diskimage-builder/diskimage_builder/elements/epel/pkg-map

{
 "distro": {
    "centos7": {
       "wget": "wget",
       "yum-utils": "yum-utils"
    },
    "rhel7": {
       "wget": "wget",
       "yum-utils": "yum-utils"
    }
 },
 "default": {
   "wget": "",
   "yum-utils": ""
 }
}