#!/bin/bash
# This script creates new initramdisk with LUKS config within
set -euo pipefail

old_initrd=$1
new_initrd=$2

# Unpacking existing initramdisk
workdir=$(mktemp -d -p /tmp se-initramfs-XXXXXX)
cd ${workdir}
gzip -cd ${old_initrd} | cpio -imd --quiet

# Adding LUKS root key and crypttab config
mkdir -p etc/luks
cp -f /etc/luks/root etc/luks/
cp -f /etc/crypttab etc/

# Creating new initramdisk image
find . | cpio --quiet -H newc -o | gzip -9 -n >> ${new_initrd}

# Cleanup
rm -rf ${workdir}