How to display a user’s avatar instead of the generic avatar on the LightDM GTK Greeter screen in Lubuntu 17.10

I recently installed Lubuntu 17.10 on my family’s PC (single-seat, multi-user). The default avatar was displayed for each user on the LightDM greeter screen, rather than each user’s individual avatar. I have experienced this problem in more than one Linux distribution (Gentoo, Sabayon and now Lubuntu 17.10), more than one Desktop Environment (KDE, GNOME and now LXDE), and more than one Display Manager (LightDM and SDDM), so my suspicion is that the problem lies with AccountsService rather than the DE or DM. Anyway, here is how I fixed the problem in Lubuntu 17.10. The example below is for user fitzcarraldo, and I used the same procedure for each username in the installation.

1. Create a 96×96 PNG avatar /home/fitzcarraldo/Pictures/fitzcarraldo.png

2. Edit the file /var/lib/AccountsService/users/fitzcarraldo to contain the following:

[User]
XSession=Lubuntu
SystemAccount=false
Icon=/var/lib/AccountsService/icons/fitzcarraldo	

3. Make sure that the file has 644 permissions:

$ ls -la /var/lib/AccountsService/users/fitzcarraldo
-rw-r--r-- 1 root root 85 Jan  1 02:53 /var/lib/AccountsService/users/fitzcarraldo

4. Copy the avatar to the relevant directory and make sure it has 644 permissions:

$ sudo cp /home/fitzcarraldo/Pictures/fitzcarraldo.png /var/lib/AccountsService/icons/fitzcarraldo
$ ls -la /var/lib/AccountsService/icons/fitzcarraldo
-rw-r--r-- 1 root root 14860 Jan  1 02:54 /var/lib/AccountsService/icons/fitzcarraldo

After rebooting, the desired avatar should be displayed on LightDM’s GTK Greeter screen.

Background reading

  1. KDE Bug Report No. 336994 – User Manager does not show one particular user in the list unless I login as that user
  2. Gentoo Forums – user-manager in plasma desktop not populating users
  3. Gentoo Forums – LightDM greeter username in list stuck and can’t add others
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How to capture a screenshot of the LightDM greeter screen

  1. If they are not already installed, install the packages x11-apps/xwd and media-gfx/imagemagick.

  2. Create the Bash script ~/lightdm-greeter-capture.sh containing the following:
    #!/bin/bash
    sleep 30
    DISPLAY=:0 XAUTHORITY=/var/run/lightdm/root/$DISPLAY xwd -root > /tmp/greeter.xwd
    convert /tmp/greeter.xwd /home/fitzcarraldo/greeter.png
    

    Make sure you make it executable:

    user $ chmod +x lightdm-greeter-capture.sh

  3. Log out of the Desktop Environment so that the LightDM greeter screen is displayed.

  4. Press Ctrl+Alt+F2 to switch to VT2.

  5. Log in to you user account and enter the following command (do not wait for it to complete):

    user $ sudo /home/fitzcarraldo/lightdm-greeter-capture.sh

  6. As soon as you have pressed Enter for the above command, press Ctrl+Alt+F7 to switch back to VT7.

  7. Wait for at least 30 seconds to be sure the Bash script has made a snapshot of the LightDM greeter screen, then log in.

  8. You should now find the file ~/greeter.png containing a snapshot of your LightDM greeter screen.

If you install media-libs/netpbm instead of (or as well as) media-gfx/imagemagick then you can use a different command to convert in the Bash script:

#!/bin/bash
sleep 30
DISPLAY=:0 XAUTHORITY=/var/run/lightdm/root/$DISPLAY xwd -root | xwdtopnm | pnmtopng > /home/fitzcarraldo/greeter.png

The resulting PNG image looks equally good to my eyes.

Fixing all-white log-in screen when using the LightDM KDE greeter with Plasma 5 in Gentoo Linux

In a previous post I explained how I got LightDM to work on my Clevo W230SS laptop running KDE Plasma 5 in Gentoo Linux (Stable Branch). However, following a world update a few weeks later, the LightDM log-in screen (‘greeter’) became all white. Searching the Web showed me that this is a common problem with LightDM, although the cause appeared to be different in many other cases, as I could still see the password-entry box and the button to select the session.

To summarise what was already installed:

fitzcarraldo@clevow230ss ~ $ uname -a
Linux clevow230ss 3.18.11-gentoo #47 SMP Thu May 26 11:03:29 BST 2016 x86_64 Intel(R) Core(TM) i7-4810MQ CPU @ 2.80GHz GenuineIntel GNU/Linux
fitzcarraldo@clevow230ss ~ $ eix -I plasma-meta
[I] kde-plasma/plasma-meta
     Available versions:  (5) 5.6.5 ~5.7.3
       {bluetooth +display-manager grub gtk +handbook mediacenter networkmanager pam plymouth pulseaudio +sddm sdk +wallpapers}
     Installed versions:  5.6.5(5)(12:28:08 26/07/16)(bluetooth display-manager gtk handbook networkmanager pam pulseaudio wallpapers -grub -mediacenter -plymouth -sddm -sdk)
     Homepage:            https://www.kde.org/workspaces/plasmadesktop/
     Description:         Merge this to pull in all Plasma 5 packages

fitzcarraldo@clevow230ss ~ $ eix -I lightdm
[I] x11-misc/lightdm
     Available versions:  1.10.5^t 1.16.7^t ~1.17.6^t ~1.18.1^t ~1.19.0^t ~1.19.3^t {audit +gnome +gtk +introspection kde qt4 qt5}
     Installed versions:  1.16.7^t(04:11:41 23/08/16)(introspection kde qt4 qt5 -audit -gnome -gtk)
     Homepage:            https://www.freedesktop.org/wiki/Software/LightDM
     Description:         A lightweight display manager

[I] x11-misc/lightdm-kde
     Available versions:  (4) 0.3.2.1-r1
       {aqua debug L10N="bs cs da de el es et fi fr ga gl hu it ja km lt mr nds nl pl pt pt-BR ro ru sk sl sv tr uk"}
     Installed versions:  0.3.2.1-r1(4)(01:13:13 12/07/16)(-aqua -debug L10N="pt-BR -bs -cs -da -de -el -es -et -fi -fr -ga -gl -hu -it -ja -km -lt -mr -nds -nl -pl -pt -ro -ru -sk -sl -sv -tr -uk")
     Homepage:            https://projects.kde.org/projects/playground/base/lightdm
     Description:         LightDM KDE greeter

Found 2 matches

And this is what I had previously configured:

fitzcarraldo@clevow230ss ~ $ grep -v ^# /etc/lightdm/lightdm.conf
[LightDM]

session-wrapper=/etc/lightdm/Xsession
[Seat:*]
greeter-session=lightdm-kde-greeter
session-wrapper=/etc/lightdm/Xsession
display-setup-script=/etc/X11/Sessions/plasma

[XDMCPServer]

[VNCServer]
fitzcarraldo@clevow230ss ~ $ cat /etc/X11/Sessions/plasma
#!/bin/bash
GPU=`eselect opengl list | grep \* | awk '{ print $2 }'`
if [ "$GPU" = "nvidia" ]; then
    xrandr --setprovideroutputsource modesetting NVIDIA-0
    xrandr --auto
fi

Now, given that I had installed the LightDM KDE Greeter, I would have expected there to be a default configuration file lightdm-kde-greeter.conf for it, but there was none:

fitzcarraldo@clevow230ss ~ $ ls /etc/lightdm/
Xsession  keys.conf  lightdm.conf  users.conf

So I created the file /etc/lightdm/lightdm-kde-greeter.conf with the following contents:

[greeter]
theme-name=classic

[greeter-settings]
Background=/home/fitzcarraldo/Pictures/Wallpaper/Linux/kde-1920x1080.jpg
BackgroundKeepAspectRatio=true
GreetMessage=Welcome to %hostname%

I downloaded a nice KDE wallpaper file from the Web, which I saved as /home/fitzcarraldo/Pictures/Wallpaper/Linux/kde-1920x1080.jpg, but you can save it anywhere you like and give it any name you want.

I found that the package manager had installed two themes, so I could have specified either:

fitzcarraldo@clevow230ss ~ $ ls /usr/share/apps/lightdm-kde-greeter/themes/
classic  userbar

Anyway, the outcome is that the LightDM login screen (greeter) is no longer white and displays a wallpaper of my choice. Mission accomplished.