live-build/scripts/build/chroot_resolv

#!/bin/sh

# lh_chroot_resolv(1) - manage /etc/resolv.conf
# Copyright (C) 2006-2010 Daniel Baumann <daniel@debian.org>
#
# live-helper comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
# This is free software, and you are welcome to redistribute it
# under certain conditions; see COPYING for details.

set -e

# Including common functions
. "${LH_BASE:-/usr/share/live/build}"/scripts/build.sh

# Setting static variables
DESCRIPTION="$(Echo 'manage /etc/resolv.conf')"
HELP=""
USAGE="${PROGRAM} {install|remove} [--force]"

Arguments "${@}"

# Reading configuration files
Read_conffiles config/all config/common config/bootstrap config/chroot config/binary config/source
Set_defaults

# Requiring stage file
Require_stagefile .stage/config .stage/bootstrap

case "${1}" in
	install)
		Echo_message "Configuring file /etc/resolv.conf"

		# Checking stage file
		Check_stagefile .stage/chroot_resolv

		# Checking lock file
		Check_lockfile .lock

		# Creating lock file
		Create_lockfile .lock

		if [ -e chroot/etc/resolv.conf ]
		then
			# Save resolv file or symlink
			mv chroot/etc/resolv.conf chroot/etc/resolv.conf.orig

			# Also truncate it, otherwise we'll end up with the one
			# created by debootstrap in the final image.
			#
			# If you want to have a custom resolv.conf, please
			# overwrite it with normal local_includes mechanism.
			Truncate chroot/etc/resolv.conf.orig
		fi

		if [ -f /etc/resolv.conf ]
		then
			# Copy resolv file
			cp /etc/resolv.conf chroot/etc/resolv.conf
		fi

		# Creating stage file
		Create_stagefile .stage/chroot_resolv
		;;

	remove)
		Echo_message "Deconfiguring file /etc/resolv.conf"

		# Checking lock file
		Check_lockfile .lock

		# Creating lock file
		Create_lockfile .lock

		if [ -e config/chroot_local-includes/etc/resolv.conf ]
		then
			# Copying local resolv.conf
			cp -a config/chroot_local-includes/etc/resolv.conf chroot/etc/resolv.conf
			rm -f chroot/etc/resolv.conf.orig
		elif [ -e chroot/etc/resolv.conf.orig ]
		then
			# Restoring resolv file or symlink
			mv chroot/etc/resolv.conf.orig chroot/etc/resolv.conf
		else
			# Truncating resolv file
			Truncate chroot/etc/resolv.conf
		fi

		# Removing stage file
		rm -f .stage/chroot_resolv
		;;

	*)
		Usage
		;;
esac