利用Shell开发跳板机功能脚本案例

范例17_6：：开发企业级Shell跳板机案例。要求用户登录到跳板机仅能执行管理员给定的选项动作，不允许以任何形式中断脚本到跳板机服务器上执行任何系统命令。方法1：1）首先做好SSH密钥验证（跳板机地址192.168.33.128）。以下操作命令在所有机器上操作：[root@oldboy ~]# useradd jump  #<==要在所有机器上操作。[root@oldboy ~]# echo 123456|passwd --stdin jump  #<==要在所有机器上操作。Changing password for user jump.passwd: all authentication tokens updated successfully.以下操作命令仅在跳板机上操作：[root@oldboy ~]# su - jump[jump@oldboy ~]$ ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa >/dev/null 2>&1  #<==生成密钥对。[jump@oldboy ~]$ ssh-copy-id -i ~/.ssh/id_dsa.pub 192.168.33.130   #<==将公钥分发到其他服务器。The authenticity of host '192.168.33.130 (192.168.33.130)' can't be established.RSA key fingerprint is fd:2c:0b:81:b0:95:c3:33:c1:45:6a:1c:16:2f:b3:9a.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added '192.168.33.130' (RSA) to the list of known hosts.jump@192.168.33.130's password: Now try logging into the machine, with "ssh '192.168.33.130'", and check in:.ssh/authorized_keys
to make sure we haven't added extra keys that you weren't expecting.[jump@oldboy ~]$ ssh-copy-id -i ~/.ssh/id_dsa.pub 192.168.33.129  #<==将公钥分发到其他服务器。
The authenticity of host '192.168.33.129 (192.168.33.129)' can't be established.RSA key fingerprint is fd:2c:0b:81:b0:95:c3:33:c1:45:6a:1c:16:2f:b3:9a.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added '192.168.33.129' (RSA) to the list of known hosts.jump@192.168.33.129's password: Now try logging into the machine, with "ssh '192.168.33.129'", and check in:.ssh/authorized_keysto make sure we haven't added extra keys that you weren't expecting.
2）实现传统的远程连接菜单选择脚本。菜单脚本如下：                cat <<menu                  1)oldboy-192.168.33.129                  2)oldgirl-192.168.33.130                  3)exitmenu3）利用linux信号防止用户中断信号在跳板机上操作。function trapper () {        trap ':' INT  EXIT TSTP TERM HUP  #<==屏蔽这些信号。}4）用户登录跳板机后即调用脚本（不能命令行管理跳板机），并只能按管理员的要求选单。以下为实战内容。脚本放在跳板机上：[root@oldboy ~]# echo '[ $UID -ne 0 ] && . /server/scripts/jump.sh' >/etc/profile.d/jump.sh   [root@oldboy ~]# cat /etc/profile.d/jump.sh[ $UID -ne 0 ] && . /server/scripts/jump.sh [root@oldboy scripts]# cat /server/scripts/jump.sh #!/bin/sh#oldboy trainingtrapper() {    trap ':' INT  EXIT TSTP TERM HUP  #<==定义需要屏蔽的信号，冒号表示啥都不做。}main(){while :do      trapper      clear      cat <<menu       1)Web01-192.168.33.129       2)Web02-192.168.33.130menuread -p "Pls input a num.:" numcase "$num" in     1)        echo 'login in 192.168.33.129.'        ssh 192.168.33.129        ;;    2)        echo 'login in 192.168.33.130.'        ssh 192.168.33.130        ;;    110)        read -p "your birthday:" char        if [ "$char" = "0926" ];then          exit          sleep 3        fi        ;;    *)        echo "select error."        esacdone}main执行效果如下：[root@oldboy ~]# su - jump  #<==切到普通用户即弹出菜单，工作中直接用jump登录，即弹出菜单。     1)Web01-192.168.33.129     2)Web02-192.168.33.130Pls input a num.:     1)Web01-192.168.33.129     2)Web02-192.168.33.130Pls input a num.:1  #<==选1进入Web01服务器。login in 192.168.33.129.Last login: Tue Oct 11 17:23:52 2016 from 192.168.33.128[jump@littleboy ~]$  #<==按ctrl+d退出到跳板机服务器再次弹出菜单。     1)Web01-192.168.33.129     2)Web02-192.168.33.130Pls input a num.:2     #<==选2进入Web02服务器。login in 192.168.33.130.Last login: Wed Oct 12 23:30:14 2016 from 192.168.33.128[jump@oldgirl ~]$   #<==按ctrl+d退出到跳板机服务器再次弹出菜单。     1)Web01-192.168.33.129     2)Web02-192.168.33.130Pls input a num.:110    #<==选110进入跳板机命令提示符。your birthday:0926      #<==需要输入特别码才能进入的，这里管理员通道，密码要保密呦。[root@oldboy scripts]#  #<==跳板机管理命令行。

本文内容来源于：《跟老男孩学linux运维：Shell高级编程实战》

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