ssh免密登录

生成公钥和私钥

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:
fe:57:d1:05:6b:84:7d:02:8e:5d:d5:11:c1:eb:f7:c7 root@localhost
The key's randomart image is:
+--[ RSA 2048]----+
|            .+=**|
|           +.ooo+|
|          . o o+o|
|             ....|
|        S     .. |
|       .      ...|
|        .    . .o|
|         .  .   E|
|          ..    .|
+-----------------+
#一直回车，不设置私钥密码

将公钥拷贝到需要免密登录的服务器

ssh-copy-id  xx.xx.xx.xx
#提示输入目标服务器的密码

如果ssh端口不是默认的22可以通过-p参数指定

ssh-copy-id  -p 6666  xx.xx.xx.xx

如果公钥的位置不是默认的~/.ssh/id_rsa.pub,可以通过-i 参数指定

ssh-copy-id -i /id_rsa.pub  xx.xx.xx.xx

如果不是默认的root用户

ssh-copy-id user@xx.xx.xx.xx