README.Singularity.md

Singularity container

Simulations for the MOLLER experiment can be run using Singularity containers on High Performance Computing (HPC) system.

The instructions below explicitly use the develop code branch. Every branch is available as a pre-built Docker container on Docker Hub which is used to build a local Singularity container, but only the develop and master branches are available as pre-built Singularity containers on CernVM-FS.

Requirements

• Singularity >= 2.6.1

On many HPC systems, the singularity command is either installed systemwide or available through environment modules (module load singularity).

Building a local Singularity container

You can build a local Singularity container from the docker container with:

singularity pull docker://jeffersonlab/remoll:develop

This will create the file jeffersonlab_remoll_develop.sif (or similar) in your local directory.

Using the Singularity container on CernVM-FS

You can use a singularity container hosted on the global CernVM-FS filesystem, courtesy of the Open Science Grid. This pre-built Singularity container is located at /cvmfs/singularity.opensciencegrid.org/jeffersonlab/remoll:develop. This is a directory, not a single file, but can be used instead of the file name below.

Running simulations with the Singularity container

singularity run jeffersonlab_remoll_develop.sif remoll -h

Input and output locations

In addition to the geometry and macros that are included in the Singularity container at /jlab/remoll/, you can also use any (user) directory in your local filesystem. By default the simulation will run in your current directory. In that directory,