在CentOS8上使用yum时报错:“Failed to download metadata for repo ‘appstream”

在CentOS8上使用yum时报错

CentOS-8 - AppStream                             94  B/s |  38  B     00:00    
Error: Failed to download metadata for repo 'AppStream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

解决方法:修改CentOS-Base.repo和CentOS-AppStream.repo内容

[root@centos80 ~]# cd /etc/yum.repos.d/
[root@centos80 yum.repos.d]# ll
total 48
-rw-r--r--. 1 root root  808 Mar 25 11:15 CentOS-AppStream.repo
-rw-r--r--. 1 root root  793 Mar 25 11:14 CentOS-Base.repo
-rw-r--r--. 1 root root 1292 Aug  4  2021 CentOS-CDROM.repo
-rw-r--r--. 1 root root  798 Aug 14  2019 CentOS-centosplus.repo
-rw-r--r--. 1 root root 1320 Aug 14  2019 CentOS-CR.repo
-rw-r--r--. 1 root root  668 Aug 14  2019 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root  756 Aug 14  2019 CentOS-Extras.repo
-rw-r--r--. 1 root root  338 Aug 14  2019 CentOS-fasttrack.repo
-rw-r--r--. 1 root root  928 Aug 14  2019 CentOS-Media.repo
-rw-r--r--. 1 root root  736 Aug 14  2019 CentOS-PowerTools.repo
-rw-r--r--. 1 root root 1382 Aug 14  2019 CentOS-Sources.repo
-rw-r--r--. 1 root root   74 Aug 14  2019 CentOS-Vault.repo

[root@centos80 yum.repos.d]# vi CentOS-Base.repo

[baseos]
name=CentOS Linux $releasever - BaseOS
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=BaseOS&infra=$infra
#baseurl=http://mirror.centos.org/$contentdir/$releasever/BaseOS/$basearch/os/
baseurl=https://vault.centos.org/centos/$releasever/BaseOS/$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

[root@centos80 yum.repos.d]# vi CentOS-AppStream.repo

[AppStream]
name=CentOS-$releasever - AppStream
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=AppStream&infra=$infra
#baseurl=http://mirror.centos.org/$contentdir/$releasever/AppStream/$basearch/os/
baseurl=https://vault.centos.org/centos/$releasever/AppStream/$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

[root@centos80 yum.repos.d]# yum clean all   
Repository AppStream is listed more than once in the configuration
0 files removed

[root@centos80 yum.repos.d]# yum makecache
Repository AppStream is listed more than once in the configuration
CentOS-8 - AppStream                                                         5.6 MB/s | 8.4 MB     00:01    
CentOS Linux 8 - BaseOS                                                      4.0 MB/s | 4.6 MB     00:01    
CentOS-8 - Extras                                                            181  B/s |  11 kB     01:00    
Metadata cache created.