在這裏提到的不僅僅是爲了hadoop的配置，而是更一般的情況，你可以利用它登錄在其他任意服務器的帳戶，而免去每次輸入密碼的煩惱。由於當初記錄時使用的英文，描述很簡單，這裏就不翻譯了。
1. Connect to host via ssh without password
i) Generate your private key and public key of your own client:
$ ssh-keygen -t rsa
Also, you can generate key with specifying the file storing the private/public key
$ ssh-keygen -t rsa -f ~/.ssh/id_rsa.github -C "Key, e.g. user name"
ii) Put the public key on the remote host, append the public key into the authorized_key file
2. Configure of ssh
If you want to connect to many hosts with different profiles, e.g., different user names, without password. There will be many private key . You need to configure your ssh profiles in your client to tell ssh which . Here is an example:
Host *.workdomain.com
IdentityFile ~/.ssh/id_rsa.work
User lee
Host github.com
IdentityFile ~/.ssh/id_rsa.github
User git