#兩臺主機做免密登錄
[root@localhost ~]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
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:
SHA256:0zPiM+3ypvmYPisJbeL8LhA2QApiAVqwF9C+gyASonU root@localhost.localdomain
The key's randomart image is:
+---[RSA 3072]----+
|OB+              |
|Xoo.E            |
|*=..             |
|=.=      .       |
|+o + .  S +      |
|. + o o. + o     |
|   = + .+ .      |
|    + o oB.      |
|     +ooBO+      |
+----[SHA256]-----+

[root@localhost ~]# ssh-copy-id root@192.168.8.131
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.8.131 (192.168.8.131)' can't be established.
ECDSA key fingerprint is SHA256:WbxvLgdwExwRlMT4gaAC1bVyIovZnAwwX1DX8dv6Rs0.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.8.131's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@192.168.8.131'"
and check to make sure that only the key(s) you wanted were added.

#安裝軟件
[root@localhost ~]# yum -y install git maven