Linux之expect非交互式功能

我在上一篇博文linux之SSH密钥认证 提过ssh之间的相互认证，但是每次使用ssh登录到其它服务器还是要输入密码的。

expect是用于提供自动交互的工具，自动连接被管理的服务器，不需要手动输入密码。

1、安装expect

[root@mg ~]# yum install -y expect

2、编写expect脚本，直接分发SSH公钥，不用手工输入密码。

vim /server/scripts/expect.exp

 #!/usr/bin/expect

 #-------------CopyRight-------------
 #   Name:ssh send password
 #   Version Number:1.00
 #   Type:sh
 #   Language:expect
 #   Date:--
 #   Author:sandy
 #   QQ:
 #   Email:eeexu123@.com
 #   Blog:https://www.cnblogs.com/eeexu123/

 if { $argc !=  } {
   send_user "usage: expect fenfa_expect file host\n"     //判断传入参数是否是2个
   exit
 }

 #define var
 set file [lindex $argv ]   //第一个参数是ssh公钥
 set host [lindex $argv ]   //第二个参数是连接的远程主机地址
 set passwd "herine"         //设置连接用户的密码

 #send ssh key
 spawn ssh-copy-id -i $file "-p 22 root@$host"     //发送ssh公钥命令
 expect {
   "yes/no" {send "yes\r";exp_continue}      //是否继续连接，expect交互式功能，自动添加yes，并继续。yes后成必须加\r回车符 }

 sleep 3　　　　　　　　　 //等待连接到远程主机
 expect "*password"     //输入密码，expect交互功能，自动添加密码变量。后面加\r回车符
 send "$passwd\r"
 expect eof

 exit -onexit {
   send_user "Goodbye!\n"    //退出
 }

3、测试

/usr/bin/expect test_expect.exp ~/.ssh/id_dsa.pub 172.16.1.72
上面一条命令可以放在脚本里，大批量建立ssh密钥连接

 [root@mg scripts]# /usr/bin/expect test_expect.exp ~/.ssh/id_dsa.pub 172.16.1.72
 spawn ssh-copy-id -i /root/.ssh/id_dsa.pub -p  root@172.16.1.72
 The authenticity of host '172.16.1.72 (172.16.1.72)' can't be established.
 RSA key fingerprint is a5::d4:::::aa::8d:f0:ce::5a:d3:f4.
 Are you sure you want to continue connecting (yes/no)? yes
 Warning: Permanently added '172.16.1.72' (RSA) to the list of known hosts.
 root@172.16.1.72's password:
 Now try logging into the machine, with "ssh '-p 22 root@172.16.1.72'", and check in:

   .ssh/authorized_keys

 to make sure we haven't added extra keys that you weren't expecting.

 Goodbye!

ssh远程使用命令

 [root@mg scripts]# ssh root@172.16.1.72 "/sbin/ifconfig eth1"
 eth1      Link encap:Ethernet  HWaddr :0C::8D::
           inet addr:172.16.1.72  Bcast:172.16.1.255  Mask:255.255.255.0
           inet6 addr: fe80::20c:29ff:fe8d:/ Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:  Metric:
           RX packets: errors: dropped: overruns: frame:
           TX packets: errors: dropped: overruns: carrier:
           collisions: txqueuelen:
           RX bytes: (70.5 KiB)  TX bytes: (38.8 KiB)

由上可以，expect交互功能在SSH免密码操作成功。