vim /etc/yum.repos.d/epel.repo 如下：
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch
#mirrorlist=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
安装完成之后yum clean yum list
如果有获取 GPG 密钥失败：[Errno 14] curl#37 - "Couldn't open file /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7"报错请执行下面命令
第一步：cd /etc/pki/rpm-gpg/
[root@local63 rpm-gpg]# wget https://archive.fedoraproject.org/pub/epel/RPM-GPG-KEY-EPEL-7
执行完在yum clean yum list
如下代码在centos7安装epel源
yum -y install epel-release
