Backup script using rsync and tar. Automatically delete old backups when space not sufficient.

server_backup.bash

###################
# settings
backup_dir=<path to the backup directory> # e.g. /root/backup
remote_server=<example.com> # ip address or server name set in ssh config, same as using the ssh or scp
server_name=<server_name> # a tag for the log purpose and will be the backup folder name
###################

startTime=$(date +%s)

# define color
GREEN='\033[0;32m'
RED='\033[0;31m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# define header
INFO="${BLUE}[INFO]${NC}"
WARNING="${YELLOW}[WARNING]${NC}"
SUCCESS="${GREEN}[SUCCESS]${NC}"
ERROR="${RED}[ERROR]${NC}"

# initialize
printf "${GREEN}"
printf "================================== \n"
printf "BACKUP SCRIPT                      \n"
printf " \n"
printf "Server: $server_name\n"
printf "Date: $(date)\n"
printf "================================== \n"
printf "${NC}\n"

if [ -d "$backup_dir/$server_name" ]; then
    cd $backup_dir/$server_name
else
    print "${ERROR} Backup path ${backup_dir}/${server_name} not found, abort!\n"
    exit 1
fi

# tar & compress backup from 2 days ago
tmpDate=$(date -d '-2 day' '+%Y%m%d')
if [ -d "$tmpDate" ]; then
    printf "${INFO} Compressing the backup ${tmpDate} into tar.gz ...\n"
    find ${tmpDate} -type s -print > ./${tmpDate}.sockets-to-exclude
    tar cfz ${tmpDate}.tar.gz -X ./${tmpDate}.sockets-to-exclude $tmpDate
    rm -rf $tmpDate
    rm -rf ${tmpDate}.sockets-to-exclude
fi


curDate=$(date +'%Y%m%d')

# check disk size
diskTotal=$(df -lh | grep /dev/simfs | awk '{print $2}')
diskAvail=$(df -lh | grep /dev/simfs | awk '{print $4}')
diskUsed=$(df -lh | grep /dev/simfs | awk '{print $3}')
diskAvailQuation=$(df -lh | grep /dev/simfs | awk '{print $5}')

printf "${INFO} Disk: %6s %6s %6s %6s\n" Size Avail Used Use%
printf "             %6s %6s %6s %6s\n" $diskTotal $diskAvail $diskUsed $diskAvailQuation

# delete old backups if disAvailable is smaller than 50G
diskAvailByte=$(df | grep /dev/simfs | awk '{print $4}')

while [ ${diskAvailByte} -lt 52428800 ]
do
    oldestBackup=$(ls . | head -1)
    printf "${WARNING} Disk remaining size is smaller than 50G\n" >&2
    printf "${INFO} oldest backup: ${oldestBackup}.tar.gz\n"

    # check if the system still doesn't have enough space to backup
    remainingBackupNumber=$(ls . | wc -l)
    if [ ${remainingBackupNumber:0} -le 1 ]; then
        printf "${ERROR} There is still no sufficient space! Leaving the latest backup untouched and aborting ...\n" >&2
        exit 1
    fi

    printf "${INFO} Deleting the oldest backup: ${oldestBackup}.tar.gz ... \n"
    rm -rf ${oldestBackup}.tar.gz
    wait

    # check again whether directory is deleted
    if [ -d "${oldestBackup}.tar.gz" ] ; then
        printf "${ERROR} Failed to delete the oldest backup\n" >&2
        exit 1
    else
        printf "${SUCCESS} Successfully deleted the oldest backup: ${oldestBackup}.tar.gz\n"
	diskAvailByte=$(df | grep /dev/simfs | awk '{print $4}')
    fi
done

# create backup dir if not exists
if [ ! -d "$curDate" ]; then
    mkdir $curDate
fi

printf "${INFO} Backup directory: $backup_dir/$server_name/$curDate\n"

printf "${INFO} Executing rsync ...\n"

rsync -ah $remote_server:/ $curDate --progress \
--exclude=/dev/* \
--exclude=/home/*/.gvfs \
--exclude=/home/*/.mozilla/firefox/*/Cache \
--exclude=/home/*/.cache/chromium \
--exclude=/home/*/.thumbnails \
--exclude=/media/* \
--exclude=/mnt/* \
--exclude=/proc/* \
--exclude=/sys/* \
--exclude=/tmp/* \
--exclude=/etc/fstab \
--exclude=/var/run/* \
--exclude=/var/lock/* \
--exclude=/lib/modules/*/volatile/.mounted \
--exclude=/var/cache/apt/archives/* \
--exclude=/var/lib/docker/* \
--exclude=/root/swapfile > /dev/null # comment "> /dev/null out" if you want to see standard output

retCode=$?
# echo $retCode
if [ ${retCode} -ne 0 ]; then
    printf "${ERROR} rsync exited with errors!\n" >&2
    exit 1
else
    printf "${SUCCESS} Backup finished!\n"
fi

endTime=$(date +%s)
runtime=$(echo "$endTime - $startTime" | bc -l)
printf "${INFO} Total time used: $(date -d@$runtime -u +%H:%M:%S)\n"
exit 0