mk_sierra_iso.sh

#!/bin/sh
#
# Created 18H12
#

if [ $# -ne 1 ]; then
    echo "`basename $0` installer_app"
    exit 1
fi

set -ex

OSX_APP="$1"
VOL_INSTALL="/Volumes/install_app"
VOL_BUILD="/Volumes/install_build"
VOL_BASE="/Volumes/OS X Base System"
IMG_CDR="/tmp/Sierra.cdr"

if [ ! -d "$OSX_APP" ]; then
	echo "$OSX_APP not directory"
	exit 1
fi

if [ ! -f "$OSX_APP"/Contents/SharedSupport/InstallESD.dmg ]; then
	echo "InstallESD.dmg not found in $OSX_APP"
	exit 2
fi

hdiutil attach "$OSX_APP"/Contents/SharedSupport/InstallESD.dmg \
		-noverify -nobrowse -mountpoint $VOL_INSTALL
hdiutil create -o $IMG_CDR -size 7316m \
		-layout SPUD -fs HFS+J
hdiutil attach ${IMG_CDR}.dmg -noverify -nobrowse \
		-mountpoint $VOL_BUILD
asr restore -source $VOL_INSTALL/BaseSystem.dmg \
		-target $VOL_BUILD -noprompt -noverify -erase
rm -rf "$VOL_BASE"/System/Installation/Packages
cp -rp $VOL_INSTALL/Packages "$VOL_BASE"/System/Installation
cp -rp $VOL_INSTALL/BaseSystem.chunklist "$VOL_BASE"
cp -rp $VOL_INSTALL/BaseSystem.dmg "$VOL_BASE"
hdiutil detach $VOL_INSTALL
hdiutil detach "$VOL_BASE"
hdiutil convert ${IMG_CDR}.dmg -format UDTO \
		-o /tmp/Sierra.iso
rm -f ${IMG_CDR}.dmg
mv /tmp/Sierra.iso.cdr ~/Desktop/Sierra.iso

Hello world!