Moongreet

A greetd greeter for Wayland, built with Rust + GTK4 + gtk4-layer-shell. Part of the Moonarch ecosystem.

Features

• greetd IPC — Communicates via $GREETD_SOCK (length-prefixed JSON)
• User list — Parsed from /etc/passwd (UID 1000–65533)
• Avatars — AccountsService icons, ~/.face fallback, default SVG with theme tinting
• Sessions — Discovered from /usr/share/wayland-sessions/ and /usr/share/xsessions/
• Last user/session — Remembered in /var/cache/moongreet/
• Power actions — Reboot / Shutdown via loginctl
• Layer Shell — Fullscreen via gtk4-layer-shell (TOP layer)
• Multi-monitor + hotplug — Full greeter UI on all monitors (keyboard input on first), hotplugged monitors get windows automatically
• GPU blur — Background blur via GskBlurNode (shared cache across monitors)
• i18n — German and English (auto-detected from system locale)
• Faillock warning — Warns after 2 failed attempts, locked message after 3
• Fingerprint — fprintd support via greetd multi-stage PAM (configurable)
• Journal logging — journalctl -t moongreet, debug level via MOONGREET_DEBUG env var
• Password wiping — Zeroize on drop

Requirements

• GTK 4
• gtk4-layer-shell (for Wayland fullscreen)
• greetd

Building

cargo build --release

Installation

# Install binary
sudo install -Dm755 target/release/moongreet /usr/bin/moongreet

# Install config
sudo mkdir -p /etc/moongreet
sudo cp config/moongreet.toml /etc/moongreet/moongreet.toml

System Setup

1. Edit /etc/moongreet/moongreet.toml — set an absolute path for the wallpaper.

2. Create cache directory:

   sudo mkdir -p /var/cache/moongreet/last-session
   sudo chown greeter:greeter /var/cache/moongreet
   

3. Configure greetd (/etc/greetd/config.toml):

   [default_session]
   command = "niri -c /etc/greetd/niri-greeter.kdl"
   user = "greeter"
   

Development

# Run tests
cargo test

# Build release
cargo build --release

# Run locally (without greetd, disables layer-shell)
MOONGREET_NO_LAYER_SHELL=1 ./target/release/moongreet

License

MIT