greetd-moongreet/CLAUDE.md
nevaforget 226bbb75e4 Rewrite moongreet from Python to Rust (v0.3.0)
Complete rewrite of the greetd greeter from Python/PyGObject to Rust/gtk4-rs
for consistency with moonset, single binary without Python runtime, and
improved security through Rust memory safety.

Modules: main, greeter, ipc, config, i18n, users, sessions, power
86 unit tests covering all modules including login_worker IPC flow.
Security hardening: shell-word splitting for exec_cmd, absolute path
validation for session binaries, session-name sanitization, absolute
loginctl path, atomic IPC writes.
2026-03-27 22:08:33 +01:00

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2.2 KiB
Markdown

# Moongreet
**Name**: Selene (Mondgöttin — passend zu Moon-greet)
## Projekt
Moongreet ist ein greetd-Greeter für Wayland, gebaut mit Rust + gtk4-rs + gtk4-layer-shell.
Teil des Moonarch-Ökosystems.
## Tech-Stack
- Rust (Edition 2024), gtk4-rs 0.11, glib 0.22
- gtk4-layer-shell 0.8 für Wayland Layer Shell (TOP Layer)
- greetd IPC über Unix Domain Socket (length-prefixed JSON)
- `cargo test` für Unit-Tests
## Projektstruktur
- `src/` — Rust-Quellcode (main.rs, greeter.rs, ipc.rs, config.rs, users.rs, sessions.rs, i18n.rs, power.rs)
- `resources/` — GResource-Assets (style.css, wallpaper.jpg, default-avatar.svg)
- `config/` — Beispiel-Konfigurationsdateien für `/etc/moongreet/` und `/etc/greetd/`
## Kommandos
```bash
# Tests ausführen
cargo test
# Release-Build
cargo build --release
# Greeter starten (nur zum Testen, braucht normalerweise greetd)
LD_PRELOAD=/usr/lib/libgtk4-layer-shell.so ./target/release/moongreet
```
## Architektur
- `ipc.rs` — greetd Socket-Kommunikation (4-byte LE header + JSON)
- `users.rs` — Benutzer aus /etc/passwd, Avatare (AccountsService + ~/.face), Symlink-Rejection
- `sessions.rs` — Wayland/X11 Sessions aus .desktop Files
- `power.rs` — Reboot/Shutdown via loginctl
- `i18n.rs` — Locale-Erkennung (LANG / /etc/locale.conf) und String-Tabellen (DE/EN)
- `config.rs` — TOML-Config ([appearance] background, gtk-theme) + Wallpaper-Fallback
- `greeter.rs` — GTK4 UI (Overlay-Layout), Login-Flow via greetd IPC, Faillock-Warnung, Avatar-Cache, Last-User/Last-Session Persistence
- `main.rs` — Entry Point, GTK App, Layer Shell Setup, Multi-Monitor
- `resources/style.css` — Catppuccin-inspiriertes Theme
## Design Decisions
- **TOP Layer statt OVERLAY**: Greeter läuft unter greetd, nicht über Waybar
- **GResource-Bundle**: CSS, Wallpaper und Default-Avatar sind in die Binary kompiliert
- **Async Login**: `glib::spawn_future_local` + `gio::spawn_blocking` statt raw Threads
- **Socket-Cancellation**: `Arc<Mutex<Option<UnixStream>>>` + `AtomicBool` für saubere Abbrüche
- **Avatar-Cache**: `HashMap<String, gdk::Texture>` in `Rc<RefCell<GreeterState>>`
- **Symmetrie mit moonset**: Gleiche Patterns (i18n, config, users, power, GResource)