Make OS X installer ISO (CDR) from OS Install app

makeinstaller.sh

#!/bin/sh

user_id=`id -u`

if [ $user_id -ne 0 ]; then
	echo "$0: must be root"
	exit 1
fi

if [ $# -lt 2 ]; then
	echo "$0: not enough parameters. usage:"
	echo "$0 <path-to-installer> <path-to-destination>"
	exit 1
fi

installer_app_path="$1"
dest_dir="$2"

install_esd="$installer_app_path/Contents/SharedSupport/InstallESD.dmg"
install_esd_mount="/Volumes/OS X Install ESD"

if [ ! -f "$install_esd" ]; then
	echo "$0: invalid installer app path"
	exit 1
fi

if [ ! -d "$dest_dir" ]; then
	echo "$0: invalid destination path"
	exit 1
fi

base_sys="$install_esd_mount/BaseSystem.dmg"
temp_installer="$dest_dir/TempInstaller.sparseimage"
installer="$dest_dir/Installer.cdr"

if [ -f "$temp_installer" ]; then
	echo "$0: temporary image exists"
	echo "please delete $temp_installer"
	exit 1
fi

if [ -f "$installer" ]; then
	echo "$0: previous image exists"
	echo "please delete $installer"
	exit 1
fi

echo "Mounting ESD"
hdiutil attach \
	-noverify \
	-nobrowse \
	"$install_esd"
echo "Converting BaseSystem"
hdiutil convert \
	"$base_sys" -format UDSP -o "$temp_installer"

echo "Resizing converted BaseSystem"
hdiutil resize -size 8g "$temp_installer"

base_sys_mount="/Volumes/OS X Base System"

echo "Mounting converted BaseSystem"
hdiutil attach \
	"$temp_installer" \
	-noverify \
	-nobrowse

rm "$base_sys_mount/System/Installation/Packages"
echo "Copying installer packages"
cp -pR "$install_esd_mount/Packages" "$base_sys_mount/System/Installation/"

echo "Ejecting Base"
hdiutil eject "$base_sys_mount"

echo "Ejecting ESD"
hdiutil eject "$install_esd_mount"

echo "Converting to UDTO"
hdiutil convert \
	"$temp_installer" -format UDTO -o "$installer"

echo "Removing temp installer"
rm "$temp_installer"


echo
echo
echo 'Your shiney new installer CDR should be here:'
echo "    $installer"

Note also https://github.com/timsutton/osx-vm-templates/blob/master/prepare_iso/prepare_iso.sh