# Gebos

IoT telemetry stack on bare-metal NixOS.

This repo is a monorepo containing all code, NixOS modules, host configurations,
and CI/CD pipelines for the project. Everything is one `flake.nix`.

## Architecture

Three hosts (see issue #21 for the full design discussion):

| Host          | Role                                      | Public hostname        | Private IP |
| ------------- | ----------------------------------------- | ---------------------- | ---------- |
| `mqtt-ingest` | HiveMQ CE + Go MQTT→Postgres ingester     | `ingest.gebos.online`     | `10.0.0.4` |
| `db-host`     | Postgres 17 + TimescaleDB (telemetry+auth)| `db.gebos.online` (SSH only) | `10.0.0.2` |
| `app-host`    | Caddy + Kong + Supabase (compose) + SPA   | `app.gebos.online`, `api.gebos.online` | `10.0.0.3` |

Public REST surface is PostgREST + SQL `/rpc/` functions, fronted by Kong, TLS-terminated by Caddy.
Supabase Studio is bound to `127.0.0.1` on `app-host` — reach it with `ssh -L 3000:127.0.0.1:3000 app-host`.

### Networking

There is no private DNS. Each host has a public hostname (used for `deploy-rs`
SSH access from the Gitea runner, which is **not** on the private network, plus
TLS ingress where applicable), and a static `10.0.0.0/8` IP used for all
host-to-host traffic:

- `db.gebos.online` is for SSH/deploy only — Postgres is never exposed publicly.
- `app-host` and `mqtt-ingest` reach Postgres at `10.0.0.2:5432` over the private
  network.
- `db-host` only accepts Postgres (port 5432) from `10.0.0.0/8` (firewall rule
  in `nix/hosts/db-host.nix`).

## Repo layout

```
flake.nix
frontend/                # Vite + React SPA
ingester/                # Go MQTT → Postgres
nix/
  modules/               # NixOS modules (one per service)
  hosts/                 # nixosConfigurations: mqtt-ingest, db-host, app-host
  supabase/              # vendored Supabase docker-compose, db init SQL
  dev/                   # process-compose for local development
  deploy.nix             # deploy-rs node map
.gitea/workflows/        # CI + CD
```

## Local development

```
nix run .#dev
```

Brings the full stack up on one machine via process-compose-flake (Postgres,
Supabase compose, Kong, Caddy, ingester, Vite dev server). NixOS required.

## Deployment

`deploy-rs` from a Gitea Actions runner on push to `main`. Closures are built
once, copied to each host, activated with auto-rollback. Order: `db-host` →
`app-host` → `mqtt-ingest`.

```
nix run github:serokell/deploy-rs -- .#db-host       # one host
nix run github:serokell/deploy-rs -- .                # all hosts
```

## Secrets

[sops-nix](https://github.com/Mic92/sops-nix) + [age](https://github.com/FiloSottile/age).
Single encrypted file at `nix/secrets/secrets.yaml`; each host decrypts only the
keys it needs at activation, rendered into a tmpfs env file consumed by systemd
`EnvironmentFile=`. Plaintext never enters the Nix store. See
[`nix/secrets/README.md`](nix/secrets/README.md) for bootstrap and rotation.

Local dev needs **no** secrets bootstrap — `nix run .#dev`, `go run ./ingester`,
and `npm --prefix frontend run dev` all default to the local dev stack values
defined in `nix/dev/process-compose.nix`.