# planck — 20-node Raspberry Pi 4 home lab

20× Raspberry Pi 4 (8GB, ARM64), each booting a 240GB NVMe-in-USB stick.
Fresh Raspberry Pi OS Lite (Debian 13) everywhere, running a k3s Kubernetes
cluster: servers planck002/003/004 (embedded etcd), workers 001 + 005–020.

**Home page: https://carr.pub** (served by this cluster).

## The map

| Path | What it is |
|------|-----------|
| `docs/PLAN.md` | Full history: what was built, every bug and its fix, postmortems. READ FIRST |
| `docs/IPS.md` | Node ↔ IP ↔ MAC table (static IPs, pinned on nodes) |
| `docs/INVENTORY.md` | Hardware inventory per node |
| `scripts/flash-one.sh` | Reimage a node's NVMe stick (run on laptop via pkexec) |
| `scripts/k3s-join.sh` | Join servers/agents to the cluster (needs K3S_TOKEN) |
| `scripts/loadtest.sh` | Spawn a k6 load swarm across N nodes |
| `scripts/inventory.sh` | Regenerate hardware inventory |
| `manifests/monitoring/` | Prometheus, node-exporter, Grafana, DDNS CronJob |
| `manifests/loadtest/` | k6 rig + practice target |
| `manifests/web/` | The carr.pub site + Ingress |
| `manifests/cluster-issuer.yaml` | Let's Encrypt issuer |
| `configs/` | Node password (gitignored), installer internals, retired netboot servers |

## Daily operations

- kubectl on the laptop: `~/.local/bin/kubectl` (kubeconfig `~/.kube/config`)
- SSH any node: `ssh adamcarr@planck0NN.local` (passwordless sudo)
- Grafana: `kubectl -n monitoring port-forward svc/grafana 3000:3000`
- Load test: `scripts/loadtest.sh <url> [pods] [vus-per-pod] [duration]`
- New public site: Ingress in `web` namespace on `<name>.carr.pub` with the
  `cert-manager.io/cluster-issuer: letsencrypt-prod` annotation + DNSimple
  record

Agent documentation lives in `~/.agents/skills/planck-cluster/SKILL.md`
(loaded automatically by opencode sessions).

## Safety rules

- Never reboot more than ONE of planck002/003/004 at once (etcd quorum)
- Images must be linux/arm64 multi-arch
- The cluster room switch shares a PSU with nodes 011–015