# NUC Fleet Netboot (Unifi)

This runbook provisions x86_64 NUCs from runner netboot artifacts without USB image flashing.

Supported modes:

- ProxyDHCP mode: recommended when you want automatic stage-1/2 iPXE handling.
- UniFi-only mode: DHCP options 66/67 in UniFi, no ProxyDHCP.

## Prerequisites

- Linux boot server on the same VLAN/L2 domain as the NUCs.
- Unifi network with DHCP enabled.
- Local DNS record on that VLAN: `boot.every.channel -> <boot-server-ip>`.
- `curl`, `tar`, `python3`, `dnsmasq` installed on the boot server.
- For UniFi-only mode with reliable chainloading: `git` and `make` to build embedded iPXE.
- `openssl` (or equivalent) if you want generated chain tokens.
- Runner netboot artifact published to Forgejo Releases (or available as local tarball).

## Persistent NixOS service (recommended)

Instead of running scripts manually, use the exported NixOS module and keep netboot
staging/serving declarative:

```nix
{
  imports = [ every-channel.nixosModules.ec-netboot ];

  services.every-channel.netboot = {
    enable = true;
    listenIP = "10.20.30.2";
    interface = "enp195s0";
    hostname = "boot.every.channel";
    tftpBootFilename = "ec-ipxe.efi";
    httpAllowedCIDRs = [ "10.20.30.0/24" ];
    chainTokenFile = "/run/agenix/every-channel-netboot-chain-token";

    # UniFi-only mode by default (no ProxyDHCP):
    proxyDhcp.enable = false;

    release.host = "https://git.every.channel";
    release.repo = "every-channel/every.channel";
    # release.tag = "boot-v2026.03.02"; # optional pin
    # release.tokenFile = "/run/agenix/forgejo-api-token"; # optional private repo token
  };
}
```

Operational commands:

```sh
sudo systemctl start every-channel-netboot-stage.service
sudo systemctl restart every-channel-netboot.service
sudo systemctl status every-channel-netboot.service
```

If you prefer ProxyDHCP mode:

```nix
services.every-channel.netboot.proxyDhcp.enable = true;
services.every-channel.netboot.proxyDhcp.subnet = "10.20.30.0/24";
```

## 1) Build embedded iPXE (UniFi-only mode)

This removes iPXE boot loops without requiring ProxyDHCP.

```sh
EVERY_CHANNEL_NETBOOT_HOSTNAME=boot.every.channel \
EVERY_CHANNEL_NETBOOT_HTTP_PORT=8080 \
EVERY_CHANNEL_NETBOOT_CHAIN_TOKEN="$(openssl rand -hex 16)" \
./scripts/netboot-build-ipxe.sh
```

Output:

- `tmp/netboot/tftp/ec-ipxe.efi` (use this as DHCP option 67 filename)

## 2) Stage runner netboot artifacts

```sh
EVERY_CHANNEL_NETBOOT_HOSTNAME=boot.every.channel \
EVERY_CHANNEL_NETBOOT_CHAIN_TOKEN="<same-token-as-step-1>" \
EVERY_CHANNEL_NETBOOT_IPXE_EFI_PATH=tmp/netboot/tftp/ec-ipxe.efi \
EVERY_CHANNEL_NETBOOT_IPXE_EFI_FILENAME=ec-ipxe.efi \
./scripts/netboot-stage.sh
```

Optional inputs:

- `EVERY_CHANNEL_NETBOOT_RELEASE_TAG=boot-v2026.02.28`
- `EVERY_CHANNEL_NETBOOT_TARBALL=/path/to/ec-runner-x86_64-netboot-....tar.gz`
- `EVERY_CHANNEL_FORGE_TOKEN=<token>` for private releases
- `EVERY_CHANNEL_NETBOOT_ALLOW_REMOTE_IPXE=true` only if you intentionally want to download iPXE from URL
- `EVERY_CHANNEL_IPXE_EFI_SHA256=<sha256>` to pin iPXE binary integrity

This stages:

- `tmp/netboot/http/{kernel,initrd,netboot.ipxe}`
- `tmp/netboot/tftp/ec-ipxe.efi`

## 3) Serve HTTP + TFTP

UniFi-only mode (no ProxyDHCP):

```sh
sudo \
  EVERY_CHANNEL_NETBOOT_LISTEN_IP=10.20.30.2 \
  EVERY_CHANNEL_NETBOOT_INTERFACE=eth0 \
  EVERY_CHANNEL_NETBOOT_HOSTNAME=boot.every.channel \
  EVERY_CHANNEL_NETBOOT_CHAIN_TOKEN="<same-token-as-step-1>" \
  EVERY_CHANNEL_NETBOOT_HTTP_ALLOWED_CIDRS=10.20.30.0/24 \
  EVERY_CHANNEL_NETBOOT_PROXY_DHCP=false \
  EVERY_CHANNEL_NETBOOT_TFTP_BOOT_FILENAME=ec-ipxe.efi \
  ./scripts/netboot-serve.sh
```

ProxyDHCP mode:

```sh
sudo \
  EVERY_CHANNEL_NETBOOT_LISTEN_IP=10.20.30.2 \
  EVERY_CHANNEL_NETBOOT_INTERFACE=eth0 \
  EVERY_CHANNEL_NETBOOT_PROXY_SUBNET=10.20.30.0/24 \
  EVERY_CHANNEL_NETBOOT_HOSTNAME=boot.every.channel \
  EVERY_CHANNEL_NETBOOT_CHAIN_TOKEN="<same-token-as-step-1>" \
  EVERY_CHANNEL_NETBOOT_HTTP_ALLOWED_CIDRS=10.20.30.0/24 \
  EVERY_CHANNEL_NETBOOT_PROXY_DHCP=true \
  EVERY_CHANNEL_NETBOOT_TFTP_BOOT_FILENAME=ec-ipxe.efi \
  ./scripts/netboot-serve.sh
```

## 4) UniFi settings (you do this)

UniFi-only mode:

- `Network Boot`: enabled
- `Server`: `boot.every.channel` (or boot server IP)
- `Filename`: `ec-ipxe.efi`
- `TFTP Server`: `boot.every.channel`

ProxyDHCP mode:

- leave UniFi boot/TFTP options unset.

NUC BIOS:

- Enable UEFI PXE boot.
- Disable Legacy/CSM where possible.
- Put network boot first for initial install.

## Security hardening

- Keep provisioning on an isolated VLAN.
- Allow only required ports from NUC VLAN to boot server: UDP 69, TCP 8080 (and DHCP if ProxyDHCP mode).
- Keep provisioning services up only during rollout, then stop them.
- Use `EVERY_CHANNEL_NETBOOT_HTTP_ALLOWED_CIDRS` to limit HTTP artifact access to NUC subnet(s).
- Use `EVERY_CHANNEL_NETBOOT_CHAIN_TOKEN` so only tokened iPXE chain requests receive `netboot.ipxe`.
- Use checksum verification in `netboot-stage.sh` (enabled by default when release has `SHA256SUMS.txt`).
- `netboot-stage.sh` now defaults to local iPXE binaries; remote URL download requires explicit opt-in.
- Prefer embedded `ec-ipxe.efi` with fixed chain target over generic unsigned internet binaries.
- If Secure Boot is required, use signed boot chain and keys for your environment (outside this basic runbook).
