In previous versions of Ubuntu I could create custom keyboard shortcut to run terminal commands, with something like gksudo reboot
for example, and then assign that to something like win+r.
I can't find that option in Ubuntu 17.10 or Ubuntu 18.04 daily build.
Am I missing something?
Follow the steps below.
For those who can't manage to find the adequate Settings (Ubuntu 18.04 maybe?), run in a terminal:
gnome-control-center
...then follow the procedure that @opensas mentioned: