ssh-keygen生成秘钥对(使用自定义名字)

$ ssh-keygen -t rsa -f ~/.ssh/id_ras_my
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /Users/xxx/.ssh/id_ras_my.
Your public key has been saved in /Users/xxx/.ssh/id_ras_my.pub.
The key fingerprint is:
SHA256:kZ8R2xLXlJHpsH9iXgvCgkFViQ102F+auRihxVvZykw [email protected]
The key's randomart image is:
+---[RSA 2048]----+
|        o+@ooo== |
|       . +.&.E=o |
|      . o * X+*  |
|       . + *.O.  |
|        S + o..  |
|       . . + o+ o|
|          . .o.+.|
|              .. |
|                 |
+----[SHA256]-----+
$ 

ssh-copy-id 复制公钥到服务器
ssh-copy-id 把密钥追加到远程主机的 .ssh/authorized_key

$ ssh-copy-id -i ~/.ssh/id_rsa_my.pub [email protected]
ligh@remote-host‘s password:
Now try logging into the machine, with ―ssh ?remote-host‘‖, and check in: 
.ssh/authorized_keys to make sure we haven‘t added extra keys that you weren‘t expecting.

现在就可以用ssh连接远程服务器了

$ ssh [email protected] -i ~/.ssh/id_rsa_my
Last login: Sun Nov 16 17:22:33 2008 from 192.168.1.2 

但是到这一步只是做到了免密，如果不用默认名id_rsa的话，那么每次连接都需要使用ssh-i 还是不够简练，所以还需要最后一步

配置~/.ssh/config内容

	#自定义远程主机名( #注释需要单独一行)
    Host myHost                
    #服务器IP
    HostName XX.XX.XX.XX
    #服务器用户名         
    User root                      
    #端口 
    Port 22                         
     #私钥地址
    IdentityFile ~/.ssh/id_ras_my     

配置完成就可以直接在终端使用 ssh myHost 连接主机了
包括其他如 rsync,scp,都可以不用密码，不用-i了

$ ssh myHost
Last login: Wed May 29 21:42:04 2019 from 36.102.10.130
[root@VM_0_14_centos ~]#