Judge0 deployment failing with cgroup and sudo errors on Railway
durga-chikkala
PROOP

10 days 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 /box directory in pre-deploy

  • Used the official judge0/judge0:latest Docker image

The issue: Judge0 appears to require:

  • sudo access to manage system resources

  • Direct access to /sys/fs/cgroup for process isolation

  • Root-level directory creation at /box

My question: Is Judge0 compatible with Railway's containerized environment?

Solved$20 Bounty

1 Replies

Railway
BOT

10 days ago

This thread has been marked as public for community involvement, as it does not contain any sensitive or personal information. Any further activity in this thread will be visible to everyone.

Status changed to Open Railway 10 days ago


i-smuglov
FREETop 5% Contributor

9 days 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.

  • sudo is 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/cgroup as read-only or not at all.

  • Hence: Failed to create control group.

3) Root-level filesystem writes (/box)

  • Judge0 expects to create and manage /box as a working directory.

  • Railway containers:

    • have ephemeral filesystems

    • restrict root-level writes

  • Result: cannot access '/box'.


Status changed to Solved Railway 9 days ago


Welcome!

Sign in to your Railway account to join the conversation.

Loading...