start

#!/bin/bash
#-x

###############################
# nas backup connections
NAS=nas
NAS_IP=192.168.178.10
MOUNT_NFS="$NAS_IP:pool0"
MOUNT_LOCAL="/data/pool0"

###############################
# mail options
MAIL_PREFRACE="[nas-backup]"

###############################
# Backup dirs; relative from Mount or full path
NAS_MOUNT_DIR=$PWD/nasmount
BACKUP_DIRS="homes photo docs docker cloud video /etc"
KEYFILE="$PWD/key.txt"

###############################
# Backup Log folder
LOGBASE=$PWD/backup.log
LOGFILE=$LOGBASE/$NOW.backup.log
FILELIST=$LOGBASE/$NOW.tar.list
TAPENAMES=$LOGBASE/$NOW.backup.tapenames.txt

###############################
# Tape devie name
TAPE="/dev/st0"
TAPESIZE="400*1000*1000*1000"
TAPESPEED="70*1000*1000"
BLOCKSIZE="512K"

###############################
# Tar options
TAR_ARGS="-b 1024"
TAPE_BUFF="3g"

###############################
#compression
# please add the pipe in order to also diable this compression completely
#COMPRESSION_CMD="pigz -3 -p 32 "
#DECOMPRESSION_CMD="pigz -dc -3 -p 32"
COMPRESSION_CMD="zstd -3"
DECOMPRESSION_CMD="zstd -3 -d"

###############################
# Path to binaries
TAR=/bin/tar
MT=/usr/bin/mt-st
MKDIR=/bin/mkdir
MBUFFER=/usr/bin/mbuffer
OPENSSL=/usr/bin/openssl
PIPEMETER=/usr/bin/pipemeter
COMPRESSION=/usr/bin/zstd
UUENCODE=/usr/bin/uuencode

#endof cfg
###############################

WORKDIR=$PWD
SCRIPT=$(readlink -f $0 2>/dev/null)

# Get todays day like Mon, Tue and so on
NOW=$(date +"%a")


wait_for_next_tape() {
    sendmail_event NEXTTAPE
    eject_tape
    echo_log "wait for tape"
    while true
    do
        mt -f /dev/st0 status | grep ONLINE >/dev/null
            rt=$?
            if [[ $rt -eq 0 ]]
            then
            break;
        fi
        sleep 2
    done
}

eject_tape() {
    [ -e $MT ] && mt -f /dev/st0 status | grep ONLINE >/dev/null
        rt=$?
    if [[ $rt -eq 0 ]]
    then
        [ -e $MT ] && $MT -f $TAPE rewind
        [ -e $MT ] && $MT -f $TAPE eject
    fi
}


###############################################################################
# log helper functions
LOGDELIM="###############################################################################"
cleanup_log() {
    echo "" > $LOGFILE
    echo "" > $FILELIST
}
echo_log() {
    >&1 echo $@
    echo $@  >> $LOGFILE
}

error() {
    error_log $@
    sendmail_event FAIL
    #exit -1
}

error_log() {
    echo_log "$LOGDELIM"
    echo_log "BACKUP FAILED"
    echo_log "$LOGDELIM"
    echo_log "reason: $@"
    echo_log "$LOGDELIM"
}

###############################################################################

###############################################################################
# helper function for tape change

calc_time()
{
    seconds=$( calc "(( $1 ) % 60 )" )
    minutes=$( calc "(( $1 ) / 60 ) % 60 " | sed -n "s/\([0-9]*\).*/\1/p" )
    hours=$(   calc "(( $1 ) / 60 ) / 60 " | sed -n "s/\([0-9]*\).*/\1/p"  )
    echo "$hours:$minutes:$seconds"
}
sendmail_for_backup_needed()
{
    sendmail \
        "please start a tapebackup" \
        "A tape backup would be needed now\n" \
        "$( main estimate-tapes )"
}

estimate_size()
{
    cd $NAS_MOUNT_DIR > /dev/null
    du -sbc $BACKUP_DIRS | sed -n "s/\([0-8]*\).*/\1/p" | tail -n1
    cd - > /dev/null
}

#### Custom functions #####
sendmail_event()
{
    case $1 in
        FULLSTART)
                export start_time=$SECONDS
                sendmail "Full Backup started" "Full backup started for $BACKUP_DIRS"
            ;;
        FULLEND)
                end_time=$SECONDS
                time=$(( end_time - start_time ))
                time_str=$( calc_time $time )
                if [[ -e $FILELIST ]]
                then
                    tar -cjf $FILELIST.bz2.tar $FILELIST
                fi

                sendmail \
                    "finished backup" \
                    $FILELIST.bz2.tar \
                    "sucessfull backuped the following dirs $BACKUP_DIRS \n" \
                    "Time needed was $time_str"
            ;;
        NEXTTAPE)
                sendmail "Next Tape please" "test" "Please change tape and not the order."
            ;;
        FAIL)
                end_time=$SECONDS
                time=$(( end_time - start_time ))
                time_str=$( calc_time $time )
                sendmail \
                    "failed to backup" \
                    $TAPENAMES  \
                    "failed to backup the following dirs $BACKUP_DIRS \n" \
                    "Time needed was $time_str"
            ;;
        *)
                error_log "failed invalid send event"
            ;;
    esac
}

sendmail() {
    SUBJECT=$1
    shift
    local attachments

    if [[ -e $LOGFILE ]]
    then
        attachments+="$UUENCODE $LOGFILE $( basename $LOGFILE) ; "
    fi

    while true
    do
        if [[ -e $1 ]]
        then
            attachments+="$UUENCODE $1 $(basename $1) ; "
            shift
        else
            break
        fi
    done

    BODY=$@

    eval "( echo -e '$BODY' ; $attachments ) | mail root --subject=\"$MAIL_PREFRACE $SUBJECT\" $LOG_ATTACHMENT"
    echo "( echo -e '$BODY' ; $attachments ) | mail root --subject=\"$MAIL_PREFRACE $SUBJECT\" $LOG_ATTACHMENT"
}

###############################################################################
# mount nas directories
mount_nas() {
    if [[ "$HOSTNAME" == "$NAS" ]]
    then
        echo_log "no need to mount nas"
        [[ -e $NAS_MOUNT_DIR ]] || ln -s $MOUNT_LOCAL $NAS_MOUNT_DIR
    else
        echo_log "mount nas"

        $MKDIR $NAS_MOUNT_DIR
        sudo mount.nfs $MOUNT_NFS $NAS_MOUNT_DIR
    fi
}
###############################################################################

# Make sure all dirs exits
verify() {

    local s=0
    [ -d $LOGBASE ] || $MKDIR -p $LOGBASE || ( error_log "error could not create log file -> stop" && s=1)

    echo_log "verify programs"
    [ -e $TAR ]         || ( error_log "tar is not installed (curr set to '$TAR' -> stop" && s=1)
    [ -e $MT ]          || ( error_log "mt is not installed (curr set to '$MT' -> stop" && s=1)
    [ -e $MKDIR ]       || ( error_log "mkdir is not installed (curr set to '$MKDIR' -> stop" && s=1)
    [ -e $MBUFFER ]     || ( error_log "mbuffer is not installed (curr set to '$MBUFFER' -> stop" && s=1)
    [ -e $OPENSSL ]     || ( error_log "opensll is not installed (curr set to '$OPENSSL' -> stop" && s=1)
    [ -e $PIPEMETER ]   || ( error_log "pipemeter is not installed (curr set to '$PIPEMETER' -> stop" && s=1)
    [ -e $COMPRESSION ] || ( error_log "compression is not installed (curr set to '$COMPRESSION' -> stop" && s=1)
    [ -e $UUENCODE ]    || ( error_log "uuencode is not installed (curr set to '$UUENCODE' -> stop" && s=1)

    echo_log "verify dirs"
    for d in $BACKUP_DIRS
    do
        local test_dir
        if [[ $d = /* ]]
        then
            test_dir=$d
        else
            test_dir=$NAS_MOUNT_DIR/$d
        fi

        if [ ! -d $test_dir ];
        then
            echo_log "Error : $test_dir directory does not exits!"
            s=1
        fi
    done

    ( [ -e $MT ] && [ -e $TAPE ]) || ( error_log "tape is not present at '$TAPE' -> stop" && s=1)

    [ -e $KEYFILE ]  || ( error_log "key file is empty please generate one with 'openssl rand 512 > $KEYFILE'" && s=1)

    # if not; just die
    [ $s -eq 1 ] && error "failed -> stop"
}

print_help() {
    echo "usage:"
        echo "sudo $( basename $SCRIPT ) backup-full                                      | do a full backup of all files to the tape drive"
        echo "sudo $( basename $SCRIPT ) estimate-tapes                                   | estimates the number of tapes for the backup"
        echo "sudo $( basename $SCRIPT ) tape-list                                        | lists the content of the tape drive"
        echo "sudo $( basename $SCRIPT ) recover-data <output dir> [selective file list]  | recovers data from the tape drive "
}

#### Main logic ####

# Make sure log dir exits
main() {

    echo_log "today is $NOW"

    # Okay let us start backup procedure
    # If it is monday make a full backup;
    # For Tue to Fri make a partial backup
    # Weekend no backups
    case $1 in
        "backup-full")
                cleanup_log
                mount_nas
                verify
                backup "backup-full"
            ;;
        "tape-list")
                cleanup_log
                verify
                backup "tape-list"
            ;;
        "tape-restore")
                cleanup_log
                verify
                backup "tape-restore" $@
            ;;
        "estimate-tapes")
                verify
                backup "estimate-tapes"
            ;;
        *)
                print_help
            ;;
    esac

}

calc() {
    awk "BEGIN{printf \"%.2f\", $1}"
}

# Make a full backup
backup() {
    local old=$(pwd)

    case $1 in
        backup-full)
            cd $NAS_MOUNT_DIR
            echo_log "start full backup"
            sendmail_event FULLSTART
            echo_log "estimate time for $BACKUP_DIRS"
            echo_log "please insert tape in the mean time if not already done"
            size=$( estimate_size )

            echo_log "estimates size is \'$size\'b"
            $TAR $TAR_ARGS -cvf - $BACKUP_DIRS  2> $FILELIST | \
                pipemeter -s $size -a -b $BLOCKSIZE -l | \
                $COMPRESSION_CMD | \
                $OPENSSL enc -aes-256-cbc -pass file:$KEYFILE | \
                $MBUFFER \
                    -A "bash -c \"source $SCRIPT; wait_for_next_tape\"" \
                    -P 95 \
                    -m $TAPE_BUFF \
                    -f \
                    -o $TAPE \
                    -L \
                    -s$BLOCKSIZE
            rt=$?
            if [ ! $rt -eq 0 ]
            then
               error "tar command failed with $rt"
            else
               sendmail_event FULLEND
            fi
            eject_tape
            cd $old
        ;;

    tape-list)
        ;&
    tape-restore)
            if [[ $1 == tape-restore ]]
            then
                OPT="x"
            OUTPUT_DIR="-C $2"
            shift
            else
                OPT="t"
            fi
                shift #remove tape-restor rest is files and paths

            echo please enter the number of tapes to read
            read tapes_count

            $MBUFFER -n $tapes_count -i $TAPE \
                -A "bash -c \"source $SCRIPT; wait_for_next_tape\"" \
                -P 95 \
                -m 0.5g \
                -f \
                -L \
                -q \
                -s$BLOCKSIZE |
                $OPENSSL enc -d -aes-256-cbc -pass file:$KEYFILE |
                $DECOMPRESSION_CMD | \
                $TAR $TAR_ARGS -${OPT}vf - $OUTPUT_DIR $@ 2> $FILELIST
        ;;

    estimate-tapes)
            size=$( estimate_size )
            echo $size

            size_str=$( numfmt --to iec --format "%8.4f" "$size" )

            tapenumer=$( calc "$size/($TAPESIZE)" )
            tapetime=$( calc "$size/($TAPESPEED)" )

            time_str=$( calc_time $tapetime )

            echo_log "estimated tapes are $tapenumer for the $size_str"
            echo_log "estimated time is $time_str (not counting the delay of changes)"
            echo_log "with the backup of the following dirs $BACKUP_DIRS"
        ;;

    *)
            error "unkown backup cmd"
        ;;
    esac

}

#### Main logic ####

# Make sure log dir exits

#sendmail "Full Backup started" "Full backup started for $BACKUP_DIRS"

case "$0" in
    *start)
        echo "Script is a subshell"
        main $@
        ;;
    *)
        echo "Script is being sourced"
        ;;
esac
#> $LOGFILE 2>&1
#main