Re: temporarily disable shutdown

[David Wright <deblis@lionunicorn.co.uk>]

Quoting Matthias Bodenbinder (matthias@bodenbinder.de):
> Am 29.03.2015 um 17:35 schrieb Michael Biebl:
> > Am 29.03.2015 um 11:42 schrieb Matthias Bodenbinder:
> >> Am 28.03.2015 um 18:51 schrieb Michael Biebl:
> >>> You can run something like
> >>>
> >>> systemd-inhibit --what=shutdown --mode=block /bin/sleep 3600
> >>>
> >>> to block shutdown for 1h.
> >>
> >> This does NOT work. I tested it with debian testing.
> > 
> > Are you sure you are using systemd as PID 1?
> 
> PID 1 is /sbin/init 
> with
> lrwxrwxrwx 1 root root 20 Feb 13 12:22 /sbin/init -> /lib/systemd/systemd
> 
> All my tests where with local root: KDE+konsole, as regular user. Either executing "poweroff" via "su -" in the konsole or clicking shutdown button in KDE.
> 
> Example:
> 
> In konsole #1:
> 	su -
> 	systemd-inhibit --what="idle:sleep:shutdown" --mode=block sleep 3600
> 
> In konsole #2:
> 	su - 
> 	poweroff
> 
> The computer is just powered off.

Not using KDE myself, I can only comment on the CLI (and thanks for
the clear posting). I think you need to understand that root privilege
overrides any inhibitions, as one might expect.

This is what works for me:

jessiebox ~$ /bin/su -
Password: 
jessiebox ~# systemd-inhibit --what="idle:sleep:shutdown" --mode=block sleep 3600

and moving to a VC or another xterm:

jessiebox ~$ /sbin/poweroff 
Operation inhibited by "sleep 3600" (PID 28227 "systemd-inhibit", user root), reason is "Unknown reason".
Please retry operation after closing inhibitors and logging out other users.
Alternatively, ignore inhibitors and users with 'systemctl poweroff -i'.
jessiebox ~$ 

jessiebox ~$ systemctl poweroff -i
==== AUTHENTICATING FOR org.freedesktop.login1.power-off-ignore-inhibit ===
Authentication is required for powering off the system while an application asked to inhibit it.
Authenticating as: root
Password: [password not typed] Failed to execute operation: Connection timed out
Failed to start poweroff.target: Access denied
polkit-agent-helper-1: pam_authenticate failed: Authentication failure
jessiebox ~$ 

Now that would have worked if I had typed the password.

jessiebox ~$ systemd-inhibit --list
     Who: /bin/sleep 3600 (UID 0/root, PID 4051/systemd-inhibit)
    What: shutdown
     Why: Unknown reason
    Mode: block

1 inhibitors listed.
jessiebox ~$ 

AIUI it's up to root to check for inhibitions. I also get te
impression that mollyguard is really just for trying to prevent you
accidently closing down a machine you've ssh'd to because you think
you're still local. (I prevent this by using differently coloured
prompt strings.) I don't know how well it's integrated with systemd.

Cheers,
David.