centos7配置互相免密登录

本是古典何须时尚 2022-11-11 14:41 234阅读 0赞

### centos7配置互相免密登录 ###

*  具体步骤
 *   *   *  1.新建hadoop用户，设置密码为8ik,(OL>，并设置用户权限。------\*\*3台机器同时操作\*\*
         *  2.修改主机名称------\*\*3台依次修改\*\*
         *  3.切换用户hadoop---------\*\*3台同时操作\*\*
         *  4.生成秘钥，并发送到别的机器---------\*\*3台同时操作\*\*
         *  5.验证
 *  KATA练手-多台同时操作

# 具体步骤 #

准备3台机器，192.168.11.131-133，设置他们在用户hadoop上的免密登录。

### 1.新建hadoop用户，设置密码为8ik,(OL>，并设置用户权限。------**3台机器同时操作** ###

[root@localhost ~]# useradd hadoop
    [root@localhost ~]# passwd hadoop
    
    // 修改用户权限
    [root@localhost ~]# vim /etc/sudoers
    ...最后吗加入下面一行，再  :wq! 强制保存
    hadoop  ALL=(ALL)       NOPASSWD: ALL

### 2.修改主机名称------**3台依次修改** ###

// 131名称为hadoop1，其它2台分别为hadoop2、hadoop3
    [root@localhost hadoop]# cat /etc/hostname
    hadoop1
    
    // 修改hosts
    [root@localhost hadoop]# vim /etc/hosts
    192.168.11.131 hadoop1
    192.168.11.132 hadoop2
    192.168.11.133 hadoop3
    
    // 验证第一台是否对的（后面两台依次hadoop2、hadoop3）
    [root@localhost hadoop]# cat /etc/hostname
    hadoop1

### 3.切换用户hadoop---------**3台同时操作** ###

[root@localhost ~]# su hadoop
    [hadoop@localhost root]$ cd /home/hadoop

### 4.生成秘钥，并发送到别的机器---------**3台同时操作** ###

[hadoop@localhost ~]$ cd .ssh
    	bash: cd: .ssh: 没有那个文件或目录
    
    // 没有.ssh目录，用下面命令出发创建
    [hadoop@localhost ~]$ ssh localhost
    	The authenticity of host 'localhost (::1)' can't be established.
    	ECDSA key fingerprint is SHA256:teaT7e7DpRCNeXsp7jPsqbUIcoMTVicl/zepbVucdtQ.
    	ECDSA key fingerprint is MD5:fd:cd:57:cf:52:70:a1:47:6b:9f:10:da:02:48:ea:d4.
    	Are you sure you want to continue connecting (yes/no)? yes
    	Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
    	
    	// 这里输入hadoop用户的登录密码
    	hadoop@localhost's password: 
    	Last failed login: Sun Mar 21 07:07:55 CST 2021 from localhost on ssh:notty
    	There were 2 failed login attempts since the last successful login.
    	Last login: Sun Mar 21 07:05:09 2021
    
    // 下面就已经有.ssh目录了
    [hadoop@localhost ~]$ cd .ssh
    
    [hadoop@localhost .ssh]$ ssh-keygen -t rsa
    
    	// 下面会要求输入3次空格
    	Generating public/private rsa key pair.
    	Enter file in which to save the key (/home/hadoop/.ssh/id_rsa): 
    	Enter passphrase (empty for no passphrase): 
    	Enter same passphrase again: 
    	Your identification has been saved in /home/hadoop/.ssh/id_rsa.
    	Your public key has been saved in /home/hadoop/.ssh/id_rsa.pub.
    	The key fingerprint is:
    	SHA256:OH6f0633Wd5yQxDwO0CIofXRFtNvTsXySxYTAdlsR9s hadoop@localhost.ydfind
    	The key's randomart image is:
    	+---[RSA 2048]----+
    	|       oo.o=+.==+|
    	|      o...ooo+.**|
    	|     .   ... .++E|
    	|       .    ...*.|
    	|      o S    oB .|
    	|     . .      .+ |
    	|      . .  . .. .|
    	|       . .... +o=|
    	|          o..o ==|
    	+----[SHA256]-----+
    
    [hadoop@localhost .ssh]$ ssh-copy-id hadoop1
    [hadoop@localhost .ssh]$ ssh-copy-id hadoop2
    [hadoop@localhost .ssh]$ ssh-copy-id hadoop3

### 5.验证 ###

[hadoop@localhost .ssh]$ ssh hadoop1
    	Last failed login: Sun Mar 21 07:12:49 CST 2021 from hadoop1 on ssh:notty
    	There were 3 failed login attempts since the last successful login.
    	Last login: Sun Mar 21 07:08:00 2021 from localhost
    [hadoop@localhost ~]$ exit
    	登出
    	Connection to hadoop1 closed.
    [hadoop@localhost .ssh]$ ssh hadoop2
    	Last login: Sun Mar 21 07:08:00 2021 from localhost
    [hadoop@localhost ~]$ exit
    	登出
    	Connection to hadoop2 closed.
    [hadoop@localhost .ssh]$ ssh hadoop3
    	Last login: Sun Mar 21 07:08:00 2021 from localhost
    [hadoop@localhost ~]$ exit
    	登出
    	Connection to hadoop3 closed.

可以看到3台机器都可以免密登录了

# KATA练手-多台同时操作 #

1）添加用户flink

cut -d : -f 1 /etc/passwd | grep flink --------验证是否有flink用户
    useradd flink
    passwd flink
    vim /etc/sudoers
    	flink ALL=(ALL)       NOPASSWD: ALL

2）修改主机名、host映射

vim /etc/hostname-------依次改为node1、node2、node3
    vim /etc/hosts
    192.168.11.131 node1
    192.168.11.132 node2
    192.168.11.133 node3
    // win10的hosts也可以加入，方便测试

3）设置免密

su flink
    cd /home/flink/.ssh --------若没有.ssh，可以用flink用户运行ssh localhost
    ssh-keygen -t rsa
    ssh-copy-id node1
    ssh-copy-id node2
    ssh-copy-id node3