Files
CashuMints.space/deploy/alert.env.example
T
michilisandClaude Opus 5 0ebc8ada54 Make a crash loop reach somebody instead of scrolling past.
`Restart=on-failure` with no start limit is an infinite loop by definition: the
unit never reaches `failed`, `systemctl status` stays active (auto-restart), and
the only evidence is a journal moving at four lines a second. That is how 464
restarts over fifteen hours went unnoticed.

All three units now stop after five failures in 120s and run
OnFailure=cashumints-alert@%n.service. The window is 120s and not 60s because
RestartSec=5s plus a process that takes a few seconds to die can spread five
failures past a sixty second window, reset the counter, and loop forever anyway.

cashumints-alert@.service is a oneshot that takes the failed unit's name as its
instance. Configuration is /etc/cashumints/alert.env: NTFY_URL gets a plain-text
body, WEBHOOK_URL gets JSON carrying `content` so one payload fits Discord and
Slack-compatible endpoints. With neither set — or the file absent — it still
writes to the journal at ERROR via a `<3>` syslog prefix, so `journalctl -p err -t
cashumints-alert` is a complete history on a host nobody configured.

It cannot become a second thing to debug: each curl is bounded at 10s, each
failure falls back to a journal line, and the shell ends in `true`, so the alerter
always exits 0. Verified with systemd-analyze verify and by running the ExecStart
body against a local sink — the JSON parses, and every branch exits 0.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-25 16:10:01 +02:00

24 lines
1.1 KiB
Bash

# /etc/cashumints/alert.env
#
# Read by cashumints-alert@.service, which systemd starts when any of the three units
# fails. Everything here is optional: with the file absent or both values empty, an
# alert is still written to the journal at ERROR priority and is readable with
#
# journalctl -p err -t cashumints-alert
#
# Set one or both to have failures leave the machine.
#
# Install it root-owned and not world-readable — a webhook URL is a capability:
# sudo install -d -m 0755 /etc/cashumints
# sudo install -m 0640 -o root -g root deploy/alert.env.example /etc/cashumints/alert.env
# sudo systemctl daemon-reload
# An ntfy topic URL. Free and public at ntfy.sh; pick a topic name nobody will guess,
# because anyone who knows it can read and post to it.
#NTFY_URL=https://ntfy.sh/cashumints-alerts-CHANGE-ME
# Anything that accepts a JSON POST. The body carries `unit`, `host`, `at`, `text` and
# `content` — the last of which is what Discord and most Slack-compatible endpoints read,
# so one payload fits all three.
#WEBHOOK_URL=https://discord.com/api/webhooks/…