#!/usr/bin/env bash
#
# A Linux system generalizer to prep for problem-free cloning
# Copyright (C) 2016  Aaron Ball <nullspoon@oper.io>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#
# Description
# -----------
#
# **Danger, Will Robinson! Danger!**
# This script is catastrophic!
#
# This script will generalize the system it is executed on, and remove itself
# afterwards, leaving no trace.
#
# The intent is to produce a linux system that can be cloned without having
# duplicate mac addresses, duplicate ssh host keys, strange unexpected shell
# histories, etc.
#
# NOTE: This only fully works on Centos 6 and 7 presently.
#

# Set the log file
# If not set, logs will be output to stdout
#logfile=/root/cleanup.log

function log {
  timestamp=$(date '+%F %T')
  if [[ -z ${logfile} ]]; then
    # Output to stdout if no logfile is specified
    echo "[${timestamp}]: ${*}"
  else
    # Logfile var set. Output there.
    echo "[${timestamp}]: ${*}" >> ${logfile}
  fi
}


function main {
  if [[ $(id -u) != 0 ]]; then
    echo "This script must be run as root, which you are not."
    return 1
  fi

  log "Initializing cleanup"

  log "Removing ssh host_keys"
  rm -f /etc/ssh/ssh_host_*


  log "Preventing root command history from being written"
  unset HISTFILE
  log "Cleanup of root history file"
  rm -f /root/.bash_history


  log "Removing hard-coded mac addresses."
  service network stop
  local ifcfg_files=/etc/sysconfig/network-scripts/ifcfg-e*
  sed -i '/^HWADDR=.*$/d' ${ifcfg_files}


  log "Cleaning up nic udev rules..."
  # Centos 6 udev net rules file
  local net_6udev='/etc/udev/rules.d/70-persistent-net.rules'
  [[ -f "${net_6udev}" ]] && rm -f "${net_6udev}"

  # CentOS 7 udev net rules file
  local net_7udev='/etc/udev/rules.d/70-persistent-ipoib.rules'
  [[ -f "${net_7udev}" ]] && rm -f "${net_7udev}"

  # Delete myself (don't worry, I'll still exist in your memories/ram)
  rm -f ${mypath}

  log "Cleanup complete. Shutting down in 5 seconds."

  # Sleep for a few seconds so the user has a chance to cancel
  sleep 5

  # Shutdown
  shutdown -h now
}

main ${@}