How does Ubuntu keep track of the "System restart required" flag in motd?
Check for the presence of
The script that generates the reboot required part of motd is /usr/lib/update-notifier/update-motd-reboot-required which contains:
#!/bin/sh -e # # helper for update-motd if [ -f /var/run/reboot-required ]; then cat /var/run/reboot-required fi
Your nagios check could check for the existence of /var/run/reboot-required.
Additionally the file '/var/run/reboot-required.pkgs' lists the packages that requested the reboot. For example:
$ cat /var/run/reboot-required.pkgs linux-image-2.6.32-28-generic dbus $
On Ubuntu Lucid (10.4).
Debian and Ubuntu packages can trigger the creation of
/var/run/reboot-required* in their
postinst file by executing the helper script
Thus the "official" way to process reboots is handled by the package maintainer. I have been doing it previously in a script by comparing time booted against mtimes in /boot.
#!/bin/bash if [ ! -f /var/run/reboot-required ]; then # no reboot required (0=OK) echo "OK: no reboot required" exit 0 else # reboot required (1=WARN) echo "WARNING: `cat /var/run/reboot-required`" exit 1 fi