【IT Notes】CentOS8下載工具出現“Failed to download metadata for repo 'AppStream' “錯誤

 CentOS已經於去年底停更，所以安裝完後AppStream的repo會在安裝工具或套件時出錯，跳出找不到可安裝套件的訊息，官方可以說是放棄CentOS8的更新。

解決方式：將AppStream和BaseOS repo都更新

# cd /etc/yum.repos.d
# vi CentOS-AppStream.repo
# vi CentOS-Base.repo

在repo檔案內更新內容，舊的連結註解掉、添增新的url

[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

[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/

baseurl=https://vault.centos.org/centos/$releasever/AppStream/$basearch/os/ 

gpgcheck=1

enabled=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial

接著要安裝工具時又出現以下錯誤，很煩！

錯誤：無法下載「appstream」軟體庫的中介資料：Cannot prepare internal mirrorlist: No URLs in mirrorlist

解決方式：繼續添加新的下載連結

# sudo sed -i -e "s|mirrorlist=|#mirrorlist=|g" /etc/yum.repos.d/CentOS-*

# sudo sed -i -e "s|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g" /etc/yum.repos.d/CentOS-*

# yum install wget -y

終於下載完成了！