遇到问题：ssh: Could not resolve hostname github: Temporary failure in name resolution
解决方法：github添加ssh的key

步骤：

cd ~/.ssh
ls

>>id_rsa  id_rsa.pub #有这两个文件说明已经添加过ssh key，但一般需要重新生成

ssh-keygen -t rsa -C "你的邮箱地址" #创建ssh key
#-t 指定密钥类型，默认rsa ，可省略；
#-C 设置注释文字，比如邮箱；
#-f 指定密钥文件存储文件名。

Generating public/private rsa key pair.
Enter file in which to save the key (/home/overlord/.ssh/id_rsa):  #Enter回车
/home/overlord/.ssh/id_rsa already exists.
Overwrite (y/n)? y #输入y
Enter passphrase (empty for no passphrase): #Enter回车
Enter same passphrase again: #Enter回车
Your identification has been saved in /home/XX/.ssh/id_rsa
Your public key has been saved in /home/XX/.ssh/id_rsa.pub
The key fingerprint is:
XXXXXX
The key's randomart image is:
+---[RSA XXXX]----+
|                 |
| XXXxx           |
|                 |
|   xXXXXXX       |
|XXXXXXXXXXX      |
|X        X       |
|XXXXXXXXX        |
|XXXXXXXX         |
|    XXXXX        |
+----[XXXX]-----+
##创建成功

接着复制刚刚生成的密钥，vi id_rsa.pub ，打开文件后全部copy
也可以用这个指令：cat ~/.ssh/id_rsa.pub

下面登录你刚刚输入的邮箱所创建的github账号，按照如下步骤操作：

至此添加成功！
再次测试ssh -T git@github.com

Hi XX! You've successfully authenticated, but GitHub does not provide shell access.

问题解决~