UPS canary script

canary.sh

# Ping the specified host (argument $1). If it's not there, wait 30 seconds and try again.
# If its not there for 2 minutes, do a clean shutdown.
# The host should be connected to the nextwork and plugged into a socket that's not backed up by the UPS.
# This should be run on a host that is backed up by the UPS, on a cron job.
tail -c 10000 /var/log/canary.log > /var/log/canary.log
REBOOT=true
for e in a b c d
do
    sleep 30
    if ping -c1 $1
    then
	 REBOOT=false
	 break
    fi
done
if $REBOOT
then
     echo "Canary has died, shutting down\n"
     /sbin/shutdown -h now
fi
echo "Canary is alive, exiting\n"