centos-基础镜像中安装失败，提示：Error:-Failed-to-download-metadata-for-repo-‘AppStream‘:-Cannot-prepare-internal

1、修改源

cd /etc/yum.repos.d/
sed -i ;s/mirrorlist/#mirrorlist/g; /etc/yum.repos.d/CentOS-*
sed -i ;s|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g; /etc/yum.repos.d/CentOS-*

2、更新源

yum update -y

3、安装指定软件

yum install git