export DEBIAN_FRONTEND=noninteractive
apt-get update
apt-get dist-upgrade -y
apt-get -y --force-yes install distro-info openssh-server update-manager-core
if [ $(lsb_release -sc) == $(distro-info --lts) ] ; then
    sed 's/Prompt=lts/Prompt=normal/' -i /etc/update-manager/release-upgrades
fi
do-release-upgrade -d -f DistUpgradeViewNonInteractive