linux免密登录配置

第一步：安装openssh-clients
　　yum install -y openssh-clients.x86_64
第二步：生成密钥
　　ssh-keygen
第三步：拷贝公钥到其他机器
　　ssh-copy-id hostname

使用脚本批量配置每台机器互相免密登录

　　环境：centos6.10

　　安装脚本编程交互工具expect

　　　　yum install -y expect

　　脚本编写，小例子

　　

　　generatekey.expect

#!/usr/bin/expect
spawn ssh-keygen
expect "*id_rsa*"
send
expect {
"*verwrite*" {
send y
expect "*passphrase*"
send
expect "*again*"
send
}
"*assphrase*" {
send
expect "*again*"
send
}
}
expect "*randomart*"
send_user "generate successful "

　　

　　copykey.expect

#!/usr/bin/expect
set from [lindex $argv 0]
set hostname [lindex $argv 1]
spawn ssh-copy-id $from@$hostname
expect {
"*assword*" { # "*password*"和左大括号之见一定要留间隔，否则不能识别
send wanger
expect "*check*"
send_user "add to $hostname successful! "
}
"*yes/no*" {
send yes
expect "*assword*"
send wanger
expect "*check*"
send_user "add to $hostname successful! "
}
"*check*" {
send_user "already added to $hostname! "
}
}

　

　　machines：把所有机器的hostname添加到这个文件

tdh1
tdh2
tdh3
tdh4

　

　　passphraseless_onetomutiple.sh

#!/bin/bash
dirname=/home/wanger/code/passphraseless
$dirname/generatekey.expect
input="$dirname/machines"
while read -r hostname
do
$dirname/copykey.expect $1 $hostname
done < $input

　　

　　passphraseless_all

#!/bin/bash
current_host=`hostname`
dirname=/home/wanger/code/passphraseless
input=$dirname/machines
# echo $current_host
$dirname/passphraseless_onetomutiple.sh wanger

for hostname in `awk  '$1' $input`
do
if [ $hostname != $current_host ];
then
  scp -r ../passphraseless wanger@$hostname:/home/wanger/code/
  $dirname/scp.expect $hostname
  ssh wanger@$hostname $dirname/passphraseless_onetomutiple.sh wanger
fi
done

　　

　　给执行权限后，在任意一台机器上执行./passphraseless_all即可

root版本配置代码在github上: https://github.com/cqdxwjd/code/tree/master/linux/shell/passphraseless_root