The Sofia Raspberry Pi hung this morning (network wedged ~10:13, HA
sensors dead, and its local journal had been silent since Apr 27 — a
2017 SD card intermittently flipping the rootfs read-only). Nothing was
captured because logging lived only on the failing card. Ship telemetry
off-box so the next failure is diagnosable centrally:
- Prometheus scrape job `rpi-sofia` (rpi-sofia.viktorbarzin.lan:9100) —
node_exporter + a vcgencmd textfile collector on the Pi exporting
under-voltage/throttle/SoC-temp as rpi_* metrics.
- Alert group "RPi Sofia": node_exporter Down, rootfs ReadOnly (the
exact SD-failure signature), Under-voltage since boot, High SoC temp.
- LAN-gated Loki write ingress (loki.viktorbarzin.lan) so the Pi's
promtail can push its journal — Loki was ClusterIP-only.
- Grafana dashboard "RPi Sofia" (Hardware): status, undervoltage/
throttle, temp, load, memory, disk, network.
The Pi separately got a systemd hardware watchdog (auto-reboot on a hard
hang; today it stayed down ~5h until a manual power-cycle).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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