CentOS7 기준.

yum install wget
wget -r --no-parent -A 'epel-release-*.rpm' http://dl.fedoraproject.org/pub/epel/7/x86_64/e/ 
rpm -Uvh dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-*.rpm

rpm -ivh http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-2.noarch.rpm

amazon linux
https://aws.amazon.com/ko/premiumsupport/knowledge-center/ec2-enable-epel/

참고 :
Install EPEL repo on CentOS 7 and RHEL 7
http://sharadchhetri.com/2014/09/07/install-epel-repo-centos-7-rhel-7/