chroot into an initramfs with a single command

ramfs-chroot

#!/bin/bash

set -e

if [[ $# -ne 1 ]]; then
	echo "usage: ramfs-chroot <ramfs_image>"
	exit 1
fi

RAMFS=$1
DIR=$(mktemp -d)

trap "rm -rf '$DIR'" EXIT
trap "exit" SIGINT SIGTERM

echo "-> unpacking $1 to $DIR"

unmkinitramfs "$1" "$DIR"

echo -n "-> "
ls "$DIR/main"

echo "-> changing root"
fakechroot chroot "$DIR/main" "/bin/sh"

echo ""  # add linebreak after last sh prompt

note that this keeps the host's environment variables, which should be fixed at some point (how exactly do the initramfs environment variables look? are there any?)