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 + 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 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.