Death by OOM

Read a container post-mortem: exit codes, OOMKilled, and the fix.

A advanced Docker challenge worth 20 points. Solve it hands-on in a real Docker environment in your browser - no local setup, no fake shells.

The Challenge

Scenario: 3 AM page: the nightly batch-job died again. It's not running, and the handover note says "it keeps dying, look at it".

Tasks:

• Diagnose WHY it died: docker inspect batch-job — look at .State.ExitCode (137 = 128+SIGKILL) and .State.OOMKilled
• Write the cause — the word oom — to /root/cause.txt
• The devs fixed the leak; redeploy: recreate batch-job (image alpine, command sleep infinity) with --memory 256m

Commands to learn: exit-code forensics, .State.OOMKilled, --memory

Run check when done.