#!/bin/ksh -p

IMAGES=/var/lib/libvirt/images
XML=/etc/libvirt/qemu

machine=$1
size=$2

if [ -z "$size" ]
then
  echo "Syntax: ${0##*/} machine_name size"
  echo "    Size must be numeric, and is in Megabytes"
  exit
fi

case $size in
  +([0-9])) # All numeric, fine
            ;;
         *) echo Size must be numeric, and is in Megabytes
            exit
esac

if [ ! -r $XML/$machine.xml ]
then
  echo $XML/$machine.xml does not exist
  echo aborted
  exit
fi

disk_img=
for a in k j i h g f e d c b
do
  tst=$IMAGES/$machine.disk$a.img
  if [ ! -f $tst ]
  then
    disk_img=$tst
    sd=vd$a
  fi
done

if [ -z "$disk_img" ]
then
  echo Already 10 disks... aborted
  exit
fi

echo Creating $disk_img
dd if=/dev/zero of=$disk_img bs=1M count=$size
ls -l $disk_img

echo Updating VM
t=$(mktemp)
to_add="
<disk type='file' device='disk'>
  <driver name='qemu' type='raw' cache='none'/>
  <source file='$disk_img'/>
  <target dev='$sd' bus='virtio'/>
</disk>
"

if [ -n "$(virsh list | awk '$2 =="'$machine'" { print $0}')" ]
then
  echo Hot adding
  echo "$to_add" > $t
  virsh attach-device $machine $t
fi

echo Adding to permanent config
cp $XML/$machine.xml $t
print "/<.devices
i
$to_add
.
w
q" | ed -s $t

virsh define $t
echo Done

rm $t