shell脚本调用expect实现shell免密登录

• 脚本源代码

#!/bin/bash
if [ $UID -ne 0 ];then
	echo "请使用root用户执行此脚本"
	exit
fi

which expect
if [ $? -ne 0 ];then
	yum install -y expect
fi
ls .ssh/ | grep id
if [ $? -ne 0 ];then
	#创建公钥 -P:密码为空 -f：指定公钥位置（实现无交互创建公钥）
	ssh-keygen -P "" -f ~/.ssh/id_rsa
fi
read -p "请输入你远程连接主机的密码：" password
read -p "请输入你想远程连接主机网段：(例：192.168.80)" wd
bj=$(ifconfig ens33|awk -F '[ :]+' 'NR==2 {print $3}')
echo $bj
##判断主机是否在线
for i in {2..254}
do
	{
	ip=$wd.$i
	ping -c1 -W1 $ip &> /dev/null
	if [ $? -eq 0 ];then
		echo "$ip" >> ip.txt
	#	if [ $bg -eq $ip ];then
	#		continue
	#	fi
	#调用expect
		/usr/bin/expect <<-EOF  
		spawn ssh-copy-id $ip
		expect {
			"*yes/no*" { send "yes\r"; exp_continue }
			"*password:" { send "$password\r" }
		}
		expect eof
		EOF
	fi
	}&
done

• 脚本使用方法

[root@localhost ~]# bash ssh.sh 

(这时候肯定有der说：哎，expect的环境变量是/usr/bin/expect，你bash的环境变量是 /bin/bash,不能执行，大哥，看好了，我这写的是shell脚本，中间特意写了expect的环境变量，用于shell调用)

[root@localhost ~]# bash ssh.sh 
/usr/bin/expect
id_rsa
id_rsa.pub
请输入你远程连接主机的密码：123456 						#输入密码
请输入你想远程连接主机网段：(例：192.168.80)192.168.80     #输入网段
ssh.sh: line 18: ifconfig: command not found

[root@localhost ~]# spawn ssh-copy-id 192.168.80.21
spawn ssh-copy-id 192.168.80.31
spawn ssh-copy-id 192.168.80.254
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/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: ERROR: ssh: connect to host 192.168.80.254 port 22: Connection refused

expect: spawn id exp6 not open
    while executing
"expect eof"
/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: 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
root@192.168.80.31's password: 

/usr/bin/ssh-copy-id: WARNING: All keys were skipped because they already exist on the remote system.
		(if you think this is a mistake, you may want to use -f option)

expect: spawn id exp6 not open
    while executing
"expect eof"
Permission denied, please try again.
root@192.168.80.31's password:       #这边因为shell脚本把自己也算进去了，所以会连接自己，这边需要手动ctrl +c 打断 

[root@localhost ~]# cat ip.txt  #存活的ip
192.168.80.21 	#本机
192.168.80.31	#另一台主机
192.168.80.254	#网关

[root@localhost ~]# ssh 192.168.80.21
Activate the web console with: systemctl enable --now cockpit.socket

Last login: Sun Jun  6 01:05:14 2021 from 192.168.80.31
[root@z1 ~]#             #成功登录