I currently use Fedora 22 with a plain Awesome WM session. I can lock the screen with say slock.
There are ways to lock the screen on suspend with the system wide instance of systemd, see this question for instance. The problem with that approach is that it uses a hard-coded DISPLAY variable which is not a nice thing to do. The systemd --user instance cannot depend on system targets, therefore one cannot couple a user task to sleep.target.
On Ubuntu I have been using xss-lock for this task but that is not packaged in Fedora 22 yet. There one runs this tool that will spawn a process when the computer suspends.
Is there some nice way to automatically lock the screen on suspend that works out of the box with Fedora 22?