live-build/scripts/build/chroot_hosts

#!/bin/sh

## live-build(7) - System Build Scripts
## Copyright (C) 2016-2020 The Debian Live team
## Copyright (C) 2006-2015 Daniel Baumann <mail@daniel-baumann.ch>
##
## This program 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
[ -e "${LIVE_BUILD}/scripts/build.sh" ] && . "${LIVE_BUILD}/scripts/build.sh" || . /usr/lib/live/build.sh

# Setting static variables
DESCRIPTION="Manage /etc/hosts"
USAGE="${PROGRAM} {install|remove} [--force]"

# Processing arguments and configuration files
Init_config_data "${@}"

_ACTION="${1}"
shift

# Requiring stage file
Require_stagefiles config bootstrap

case "${_ACTION}" in
	install)
		Echo_message "Configuring file /etc/hosts"

		# Checking stage file
		Check_stagefile

		# Acquire lock file
		Acquire_lockfile

		if [ -f chroot/etc/hosts ]
		then
			# Save hosts file
			mv chroot/etc/hosts chroot/etc/hosts.orig
		fi

		# Creating hosts file

cat > chroot/etc/hosts << EOF
127.0.0.1	localhost localhost.localdomain
127.0.1.1	debian
EOF

		if [ -f /etc/hosts ]
		then
			# Append hosts file
			#grep -e "127.0.0.1" -e "127.0.1.1" /etc/hosts >> chroot/etc/hosts
			cat /etc/hosts >> chroot/etc/hosts
		fi

		# Creating stage file
		Create_stagefile
		;;

	remove)
		Echo_message "Deconfiguring file /etc/hosts"

		# Checking stage file
		Ensure_stagefile_exists

		# Acquire lock file
		Acquire_lockfile

		# Copying hosts from includes, if existing
		INCLUDE_DIR=$(select_includes_chroot)
		# includes.chroot_before_packages takes the highest precedence
		if [ -e config/includes.chroot_before_packages/etc/hosts ]
		then
			INCLUDE_DIR="includes.chroot_before_packages"
		fi
		if [ -n "${INCLUDE_DIR}" ] && [ -e config/"${INCLUDE_DIR}"/etc/hosts ]
		then
			cp config/"${INCLUDE_DIR}"/etc/hosts chroot/etc/hosts
			chmod 644 chroot/etc/hosts
			Chroot chroot "chown root:root /etc/hosts"
			rm -f chroot/etc/hosts.orig
		elif [ -f chroot/etc/hosts.orig ]
		then
			# Restore hosts file
			mv chroot/etc/hosts.orig chroot/etc/hosts
		else
			# Blank out hosts file, don't remove in case its a symlink
			Truncate chroot/etc/hosts
		fi

		# Removing stage file
		Remove_stagefile
		;;

	*)
		Echo_error "Invalid action parameter: '${_ACTION}'"
		Usage --fail
		;;
esac