How to restart GDM3 with autologin on 18.04 and 19.04

Question

On Ubuntu 16.04 with lightdm, and an autologin account, I can restart the graphical session with command :

sudo service lightdm restart

The account logs in automatically.

On Ubuntu 18.04 (and also on 19.04), the same autologin account is setup, but the command :

sudo service gdm3 restart

fails to autologin, and bring the display to the login page.

In gdm logs, I can find

systemd[1]: gdm.service: Succeeded.
systemd[1]: Stopped GNOME Display Manager.
systemd[1]: Starting GNOME Display Manager...
systemd[1]: Started GNOME Display Manager.
gdm-autologin][4091]: gkr-pam: no password is available for user
gdm-autologin][4091]: pam_unix(gdm-autologin:session): session opened for user screen by (uid=0)
gdm-autologin][4091]: gkr-pam: couldn't unlock the login keyring.

How to properly restart the user session, with autologin user logged in on ubuntu 18.04 ?

Answer 1

Had the same issue, I solved it by enabling 'Timed Login' in the /etc/gdm3/custom.conf file. Mine looks like:

# GDM configuration storage
#
# See /usr/share/gdm/gdm.schemas for a list of available options.

[daemon]
AutomaticLoginEnable=true
AutomaticLogin=username

# Uncoment the line below to force the login screen to use Xorg
#WaylandEnable=false

# Enabling automatic login

# Enabling timed login
TimedLoginEnable = true
TimedLogin = username
TimedLoginDelay = 10

[security]

[xdmcp]

[chooser]

[debug]
# Uncomment the line below to turn on debugging
# More verbose logs
# Additionally lets the X server dump core if it crashes
#Enable=true

Answer 2

Slight change to Celly's answer above. The default, or OOB, custom.conf file has the AutomaticLoginEnable and AutomaticLogin parameters commented out. I left those parameters commented out and uncommented/set TimedLoginEnable, TimedLogin, and TimedLoginDelay. It still works. Thank-you Celly!

Answer 3

This seems to be fixed on Ubuntu 20.04 : gdm3 service restart will result in successful autologin.