suspend AND lock screen on closing lid in arch/systemd

Question

what is the most straightforward way to lock the screen AND suspend when closing the lid? I'm using event hooks in /etc/systemd/logind.conf and successfully suspend upon closing the lid. However I'm lost when it comes to the locking part - am I supposed to enable some screensaver service and how can I trigger two events at once in logind.conf?

Answer 1

There are a couple of examples in the Arch Wiki.

Basically, it involves creating a service file for your screen locker and ensuring it is hooked to either the suspend, hibernate or sleep targets.

If you use a simple screen locker like slock, /etc/systemd/system/lock.service would look like this:

[Unit]
Description=Lock the screen on resume from suspend

[Service]
User=jason
Environment=DISPLAY=:0
ExecStart=/usr/bin/slock

[Install]
WantedBy=suspend.target

Other examples on the wiki have more complex options, including shutting down and bringing up other services, etc.

Answer 2

While jasonwryan's reply is correct, it is incomplete. In order to safely lock after suspending, instead of before - where a non-root process may prevent the kernel from suspending, you must add a Before= instance which forces systemd to wait for the ExecStart call to slock to start before suspending. Using sleep.target covers suspend, hibernate, and hybrid sleep.

[Unit]
 Description=Lock
+Before=sleep.target

 [Service]
 User=mustapha
 Environment=DISPLAY=:0
 ExecStart=/usr/local/bin/slock

 [Install]
-WantedBy=suspend.target
+WantedBy=sleep.target

Answer 3

If you use openrc with elogind is there an alternative solution (which is not systemd dependent):

#!/bin/sh
#
# /lib/elogind/system-sleep/lock.sh
# Lock before suspend integration with elogind

username=lerax
userhome=/home/$username
export XAUTHORITY="$userhome/.Xauthority"
export DISPLAY=":0.0"

case "${1}" in
        pre)
            su $username -c "/usr/bin/slock" &
            sleep 1s;
            ;;
esac

ref: https://gist.github.com/ryukinix/bd0c1ddcbbafdb4149ae70e41b7c822b

I'm posting this because was very difficult to find it a proper way that it works and this thread appears on first results of google about "lock after suspend" or whatever.

Answer 4

All answers presented here have one fundamental flaw: They set the DISPLAY variable irespectively of what seat/session is active. And they involve writing your own systemd service file.

Thus, I suggest using the fact that logind (part of systemd, I believe) sends DBUS notifications before suspending. If you subscribe to these messages, you can start the screen locker from within you desktop environment and really lock the correct screen/session.

Additionally, there are programs like https://github.com/swaywm/swayidle that already implement this. For example, I've got this in my window manager's config:

exec swayidle -w \
    timeout 300  'swaylock -i $wallpaper' \
    timeout 600  'swaymsg "output * dpms off"' \
    resume       'swaymsg "output * dpms on"' \
    before-sleep 'swaylock -i $wallpaper' \
    lock         'swaylock -i $wallpaper'

To automagically lock the screen after some time, before suspending and whenever screen locking is requested. I've set HandleLidSwitch=lock in /etc/systemd/logind.conf to have my laptop locked when I close it.

Edit: You will also need to enable DBUS support your desktop session. I launch my window manager (sway) directly from the console, so my call became

exec dbus-run-session sway

Similarly, you could probably (I did not properly test this part) start your X window manger, i3 in the example using the following line in you ~/.xinitrc

exec dbus-launch i3 > /dev/null

Edit: Please note, that this answer is given much later. I do not if this was already possible when these answers were given and do not wish to discredit any of the other authors.