#!/bin/bash
#
# Sysprep OS for vmware template creation.  
#
# Shamelessly taken from https://oitibs.com/linux-vm-template-creation/
 
echo "Removing openssh-server's host keys..."
rm -vf /etc/ssh/ssh_host_*
cat /dev/null > /etc/rc.local
chmod +x /etc/rc.local
cat << 'EOL' | sudo tee /etc/rc.local
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
# dynamically create hostname (optional)
if hostname | grep localhost; then
    hostnamectl set-hostname "$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 13 ; echo '')"
fi
test -f /etc/ssh/ssh_host_dsa_key || dpkg-reconfigure openssh-server
if [ ! -f /etc/machine-id ]
then
  /usr/bin/systemd-machine-id-setup
fi
exit 0
EOL


echo "Cleaning up /var/mail..."
rm -vf /var/mail/*
 
echo "Clean up apt cache..."
find /var/cache/apt/archives -type f -exec rm -vf \{\} \;
 
echo "Clean up ntp..."
rm -vf /var/lib/ntp/ntp.drift
rm -vf /var/lib/ntp/ntp.conf.dhcp
 
echo "Clean up dhcp leases..."
rm -vf /var/lib/dhcp/*.leases*
rm -vf /var/lib/dhcp3/*.leases*
 
echo "Clean up udev rules..."
rm -vf /etc/udev/rules.d/70-persistent-cd.rules 
rm -vf /etc/udev/rules.d/70-persistent-net.rules
 
echo "Clean up urandom seed..."
rm -vf /var/lib/urandom/random-seed
 
echo "Clean up backups..."
rm -vrf /var/backups/*;
rm -vf /etc/shadow- /etc/passwd- /etc/group- /etc/gshadow- /etc/subgid- /etc/subuid-
 
echo "Cleaning up /var/log..."
find /var/log -type f -name "*.gz" -exec rm -vf \{\} \;
find /var/log -type f -name "*.1" -exec rm -vf \{\} \;
find /var/log -type f -exec truncate -s0 \{\} \;
   
echo "Compacting drive..."
dd if=/dev/zero of=EMPTY bs=1M > /dev/null
rm -vf /root/EMPTY
fstrim -av
 
echo "Clearing bash history..."
cat /dev/null > /root/.bash_history
history -c
 
echo "Process complete..."
poweroff