EPEL(Extra Packages for Enterprise Linux)是由Fedora Special Interest Group维护的 Enterprise Linux（RHEL、CentOS）中经常用到的包，这个里面包含了很多软件扩展包，比如 FreeTDS、ninja 等软件，这个扩展包非常好，直接从EPEL中安装软件不仅安装方便，还省去了从 GitHub 上下载源码编译的过程。
安装 EPEL扩展包
EPEL 镜像由很多，如下列举了三个镜像源：
(镜像源的版本可以根据实际情况选择，这里选择了 release7 版本)
1. 用 yum 安装 阿里云 EPEL 镜像
命令：yum install https://mirrors.aliyun.com/epel/epel-release-latest-7.noarch.rpm
[root@localhost ~]# yum install https://mirrors.aliyun.com/epel/epel-release-latest-7.noarch.rpm
Configuration file /etc/yum/pluginconf.d/license-manager.conf not found
Unable to find configuration file for plugin license-manager
Loaded plugins: fastestmirror
epel-release-latest-7.noarch.rpm | 15 kB 00:00:00
Examining /var/tmp/yum-root-ruJduU/epel-release-latest-7.noarch.rpm: epel-release-7-14.noarch
Marking /var/tmp/yum-root-ruJduU/epel-release-latest-7.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package epel-release.noarch 0:7-14 will be installed
>>>>>>>>>>>>>> 中间的安装过程省略 <<<<<<<<<<<<<<
Installed:
epel-release.noarch 0:7-14
Complete!
[root@localhost ~]#
2. 用 yum 安装 清华大学开源软件 EPEL 镜像
命令：yum install https://mirrors.tuna.tsinghua.edu.cn/epel/7/x86_64/Packages/e/epel-release-7-14.noarch.rpm
[root@localhost ~]# yum install https://mirrors.tuna.tsinghua.edu.cn/epel/7/x86_64/Packages/e/epel-release-7-14.noarch.rpm
Configuration file /etc/yum/pluginconf.d/license-manager.conf not found
Unable to find configuration file for plugin license-manager
Loaded plugins: fastestmirror
epel-release-7-14.noarch.rpm | 15 kB 00:00:00
Examining /var/tmp/yum-root-ruJduU/epel-release-7-14.noarch.rpm: epel-release-7-14.noarch
Marking /var/tmp/yum-root-ruJduU/epel-release-7-14.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package epel-release.noarch 0:7-14 will be installed
>>>>>>>>>>>>>> 中间的安装过程省略 <<<<<<<<<<<<<<
Installed:
epel-release.noarch 0:7-14
Complete!
[root@localhost ~]#
3. 用 yum 安装 Fedora EPEL 镜像
命令：yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
[root@localhost ~]# yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
Configuration file /etc/yum/pluginconf.d/license-manager.conf not found
Unable to find configuration file for plugin license-manager
Loaded plugins: fastestmirror
epel-release-latest-7.noarch.rpm | 15 kB 00:00:00
Examining /var/tmp/yum-root-ruJduU/epel-release-latest-7.noarch.rpm: epel-release-7-14.noarch
Marking /var/tmp/yum-root-ruJduU/epel-release-latest-7.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package epel-release.noarch 0:7-14 will be installed
>>>>>>>>>>>>>> 中间的安装过程省略 <<<<<<<<<<<<<<
Installed:
epel-release.noarch 0:7-14
Complete!
[root@localhost ~]#
以上三种EPEL镜像源的安装，都亲测有效，你可以选择任何一种进行安装。
