jonallie.com: more right than you

        #!/bin/bash
        ##################################################################
        # sqlbackup.sh:
        #   rolling sqlbackups using mysqldump
        #
        #
        #   This script will dump mysql databases to a specified directory
        #   with optional encrytion.
        #
        #
        ###################################################################
    
        # program options
        backup_dir=/backup
        backup_age=28
        use_encryption=0
        use_bzip=0
        nice_level=19
        mysql_user=root
        mysql_passfile=/etc/keys/.mysqlpass
        openssl_passfile=/etc/keys/.opensslpass
        date=`date +%Y%m%d`
        exten=".sql"
        logfile=/var/log/mysqlbackup.log
        mysqldump_options=" --all-databases --single-transaction --quote-names "
    
        # program paths
        mysqldump=/usr/bin/mysqldump
        openssl=/usr/bin/openssl
        bzip2=/usr/bin/bzip2
    
    
        # usage summary
        function usage {
        echo "
        sqlbackup.sh:
            creates backups of sql databases using the mysqldump command,
            including optional encryption, bzip2 compression, and 
            variable backup aging
    
        Usage: sqlbackup.sh [OPTIONS]
    
            Options:
    
            -h              : display this help
    
            -b <dir>        : select directory to store backups. This directory 
                            will not be created.
    
            -e              : enable encryption using openssl's des3 encryption. 
    
            -k <file>       : specify file containing password to be used for encryption
                            This defaults to /etc/keys/.opensslpass
                    
            -u <user>       : username to use for connecting to MySQL
    
            -p </user></file><file>       : specifies a file containing a password to be used for
                            connecting to MySQL
        
            -z              : enable bzip2 compression of backups
    
            -a <days>       : backup age in days. Backups older than this will be deleted
    
            -n <level>      : Specifies a nice level. This level will apply to all operations of the 
                            backup. Defaults to 19 (very nice)
                    
            -l </level></days></file><file>       : logfile path. Alternate path to a file for logging. Defaults
                            to '/var/log/mysqlbackup.log'
                    
        "
        }      
    
        # echo a string to screen and log
        function echo_and_log {
            logstring="[ `date` ] : $*"
            echo $logstring
            echo $logstring >> $logfile
        }
    
    
        # print error to screen and exit
        function exit_with_error {
            echo_and_log "Error: $*"
            echo_and_log "Exiting with code 1"
            exit 1
        }
    
        # funtion to delete old backups
        function clean_backups {
        find $backup_dir -type f -mtime +${backup_age} -exec rm -f {} \;
        [ "$?" == "0" ] || echo_and_log "Error encountered when cleaning old backups from $backup_dir"
        }
    
    
        # process command line options
        while getopts ":hb:ek:u:p:za:n:l:" opt 
        do
            case $opt in
                b) backup_dir=$OPTARG ;;
                e) use_encryption=1 ;;
                k) openssl_passfile=$OPTARG ;;
                u) mysql_user=$OPTARG ;;
                p) mysql_passfile=$OPTARG ;;
                z) use_bzip=1 ;;
                a) backup_age=$OPTARG ;;
                n) nice_level=$OPTARG ;;
                l) logfile=$OPTARG ;;
                h) usage 
                    exit 0 ;;
                \?) echo "unknown option"
                    usage 
                    exit 1 ;;
                *)  usage
                    exit 1 ;;
            esac
        done
    
        # set umask
        umask 0077
    
        # start processing
        echo_and_log "Starting MySQL backup: encryption = $use_encryption, bzip = $use_bzip, backup directory = $backup_dir"
        
        # error checking and validation
        [ -d $backup_dir ] || exit_with_error "Backup directory '$backup_dir' does not exist"
        [ -n "$logfile" ] || exit_with_error "No log file specified."
        [ -f $mysql_passfile ] || exit_with_error "MySQL password file '$mysql_passfile' does not exist"
        [ -x $mysqldump ] || exit_with_error "MySQLDump program at '$mysqldump' does not exist or is not executable"
        # validate compression options
        if [ "$use_bzip" == "1" ]
        then
            [ -x $bzip2 ] || exit_with_error "Bzip2 program at '$bzip2' does not exist or is not executable"
            bzip2_command=" | nice -n $nice_level $bzip2 "
            exten="${exten}.bz2"
        fi
    
        # validate encryption options
        if [ "$use_encryption" == "1" ]
        then 
            [ -x $openssl ] || exit_with_error "OpenSSL program at '$openssl' does not exist or is not executable"
            [ -f $openssl_passfile ] || exit_with_error "OpenSSL password file '$openssl_passfile' does not exist"
            openssl_command=" | nice -n $nice_level $openssl des3 -salt -pass file:${openssl_passfile} "
            exten="${exten}.cryp"
        fi
    
        # call funtion to clean backup directory
        clean_backups
    
        # execute dump command
        command="$mysqldump $mysqldump_options --user=${mysql_user} --password=$(<$mysql_passfile) $bzip2_command $openssl_command > $backup_dir/mysqlbackup_${date}${exten}"
        eval $command
        [ "$?" == "0" ] || exit_with_error "MySQLDump command returned non-zero error code. Backup not completed successfully"
    
        # finish
        echo_and_log "Backup complete"
        exit 0
    
</file></dir>