修复 CentOS 中的“无法找到 repo 的有效 baseurl”

背景

由于 CentOS 7 已达到 EOL 级别，镜像已移至 vault。执行 yum 时会返回错误“Cannot find a valid baseurl for repo: base/7/x86_64”。

解决方案

我们需要CentOS-Base.repo更新/etc/yum.repos.d/CentOS-Base.repo。

取消注释以开头的行baseurl。
全部更新http://mirrorlist.centos.org至http://vault.centos.org。
全部更新http://mirror.centos.org至http://vault.centos.org。
我们可以使用清除缓存sudo yum clean all。

命令：

repo_file=/etc/yum.repos.d/CentOS-Base.repo
cp ${repo_file} ~/CentOS-Base.repo.backup
sudo sed -i s/#baseurl/baseurl/ ${repo_file}
sudo sed -i s/mirrorlist.centos.org/vault.centos.org/ ${repo_file}
sudo sed -i s/mirror.centos.org/vault.centos.org/ ${repo_file}
sudo yum clean all

文件看起来是这样的。

# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# 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, as a fall back you can try the 
# remarked out baseurl= line instead.
#
#

[base]
name=CentOS-$releasever - Base
mirrorlist=http://vault.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
baseurl=http://vault.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

#released updates 
[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://vault.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
baseurl=http://vault.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
mirrorlist=http://vault.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
baseurl=http://vault.centos.org/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
mirrorlist=http://vault.centos.org/?release=$releasever&arch=$basearch&repo=centosplus&infra=$infra
baseurl=http://vault.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

文章来源：https://dev.to/franzwong/fix-cannot-find-a-valid-baseurl-for-repo-in-centos-1h07