access to
/sys/fs/cgroupfor process isolation - Root-level directory creation at
/box
My question: Is Judge0 compatible with Railway's containerized environment?
1 Replies
2 months ago
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Status changed to Open Railway • 2 months ago
2 months ago
Short answer: not directly. Judge0 relies on low-level OS features that Railway does not expose.
Why your deployment fails
The errors you’re seeing come from missing capabilities that Judge0 expects:
1) sudo / privileged operations
- Railway containers run as non-root with restricted capabilities.
sudois blocked →unable to send audit message.
2) cgroups access (/sys/fs/cgroup/...)
- Judge0 uses cgroups for:
- memory limits
- CPU throttling
- process isolation
- Railway does not allow direct control of cgroups, and often mounts
/sys/fs/cgroupas read-only or not at all. - Hence:
Failed to create control group.
3) Root-level filesystem writes (/box)
- Judge0 expects to create and manage
/boxas a working directory. - Railway containers:
- have ephemeral filesystems
- restrict root-level writes
- Result:
cannot access '/box'.
Status changed to Solved Railway • 2 months ago