CentOs7.3 Hadoop 用户 ssh 免密登录

hostnamectl set-hostname <hostname>

sudo hostnamectl set-hostname node1

$ reboot

su root
vi /etc/hosts

$ cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
# 以下是添加的
192.168.252.121 node1
192.168.252.122 node2
192.168.252.123 node3

for a in {1..3} ; do scp /etc/hosts node$a:/etc/hosts ; done

for a in {1..3} ; do ssh node$a cat /etc/hosts ; done

vi /etc/ssh/sshd_config 

RSAAuthentication yes      #开启私钥验证
PubkeyAuthentication yes   #开启公钥验证

for a in {1..3} ; do scp /etc/ssh/sshd_config node$a:/etc/ssh/sshd_config ; done

su hadoop
ssh-keygen -t rsa -P ''

Generating public/private rsa key pair.
Enter file in which to save the key (/home/hadoop/.ssh/id_rsa): 
Created directory '/home/hadoop/.ssh'.
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:
aa:be:0e:46:9a:e8:d5:dc:79:ea:5a:b8:9b:08:e2:dd hadoop@node2
The key's randomart image is:
+--[ RSA 2048]----+
|                 |
|                 |
|                 |
|                 |
|  .     S        |
|.+  o o..        |
|=.o. +.+ .       |
|+.+.o.+ o        |
| o ==E+o         |
+-----------------+

for a in {1..3}; do sudo ssh hadoop@node$a cat /home/hadoop/.ssh/id_rsa.pub >> /home/hadoop/.ssh/authorized_keys; done

for a in {1..3}; do sudo scp /home/hadoop/.ssh/authorized_keys hadoop@node$a:/home/hadoop/.ssh/authorized_keys ; done

chmod 700 /home/hadoop/.ssh/
chmod 700 /home/hadoop/
chmod 600 /home/hadoop/.ssh/authorized_keys 

sudo systemctl restart sshd.service

ssh hadoop@node2

[hadoop@node1 ~]# exit
logout
Connection to node1 closed.