How can I autologin to desktop with systemd?

This is described in the Arch Wiki:

Create a new service file similar to [email protected] by copying it to /etc/systemd/system/

cp /usr/lib/systemd/system/[email protected] /etc/systemd/system/[email protected]

This basically copies the already existing [email protected] to a new file [email protected] which can be freely modifed. It is copied to /etc/systemd/system because that's where site-specific unit files are stored. /usr/lib/systemd/system contains unit files provided by packages so you shouldn't change anything in there.

You will then have to symlink that [email protected] to the getty service for the tty on which you want to autologin, for examply for tty1:

ln -s /etc/systemd/system/[email protected] /etc/systemd/system/getty.target.wants/[email protected]

Up to now, this is still the same as the usual [email protected] file, but the most important part is to modify the [email protected] to actually log you in automatically. To do that, you only need to change the ExecStart line to read

ExecStart=-/sbin/agetty -a USERNAME %I 38400

The difference between the ExecStart line in [email protected] and [email protected] is only the -a USERNAME which tells agetty to log the user with the username USERNAME in automatically.

Now you only have to tell systemd to reload its daemon files and start the service:

systemctl daemon-reload
systemctl start [email protected]

(I'm not sure if the service will start properly if you're already logged in on tty1, the safest way is propably to just reboot instead of starting the service).

If you then want to automatically start X, insert the following snippet into your ~/.bash_profile (taken from the wiki again):

if [[ -z $DISPLAY ]] && [[ $(tty) = /dev/tty1 ]]; then
    exec startx
fi

You will have to modify your ~/.xinitrc to start your desktop environment, how to do that depends on the DE and is probably described in the Arch wiki as well.

Directly modify the file /etc/systemd/system/getty.target.wants/[email protected] (which is a symlink to /lib/systemd/system/getty@service):

Append -a/--autologin USERNAME to the line:

ExecStart=-/sbin/agetty --noclear %I $TERM

Hence:

ExecStart=-/sbin/agetty -a USERNAME %I $TERM

You might also remove -o '-p -- \\u' (as present on the current Arch installation) as this would start the login for USERNAME but still asks for the password.

After rebooting, you will be logged in automatically.

P.s. Change the filename [email protected] to the tty you want to log into.

IMO, the Arch Wiki currently recommends a much simpler solution:

Either run the helper (systemctl edit getty@tty1) or do what I did manually:

mkdir -p /etc/systemd/system/[email protected]/
touch /etc/systemd/system/[email protected]/override.conf

The text you want to enter (by either method) is (be sure to change username appropriately):

[Service]
ExecStart=
ExecStart=-/usr/bin/agetty --autologin username --noclear %I $TERM

NOTE: The empty line is important! (admittedly I'm not sure why...)

Now, restart (shutdown -r 0) and something to the effect of ... login: username (automatic login) will happen where it previously blocked waiting for username/password input

---

Once rebooted, and auto-logged in, if you're like me and want to SSH into this system now, you probably need to run:

systemctl enable sshd.service

Which will create the symlink (e.g. ln -s '/usr/lib/systemd/system/sshd.service' '/etc/systemd/system/multi-user.target.wants/sshd.service')