GDM Autologin

Skip the GDM login screen after LUKS unlock at boot. The screen lock on suspend/idle still requires your password.

Boot behavior:

Configuration

Edit the GDM config:

sudo nano /etc/gdm/custom.conf

Add AutomaticLoginEnable and AutomaticLogin under [daemon]:

[daemon]
AutomaticLoginEnable=True
AutomaticLogin=sten

Full example for reference:

# GDM configuration storage
[daemon]
AutomaticLoginEnable=True
AutomaticLogin=sten

[security]

[xdmcp]

[chooser]

[debug]

Save with Ctrl+X, y then reboot:

sudo reboot

After reboot, LUKS will prompt for a password. Once entered, the desktop should load immediately without a GDM login screen.

To confirm autologin is active:

sudo cat /etc/gdm/custom.conf | grep -i auto

Expected output:

AutomaticLoginEnable=True
AutomaticLogin=sten

Autologin only applies to the initial boot session. GDM does not trigger when resuming from suspend.
The GNOME screen lock (Super+L, lid close, idle timeout) is handled by gnome-screensaver / gnome-shell, not GDM. It always requires your user password regardless of autologin settings.
If you have a second user account on the system, only the configured user gets autologin. Other accounts always get a GDM prompt.

Autologin not working after config change

Verify the config file is correct:

sudo cat /etc/gdm/custom.conf

Ensure AutomaticLoginEnable=True is under [daemon] and the username matches exactly:

whoami

Also check that GDM is the active display manager:

systemctl status gdm

Disable autologin

sudo nano /etc/gdm/custom.conf

Remove or comment out the two lines:

#AutomaticLoginEnable=True
#AutomaticLogin=sten

Reboot to apply.