luks-create

#!/bin/bash

set -ueo pipefail
shopt -s inherit_errexit

APP=${0##*/}

if [ $# -lt 1 ]; then
	echo "$APP"
	echo
	echo "Syntax: $APP <file> <size in MB>"
	echo
	exit 1
fi >&2

CONTAINER=$1
CONTAINER_BACKUP="$CONTAINER.header-backup"
SIZE=$2

checkBinarys() {
        local i
        for i in "$@"; do
                hash "$i" 2>/dev/null || {
                        echo "Binary missing: $i"
                        echo
                        exit 1
                } >&2
        done
}
checkBinarys dd cryptsetup luksformat

if [[ -f "$CONTAINER" || -f "$CONTAINER_BACKUP" ]]; then
	echo "Error: File '$CONTAINER' or '$CONTAINER_BACKUP' already exists."
	echo
	exit 1
fi >&2

# create empty file
echo "Creating ${SIZE}M file.."
dd if=/dev/zero of="$CONTAINER" bs=1M count="$SIZE" status=progress
echo

# -m    Specify the percentage of the FS blocks reserved for the super-user.
#       This allows root-owned daemons, such as syslogd(8), to continue to function correctly
#       after non-privileged  processes are prevented from writing to the file system.
luksformat -t ext4 "$CONTAINER" -m 0

echo "Creating luks header backup.."
exe "cryptsetup luksHeaderBackup '$CONTAINER' --header-backup-file '$CONTAINER_BACKUP'"
echo