1、进入到/etc/yum.repos.d目录里面。
2.分别修改CentOS-AppStream.repo、CentOS-Base.repo、CentOS-Extras.repo、CentOS-PowerTools.repo文件中的baseurl。
[AppStream]
name=CentOS-$releasever - AppStream
#baseurl=http://mirrors.cloud.aliyuncs.com/$contentdir/$releasever/AppStream/$basearch/os/
baseurl=https://mirrors.aliyun.com/centos/8-stream/AppStream/$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
[BaseOS]
name=CentOS-$releasever - Base
#baseurl=http://mirrors.cloud.aliyuncs.com/$contentdir/$releasever/BaseOS/$basearch/os/
baseurl=https://mirrors.aliyun.com/centos/8-stream/BaseOS/$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
[extras]
name=CentOS-$releasever - Extras
#baseurl=http://mirrors.cloud.aliyuncs.com/$contentdir/$releasever/extras/$basearch/os/
baseurl=https://mirrors.aliyun.com/centos/8-stream/extras/$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
[PowerTools]
name=CentOS-$releasever - PowerTools
#baseurl=http://mirrors.cloud.aliyuncs.com/$contentdir/$releasever/PowerTools/$basearch/os/
baseurl=https://mirrors.aliyun.com/centos/8-stream/PowerTools/$basearch/os/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
