#!/bin/bash

set +x

trap clean_exit EXIT
function clean_exit() {
        [[ -f /tmp/backup-running ]] && rm -f /tmp/backup-running
}

# Path, where backups should be stored
DST=/srv/backup/kvm

# Path, where temporary snapshots should be created
SNAP=/var/backups/snapshots

test -d ${DST} || mkdir -p ${DST}
test -d $SNAP || mkdir -p $SNAP

date=$(date +"%Y%m%d")

if [[ -f /tmp/backup-running ]]; then
        exit 1
fi
touch /tmp/backup-running

#mount /dev/sda1 ${DST} >/dev/null 2>&1

#if [[ "$?" -ne 0 ]]; then
#        echo "Unable to mount backup drive!"
#        exit 1
#fi

rm -f ${DST}/LATEST_*

for VM in $(virsh list --name); do
        echo "Backup KVM guest ${VM}"

        if [[ -f ${DST}/${VM}.img ]]; then
                echo "Remove old backup guest image..."
                rm -f ${DST}/${VM}.img
        fi
        if [[ -f ${DST}/${VM}.xml ]]; then
                echo "Remove old backup guest XML definition..."
                rm -f ${DST}/${VM}.xml
        fi

        echo "Create Snapshot..."
        virsh snapshot-create-as ${VM} "backup-${VM}" \
                --diskspec vda,file=${SNAP}/backup-snapshot-${VM}.qcow2 \
                --disk-only \
                --atomic \
                --quiesce \
                --no-metadata

        echo "Copy guest image to backup drive..."
        cp --sparse=always /var/lib/libvirt/images/${VM}.img ${DST}/

        echo "Copy XML to backup drive..."
        cp /etc/libvirt/qemu/${VM}.xml ${DST}/

        echo "Merge snapshot with guest image..."
        virsh blockcommit ${VM} vda --wait --active --verbose --pivot

	# Make sure, snapshot merging was successfull
	current_disk=$(virsh domblklist ${VM} --details | grep vda | awk '{ print $4; }' | cut -d "/" -f -5)
	
	if [[ "$current_disk" == "/var/lib/libvirt/images" ]]; then
	        echo "Remove snapshot..."
        	rm -f ${SNAP}/backup-snapshot-${VM}.qcow2
	fi

        touch ${DST}/LATEST_$date
done

#echo "Syncing disk..."
#sync
#umount /mnt

rm -f /tmp/backup-running

exit 0