ssh 脚本返回 255 错误 [英] ssh script returns 255 error

问题描述

在我的代码中，我有以下内容来运行远程脚本.

In my code I have the following to run a remote script.

ssh [e-mail] "sh /home/user/backup_mysql.sh"

出于某种原因，它一直对我保持 255 秒.有什么想法吗?

For some reason it keeps 255'ing on me. Any ideas?

我可以通过 SSH 进入盒子就好了(无密码密钥设置)

I can SSH into the box just fine (passless keys setup)

远程脚本:

MUSER='root' 
MPASS='123123'
MHOST="127.0.0.1"
VERBOSE=0

### Set bins path ###
GZIP=/bin/gzip
MYSQL=/usr/bin/mysql
MYSQLDUMP=/usr/bin/mysqldump
RM=/bin/rm
MKDIR=/bin/mkdir
MYSQLADMIN=/usr/bin/mysqladmin
GREP=/bin/grep

### Setup dump directory ###
BAKRSNROOT=/.snapshots/tmp

#####################################
### ----[ No Editing below ]------###
#####################################
### Default time format ###
TIME_FORMAT='%H_%M_%S%P'

### Make a backup ###
backup_mysql_rsnapshot(){
        local DBS="$($MYSQL -u $MUSER -h $MHOST -p$MPASS -Bse 'show databases')"
        local db="";
        [ ! -d $BAKRSNROOT ] && ${MKDIR} -p $BAKRSNROOT
        ${RM} -f $BAKRSNROOT/* >/dev/null 2>&1
#       [ $VERBOSE -eq 1 ] && echo "*** Dumping MySQL Database ***"
#       [ $VERBOSE -eq 1 ] && echo -n "Database> "
        for db in $DBS
        do
                local tTime=$(date +"${TIME_FORMAT}")
                local FILE="${BAKRSNROOT}/${db}.${tTime}.gz"
#               [ $VERBOSE -eq 1 ] && echo -n "$db.."
                ${MYSQLDUMP} --single-transaction -u ${MUSER} -h ${MHOST} -p${MPASS} $db | ${GZIP} -9 > $FILE
        done
#               [ $VERBOSE -eq 1 ] && echo ""
#               [ $VERBOSE -eq 1 ] && echo "*** Backup done [ files wrote to $BAKRSNROOT] ***"
}

### Die on demand with message ###
die(){
        echo "$@"
        exit 999
}

### Make sure bins exists.. else die
verify_bins(){
        [ ! -x $GZIP ] && die "File $GZIP does not exists. Make sure correct path is set in $0."
        [ ! -x $MYSQL ] && die "File $MYSQL does not exists. Make sure correct path is set in $0."
        [ ! -x $MYSQLDUMP ] && die "File $MYSQLDUMP does not exists. Make sure correct path is set in $0."
        [ ! -x $RM ] && die "File $RM does not exists. Make sure correct path is set in $0."
        [ ! -x $MKDIR ] && die "File $MKDIR does not exists. Make sure correct path is set in $0."
        [ ! -x $MYSQLADMIN ] && die "File $MYSQLADMIN does not exists. Make sure correct path is set in $0."
        [ ! -x $GREP ] && die "File $GREP does not exists. Make sure correct path is set in $0."
}

### Make sure we can connect to server ... else die
verify_mysql_connection(){
        $MYSQLADMIN  -u $MUSER -h $MHOST -p$MPASS ping | $GREP 'alive'>/dev/null
        [ $? -eq 0 ] || die "Error: Cannot connect to MySQL Server. Make sure username and password are set correctly in $0"
}

### main ####
verify_bins
verify_mysql_connection
backup_mysql_rsnapshot

推荐答案

这通常发生在遥控器关闭/不可用时；或者远程机器没有安装 ssh；或者防火墙不允许与远程主机建立连接.

This is usually happens when the remote is down/unavailable; or the remote machine doesn't have ssh installed; or a firewall doesn't allow a connection to be established to the remote host.

ssh 发生错误时返回 255 或远程脚本返回 255:

ssh returns 255 when an error occurred or 255 is returned by the remote script:

 EXIT STATUS

     ssh exits with the exit status of the remote command or
     with 255 if an error occurred.

通常您会收到类似于以下内容的错误消息:

Usually you would an error message something similar to:

ssh: connect to host host.domain.com port 22: No route to host

或

ssh: connect to host HOSTNAME port 22: Connection refused

检查清单:

• 如果直接从命令行运行 ssh 命令会发生什么?

• What happens if you run the ssh command directly from the command line?

你能ping那台机器吗?

远程是否安装了 ssh?

Does the remote has ssh installed?

如果安装了，那么ssh服务是否在运行?

If installed, then is the ssh service running?

这篇关于ssh 脚本返回 255 错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！