nixfiles/README.md

# nixfiles

NixOS / nix-darwin / home-manager configuration for all hosts, built from a
single flake.

## Hosts

Defined in the host table in [`flake.nix`](./flake.nix):

| Configuration         | System           | Machine                                                                                                     |
| --------------------- | ---------------- | ----------------------------------------------------------------------------------------------------------- |
| `lyrathorpe-mbp`      | `aarch64-linux`  | MacBook Pro (Apple Silicon, Asahi)                                                                          |
| `lyrathorpe-t400`     | `x86_64-linux`   | ThinkPad T400 — [install notes](./hosts/T400/README.md)                                                     |
| `lyrathorpe-macpro31` | `x86_64-linux`   | Mac Pro 3,1, desktop — [install notes](./hosts/MacPro31/README.md)                                          |
| `emmathorpe-edaas`    | `x86_64-linux`   | Work WSL box (NixOS-WSL) — [notes](./hosts/EDaaS/README.md)                                                 |
| `lyrathorpe-rpi5`     | `aarch64-linux`  | Raspberry Pi 5 headless server: Docker host + nginx reverse proxy — [install notes](./hosts/RPi5/README.md) |
| `lyrathorpe-mac`      | `aarch64-darwin` | macOS (nix-darwin) — [notes](./hosts/Darwin/README.md)                                                      |

Shared layers: `home` (home-manager: shell, git, editor),
`modules/common-nixos.nix` (all NixOS hosts: fonts, nix-ld, caches),
`modules/workstation.nix` (physical graphical hosts: audio, thermald,
earlyoom, fwupd), `modules/laptop.nix` (laptops: Wi-Fi, Bluetooth, power,
lid), `modules/desktop.nix` (wired desktops: NetworkManager), and
`modules/ssh.nix` (key-only sshd). The x86 hosts also pull `nixos-hardware`
profiles. The full module catalogue is below.

## Repository layout

```
flake.nix              # inputs, mkHost/mkDarwinHost, the host tables, dev shell + checks
flake.lock             # pinned input revisions (Renovate keeps this fresh)
modules/               # reusable NixOS system modules (see "Module catalogue")
home/                  # home-manager profile: shell, git, editor, claude, desktop, sway
users/                 # identity registry + per-user home extras (see "Users")
hosts/<Name>/          # per-machine config: configuration.nix + hardware-configuration.nix
lib/                   # small pure helpers (currently the Catppuccin Mocha palette)
.gitea/workflows/      # CI (nix flake check + per-host eval)
statix.toml            # lint config (house-style lints disabled)
.editorconfig          # base whitespace style
tf-inspect/            # UNRELATED scratch project (gitignored, its own git repo);
                       #   RouterOS / home-services Terraform, not part of this flake
```

Each `nixosConfiguration` / `darwinConfiguration` is assembled in `flake.nix`
from three layers: the shared `baseModules` (or `darwinBaseModules`), the
per-form-factor and `nixos-hardware` modules listed in the host table, and the
per-machine `hosts/<Name>/configuration.nix`. Home-manager is wired in as a
system module; each user's home is composed from the `homeModules` list in that
host's table entry.

## Module catalogue

Reusable NixOS modules under [`modules/`](./modules). "Imported by" says how a
module reaches a host: **baseModules** (every NixOS host, via `flake.nix`),
**host table** (listed explicitly per host in `flake.nix`), or **transitively**
(pulled in by another module's `imports`).

| Module             | Imported by                       | What it does / when to use it                                                                                                                                                                             |
| ------------------ | --------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `common-nixos.nix` | baseModules (all NixOS)           | Timezone/locale, store hygiene (auto-optimise, big download buffer, **no** auto-GC), the nix-community binary cache, `nix-ld`, base CLI (`git`, `fastfetch`), and the fleet-wide font stack.              |
| `users.nix`        | baseModules (all NixOS)           | Builds `users.users` from the registry for the host's `hostUsers`; enables zsh; enables Firefox + Thunderbird **only** when `features.swayDesktop.enable` is on. Applies per-user `linger`.               |
| `features.nix`     | baseModules (all NixOS)           | Declares feature-flag options (currently `features.swayDesktop.enable`) so any host can read/set them without importing the heavy implementation module.                                                  |
| `workstation.nix`  | transitively (via laptop/desktop) | Form-factor-agnostic base for physical graphical hosts: turns on `swayDesktop`, Dvorak console, PipeWire, firewall (default-deny), fstrim, earlyoom, fwupd, thermald (x86), redistributable fw.           |
| `laptop.nix`       | host table (MBP, T400)            | `imports` workstation.nix, then adds the portable bits: iwd Wi-Fi, lid suspend/lock, Bluetooth + blueman.                                                                                                 |
| `desktop.nix`      | host table (Mac Pro)              | `imports` workstation.nix, then swaps Wi-Fi for wired NetworkManager. Pair with `portable = false` in the host table.                                                                                     |
| `sway.nix`         | host table (graphical hosts)      | Implementation of `features.swayDesktop`: the system Sway package, the greetd/ReGreet (cage) greeter forced to Dvorak, xdg-portal, Wayland utility packages. Home-side Sway config is in `home/sway.nix`. |
| `ssh.nix`          | host table (T400, Mac Pro, RPi5)  | Enables sshd, opens port 22, enforces a key-only policy (no password / keyboard-interactive, no root). Authorized keys come from the registry via `users.nix`.                                            |
| `firmware/`        | referenced by MBP host config     | Committed Apple peripheral firmware blobs for the Asahi MBP (see "MacBook (Asahi) firmware").                                                                                                             |

Form-factor decision: a **laptop** imports `laptop.nix` (default
`portable = true`); a **wired desktop** imports `desktop.nix` and sets
`portable = false`; a **headless server** imports neither (leaves
`features.swayDesktop.enable` at its default `false`) and adds only what it
serves. `portable` is threaded through to `home/sway.nix`, which drops the
battery block and brightness keys on desktops.

## Users

Identity is data, kept separate from the reusable modules:

- [`users/registry.nix`](./users/registry.nix) — one entry per user (display
  name, email, supplementary groups, authorized + signing keys). This is the
  single source of identity; no user data is hardcoded in the modules.
- Each host's table entry declares a `users` set keyed by username; every entry
  lists that user's home-module composition (the shared `./home` bundle plus any
  per-user modules, e.g. [`users/emmathorpe/work.nix`](./users/emmathorpe/work.nix))
  and optional per-host-user system bits such as `linger`.
- `mkHost` builds each account from the registry and injects the matching
  identity into that user's home config as the `identity` module arg. A host can
  therefore declare any number of users.

Per-user home extras live under `users/<name>/`:

- [`users/lyrathorpe/home.nix`](./users/lyrathorpe/home.nix) — personal extras
  (an ssh host shortcut, gammastep coordinates); imported on Lyra's hosts.
- [`users/emmathorpe/work.nix`](./users/emmathorpe/work.nix) — the work
  toolchain (kubectl/helm/az/etc.), work-only LSP servers, and the corporate ssh
  handling; imports
  [`users/emmathorpe/renovate-review.nix`](./users/emmathorpe/renovate-review.nix),
  the daily headless Renovate-PR review timer (EDaaS only).

### Portable home (off-NixOS / external consumers)

The home config is also exposed for use beyond these hosts:

- `homeConfigurations."<user>@<system>"` — a standalone home-manager profile
  (the portable subset: shell + git + editor + claude) that can be activated on a
  machine this flake does **not** manage:
  `home-manager switch --flake .#"lyrathorpe@x86_64-linux"`. The desktop/sway
  modules are intentionally excluded (they rely on a NixOS-provided Sway/Firefox
  binary).
- `homeModules` — the reusable modules exported so another flake can import them
  (`inputs.<this>.homeModules.default`). Consumers must supply the module args
  these expect: `inputs` always, `identity` for git/desktop, `portable` for sway.

## Applying

```sh
# NixOS
sudo nixos-rebuild switch --flake .#<configuration>
# Darwin
darwin-rebuild switch --flake .#lyrathorpe-mac
```

On a host whose `networking.hostName` matches its flake attribute (the WSL box
and the Pi are set up this way), `nh os switch` resolves the configuration from
the hostname with no `--flake`/`-H` flag.

## Adding a new host

1. **Create `hosts/<Name>/`.** Add `configuration.nix` with the host-specific
   bits only: `networking.hostName`, bootloader (firmware-specific — it is
   deliberately not set in the shared modules), and any per-machine hardware
   quirks. Keep anything reusable in `modules/` instead.
2. **Hardware config.** Generate `hardware-configuration.nix` on the real
   machine with `nixos-generate-config` and commit it. If the machine does not
   exist yet, commit a clearly-labelled placeholder so the host still evaluates
   in CI (see the existing T400 / RPi5 placeholders), and replace it at install.
   These files are excluded from the formatter and linters.
3. **Add a host-table entry in `flake.nix`.** Under `hosts` (NixOS) or
   `darwinHosts` (macOS), set `system`, the `modules` list (host config + form
   factor + any `nixos-hardware` profiles), and the `users` map (each user's
   `homeModules`). Choose the form factor per the decision note above; a headless
   host imports neither `laptop.nix` nor `desktop.nix`.
4. **Users.** If the host introduces a new person, add them to
   `users/registry.nix` first; otherwise reference an existing username.
5. **Verify.** `nix flake check` formats, lints, and evaluates every host —
   including the new one — so a broken entry fails locally before CI. Then
   `sudo nixos-rebuild switch --flake .#<configuration>` on the machine.

No change to CI is needed: the host-eval step discovers hosts from the flake
(`attrNames` of the configuration sets), so a new entry is picked up
automatically.

## Shell environment & keybindings

- Interactive shell features (zsh, tmux, git, ssh, CLI tools, auto-tmux):
  [`home/README.md`](./home/README.md).
- All Sway / tmux / foot / zsh keyboard shortcuts:
  [`home/KEYBINDINGS.md`](./home/KEYBINDINGS.md).

## Login / greeter

Graphical (Sway) hosts log in through a Wayland greeter — `greetd` running
ReGreet inside the `cage` kiosk compositor — implemented in
[`modules/sway.nix`](./modules/sway.nix), gated on
`features.swayDesktop.enable` (the option is declared in
[`modules/features.nix`](./modules/features.nix), so headless hosts
can leave it off without importing `modules/sway.nix`). The greeter is forced to Dvorak
to match the console and Sway session. Headless hosts (the WSL work box and the
Raspberry Pi server) keep plain TTY login. The target account needs a password
(`passwd <user>`) before it can log in.

## MacBook (Asahi) firmware

The MBP host references `modules/firmware/` for Apple peripheral
firmware (Wi-Fi/Bluetooth). These blobs are **committed** (tracked) even though
`.gitignore` lists the directory: the flake is `git+file`, so it only sees
tracked files — untracking them breaks `lyrathorpe-mbp` evaluation (and the CI
host-eval) because the config can't find the firmware. They are not
redistributable; the repo is private.

To refresh them, copy the firmware extracted during the Asahi install (from
`/etc/nixos/firmware`, or re-extract per the
[Asahi NixOS docs](https://github.com/tpwrules/nixos-apple-silicon)) into
`modules/firmware/` and commit with `git add -f`.

## Development

A dev shell and a formatting/lint gate are wired through the flake:

- `nix develop` — shell with `deadnix`, `statix`, `treefmt`, and the git
  `pre-commit` hooks (installed automatically on first entry).
- `nix fmt` — formats the tree via `treefmt` (nixfmt + shfmt + prettier;
  generated files and `flake.lock` are excluded).
- `nix flake check` — runs formatting, `deadnix`, `statix`, the pre-commit
  hooks, and evaluates every host. `.editorconfig` carries the base style;
  `statix.toml` disables the two house-style lints (`repeated_keys`,
  `empty_pattern`).

## CI

[`.gitea/workflows/ci.yaml`](./.gitea/workflows/ci.yaml) runs `nix flake check`
(formatting, `deadnix`, `statix`, the pre-commit hooks) and evaluates every
NixOS and Darwin host configuration on push/PR. It always runs (no `paths:`
filter) so the required check never hangs pending; the heavy Nix steps are
skipped when a PR touches no `.nix`/lockfile/workflow file, and the job still
reports green.