[提供可行性脚本] RHEL/CentOS 7 多节点SSH免密登陆

实验说明:

在自动化部署时,会经常SSH别的机器去操作,然而每次的密码认证却很令人烦躁,尤其是很长的密码,因此SSH免密登陆就显得必不可少;

在机器数目很多的时候,使用更过的往往是Ansible分发并执行SSH免密登陆脚本,使得每台机器之间都能免密登陆。

实验环境:

  • 宿主机系统   :Fedora 28 WorkStation
  • 虚拟机管理器 :Virt-Manager 1.5.1
  • 虚拟机配置   :ha1  CentOS 7.2 1511 (minimal)   virbr0: 192.168.122.57
                 ha2  CentOS 7.2 1511 (minimal)   virbr0: 192.168.122.58
                 ha3  CentOS 7.2 1511 (minimal)   virbr0: 192.168.122.59

实验步骤:

  1. 安装系统并配置网络(所有虚拟机都需联网)

  2. 先操作第一台虚拟机(ha1)

  3. 编写主机名与IP的映射关系

    1 [root@ha1 ~]# vi /etc/hosts
    2 127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
    3 ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
    4 192.168.122.57    ha1
    5 192.168.122.58    ha2
    6 192.168.122.59    ha3
  4. 创建公有密钥

     1 [root@ha1 ~]# ssh-keygen -t rsa 
     2 Generating public/private rsa key pair.
     3 Enter file in which to save the key (/root/.ssh/id_rsa): 
     4 /root/.ssh/id_rsa already exists.
     5 Overwrite (y/n)? y
     6 Enter passphrase (empty for no passphrase): 
     7 Enter same passphrase again: 
     8 Your identification has been saved in /root/.ssh/id_rsa.
     9 Your public key has been saved in /root/.ssh/id_rsa.pub.
    10 The key fingerprint is:
    11 40:c3:81:eb:60:49:2e:f7:fe:59:bb:ef:7d:ad:bb:06 root@ha2
    12 The key's randomart image is:
    13 +--[ RSA 2048]----+
    14 |     o+.         |
    15 |  . ....         |
    16 | o . ..          |
    17 |. * .  .         |
    18 | + +    S        |
    19 |    o       E    |
    20 |   .    .    . . |
    21 |    .  o . .  o .|
    22 |     .o o+o .o++ |
    23 +-----------------+
  5. 发送公有密钥至远程机器

    1 [root@ha1 ~]# ssh-copy-id root@192.168.122.58
    2 [root@ha1 ~]# ssh-copy-id root@192.168.122.59
  6. 以上是单台虚拟机的逐条执行命令的方式,将以上操作写成脚本(脚本在本文末尾PS处)

  7. 下面操作其他虚拟机(ha2、ha3)

    1 # 虚拟机ha2
    2 [root@ha2 ~]# chmod 777 build-ssh-credit.sh 
    3 [root@ha2 ~]# ./build-ssh-credit.sh 
    1 # 虚拟机ha3
    2 [root@ha3 ~]# chmod 777 build-ssh-credit.sh 
    3 [root@ha3 ~]# ./build-ssh-credit.sh 
  8. 至此,三台虚拟机之间相互访问都无需输入密码,实现了SSH的免密登陆

  9. Complete!!!

PS:公钥初始化和实现SSH免密登陆的脚本(build-ssh-credit.sh),直接拷贝就可使用。

#!/usr/bin/bash

# 安装expect,minimal没有此rpm包,需联网或有本地yum源
yum install expect -y
expect << EOF
set timeout 10

# 创建公有密钥

spawn ssh-keygen -t rsa
expect {
        "*to save the key" {send "\n";exp_continue}
        "*(y/n)" {send "y\r";exp_continue}
        "Enter passphrase" {send "\n";exp_continue}
        "Enter same passphrase" {send "\n";exp_continue}
}

EOF

#  获取/etc/hosts文件中除localhost的映射关系
ip_list=`grep -v 'localhost' /etc/hosts | awk -F ' ' '{print $1,$2}'`
for ip in $ip_list
do
expect << EOF
        set timeout 2

        # 发送公有密钥
        spawn ssh-copy-id root@$ip
        expect {
                "yes/no" {send "yes\r";exp_continue}
                "password" {send "000000\r";exp_continue}
        }

        # 拷贝/etc/hosts文件到远程机器
        spawn scp /etc/hosts $ip:/etc
        expect {
                "yes/no" {send "yes\r";exp_continue}
                "password" {send "root\r";exp_continue}
        }
EOF
done

 

posted @ 2018-08-15 11:58 两袖清风来去匆匆 阅读(...) 评论(...) 编辑 收藏