# omalocal

**One script that turns a stock Arch Linux ISO into a headless, key-only-SSH Arch
*server* installer ISO** — one that, on first login, offers to bootstrap the
[OMATERM](https://omaterm.org) terminal toolkit and [Once](https://once.com)
(Basecamp's self-hosted app deployment platform). Burn it to a USB stick (Ventoy
or `dd`) and you get a reproducible, minimal Arch server that's ready for
self-hosting in minutes.

> **Not affiliated with OMATERM or Once.** `omalocal` is an *ISO builder*. It
> bundles and runs the official upstream installers; it does not vendor or fork
> them.

---

## What you get

Booting the generated ISO runs an automated installer that produces a **headless
Arch Linux server**:

- **UEFI-only**, systemd-boot, single 512 MB EFI partition + ext4 root.
- **Key-only SSH** — your public key is baked in at build time; password auth and
  root login over SSH are disabled.
- **Reachable on the LAN as `<hostname>.local`** via Avahi/mDNS (`ssh you@host.local`).
- **Docker** installed and enabled out of the box.
- **ufw** firewall: deny incoming by default, allowing `22`, `80`, `443`,
  `5353/udp` (mDNS) and `53317` (LocalSend).
- On **first interactive login**, a one-time prompt offers to install Once,
  [Omarchy-Send](https://github.com/28allday/omarchy-send) (optional), and
  OMATERM — after which you're dropped straight into your new tmux session.
- A small `once-mdns-sync` daemon that auto-publishes `<name>.local` for each
  Once app you deploy, so they're reachable across the LAN with no per-app setup.

---

## Requirements (on the build machine)

- A Linux box with: `xorriso`, `squashfs-tools`, `git`, `sha512sum`, `sudo`.
- A **stock Arch ISO** (filename starting with `archlinux-`) from
  <https://archlinux.org/download/>, placed next to the script.
- An SSH public key (used for the headless server's only login method).

## Build the ISO

```sh
# 1. Drop a stock Arch ISO into this folder:
#      archlinux-x86_64.iso
# 2. Run the builder (it needs sudo for squashfs work):
./omalocal.sh
# 3. Output:
#      omalocal-arch-YYYYMMDD.iso   (Ventoy-compatible, dd-bootable)
```

By default the builder uses `~/.ssh/id_ed25519.pub` (falling back to
`~/.ssh/id_rsa.pub`) as the server's authorized key. Override with:

```sh
SSH_PUBKEY=/path/to/key.pub ./omalocal.sh
```

## Install onto a machine

Either drop `omalocal-arch-*.iso` onto a [Ventoy](https://www.ventoy.net/) USB,
or write it to a stick directly:

```sh
sudo dd if=omalocal-arch-YYYYMMDD.iso of=/dev/sdX bs=4M status=progress conv=fsync
```

Boot the target in **UEFI** mode. The installer auto-starts on the console:
it brings up networking (wired or Wi-Fi), prompts for hostname / user / password
/ target disk (with a type-to-confirm guard before it wipes anything), installs
the base system, and reboots into your headless server.

## First login

SSH in with the key you baked in:

```sh
ssh <user>@<hostname>.local
```

You'll be asked once whether to set the server up. Saying yes installs **Once**,
optionally **Omarchy-Send**, then **OMATERM**, and leaves you in tmux.

### Deploying a Once app reachable on the LAN

Use the bundled `once-add` helper (single-label `.local` name, served over HTTP):

```sh
once-add                                    # interactive wizard
once-add book ghcr.io/basecamp/writebook    # non-interactive
# -> reachable at http://book.local from any machine on the LAN
```

---

## How it works

`omalocal.sh` is self-contained. It:

1. Extracts `airootfs.sfs` from the stock ISO and unsquashes it.
2. Injects an installer payload (auto-launched on `tty1`) plus your SSH key.
3. Patches boot cmdlines (`rootdelay=60` for slow USB enumeration) and re-squashes.
4. Repacks the ISO, preserving the stock boot config, hybrid MBR and volume UUID
   so it stays bootable and Ventoy-friendly.

The installed system's first-login helper, the LAN-deploy recipe, and a bundled
Claude Code skill / `CLAUDE.md` are all embedded in the single script.

## Notes & caveats

- **UEFI only** — the installer aborts on legacy BIOS boot.
- The installer **wipes the disk you select** (it asks you to type the path to
  confirm). Double-check the target.
- The build needs `sudo` to manipulate the squashfs image.

## License

MIT — see [`LICENSE`](LICENSE).