Add instructions for running Singularity/Apptainer container to README

README.md

@@ -33,7 +33,7 @@
 
 
 ## Installation
-You can install this package and dependences in a [python virtual environment](#virtual-environment) or use a [Docker container](#install-in-docker) (recommended).
+You can install this package and dependences in a [python virtual environment](#virtual-environment) or use a [Docker/Singularity/Apptainer container](#install-in-docker) (recommended).
 
   *TL;DR to install the Jax version for GPU run:*
 
@@ -89,7 +89,8 @@ pip3 install -e '.[full]'
 </details>
 
 ## Docker
-We recommend using a Docker container to ensure a similar environment to our scoring and testing environments. 
+We recommend using a Docker container to ensure a similar environment to our scoring and testing environments.
+Alternatively, a Singularity/Apptainer container can also be used (see instructions below).
 
 
 **Prerequisites for NVIDIA GPU set up**: You may have to install the NVIDIA Container Toolkit so that the containers can locate the NVIDIA drivers and GPUs. 
@@ -133,6 +134,25 @@ To use the Docker container as an interactive virtual environment, you can run a
 ### Running Docker Container (End-to-end)
 To run a submission end-to-end in a containerized environment see [Getting Started Document](./getting_started.md#run-your-submission-in-a-docker-container).
 
+### Using Singularity/Apptainer instead of Docker
+Since many compute clusters don't allow the usage of Docker due to securtiy concerns and instead encourage the use of [Singularity/Apptainer](https://github.com/apptainer/apptainer) (formerly Singularity, now called Apptainer), we also provide instructions on how to build an Apptainer container based on the here provided Dockerfile.
+
+To convert the Dockerfile into an Apptainer definition file, we will use [spython](https://github.com/singularityhub/singularity-cli):
+```bash
+pip3 install spython
+cd algorithmic-efficiency/docker
+spython recipe Dockerfile &> Singularity.def
+```
+Now we can build the Apptainer image by running
+```bash
+singularity build --fakeroot <singularity_image_name>.sif Singularity.def
+```
+To start a shell session with GPU support (by using the `--nv` flag), we can run
+```bash
+singularity shell --nv <singularity_image_name>.sif 
+```
+Similarly to Docker, Apptainer allows you to bind specific paths on the host system and the container by specifying the `--bind` flag, as explained [here](https://docs.sylabs.io/guides/3.7/user-guide/bind_paths_and_mounts.html).
+
 # Getting Started
 For instructions on developing and scoring your own algorithm in the benchmark see [Getting Started Document](./getting_started.md).
 ## Running a workload