Hello,

I have been trying to create a system service that would run a script on shutdown (hence why I went for a system service over a user service) and landed on something like this

[Unit]
Description=Run backup script on shutdown
DefaultDependencies=no
Before=poweroff.target halt.target
Requires=network.target

[Service]
Type=oneshot
RemainAfterExit=true
ExecStart=/bin/true
ExecStop=/var/home/blackeco/scripts/backup.sh
User=blackeco
Group=blackeco

[Install]
WantedBy=poweroff.target halt.target

Unfortunately, when the shutdown occurs, systemd fails to execute the script:

backup-on-shutdown.service: Unable to locate executable '/var/home/blackeco/scripts/backup.sh': Permission denied
backup-on-shutdown.service: Failed at step EXEC spawning /var/home/blackeco/scripts/backup.sh: Permission denied

This script is correctly owned by user blackeco and permissions look fine

$ ls -la /var/home/blackeco/scripts
drwxr-xr-x. 1 blackeco blackeco 154  5 Feb. 13:50 ./
drwxr-xr-x. 1 blackeco blackeco 116  3 Feb. 13:07 ../
-rwxr-xr-x. 1 blackeco blackeco 794  4 Feb. 15:44 backup.sh*

I’m very puzzled as to why. I’m running Bluefin 41 (itself based on Fedora Silverblue 41).

  • BlackEcoOPAEnglish
    5·
    9 months ago

    From what I gathered from the comments, system services cannot access the home directory by design: user services should be used instead.

    But since it is nearly impossible to execute a user service on shutdown, I changed my approach and went for a user service and a timer that initiates a backup every 15 minutes. Since the backups are incremental, it shouldn’t take too much time nor space.

    • ryannathans@aussie.zoneEnglish
      1·
      9 months ago

      How long does it take to run? Can you run it on login and then execute what you need when yeu receive the sigkill signal?

  • Björn@swg-empire.deEnglish
    31·
    9 months ago

    I’m not familiar with Silverblue but home being in /var is sus. Usually it’s in /home. But maybe it’s mounted in a weird Silverblue way and gets unmounted before it runs.

    But running scripts on shutdown is hard to impossible. I always wanted to run automatic updates on shutdown but they don’t have networking even if the unit file requires networking. I haven’t seen anyone properly manage to do that yet, so good luck. And please make a post if it does end up working. Then I will revisit my own efforts again.

    • Telorand@reddthat.comEnglish
      4·
      9 months ago

      It’s not sus at all. The reason /home is in /var is because /var and /etc are the only writeable directories on the system. There is a /home, but it’s actually just a symlink to /var/home.

      This is how all of the Fedora atomic systems are set up, and it’s been the case for a lot of the other immutable distros I’ve tried. It’s just a different way of doing things.

    • whatsgoingdom@rollenspiel.forumEnglish
      2·
      9 months ago

      If that’s the reason maybe OP can add the shutdown as the last step on the script and execute the script instead of the shut down button as a work around.

      • BlackEcoOPAEnglish
        1·
        9 months ago

        No, I really don’t want to hijack the UI for this, as it could break with a DE update. And that wouldn’t work when shutting down from the console.

        • whatsgoingdom@rollenspiel.forumEnglish
          1·
          9 months ago

          Doesn’t have to be, e.g. I have a stream deck and mapped a script to one of the buttons. Or put it as an executable file on your desktop or wherever and use it instead of the normal shutdown button.

    • BlackEcoOPAEnglish
      2·
      9 months ago

      I haven’t seen anyone properly manage to do that yet, so good luck.

      Yes, that’s the whole problem, Internet is littered with posts on running a script on shutdown but none of my attempts so far has been successful.

  • Björn@swg-empire.deEnglish
    2·
    9 months ago

    Can you put the script somewhere else in var? /usr/local or /opt are usually for distro-external stuff.

    • BlackEcoOPAEnglish
      1·
      9 months ago

      I could, but I need the script to access my home in order to do the backup, and from what I gathered from Leaflet system services can’t access it.

    • BlackEcoOPAEnglish
      2·
      9 months ago

      As I said, this is a system service

        • BlackEcoOPAEnglish
          3·
          9 months ago

          I would try ProtectHome=read-only but then restic wouldn’t be able to write its local cache to ~/.restic.

          I went for a user service first to make my life easier, but unfortunately you can’t use targets poweroff.target and halt.target

          Unit /etc/systemd/user/backup-on-shutdown.service is added as a dependency to a non-existent unit poweroff.target
Unit /etc/systemd/user/backup-on-shutdown.service is added as a dependency to a non-existent unit halt.target.

          I may be in a bind then…

  • Kerb@discuss.tchncs.deEnglish
    1·
    9 months ago

    is your home folder actually under /var/home/… not under /home/… ?

    does the scripr run correctly when you paste the full path in the comandline?

    • BlackEcoOPAEnglish
      4·
      9 months ago

      is your home folder actually under /var/home/… not under /home/… ?

      Yep, it’s how Silverblue is set up

      $ ls -l /home
lrwxrwxrwx. 4 root root 8 28 janv. 13:51 /home -> var/home/

      does the scripr run correctly when you paste the full path in the comandline?

      Yes

    • BlackEcoOPAEnglish
      1·
      9 months ago
      drwxr-xr-x. 1 root root   26 28 Jan. 13:03 /var
drwxr-xr-x. 1 root root  228  3 Feb. 09:55 /var/home
drwx------. 1 blackeco blackeco 1544  5 Feb. 17:52 /var/home/blackeco
drwxr-xr-x. 1 blackeco blackeco 116  3 Feb. 13:07 /var/home/blackeco/scripts
-rwxr-xr-x. 1 blackeco blackeco 794  4 Feb. 15:44 /var/home/blackeco/scripts/backup.sh*

      And yes, blackeco can reach it

  • Telorand@reddthat.comEnglish
    1·
    9 months ago

    This might be a weird thing with how the environment variables get passed around. I’ll see if I can find my own service I wrote, but I remember having to do something with env in the ExecStart part to get my daemon to run.

    Maybe you’ll find a clue about that in the meantime!