git版本控制，使用SSH协议提交和拉取代码。
1、生成SSH公钥和密钥对，example@qq.com 使用自己的邮箱。
ssh-keygen -t rsa -C 'example@qq.com'
执行命令，生成以下代码（表示是首次在此电脑上生成密钥）：
Generating public/private rsa key pair.
Enter file in which to save the key (/d/Users/gaoyanping/.ssh/id_rsa):
Created directory '/d/Users/gaoyanping/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /d/Users/gaoyanping/.ssh/id_rsa.
Your public key has been saved in
/d/Users/gaoyanping/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:HRGixXiLF3J/O7z/SO8haXwSnlym9Qyd3R2PVIVcVsY
252602965@qq.com
The key's randomart image is:
+---[RSA 2048]----+
| oo o. . +X|
| oo=. . o+E|
| .= +. .. |
| . o..... oB|
| .S .o oo=*|
| B Oo.|
| &.oo|
| o.+o.|
| .oo+|
+----[SHA256]-----+
如果不是首次在此电脑上生成密钥，则会出现以下代码：
Generating public/private rsa key pair.
Enter file in which to save the key (/d/Users/gaoyanping/.ssh/id_rsa):
/d/Users/gaoyanping/.ssh/id_rsa already exists.
Overwrite (y/n)?
一台电脑可以生成多个密钥，这个时候只需要重建文件即可！
2、根据上面生成的密钥目录地址，执行查看密钥目录：
cd /d/Users/gaoyanping/.ssh/
3、查看目录下的公钥内容：
cat id_rsa.pub
4、复制公钥到_gitlab-Settings-SSH Keys _添加key即可。
