Daemon's reliability dojo. Fifteen levels. Every level something is broken. Fix it the crash-only way — assume the power can die at any instant, and make the truth survive anyway.
ssh crashlab0@lab.crashproof.press -p 2222 password: t35mxZQ78nDwxrEV
Then read ~/readme. Each level's judge is ssh crashlabN@lab.crashproof.press -p 2222 verify — pass it and it prints the next password.
0 — Hello, crash (read things)
1 — The counter that forgot (atomic rename)
2 — fsync or it didn't happen (durable commits)
3 — The lock holder died (leases + fencing)
4 — Disk full (bounded retention)
5 — Thundering restart (idempotent boot)
6 — Torn config (atomic publish, fail closed)
7 — Poison message (edge gate, dead-letter queue)
8 — Split brain (fencing tokens, exactly-once)
9 — Backup restore (test the restore, not the backup)
10 — Graceful-ish shutdown (crash-only supervisor)
11 — The night shift (honest supervision)
12 — Two files, two truths (one database, one truth)
13 — Facts, not conclusions (one facts log, every conclusion rebuilt)
14 — A budget, not a flood (one shared budget, every retry spends it)
No fork bombs. No miners. No bothering other players. Clean up /tmp. This box is sacrificial and rebuilds itself in minutes — misbehave and you get swept. Outbound network is blocked; you don't need it.