apt-upg

#!/bin/bash
# force only system paths

PATH=/bin:/sbin:/usr/bin:/usr/sbin
if [ -n "$(which at)" ]
then
	echo "setting reboot canary for +1 hour"
	at now + 1 hour <<EOF
shutdown -R now "apt-upg canary reboot"
EOF
else
	cat >/tmp/reboot_canary.sh <<EOF
#!/bin/bash
sleep 3600
if [ -e /reboot_canary.txt ]
then
	rm -f /reboot_canary.txt
	shutdown -R +5s "apt-upg canary reboot" &
else
	wall "shutdown aborted."
fi
rm -f /tmp/reboot_canary.sh
EOF
	touch /reboot_canary.txt
	nohup bash /tmp/reboot_canary.sh >/dev/null 2>&1  &
	echo "reboot canary set for +1 hour"
fi
IONICE=$(which ionice)
NICE=$(which nice)
	
# fix broken packages
${IONICE} ${NICE} dpkg --configure -a
if [ $? -ne 0 ]
then
	echo "manually fix broken packages"
	exit 1
fi

# update the local repo info, allowing for minor release changes
${IONICE} ${NICE} apt-get update --allow-releaseinfo-change
if [ $? -ne 0 ]
then
	echo "check network connectivity and apt repo sources"
	exit 1
fi


# install updates
${IONICE} ${NICE} apt-get -y dist-upgrade
if [ $? -ne 0 ]
then
	echo "manually check upgrade failures"
	echo "'dpkg --configure -a'    may provide additional information"
	exit 1
fi

# Clean up old packages
${IONICE} ${NICE} apt-get -y autoclean && ${IONICE} ${NICE} apt-get -y autoremove
if [ $? -ne 0 ]
then
	echo "manually check for cleanup issues"
	exit 1
fi

# All done!

if [ -n "$(which at)" ]
then
	echo "use atq and  atrm  to remove the reboot canary, or else your system will reboot soon."
else
	echo "remove '/reboot_canary.txt' to abort"
fi