diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md deleted file mode 100644 index bf9ab16..0000000 --- a/.github/copilot-instructions.md +++ /dev/null @@ -1,91 +0,0 @@ -# Copilot Instructions — nixos-config - -## Architecture - -This is a **NixOS flake** managing multiple hosts using [flake-parts](https://flake.parts). The flake output is composed entirely from `flake-parts/*.nix` — each file is auto-imported via `builtins.readDir`. - -### Layers (top → bottom) - -1. **Hosts** (`hosts/`) — minimal per-machine config: profile import, overlay IP, underlay interface, enabled services. All `.nix` files in a host directory are auto-imported recursively by `flake-parts/hosts.nix`. - - **External hosts** (`external-hosts/`) — non-NixOS devices (e.g., a phone) that participate in the overlay network and syncthing cluster but aren't managed by NixOS. They import `nixosModules.default` directly (no profile) and only declare `custom.networking` and `custom.services` options so their config values are discoverable by other hosts. This enables auto-generating nebula certs, DNS records, and syncthing device lists for them. - - `allHosts` = `nixosConfigurations // externalConfigurations` — passed to every module via `specialArgs`, so any module can query the full fleet including external devices. -2. **Profiles** (`profiles/`) — role presets. `core.nix` is the base for all hosts; `server.nix` and `workstation.nix` extend it. Profile names become `nixosModules.-profile`. -3. **Modules** (`modules/system/`, `modules/home/`) — reusable NixOS/Home Manager modules auto-imported as `nixosModules.default` / `homeModules.default`. Every module is always imported; activation is gated by `lib.mkEnableOption` + `lib.mkIf`. -4. **Users** (`users/seb/`) — Home Manager config. Per-host overrides live in `@/` subdirectories (e.g., `users/seb/@desktop/home.nix` imports `../home.nix` and adds host-specific settings). - -### Networking model - -- **Underlay** (`modules/system/networking/underlay.nix`) — physical network via systemd-networkd. -- **Overlay** (`modules/system/networking/overlay.nix`, `modules/system/services/nebula/`) — Nebula mesh VPN (`10.254.250.0/24`, domain `splitleaf.de`). All inter-host communication (DNS, Caddy, SSH) routes over the overlay. -- **DNS** (`modules/system/services/dns.nix`) — Unbound on overlay, auto-generates records from `allHosts`. - -### Web services pattern - -Each web service module (`modules/system/web-services/*.nix`) follows a consistent structure: - -```nix -options.custom.web-services. = { enable; domain; port; doBackups; }; -config = lib.mkIf cfg.enable { - # upstream NixOS service config - custom.services.caddy.virtualHosts.${cfg.domain}.port = cfg.port; # reverse proxy - custom.services.restic.backups. = lib.mkIf cfg.doBackups { ... }; # backup - custom.persistence.directories = [ ... ]; # impermanence -}; -``` - -Hosts enable services declaratively: `custom.web-services.forgejo = { enable = true; domain = "git.example.com"; doBackups = true; };` - -## Conventions - -- **All custom options** live under `custom.*` — never pollute the top-level NixOS namespace. -- **`cfg` binding**: always `let cfg = config.custom.;` at module top. -- **Pipe operator** (`|>`): used pervasively instead of nested function calls. -- **No repeated attrpaths** (per `statix`): group assignments into a single attrset instead of repeating the path. E.g. `custom.networking.overlay = { address = "..."; role = "server"; };` — not `custom.networking.overlay.address = "..."; custom.networking.overlay.role = "server";`. Setting a single attribute with the full path is fine. Conversely, don't nest single-key attrsets unnecessarily — use `custom.networking.overlay.address = "...";` not `custom = { networking = { overlay = { address = "..."; }; }; };`. -- **`lib.singleton`** instead of `[ x ]` for single-element lists. -- **`lib.mkEnableOption ""`**: empty string is intentional — descriptions come from the option path. -- **Secrets**: [sops-nix](https://github.com/Mic92/sops-nix) with age keys. Each host/user has `secrets.json` + `keys/age.pub`. The `.sops.yaml` at repo root is a placeholder — the real config is generated via `nix build .#sops-config` (see `flake-parts/sops-config.nix`). -- **Impermanence**: servers use `custom.persistence.enable = true` with an explicit `/persist` mount. Modules add their state directories via `custom.persistence.directories`. -- **Formatting**: `nix fmt` runs `nixfmt` + `prettier` + `just --fmt` via treefmt. -- **Path references**: use `./` for files in the same directory or a subdirectory. Use `${self}/...` when the path would require going up a directory (`../`). Never use `../`. -- **Cross-host data**: modules receive `allHosts` via `specialArgs` (see Hosts layer above). Used by DNS, nebula static host maps, syncthing device lists, and caddy service records. - -## Developer Workflows - -| Task | Command | -| ----------------------------- | ------------------------------------------ | -| Rebuild & switch locally | `just switch` | -| Test config without switching | `just test` | -| Deploy to remote host(s) | `just deploy hostname1 hostname2` | -| Format all files | `just fmt` or `nix fmt` | -| Run flake checks + tests | `just check` | -| Check without building | `just check-lite` | -| Update flake inputs | `just update` | -| Edit SOPS secrets | `just sops-edit hosts//secrets.json` | -| Rotate all secrets | `just sops-rotate-all` | -| Install a new host | `just install root@` | -| Open nix repl for a host | `just repl ` | - -SOPS commands auto-enter a `nix develop .#sops` shell if `sops` isn't available, which handles Bitwarden login and age key retrieval. - -## Adding a New Module - -1. Create `modules/system/services/.nix` (or `web-services/`, `programs/`, etc.). -2. Define options under `options.custom..` with `lib.mkEnableOption ""`. -3. Guard all config with `lib.mkIf cfg.enable { ... }`. -4. For web services: set `custom.services.caddy.virtualHosts`, optionally `custom.services.restic.backups`, and `custom.persistence.directories`. -5. No imports needed — the file is auto-discovered by `flake-parts/modules.nix`. - -## Adding a New Host - -1. Create `hosts//` with `default.nix`, `disko.nix`, `hardware.nix`, `secrets.json`, and `keys/` (containing `age.pub`, `nebula.pub`). -2. In `default.nix`, import the appropriate profile (`self.nixosModules.server-profile` or `self.nixosModules.workstation-profile`) and set `custom.networking.overlay.address` + `custom.networking.underlay.*`. -3. The host is auto-discovered by `flake-parts/hosts.nix` — no registration needed. - -## Tests - -Integration tests live in `tests/` and use NixOS VM testing (`pkgs.testers.runNixOSTest`). Run via `just check`. Key details: - -- Each test directory contains a `default.nix` that returns a test attrset (with `defaults`, `nodes`, `testScript`, etc.). -- The `defaults` block imports `self.nixosModules.default` and **overrides `allHosts`** with the test's own `nodes` variable: `_module.args.allHosts = nodes |> lib.mapAttrs (_: node: { config = node; });`. This scopes cross-host lookups (DNS records, nebula static maps, etc.) to only the test's VMs, preventing evaluation of real host configs. -- Test nodes define their own overlay addresses, underlay interfaces, and use pre-generated nebula keys from `tests/*/keys/`. -- The `testScript` is written in Python, using helpers like `wait_for_unit`, `succeed`, and `fail` to assert behavior.