#!/bin/sh -eux
export DEBIAN_FRONTEND=noninteractive

ubuntu_version="`lsb_release -r | awk '{print $2}'`";
major_version="`echo $ubuntu_version | awk -F. '{print $1}'`";

# Disable release-upgrades
sed -i.bak 's/^Prompt=.*$/Prompt=never/' /etc/update-manager/release-upgrades;

# Disable systemd apt timers/services
if [ "$major_version" -ge "16" ]; then
  systemctl stop apt-daily.timer;
  systemctl stop apt-daily-upgrade.timer;
  systemctl disable apt-daily.timer;
  systemctl disable apt-daily-upgrade.timer;
  systemctl mask apt-daily.service;
  systemctl mask apt-daily-upgrade.service;
  systemctl daemon-reload;
fi

# Disable periodic activities of apt to be safe
cat <<EOF >/etc/apt/apt.conf.d/10periodic;
APT::Periodic::Enable "0";
APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "0";
EOF

# Clean and nuke the package from orbit
rm -rf /var/log/unattended-upgrades;
apt-get -y purge unattended-upgrades;

# Update the package list
apt-get -y update;

# Upgrade all installed packages incl. kernel and kernel headers
apt-get -y dist-upgrade -o Dpkg::Options::="--force-confnew";

reboot