RHEL 8 New Features for Experienced Linux Administrators
In this exercise, you will examine workstation to determine which applications use Wayland natively, and practice switching between Wayland and Xorg.
Outcomes
You should be able to determine which applications use Wayland, and which use X11 with the XWayland compatibility layer. You should also be able to switch between Wayland and Xorg, which is helpful when troubleshooting issues with graphical applications.
Log in to workstation as student using student as the password.
On workstation, run the lab core-wayland start command.
[student@workstation ~]$lab core-wayland start
Launch the Cheese photo application.
Press Alt+F2 to open the Enter a Command dialog box.
Type
cheeseto launch the application.
Launch Looking Glass, the Gnome integrated debugger and inspector.
Press Alt+F2 to open the Enter a Command dialog box.
Type
lgto launch the inspector.
Use Looking Glass to determine which applications are using Wayland natively.
Click Windows at the upper right.
Click the text
gnome-shellto display the object inspection dialog box.The first line in the object inspection dialog box lists the object type, which includes the text
MetaWindowXwayland. This indicates that Gnome Shell is using the XWayland display server and so is still configured to use X11.Close the dialog box.
Click the text
student@workstation:~, which represents the open Gnome terminal.The first line in the object inspection dialog box includes the text
MetaWindowWayland, confirming that Gnome terminal is a native Wayland application.Close the dialog box.
Click the text
Take a photo, which represents the Cheese application.The first line in the object inspection dialog box includes the text
MetaWindowWayland, confirming that Cheese is a native Wayland application.Close the dialog box.
Press Esc to exit from Looking Glass.
From the terminal, verify the session type using the loginctl command.
Run the loginctl command to find your session number.
[student@workstation ~]$loginctlSESSION UID USER SEAT TTY21000 student seat0 tty2 c1 42 gdm seat0 tty1 2 sessions listed.Run the loginctl show-session command to find the session type.
[student@workstation ~]$loginctl show-session 2 -p TypeType=wayland
From the terminal, become
rootand then edit/etc/gdm/custom.conf. Uncomment the line containingWaylandEnable, save your changes, and then rebootworkstation.# Uncomment the line below to force the login screen to use Xorg WaylandEnable=False
Log in as
studentand verify the session type using the loginctl command.Open a terminal and run the loginctl command to find your session number.
[student@workstation ~]$loginctlSESSION UID USER SEAT TTY21000 student seat0 tty2 c1 42 gdm seat0 tty1 2 sessions listed.Run the loginctl show-session command to find the session type.
[student@workstation ~]$loginctl show-session 2 -p TypeType=x11
From the terminal, become
rootand edit/etc/gdm/custom.conf. Comment the line containingWaylandEnable, save your changes, and then rebootworkstation.# Uncomment the line below to force the login screen to use Xorg
#WaylandEnable=False
This concludes the guided exercise.
