Centos7通过reposync同步国内yum源-搭建局域网内网本地Yum源

https://www.cnblogs.com/vilenx/p/12533361.html

https://blog.csdn.net/u012402276/article/details/53158682

https://www.longger.net/article/41354.html

https://juejin.im/post/6844903981299449863

https://www.linuxprobe.com/linux-yum-config.html