When performing remote login on Linux, you always have to enter an account and password via SSH, which is relatively cumbersome. In work, you always first log in from your local machine to the company's intermediate machine (jump server) and then log in to the production machine, making each operation even more cumbersome. If going from A -> B, you can directly establish a mutual trust relationship to solve the problem of not having to enter a password. In the actual situation, if there are three machines A -> B -> C, and you want to go directly from A to C, you can only log in through B, thus you cannot establish a trust relationship between A -> C (this operation is mainly to protect production machines from being logged into casually). This script is designed to solve this kind of multiple dependency relationship.

Notes:

1. Use bash version >= 4.0, because the configuration needs to use associative arrays.

2. If you need to use it globally, directly modify the name of autologin and move it to a directory under PATH. e.g., mv autologin /usrl/local/bin/to (change to the name you want to use)

Script code:

#!/usr/local/bin/bash
# @Version 0.3.1
# @filename to
# 修复等不需要要配置跳板机的时候执行命令，在配置跳板机位置默认填 no 即可
# @Author [email protected]
# Bash version >= 4.0 使用关联数组

# Usage: host user passwd port jump_host command 
# 四种情况如下：
# 1. 直接登录目标机器 如 A 
# 2. 需要中间机器登陆到目标机器 如 C， 其中 B 为中间机器，会先登录 B在从 B登陆到 C然后执行 command
# 3. 直接登录目标机器并执行相应的命令 如 D

declare -A _server_config

_server_config['A']="a_host a_user a_passwd a_port"
_server_config['B']="b_host b_user b_passwd b_port"
_server_config['C']="c_host c_user c_passwd c_port B '(command eg) ls .'"
_server_config['D']="d_host d_user d_passwd d_port no 'cd /home && ll'"

_config_keys=(${!_server_config[@]})
_length=${#_server_config[@]}
_login_server=$1
_config_status=false

# 是否输入登陆机器
if [ "$_login_server" == "" ];then
    echo -e "\033[40m\033[31m Please input login server, you can choose one follows list \033[0m"
    for i in "${_config_keys[@]}";do
        echo -e "\033[41;37m $i \033[0m "
    done
    exit
fi

# 检查登陆的机器是否配置
for i in "${_config_keys[@]}";do
    if [ "$_login_server" == "$i" ];then
        _config_status=true
    fi
done

if [ "${_config_status}" == "false" ];then
    echo -ne "\033[40m\033[31m
        Not config server info ...
        Please config in _server_config like
        Host User Passwd Port Jump Command\033[0m"
    exit
fi

# 登陆 如果配置跳板机，先登陆跳板机在登陆到目标机器
_host=$(echo ${_server_config["${_login_server}"]} | awk '{print $1}')
_user=$(echo ${_server_config["${_login_server}"]} | awk '{print $2}')
_passwd=$(echo ${_server_config["${_login_server}"]} | awk '{print $3}')
_port=$(echo ${_server_config["${_login_server}"]} | awk '{print $4}')
_jump=$(echo ${_server_config["${_login_server}"]} | awk '{print $5}')
_command=$(echo ${_server_config["${_login_server}"]} | awk -F"'" '{print $2}')

if [ "${_command}" != "" ]; then
    _command="expect \"*]*\"
    send \"${_command}\r\""
fi

if [ "${_jump}" != "" ] && [ "${_jump}" != "no" ]; then
    _jump_host=$(echo ${_server_config["${_jump}"]} | awk '{print $1}')
    _jump_user=$(echo ${_server_config["${_jump}"]} | awk '{print $2}')
    _jump_passwd=$(echo ${_server_config["${_jump}"]} | awk '{print $3}')
    _jump_port=$(echo ${_server_config["${_jump}"]} | awk '{print $4}')

    expect -c "
    set timeout 30
    spawn ssh -p${_jump_port} ${_jump_user}@${_jump_host}
    expect {
        \"yes/no\" { send \"yes\r\"; exp_continue }
        \"assword\" { send \"${_jump_passwd}\r\" }
    }

    expect \"*]*\" 
    send \"ssh -p${_port} ${_user}@${_host}\r\"
    expect \"assword:\" 
    send \"${_passwd}\r\"
    ${_command}
    interact"
else
    expect -c "
    set timeout 30
    spawn ssh -p${_port} ${_user}@${_host}
    expect {
        \"yes/no\" {send \"yes\r\"; exp_continue }
        \"*assword:\" { send \"$_passwd\r\" }
    }
    ${_command}
    interact
    "
fi

GitHub code address:https://github.com/pemako/LearnShell/blob/master/lib/autologin