centos配置yum为国内源
yum repolist # 查看yum列表
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo # 执行命令
yum clean all # 清理缓存
yum makecache # 更新缓存
yum repolist # 查看yum列表
yum -y update # 更新yum
参考资料 https://www.jianshu.com/p/5c7ffdf19f30