Don’t let users reboot while root’s logged in

rebootshutdown

On my system users can reboot and shut down the system. From time to time I need to update software (or do anything else) and I don't want users to reboot/shutdown the system until I've finished.

Is there a way to prevent system from rebooting/shutting down while root is logged in (locally or over SSH)?

Best Answer

Try Molly guard:

$ sudo apt-get install molly-guard

This package will prevent unintended shutdown/reboot/suspend/hibernate by interactively prompting you to enter the hostname of the system.

However, it's trivial to configure molly-guard to completely disable shutdown/reboot/suspend/hibernate. Simply create an executable file at /etc/molly-guard/run.d/99-prevent-all that has this in it:

#!/bin/sh
exit 1

(You didn't mention the OS, this is for Ubuntu).

History

If you're curious the term molly-guard is what the cover over a red button is called. See the wikipedia article on Big Red Button if you're curious.

excerpt

A Big Red Switch often includes a molly-guard, a cover that must be lifted to trip the switch. The original molly-guard was jury-rigged from Plexiglas to prevent a programmer's young daughter Molly from pressing the BRS on an IBM 4341 server, after she had done so twice in one day.

Other distros

You can take the .deb package and use alien to convert it to an RPM suitable for Fedora/RHEL/CentOS.

$ sudo yum install alien
$ alien -r molly-guard*.deb

Related Solutions

Ssh – How to prevent shutdown when an SSH user is logged in

I would write a small program that checked for any active SSH connections via netstat and/or ps. Drop it in place of the shutdown command.

If no one else is using the machine, call shutdown when the user tries to. If someone is using the machine, simply warn the user who issued the shutdown command.

Netstat will give you output like this, and it's pretty easy to look for .ssh in the output.

netstat -a
Active Internet connections (including servers)
Proto Recv-Q Send-Q  Local Address          Foreign Address        State
tcp        0     52  10.5.6.xx.ssh          10.6.6.yy.51400        ESTABLISHED
tcp        0      0  *.ssh                  *.*                    LISTEN
udp        0      0  *.syslog               *.*

ps will give you output like this, but it's a bit harder because you have to make sure not to worry about outbound connections. Netstat is probably the right way to go.

  ps -e | grep ssh
      10084366 ?        00:00:07 /opt/sbin/sshd
        282647 ?        00:00:00 /opt/sbin/sshd

Debian – KDE: Leave –> Turn Off Computer not shutting down system

I've searched /var/log/ for any shutdown-related errors

Debian 8 using systemd, you should check ERR log with journalctl -xb

The release news says:

"Jessie" ships with a new default init system, systemd. The systemd suite provides many exciting features such as faster boot times, cgroups for services, and the possibility of isolating part of the services. The sysvinit init system is still available in "Jessie".

I am confused It would say No journal files were found.
You can check whether systemd-journald is running withsystemctl status systemd-journald And start it with:

systemctl enable systemd-journald
systemctl start systemd-journald