#!/bin/bash

#####################################################################
#
# A FOOLISH KVM BACKUP SCRIPT 
# hacked together by Miguel<m.i@gmx.at> around mid February 2018
#
# untar also needs -S !!!
#
# TODO: ADD TIMING INFO ?
#
# TODO: do not make so many assumptions about file names and locations :(
#	This script should/could be much more universal!
#	Do some BASIC error checking
#
# TODO!: 
#	 config external backup space
#	 show config and ask if ok
#	 override --all-yes with param
#	 use dash instead bash?
#	 dry run
#
#####################################################################

VERSION="0.1"

# we exit as soon as a single command fails!
set -e

echo ""
echo " 1) Are you running inside a tmux/screen?"
echo " 2) Did you cleanup the backuped system (pruning unused stuff)?"
echo " 3) Did you remember to perform sync & fstrim?"
echo " 4) Are you aware this script runs many commands with sudo?"
echo ""
echo " Please type 'YES' if you want to continue."
echo ""

read proceed
if [[ "$proceed" != "YES" ]]; then
	exit
fi

# script expects exaclty one param (see config_example)
if [ "$#" -ne 1 ]; then
    echo "Usage: $0 [config_file]"
    exit
fi

# color helpers (set on terminal only)
black=
red=
green=
yellow=
blue=
magenta=
cyan=
white=
reset=
if test -t 1; then
black=`tput setaf 0`
red=`tput setaf 1`
green=`tput setaf 2`
yellow=`tput setaf 3`
blue=`tput setaf 4`
magenta=`tput setaf 5`
cyan=`tput setaf 6`
white=`tput setaf 7`
reset=`tput sgr0`
fi

# pretty printing funcs / vars

cnt=0
all=11

function print_ok {
	echo [${green}OK$reset]
}
function print_cnt {
	printf "    [${cyan}%2s${reset}/${all}${reset}] " ${1}
}
function print_txt {
   	((++cnt))
        print_cnt $cnt
	printf "%-30s  " "${1}..."
}

# let's do it
echo
echo "### ${magenta}FOOL LIVE KVM BACKUP ${VERSION}${reset} ###"
echo
echo "    Using config file:    ${yellow}${1}${reset}"
echo
source $1

# some vars
TIMESTAMP=`date +"%Y%m%d_%H%M%S"`
LOG=${DOMAIN}_${TIMESTAMP}.log
DOMAIN_T=${DOMAIN}_${TIMESTAMP}

# tell what we gonna do
echo "    Today we backup:      ${yellow}${DISK}$reset on ${yellow}${DOMAIN}${reset} as ${yellow}${USER}${reset}"
echo "    SOURCE_DIR:           ${yellow}${SOURCE}$reset"
echo "    TARGET_DIR:           ${yellow}${TARGET}$reset"
echo "    LIMIT_RATE for tar:   ${yellow}${LIMIT_RATE}${reset}/second"
echo "    Logging to:           ${yellow}${LOG}$reset"
echo
echo "    Keep your fingers crossed!"
echo

# chande into target dir
cd $TARGET

print_txt "LOG CURRENT DOMBLK LIST"
sudo -u $USER virsh domblklist $DOMAIN > $LOG
print_ok

print_txt "DUMPING XML"
sudo -u $USER virsh dumpxml $DOMAIN > $DOMAIN_T.xml
sudo -u $USER virsh dumpxml $DOMAIN | sed "s:$SOURCE/${DOMAIN}.img:$SOURCE/${DOMAIN}.SNAP:" > ${DOMAIN_T}_snapped.xml
print_ok

print_txt "SAVING VM (RAM)"
sudo -u $USER virsh save $DOMAIN $DOMAIN_T.ram >> $LOG
print_ok

print_txt "SNAPSHOTTING DISK"
sudo -u $USER virsh snapshot-create-as $DOMAIN SNAP --disk-only --atomic --no-metadata --quiesce >> $LOG
print_ok

print_txt "RESTORING VM (RAM)"
sudo -u $USER virsh restore $DOMAIN_T.ram --xml ${DOMAIN_T}_snapped.xml >> $LOG
print_ok

print_txt "LOG CURRENT DOMBLKLIST"
sudo -u $USER virsh domblklist $DOMAIN >> $LOG
print_ok

print_txt "SAVING SNAPSHOT"
sudo -u $USER tar -C ${SOURCE} -cSf - $DOMAIN.img 2>>$LOG | pv -L $LIMIT_RATE 2>/dev/null 1> $DOMAIN_T.img.tar 
print_ok

print_txt "BLOCK-COMMITTING DELTAS"
sudo -u $USER virsh blockcommit $DOMAIN $DISK --pivot >> $LOG
print_ok

print_txt "REMOVING DELTAS"
sudo -u $USER rm ${SOURCE}/$DOMAIN.SNAP >> $LOG
print_ok

print_txt "LOG CURRENT DOMBLKLIST"
sudo -u $USER virsh domblklist $DOMAIN >> $LOG
print_ok

print_txt "LOG QCOW2 IMAGE INFO"
sudo -u $USER qemu-img info ${SOURCE}/$DOMAIN.img  >> $LOG
print_ok

echo
echo "### ${magenta}FINITO${reset} ###"
echo