众所周知，centos 7 在2024年6月30日，生命周期结束，官方不再进行支持维护，而很多环境一时之间无法完全更新替换操作系统，因此对于yum源还是需要的，特别是对于互联网环境来说，在线yum源使用方便很多，而不需要去搭建本地yum源和内网yum源。
这里以阿里云为例，其他国内开源镜像站类似。此处主要以7.9为例。
1. 备份默认的repo文件
cd /etc/yum.repos.dmkdir backupmv *.repo backup2.配置阿里云的yum源
cat > CentOS-aliyun-lhr.repo << 'EOF'
[base]
name=CentOS-$releasever - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7#released updates
[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
EOFcat > epel-aliyun.repo <<'EOF'
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=http://mirrors.aliyun.com/epel/7/$basearch
failovermethod=priority
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7[epel-debuginfo]
name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
baseurl=http://mirrors.aliyun.com/epel/7/$basearch/debug
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=0[epel-source]
name=Extra Packages for Enterprise Linux 7 - $basearch - Source
baseurl=http://mirrors.aliyun.com/epel/7/SRPMS
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=0
EOF3. 检查验证
yum clean allyum makecache fastyum install vim lrzsz wget curl net-tools 4. 其他可用yum源搜集
1）官方yum源
cat > CentOS-Base.repo <<'EOF'
[base]
name=CentOS-7.9.2009
enabled=1
failovermethod=priority
baseurl=https://vault.centos.org/7.9.2009/os/$basearch/
gpgcheck=1
gpgkey=https://vault.centos.org/RPM-GPG-KEY-CentOS-7
[updates]
name=CentOS-7.9.2009
enabled=1
failovermethod=priority
baseurl=https://vault.centos.org/7.9.2009/updates/$basearch/
gpgcheck=1
gpgkey=https://vault.centos.org/RPM-GPG-KEY-CentOS-7
[extras]
name=CentOS-7.9.2009
enabled=1
failovermethod=priority
baseurl=https://vault.centos.org/7.9.2009/extras/$basearch/
gpgcheck=1
gpgkey=https://vault.centos.org/RPM-GPG-KEY-CentOS-7
EOF2）官方epel扩展源
cat > epel.repo <<'EOF'
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
#baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch
metalink=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7[epel-debuginfo]
name=Extra Packages for Enterprise Linux 7 - $basearch - Debug
#baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch/debug
metalink=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=1[epel-source]
name=Extra Packages for Enterprise Linux 7 - $basearch - Source
#baseurl=http://download.fedoraproject.org/pub/epel/7/SRPMS
metalink=https://mirrors.fedoraproject.org/metalink?repo=epel-source-7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=1
EOFcat > epel-testing.repo <<'EOF'
[epel-testing]
name=Extra Packages for Enterprise Linux 7 - Testing - $basearch
#baseurl=http://download.fedoraproject.org/pub/epel/testing/7/$basearch
metalink=https://mirrors.fedoraproject.org/metalink?repo=testing-epel7&arch=$basearch
failovermethod=priority
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7[epel-testing-debuginfo]
name=Extra Packages for Enterprise Linux 7 - Testing - $basearch - Debug
#baseurl=http://download.fedoraproject.org/pub/epel/testing/7/$basearch/debug
metalink=https://mirrors.fedoraproject.org/metalink?repo=testing-debug-epel7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=1[epel-testing-source]
name=Extra Packages for Enterprise Linux 7 - Testing - $basearch - Source
#baseurl=http://download.fedoraproject.org/pub/epel/testing/7/SRPMS
metalink=https://mirrors.fedoraproject.org/metalink?repo=testing-source-epel7&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
gpgcheck=1
EOF3） 清华大学yum源
cat > CentOS-tsinghua.repo <<'EOF'
[base]
name=CentOS-7.9.2009
enabled=1
failovermethod=priority
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/7.9.2009/os/$basearch/
gpgcheck=1
gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/RPM-GPG-KEY-CentOS-7
[updates]
name=CentOS-7.9.2009
enabled=1
failovermethod=priority
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/7.9.2009/updates/$basearch/
gpgcheck=1
gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/RPM-GPG-KEY-CentOS-7
[extras]
name=CentOS-7.9.2009
enabled=1
failovermethod=priority
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/7.9.2009/extras/$basearch/
gpgcheck=1
gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/RPM-GPG-KEY-CentOS-7
[epel]
name=Extra Packages for Enterprise Linux 7 -
enabled=1
failovermethod=priority
baseurl=https://mirrors.tuna.tsinghua.edu.cn/epel/7/$basearch/
gpgcheck=0
gpgkey=https://mirrors.tuna.tsinghua.edu.cn/epel/RPM-GPG-KEY-EPEL-7
EOF4）中科大yum源
cat > CentOS-ustc.repo <<'EOF'
[base]
name=CentOS- - Base
baseurl=https://mirrors.ustc.edu.cn/centos-vault/centos/7.9.2009/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[updates]
name=CentOS- - Updates
baseurl=https://mirrors.ustc.edu.cn/centos-vault/centos/7.9.2009/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[extras]
name=CentOS- - Extras
baseurl=https://mirrors.ustc.edu.cn/centos-vault/centos/7.9.2009/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[centosplus]
name=CentOS- - Plus
baseurl=https://mirrors.ustc.edu.cn/centos-vault/centos/7.9.2009/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
EOF5）网易yum源
cat > CentOS-163.repo <<'EOF'
[base]
name=CentOS-$releasever - Base - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
baseurl=http://mirrors.163.com/centos-vault/7.9.2009/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7#released updates
[updates]
name=CentOS-$releasever - Updates - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://mirrors.163.com/centos-vault/7.9.2009/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://mirrors.163.com/centos-vault/7.9.2009/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - 163.com
baseurl=http://mirrors.163.com/centos-vault/7.9.2009/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7EOF其他centos版本的yum源配置：
CentOS 6 在线可用yum源配置——筑梦之路_centos6可用yum源-CSDN博客
CentOS 8 停止维护后换可用yum源——筑梦之路_centos yum 阿里云镜像还支持吗-CSDN博客
参考资料：
https://www.cnblogs.com/yeziwinone/p/17916626.html
