AppStreamからメタデータをダウンロードできないときの対処法(CentOS8)

先日から急にyumやdnfでパッケージがダウンロードできなくなってしまい、そのときの対処法のメモ。

状況　　

yum,dnfでパッケージインストール時「Failed to download metadata for repo 'appstream'」といったエラーが出てリポジトリからパッケージを落とせなくなってしまった。
「yum update」でも同様。。。

$yum update
Failed to set locale, defaulting to C.UTF-8
CentOS Linux 8 - AppStream                                                           60  B/s |  38  B     00:00    
Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

解決方法

CentOS8のEOLにより元々のリポジトリが使えなくなってしまったとのこと。
リポジトリのURLを書き換えると再度インストールできるようになる。

$sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*;
$sed -i 's|mirrorlist|#mirrorlist|g' /etc/yum.repos.d/CentOS-*; 
$yum update
Failed to set locale, defaulting to C.UTF-8
CentOS Linux 8 - AppStream                                                          569 kB/s | 8.4 MB     00:15    
CentOS Linux 8 - BaseOS                                                             404 kB/s | 4.6 MB     00:11    
CentOS Linux 8 - Extras                                                             6.1 kB/s |  10 kB     00:01    
Dependencies resolved.
~~
~~

• 書き換え前　　

$cat /etc/yum.repos.d/CentOS-Linux-AppStream.repo 
# CentOS-Linux-AppStream.repo
#
# The mirrorlist system uses the connecting IP address of the client and the
# update status of each mirror to pick current mirrors that are geographically
# close to the client.  You should use this for CentOS updates unless you are
# manually picking other mirrors.
#
# If the mirrorlist does not work for you, you can try the commented out
# baseurl line instead.
[appstream]
name=CentOS Linux $releasever - AppStream
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=AppStream&infra=$infra
#baseurl=http://mirror.centos.org/$contentdir/$releasever/AppStream/$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
$

• 書き換え後

$cat /etc/yum.repos.d/CentOS-Linux-AppStream.repo 
# CentOS-Linux-AppStream.repo
#
# The #mirrorlist system uses the connecting IP address of the client and the
# update status of each mirror to pick current mirrors that are geographically
# close to the client.  You should use this for CentOS updates unless you are
# manually picking other mirrors.
#
# If the #mirrorlist does not work for you, you can try the commented out
# baseurl line instead.

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

参考