ssh 报错 Cannot find a valid baseurl for repo: base/7/x86_64

在ssh服务器安装yum的时候报错,Cannot find a valid baseurl for repo: base/7/x86_64

其实就是没有yum源, 设置源
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
然后执行
yum clean all
yum makecache