dotfiles/guides/99_GREETD.md

Greetd

This guide goes over how to setup greetd, which is a minimalistic Display Manager (DM) that starts right after boot and asks the user to log in.

A DM is useful for letting you pick which session you wish to load after logging in (e.g. which WM/DE), but also to provide a slightly nicer UI in comparison to the default agetty TTY based login screen.

Another neat feature that greetd offers is automatic login, which will allow you to skip the login process entirely, logging you in right after the boot. This can be useful if you're already typing in your LUKS encryption password each time after a boot, which already acts as a sufficient layer of protection against attackers trying to enter your system.

Warning

If you've set up TPM unlocking for your LUKS encryption, setting up automatic login is not safe, unless you're using a TPM passphrase/PIN.

Important

If you're following while using my dotfiles, you will need to manually place the greetd config from the repo into /etc/greed/config.toml. The installation scripts don't do this, as many people prefer not using a greeter.

You will also need to follow the installation instructions to download greetd and enable it.

Greetd + tuigreet

Since I prefer a minimalistic approach to most things in my system, I like to use a terminal based greeter. Greetd itself is just a daemon that supports various greeters. Most of these greeters are graphical, but there are terminal based ones too, most notably tuigreet, which works right from the TTY.

First, install and enable greetd, to make sure it gets started on boot.

sudo pacman -S greetd greetd-tuigreet
sudo systemctl enable greetd

Now, we will want to define our greetd configuration in /etc/greetd/config.toml. There should already be a default configuraion that uses agreety greeter, which is similar to agetty, we'll want to change that to tuigreet, which in my opinion looks a lot better. We can use the following config:

[terminal]
# The VT to run the greeter on. Can be "next", "current" or a number
# designating the VT.
vt = 1

# The default session, also known as the greeter.
[default_session]

command = "tuigreet --time --remember --remember-user-session --asterisks --greeting 'Stop staring and log in already' --theme 'border=magenta;text=cyan;prompt=green;time=red;action=white;button=yellow;container=black;input=gray' --sessions /usr/share/wayland-sessions --xsessions /usr/share/xsessions --session-wrapper /usr/local/bin/greetd-session-wrapper --xsession-wrapper /usr/local/bin/greetd-session-wrapper startx /usr/bin/env"

# The user to run the command as. The privileges this user must have depends
# on the greeter. A graphical greeter may for example require the user to be
# in the `video` group.
user = "greeter"

Note

I know the tuigreet command is really hard to orient in when written in a single line like this, however, attempting to use a multi-line string doesn't seem to work with greetd (even though it is a part of the TOML standard). This issue has already been reported, yet it doesn't seem like it was addressed.

You may have noticed that I've referred to a /usr/local/bin/greetd-session-wrapper script here, that's a custom script that I wrote to get greetd to run the command to start the WM/DE session within a running user shell (bash/zsh), so that the appropriate environment variables will be set when the WM is launched.

This is the content of that script:

#!/bin/bash
set -euo pipefail

# This is a helper wrapper script for greetd.
#
# It will run the session / application using the appropriate shell configured for
# this user. That way, we can make sure all of the environment variables are set
# before the WM/DE session is started.
#
# This is very important, as without it, variables for things like qt theme
# will not be set, and applications executed by the WM/DE will not be themed properly.

script_name="$0"
shell="$(getent passwd "$USER" | awk -F: '{print $NF}')"
command=("$@")

exec "$shell" -c 'exec "$@"' "$script_name" "${command[@]}"

With this configuration, you can now reboot and check whether greetd works properly. (You will still be asked for a password.)

reboot

If everything worked properly, you should've been presented with a custom tuigreet login screen after booting.

Tip

Feel free to adjust the tuigreet settings to your liking by editing the command in the greetd settings. If you need a reference for what settings are available, you can check out the tuigreet project page.

Configuring automatic Login

To configure automatic login, we'll need to modify the greetd settings in /etc/greetd/config.toml and add an initial session section:

[terminal]
# The VT to run the greeter on. Can be "next", "current" or a number
# designating the VT.
vt = 1

# Auto-login session, triggered right after boot.
# If the user logs out, greetd will render the default session
[initial_session]
user = "itsdrike"  # TODO: CHANGE THIS
command = "/usr/local/bin/greetd-session-wrapper Hyprland"

# The default session, also known as the greeter.
[default_session]

command = "tuigreet --time --remember --remember-user-session --asterisks --greeting 'Stop staring and log in already' --theme 'border=magenta;text=cyan;prompt=green;time=red;action=white;button=yellow;container=black;input=gray' --sessions /usr/share/wayland-sessions --xsessions /usr/share/xsessions --session-wrapper /usr/local/bin/greetd-session-wrapper --xsession-wrapper /usr/local/bin/greetd-session-wrapper startx /usr/bin/env"

# The user to run the command as. The privileges this user must have depends
# on the greeter. A graphical greeter may for example require the user to be
# in the `video` group.
user = "greeter"