使用Spawn和expect实现ssh自动登陆

1. ubuntu 系统

sudo apt-get install tcl tk expect

2. centos 系统

yum install expect

3. /tmp/ssh-copy-id.sh

⚠️ spawn 命令只有在expect 环境下才有

#!/usr/bin/expect  
set timeout 10  
set username [lindex $argv 0]  
set password [lindex $argv 1]  
set hostname [lindex $argv 2]  
spawn ssh-copy-id -i /root/.ssh/id_rsa.pub $username@$hostname
expect {
            #first connect, no public key in ~/.ssh/known_hosts
            "Are you sure you want to continue connecting (yes/no)?" {
            send "yes\r"
            expect "password:"
                send "$password\r"
            }
            #already has public key in ~/.ssh/known_hosts
            "password:" {
                send "$password\r"
            }
            "Now try logging into the machine" {
                #it has authorized, do nothing!
            }
        }
expect eof

4. 执行ssh-copy-id 实现无密码登陆

sshUser="ubuntu"
password="Admin123456"
publicIp="40.83.121.212"
expect -f /fjyl/Script/ssh-copy-id.sh  ${sshUser} ${password}  ${publicIp}

执行结果：

[root@jenkins-slave~]# expect -f /tmp/ssh-copy-id.sh ubuntu Admin123456  40.83.121.212
spawn ssh-copy-id -i /root/.ssh/id_rsa.pub ubuntu@40.83.121.212
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
ubuntu@40.83.121.212's password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'ubuntu@40.83.121.212'"
and check to make sure that only the key(s) you wanted were added.

现在只要执行 ssh ubuntu@40.83.121.212 就可以进入系统了。