一、生成免密登錄公鑰
ssh-keygen -t rsa
如下:
[root@VM-0-9-centos /]# ssh-keygen -t rsa 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:ZyZSw/Ciok0MqO1My3qgo9K9ONQBxkEkz8tymflz82Q root@VM-0-9-centos The key's randomart image is: +---[RSA 2048]----+ |.++. . | |.++ + | |o.o. . = | |.= =.. o . | |o &.... S + | |.@.+. . = | |o+*.o o E | |+.+..o = | |=o.... . | +----[SHA256]-----+
注意：如果每生成過此公鑰，只需一路回車即可。
二、查看公鑰
公鑰的路徑：
Enter file in which to save the key (/root/.ssh/id_rsa):
即：/root/.ssh
[root@VM-0-9-centos /]# cd /root/.ssh/ [root@VM-0-9-centos .ssh]# ls authorized_keys id_rsa id_rsa.pub [root@VM-0-9-centos .ssh]#
authorized_keys:存放遠程免密登錄的公鑰,主要通過這個文件記錄多台機器的公鑰 id_rsa: 生成的私鑰文件 id_rsa.pub： 生成的公鑰文件 know_hosts: 已知的主機公鑰清單 如果希望ssh公鑰生效需滿足至少下面兩個條件： 1) .ssh目錄的權限必須是700 2) .ssh/authorized_keys文件權限必須是600
三、實現遠程免密登錄
在本地（或服務器A）上實現免密登錄服務器B，需要將本地（或服務器A）的公鑰（/root/.ssh/id_rsa.pub文件內容）配置到服務器B的/root/.ssh/authorized_keys里即可，多個公鑰注意換行。
四、配置方式
4.1 通過ssh-copy-id的方式
ssh-copy-id -i ~/.ssh/id_rsa.pub <username@romte_ip>
如下：
liumeng@liumengdeMacBook-Pro .ssh % ssh-copy-id -i ~/.ssh/id_rsa.pub root@106.53.***.*** /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/Users/liumeng/.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@106.53.***.***'s password: Number of key(s) added: 1 Now try logging into the machine, with: "ssh 'root@106.53.***.***'" and check to make sure that only the key(s) you wanted were added.
4.2 SCP方式
scp -p ~/.ssh/id_rsa.pub root@<remote_ip>:/root/.ssh/authorized_keys
如下：
liumeng@liumengdeMacBook-Pro .ssh % scp -P 22 ~/.ssh/id_rsa.pub root@106.53.***.***:/root/.ssh/authorized_keys root@106.53.***.***'s password: id_rsa.pub 100% 588 7.8KB/s 00:00 liumeng@liumengdeMacBook-Pro .ssh %
4.3 通過Ansible實現批量免密
將需要做免密操作的機器hosts添加到/etc/ansible/hosts下
4.4 手動復制粘貼
將本地id_rsa.pub文件的內容拷貝至遠程服務器的~/.ssh/authorized_keys文件中。
結束！