postinst is in network-manager-iodine 0.0.5-1ubuntu1.
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 | #!/bin/sh
set -e
case "$1" in
	configure)
		if [ -x "/etc/init.d/dbus" ]; then
			if [ -x /usr/sbin/invoke-rc.d ]; then
				invoke-rc.d dbus force-reload || true
			else
				/etc/init.d/dbus force-reload || true
			fi
		fi
		if ! getent passwd nm-iodine >/dev/null; then
			adduser --quiet \
				--system \
				--quiet \
				--disabled-login \
				--disabled-password \
				--home /var/run/iodine \
				--no-create-home \
				-gecos "Network Manager iodine" \
				nm-iodine
		fi
        ;;
esac
exit 0
 |