# Noisebell

[![Space status](https://your-cache-domain.example.com/badge.svg)](https://your-cache-domain.example.com/status)

Monitors the door at [Noisebridge](https://www.noisebridge.net) and tells you whether it's open or closed.

A Raspberry Pi reads a magnetic sensor on the door and pushes state changes to a cache server. The cache keeps the latest state and fans updates out to chat integrations such as Discord and Zulip.

```
Pi (door sensor) ──webhook──> Cache ──webhook──> Discord / Zulip
                                |
                     polls Pi <-+
                                |
                                +──webhook──> Pi relay ──webhook──> Home Assistant
```

## Layout

| Directory | What it is |
|-----------|------------|
| [`pi/`](pi/) | Raspberry Pi OS base with laptop-built Noisebell deploy |
| [`remote/`](remote/) | Server-side services (cache, RSS, Discord, Zulip) |
| [`hosts/noisebell-do/`](hosts/noisebell-do/) | Standalone DigitalOcean NixOS host for the remote services |
| [`secrets/`](secrets/) | Shared agenix-encrypted secrets and recipient rules |

Each directory has its own README with setup and configuration details.

For hosted deployment, this repo exports `nixosConfigurations.noisebell-do`, a small DigitalOcean NixOS host that imports `noisebell.nixosModules.default`. The host provides deployment-specific values like domains and the Pi address, while the Noisebell module itself points `agenix` at the encrypted files in `secrets/` and consumes the decrypted runtime files on the target machine.

Useful commands:

- `./scripts/deploy-do [jet@noisebell-do]` redeploys the DigitalOcean remote host
- `./scripts/nhs` redeploys the old Hetzner host using the local checkout as the flake input
- `scripts/deploy-pios-pi.sh pi@100.66.45.36` redeploys the Raspberry Pi OS machine

The full Home Assistant relay workflow is documented in `pi/README.md`.

## Observability

The DigitalOcean host runs Prometheus, Loki, Grafana, Alloy, node_exporter, and blackbox_exporter via `hosts/noisebell-do/observability.nix`. Grafana provisions the `Noisebell DO + Pi` dashboard from code, with Prometheus panels for both hosts, detailed DO-to-Pi poll health, and Loki journal panels for both hosts.

- Grafana: `http://noisebell-do:3030/` over Tailscale
- Prometheus: `http://noisebell-do:9090/` over Tailscale
- Loki: `http://noisebell-do:3100/` over Tailscale

The Pi deploy script enables persistent journald, installs `prometheus-node-exporter`, and installs `noisebell-loki-journal.service` to ship Pi journal logs to Loki on the DO host.

Prometheus is the source of truth for regular time-based data: scrape health, host CPU/memory/disk/uptime, DO-to-Pi poll counts and last results, GPIO state, Pi hardware readings, webhook counters, and retry counters. Loki/journald is reserved for sparse event logs that should be readable in chronological order: service start/stop, door state changes, cache state changes, Pi offline/online transitions, auth or rate-limit rejections, webhook retries/failures, stale events, and GPIO read errors. Routine successful polls, unchanged poll results, metrics scrapes, and badge/image/status reads are intentionally not logged at `INFO`.