#!/bin/bash
if [[ $(/usr/sbin/checkrestart | wc -l) != 1 ]]; then
  for x in {30..1}; do
    echo "pid $PID. unattended upgrade, rebooting in $((x*10)) seconds" | wall -n
    sleep 10
  done
  for x in {30..1}; do
    if ! fuser /var/lib/dpkg/lock &> /dev/null; then
      /sbin/reboot
      exit 0
    fi
    echo "pid $PID. unattended upgrade reboot waiting 10 seconds for dpkg lock" | wall -n
    sleep 10
  done
  echo "pid $PID. dpkg locked for 5 minutes, automatic reboot failed" | pee cat "wall -n"
fi