#!/bin/bash -eux
  
  # inspired by https://github.com/boxcutter/ubuntu
  
  echo "==> Disabling the release upgrader"
  sed -i.bak 's/^Prompt=.*$/Prompt=never/' /etc/update-manager/release-upgrades
  
  systemctl disable apt-daily.service
  systemctl disable apt-daily.timer
  
  echo "==> Updating list of repositories"
  apt-get -y update
  
  echo "==> Performing dist-upgrade (all packages and kernel)"
  DEBIAN_FRONTEND=noninteractive apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" dist-upgrade
  
  SSH_USER=${SSH_USERNAME:-vagrant}
  SSH_PASS=${SSH_PASSWORD:-vagrant}
  SSH_USER_HOME=${SSH_USER_HOME:-/home/${SSH_USER}}
  VAGRANT_INSECURE_KEY="ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6NF8iallvQVp22WDkTkyrtvp9eWW6A8YVr+kz4TjGYe7gHzIw+niNltGEFHzD8+v1I2YJ6oXevct1YeS0o9HZyN1Q9qgCgzUFtdOKLv6IedplqoPkcmF0aYet2PkEDo3MlTBckFXPITAMzF8dJSIFo9D8HfdOV0IAdx4O7PtixWKn5y2hMNG0zQPyUecp4pzC6kivAIhyfHilFR61RGL+GPXQ2MWZWFYbAGjyiYJnAmCP3NOTd0jMZEnDkbUvxhMmBYSdETk1rRgm+R4LOzFUGaHqHDLKLX+FIPKcF96hrucXzcWyLbIbEgE98OHlnVYCzRdK8jlqm8tehUc9c9WhQ== vagrant insecure public key"
  
  echo "==> Giving ${SSH_USER} sudo powers"
  echo "${SSH_USER}        ALL=(ALL)       NOPASSWD: ALL" >> /etc/sudoers.d/vagrant
  chmod 440 /etc/sudoers.d/vagrant
  
  if grep -q -E "^mesg n$" /root/.profile && sed -i "s/^mesg n$/tty -s \\&\\& mesg n/g" /root/.profile; then
    echo "==> Fixed stdin not being a tty."
  fi
  
  echo "==> Installing vagrant key"
  mkdir $SSH_USER_HOME/.ssh
  chmod 700 $SSH_USER_HOME/.ssh
  
  # https://raw.githubusercontent.com/mitchellh/vagrant/master/keys/vagrant.pub
  echo "${VAGRANT_INSECURE_KEY}" > $SSH_USER_HOME/.ssh/authorized_keys
  chmod 600 $SSH_USER_HOME/.ssh/authorized_keys
  chown -R $SSH_USER:$SSH_USER $SSH_USER_HOME/.ssh
  
  echo "UseDNS no" >> /etc/ssh/sshd_config
  
  if [[ $PACKER_BUILDER_TYPE =~ virtualbox ]]; then
      echo "==> Installing VirtualBox guest additions"
      VBOX_VERSION=$(cat ${SSH_USER_HOME}/.vbox_version)
      mount -o loop ${SSH_USER_HOME}/VBoxGuestAdditions_$VBOX_VERSION.iso /mnt
      sh /mnt/VBoxLinuxAdditions.run
      umount /mnt
      rm ${SSH_USER_HOME}/VBoxGuestAdditions_$VBOX_VERSION.iso
      rm ${SSH_USER_HOME}/.vbox_version
  fi
  
  echo "==> Install stlink"
  wget -qO - https://github.com/texane/stlink/archive/master.tar.gz | tar xz
  mkdir stlink-master/build && cd stlink-master/build && cmake .. && make && make install
  cd ../.. && rm -rf stlink.git
  
  echo "==> Install cli-tools"
  wget -qO - https://github.com/iot-lab/cli-tools/archive/2.1.0.tar.gz | tar xz
  cd cli-tools-* && python setup.py install && cd .. && rm -rf cli-tools-*
  
  # Remove some packages to get a minimal install
  echo "==> Removing all linux kernels except the currrent one"
  dpkg --list | awk '{ print $2 }' | grep 'linux-image-*-generic' | grep -v $(uname -r) | xargs apt-get -y purge
  echo "==> Removing linux source"
  dpkg --list | awk '{ print $2 }' | grep linux-source | xargs apt-get -y purge
  echo "==> Removing documentation"
  dpkg --list | awk '{ print $2 }' | grep -- '-doc$' | xargs apt-get -y purge
  echo "==> Removing default system Ruby"
  apt-get -y purge ruby ri doc
  echo "==> Removing X11 libraries"
  apt-get -y purge libx11-data xauth libxmuu1 libxcb1 libx11-6 libxext6
  echo "==> Removing obsolete networking components"
  apt-get -y purge ppp pppconfig pppoeconf
  echo "==> Removing other oddities"
  apt-get -y purge popularity-contest installation-report landscape-common wireless-tools wpasupplicant
  
  # Clean up the apt cache
  apt-get -y autoremove --purge
  apt-get -y autoclean
  apt-get -y clean
  
  # Clean up orphaned packages with deborphan
  apt-get -y install deborphan
  while [ -n "$(deborphan --guess-all --no-guesspython --libdevel)" ]; do
      deborphan --guess-all --no-guess-python --libdevel | xargs apt-get -y purge
  done
  apt-get -y purge deborphan dialog
  
  echo "==> Removing man pages"
  rm -rf /usr/share/man/*
  echo "==> Removing APT files"
  find /var/lib/apt -type f | xargs rm -f
  echo "==> Removing any docs"
  rm -rf /usr/share/doc/*
  echo "==> Removing caches"
  find /var/cache -type f -exec rm -rf {} \;
  
  echo "==> Cleaning up leftover dhcp leases"
  if [ -d "/var/lib/dhcp" ]; then
      rm /var/lib/dhcp/*
  fi
  
  # Add delay to prevent "vagrant reload" from failing
  echo "pre-up sleep 2" >> /etc/network/interfaces
  
  mv /tmp/udev_rules/* /etc/udev/rules.d/
  
  echo "==> Cleaning up tmp"
  rm -rf /tmp/*
  
  # Remove Bash history
  unset HISTFILE
  rm -f /root/.bash_history
  rm -f ${SSH_USER_HOME}/.bash_history
  
  # Clean up log files
  find /var/log -type f | while read f; do echo -ne '' > "${f}"; done;
  
  echo "==> Clearing last login information"
  >/var/log/lastlog
  >/var/log/wtmp
  >/var/log/btmp
  
  echo "==> whiteout /"
  count=$(df --sync -kP / | tail -n1  | awk -F ' ' '{print $4}')
  let count--
  dd if=/dev/zero of=/tmp/whitespace bs=1024 count=$count
  rm /tmp/whitespace
  
  echo "==> whiteout /boot"
  count=$(df --sync -kP /boot | tail -n1 | awk -F ' ' '{print $4}')
  let count--
  dd if=/dev/zero of=/boot/whitespace bs=1024 count=$count
  rm /boot/whitespace
  
  echo '==> Clear out swap and disable until reboot'
  set +e
  swapuuid=$(/sbin/blkid -o value -l -s UUID -t TYPE=swap)
  case "$?" in
      2|0) ;;
      *) exit 1 ;;
  esac
  set -e
  if [ "x${swapuuid}" != "x" ]; then
      # Whiteout the swap partition to reduce box size
      # Swap is disabled till reboot
      swappart=$(readlink -f /dev/disk/by-uuid/$swapuuid)
      /sbin/swapoff "${swappart}"
      dd if=/dev/zero of="${swappart}" bs=1M || echo "dd exit code $? is suppressed"
      /sbin/mkswap -U "${swapuuid}" "${swappart}"
  fi
  
  echo "==> whiteout free space"
  dd if=/dev/zero of=/EMPTY bs=1M  || echo "dd exit code $? is suppressed"
  rm -f /EMPTY
  
  sync
  
  echo "==> Disk usage"
  df -h