#!/bin/sh

if [ $(id -u) -ne 0 ]; then
    echo "This must be run as root." 1>&2
    exit 1
fi

if [ "$1" = "" ]; then
    echo "Must provide a disk as the first parameter." 1>&2
    exit 1
fi

if [ "$2" = "" ]; then
    echo "Must provide key file as a second parameter." 1>&2
    exit 1
fi

if [ \! -b $1 ]; then
    echo "The first parameter must be a block device representing an empty disk." 1>&2
    exit 1
fi

if [ "$(partx -l $1)" != "" ]; then
    partx -l $1 1>&2
    echo "The disk must not have a partition table." 1>&2
    exit 1
fi

disk=$1
keyfile=$2

# Create key file, if necessary.
if [ \! -e $2 ]; then
    oldumask=$(umask)
    umask 077
    dd if=/dev/random of=$2 bs=1 count=256
    chmod 0500 $2
    umask $oldumask
fi

# Check and randomize disk.
badblocks -b 512 -s -w -t random -v $disk || exit 2
</dev/urandom pv -s $(fdisk -l $disk |
    perl -nle 'm{^Disk '${disk}': [0-9.]+ [KMGT]B, (\d+) bytes$} and print $1') |
  dd bs=512 conv=sync,noerror of=$disk

# Add and format the LUKS partition.
echo , | sfdisk --Linux $disk
cryptsetup luksFormat --cipher aes-cbc-essiv:sha256 --batch-mode ${disk}1 $keyfile
sfdisk -R $disk; sleep 5

# Open LUKS partition, format and mount the encrypted volume.
cryptsetup --key-file $keyfile luksOpen ${disk}1 backups
mkfs -t jfs -q /dev/mapper/backups
mount /backups

# Do the initial backup.
mkdir -vp /backups/1/{etc,var,phil,postgresql,mysql,rivana}
chmod a-w /backups/1
chown rivana /backups/1/rivana
chown postgres /backups/1/postgresql
rsync -avP --filter 'merge /etc/backups/etc-filter' /etc/ /backups/1/etc/
rsync -avP --filter 'merge /etc/backups/var-filter' /var/ /backups/1/var/
rsync -avP --filter 'merge /etc/backups/phil-filter' /home/phil/ /backups/1/phil/
su -c 'pg_dumpall -v >/backups/1/postgresql/dump' postgres
mysqldump -v --all-databases >/backups/1/mysql/dump
echo -n "Hit enter when rivana is backed up.  "
read foo

# Deactivate the encrypted volume.
umount /backups
cryptsetup luksClose backups

# Add user password.
cryptsetup --key-file $keyfile --verify-passphrase luksAddKey ${disk}1

# Display the partition's UUID.
echo -n 'UUID: '
cryptsetup luksUUID ${disk}1