Ok I seem to have TKLPatch working. Now instead of using overlay with fixed config settings I would like to use di-live.

There seem to be two things I need to get sorted.

1 - di-live file

2 - system config applier file

DI-LIVE FILE

Drop this in /usr/lib/di-live.d
WHAT shuld I call the file? The TurnKey ISO file in this location seem to be pre-appended with numbers?       

#!/usr/bin/python
import sys
import common	

TARGET = "/target"

def main():
    if not common.target_mounted(TARGET):
        sys.exit(10) # return to menu

    db = common.Debconf()
    username = db.get_input('Enter value for Username', 'testuser')
    domain = db.get_input('Enter value for Domain', 'corp-domain')
    proxy = db.get_input('Enter value for Proxy', '10.1.1.1:8080')
    password = db.get_password('Enter password')
    chroot = common.Chroot(TARGET)
    chroot.system('cntlm-config %s %s %s %s' % (username, domain, proxy, password ))

if __name__ == "__main__":
    main()

SYSTEM CONFIG APPLIER FILE

place in .../overlay/usr/local/bin/cntlm-config

#!/bin/bash 
APT_CONF_FILE="/etc/cntlm.conf"
sed -e '/^Username/s/testuser/$1/g' $APT_CONF_FILE 
sed -e '/^Domain/s/corp-uk/$2/g' $APT_CONF_FILE 
sed -e '/^Password/s/password/$3/g' $APT_CONF_FILE 
sed -e '/^Proxy/s/10\.217\.112\.4.\:8080/$4/g' $APT_CONF_FILE 
sed -e '/^Listen/s/3128/9090/g' $APT_CONF_FILE

The above is untested, I will get to that shortly.

So is the approach OK?

What do I call the di-live.d file?