backup2s3.sh

#!/bin/sh
# this is written in sh not bash because I run it in the FreeBSD jail
# on a FreeNAS box

# directories 1 level under this root would be backed up, one backup file
# per firectory. Backup files would be named 'name of the directory'-'date'
# f.e. /mnt/data would be backed up as data-04-04-2015
# backup ignores all directories where it finds a file .gnutar.nobackup and all
# directories under it
ROOT=/mnt
# date format to name files
DATE=`date +\%G-\%m-\%d`
# every CYCLEDAYS the incremental backup starts from generation 0
CYCLEDAYS=31
FLAG=/var/run/s3backup.flag
# Tar program. Requires GNU tar
TAR=gtar 
# S3 bucket to backup to
BUCKET=backup_bucket

do_backup() {
    local dir=$1
    local incrfile=$dir/.gnutar.inc.file
    local incrcount=$dir/.gnutar.inc.count
    local count=0
    if [ -e "$incrcount" ]
    then
        local count=`cat $incrcount`
        if [ $count -gt $CYCLEDAYS ]
        then
            count=0
            rm $incrfile
        fi
    fi
    local bfile=`basename $dir`-$DATE-$count.tar.bz
    echo "$DATE: Backing up $dir generation $count to $bfile"
    if $TAR --exclude-tag-under=.gnutar.nobackup -g $incrfile -cjf - $dir | s3cmd -v put - s3://$BUCKET/$b
file
    then
        echo "Done"
        count=$((count+1))
        echo $count > $incrcount
    else
        echo "Failed"
    fi
}

if [ -e "$FLAG" ]
then
    date=`cat $FLAG`
    echo "Backup from $date already running, exiting"
    exit 1
else
    echo $DATE > $FLAG
    for d in $ROOT/*
    do
        if [ -d $d ]
        then
            if [ "x$1" = "x$d" -o "x$1" = "x" ]
            then
                do_backup $d
            fi
        fi
    done
    rm $FLAG
fi
exit 0
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