Display manager

List of display managers

tinydm, default on Phosh, Plasma Mobile and LXQt installations
lightdm, default on Xfce4 and MATE installations
gdm, default on GNOME installation
sddm, default on Plasma Desktop installation
lxdm, not used by default

tinydm

The tinydm log file can be located in ${XDG_STATE_HOME:-~/.local/state}/tinydm.log.

LightDM

In Xfce4 and MATE, autologin is preset by the files /usr/share/lightdm/lightdm.conf.d/64-autologin.conf (Xfce4) or /usr/share/lightdm/lightdm.conf.d/61-autologin.conf (MATE).

If you want to use LightDM as a login screen, it can be set up as follows:

1. sudo apk add lightdm-gtk-greeter

2. sudo vi /etc/lightdm/lightdm.conf

change:

greeter-session=lightdm-gtk-greeter
greeter-hide-users=false

3. sudo vi /etc/lightdm/lightdm-gtk-greeter.conf (optionally)

Background picture can be set here.

Also setting up a virtual keyboard can be done here. Keyboard onboard is preinstalled on Xfce4 and MATE. First line is a change, the other two lines are new additions. On bigger screens, layout "Phone" can be replaced by layout "Compact".

background=/usr/share/wallpapers/postmarketos.jpg
theme-name=postmarketos-dark

keyboard=onboard -l Phone -t Nightshade
keyboard-position="50%,center -0;100% 25%"
a11y-states=+keyboard

4. sudo vi /usr/share/lightdm/lightdm.conf.d/65-autologin-override.conf (new file)

Finally, to disable autologin, the content of the autologin config file can be overriden and set to empty by:

[Seat:*]
autologin-user=
autologin-user-timeout=
autologin-session=

CanGraphical issue

If LightDM starts but there is no picture on screen, check if loginctl show-seat seat0 reports it as CanGraphical=0. If that is the case, in /etc/lightdm/lightdm.conf replace #logind-check-graphical=true with logind-check-graphical=false to make LightDM ignore that nonsense.

loginctl does not see the session

Enable virtual terminals in your kernel config.