CentOS7 SSH免登录配置

之前写过一篇关于SSH免登录的文章,不过那个是专门针对hadoop来设置的,感觉写的不是很详细,所以重新写一篇操作更具体的文章。供大家参考参考。本文的操作环境是CentOS7系统,一共有四台服务器,分别被命名为master,slave1, slave2以及slave3。

设置hostname

在CentOS7中,hosts文件的所在地是/etc/hosts里面,大家直接使用vim工具将这个hosts文件打开,配置方式同windows或者mac一样。下面给出一个范例:

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127.0.0.1  localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.131.140 master
192.168.131.141 slave1
192.168.131.142 slave2
192.168.131.143 slave3

大家可以根据自己的实际情况进行相应地修改。

配置SSH免登录

使用一个工具ssh-keygen在每一台机器上生成对应的私钥和公钥。命令为ssh-keygen -t rsa -P "",然后一路回车就行:

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ssh-keygen -t rsa -P ""
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
a0:0d:8a:b4:dd:e7:92:6f:44:25:36:9a:5b:75:10:a8 [email protected]
The key's randomart image is:
+--[ RSA 2048]----+
| .oo |
| = o . |
| . . * = . |
|..o..E + |
|......=.S |
| .+. |
| o.. |
| o. |
| .. |
+-----------------+

按照同样的命令,在三台从服务器上分别生成对应的公钥和私钥。接下来就是将这些公钥拷贝到主服务器上来。

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scp ~/.ssh/id_rsa.pub [email protected]:~/.ssh/id_rsa.pub.slave1
scp ~/.ssh/id_rsa.pub [email protected]:~/.ssh/id_rsa.pub.slave2
scp ~/.ssh/id_rsa.pub [email protected]:~/.ssh/id_rsa.pub.slave3

接着将这些拷贝过来的公钥保存在主服务器的公钥文件~/.ssh/authorized_keys中。

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cat ~/.ssh/id_rsa.pub* >> ~/.ssh/authorized_keys

然后将这个公钥文件分发给每一个从服务器。

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scp ~/.ssh/authorized_keys [email protected]:~/.ssh/
scp ~/.ssh/authorized_keys [email protected]:~/.ssh/
scp ~/.ssh/authorized_keys [email protected]:~/.ssh/

好了。

测试SSH免登录

在每一台主机上面分别使用ssh命令来登录其他三台机器,看能否成功?

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[[email protected] ~]# ssh master
Last login: Sun Feb 19 13:08:38 2017 from slave2
[[email protected] ~]# logout
Connection to master closed.

成功!

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