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:2018-05-24  
#   Author:sandy
#   QQ:442656067
#   Email:eeexu123@163.com  
#   Blog:https://www.cnblogs.com/eeexu123/

if { $argc != 2 } {
  send_user "usage: expect fenfa_expect file host\n"     //判断传入参数是否是2个
  exit 1
}

#define var
set file [lindex $argv 0]   //第一个参数是ssh公钥
set host [lindex $argv 1]   //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30 }

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 22 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 a5:17:d4:89:36:79:58:aa:99:8d:f0:ce:98:5a: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 00:0C:29:8D:65:92  
          inet addr:172.16.1.72  Bcast:172.16.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe8d:6592/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:560 errors:0 dropped:0 overruns:0 frame:0
          TX packets:218 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:72275 (70.5 KiB)  TX bytes:39742 (38.8 KiB)

由上可以，expect交互功能在SSH免密码操作成功。