linux中远程主机进行免密登录

[root@k8s-master ~]# ssh-
ssh-add      ssh-agent    ssh-copy-id  ssh-keygen   ssh-keyscan  
#生成免密密钥
[root@k8s-master ~]# ssh-keygen 
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
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:QdM7NW3JpWzBAekd9xJ7hWeeoihS2LCDM0F9wWCnV5g root@k8s-master
The key's randomart image is:
+---[RSA 2048]----+
|  ...ooo*o  .*o=.|
|   ..ooE... +.Xo=|
|    o.*..  + ++O+|
|   + +.o .o .o+.+|
|    o o S ... .o |
|     . . . .     |
|      . .        |
|                 |
|                 |
+----[SHA256]-----+
#把免密号发过去
[root@k8s-master ~]# ssh-copy-id ip地址
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/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@ip地址's password: 

Number of key(s) added: 1

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