postinst is in libapache2-mod-defensible 1.4-3.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | #! /bin/sh
set -e
reload_apache() 
{
    if apache2ctl configtest 2>/dev/null; then
        if [ -x "which invoke-rc.d 2>/dev/null" ]; then
	    invoke-rc.d apache2 force-reload || /bin/true
	else
	    /etc/init.d/apache2 force-reload || /bin/true
	fi
    else
        echo "Your apache2 configuration seem to be broken, so we're not restarting it for you."
    fi
}
case "$1" in
    configure)
        if [ -n "$2" ]; then
            # we're upgrading. test if we're enabled, and if so, restart to reload the module.
            if [ -e /etc/apache2/mods-enabled/defensible.load ]; then
	       reload_apache
            fi
        fi
    ;;
    abort-upgrade|abort-remove|abort-deconfigure)
    ;;
    *)
        echo "postinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac
exit 0
 |