Eagle uses environment modules to enable use of multiple software packages. There is a detailed guide to finding and using modules. The following guides show how to utilize the more complex modules:
EPEL is no longer supported for CentOS 7. A singularity image with the CentOS 6 compute environment with EPEL has been set up in /nopt/nrel/apps/epel/centos6-epel.simg. Documentation and recipe exists to customize the image.