# greetd Display Manager Setup

Guide for configuring greetd with regreet (GTK greeter) on Gentoo with Hyprland.

## Overview

greetd is a minimal display manager that launches regreet inside a temporary Hyprland session. This provides a graphical login screen that works well with Wayland compositors.

**Architecture:**
```
greetd (daemon) → Hyprland (minimal) → regreet (GTK greeter) → User session
```

## Installation

### Required Packages
```bash
emerge gui-libs/greetd gui-apps/regreet gui-libs/display-manager-init
```

### Enable Service
```bash
# Set greetd as display manager
echo 'DISPLAYMANAGER="greetd"' > /etc/conf.d/display-manager

# Add to default runlevel
rc-update add display-manager default
```

## Configuration Files

### /etc/greetd/config.toml
Main greetd configuration:
```toml
[terminal]
vt = 7

[default_session]
command = "start-hyprland -- --config /etc/greetd/hyprland.conf > /var/log/hyprland-greeter.log 2>&1"
user = "greetd"
```

### /etc/greetd/regreet.toml
GTK greeter theming:
```toml
[background]
path = "/usr/share/backgrounds/default.png"
fit = "Cover"

[GTK]
application_prefer_dark_theme = true

[commands]
reboot = ["loginctl", "reboot"]
poweroff = ["loginctl", "poweroff"]
```

**Note:** Uses `loginctl` for power commands (OpenRC-compatible, not systemd).

### /etc/greetd/hyprland.conf
Minimal Hyprland config for the greeter session:
```bash
exec-once = regreet; hyprctl dispatch exit

env = XCURSOR_THEME,Bibata-Modern-Ice
env = XCURSOR_SIZE,24

# Force greeter to laptop display only
monitor=eDP-2, 1920x1080@60, 0x0, 1
monitor=DP-1, disable
monitor=DP-2, disable

cursor {
    default_monitor = eDP-2
}

input {
    touchpad {
        disable_while_typing = true
        natural_scroll = true
        tap-to-click = true
    }
}

misc {
    disable_hyprland_logo = true
    disable_splash_rendering = true
    disable_autoreload = true
}

debug {
    disable_logs = true
}
```

### /etc/pam.d/greetd
Custom PAM configuration to prevent `user.greetd` errors:
```
# greetd PAM configuration
# Omits pam_openrc.so to prevent user.greetd service errors

auth            include         system-local-login
account         include         system-local-login
password        include         system-local-login
session         optional        pam_loginuid.so
session         required        pam_env.so envfile=/etc/profile.env
session         include         system-auth
session         optional        pam_motd.so motd=/etc/motd
session         optional        pam_lastlog.so never showfailed
session         optional        pam_mail.so
-session        optional        pam_elogind.so
```

**Why custom PAM?** The default PAM chain includes `pam_openrc.so` which tries to start a user session service (`user.greetd`). Since greetd is a system service, not a user login, this fails and generates errors at boot.

## User Session Launcher

### /usr/local/bin/start-hyprland-dbus
Wrapper script for user Hyprland sessions with logging:
```bash
#!/bin/bash
exec dbus-run-session /usr/bin/start-hyprland > ~/.local/log/hyprland.log 2>&1
```

### Update Desktop Entry
Modify `/usr/share/wayland-sessions/hyprland.desktop`:
```ini
Exec=/usr/local/bin/start-hyprland-dbus
```

### Create Log Directory
```bash
mkdir -p ~/.local/log
```

## Log Files

| Log | Location | Purpose |
|-----|----------|---------|
| Greeter | `/var/log/hyprland-greeter.log` | Greeter Hyprland session |
| User | `~/.local/log/hyprland.log` | User Hyprland session |

The greeter log file needs correct ownership:
```bash
sudo touch /var/log/hyprland-greeter.log
sudo chown greetd:greetd /var/log/hyprland-greeter.log
```

## Customization

### Change Background
Edit `/etc/greetd/regreet.toml`:
```toml
[background]
path = "/path/to/your/wallpaper.png"
```

### Change Cursor Theme
Edit `/etc/greetd/hyprland.conf`:
```bash
env = XCURSOR_THEME,<your-cursor-theme>
env = XCURSOR_SIZE,24
```

### Enable External Monitors at Login
Remove or modify the `disable` lines in `/etc/greetd/hyprland.conf`:
```bash
# Enable external monitors
monitor=DP-1, 1920x1080@60, 0x0, 1
monitor=eDP-2, 1920x1080@60, 1920x0, 1
```

## Troubleshooting

### "failed to start user.greetd" at boot
Ensure you're using the custom `/etc/pam.d/greetd` that omits `pam_openrc.so`.

### Black screen at login
1. Check `/var/log/hyprland-greeter.log` for errors
2. Verify monitor configuration in `/etc/greetd/hyprland.conf`
3. Ensure greetd user has access to DRI devices

### regreet not appearing
1. Verify regreet is installed: `which regreet`
2. Check the exec-once line in hyprland.conf
3. Review greeter logs

### Keyboard not working
Ensure elogind is running and in boot runlevel:
```bash
rc-update add elogind boot
rc-service elogind start
```

### Service management
```bash
# Check status
rc-service display-manager status

# Restart
rc-service display-manager restart

# View logs
cat /var/log/hyprland-greeter.log
```