Containerization

How to use Apptainer on DAIC?

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Apptainer

Apptainer is a container platform. It allows you to create and run containers that package up pieces of software in a way that is portable and reproducible. You can build a container using Apptainer on your laptop, and then run it on many on an HPC cluster. Apptainer was created to run complex applications on HPC clusters in a simple, portable, and reproducible way. This repository contains a template for building a Apptainer (former Singularity) container using miniforge, and mamba (similar to conda). The examples directory also contains examples for other setups.

Apptainer features

  • Verifiable reproducibility and security, using cryptographic signatures, an immutable container image format, and in-memory decryption.
  • Integration over isolation by default. Easily make use of GPUs, high speed networks, parallel filesystems on a cluster or server by default.
  • Mobility of compute. The single file SIF container format is easy to transport and share.
  • A simple, effective security model. You are the same user inside a container as outside, and cannot gain additional privilege on the host system by default. Read more about Security in Apptainer.

Template

The Apptainer template repository maintained by the Research Engineering and Infrastructure Team is a good starting point to create your own apptainers.

How to use Apptainer on the cluster with SLURM?

Here is an example how to use the container in a SLURM script.

#!/bin/sh
#SBATCH --job-name="apptainer-job"
#SBATCH --account="my-account"
#SBATCH --partition="general"      # Request partition.
#SBATCH --time=01:00:00            # Request run time (wall-clock). Default is 1 minute
#SBATCH --nodes=1.                 # Request 1 node
#SBATCH --tasks-per-node=1         # Set one task per node
#SBATCH --cpus-per-task=4          # Request number of CPUs (threads) per task.
#SBATCH --gres=gpu:1               # Request 1 GPU
#SBATCH --mem=4GB                  # Request 4 GB of RAM in total
#SBATCH --mail-type=END            # Set mail type to 'END' to receive a mail when the job finishes. 
#SBATCH --output=slurm-%x-%j.out   # Set name of output log. %j is the Slurm jobId
#SBATCH --error=slurm-%x-%j.err    # Set name of error log. %j is the Slurm jobId

export APPTAINER_ROOT="/path/to/container/folder"
export APPTAINER_NAME="my-container.sif"

# If you use GPUs
module use /opt/insy/modulefiles
module load cuda/12.1

# Run script
srun apptainer exec \
  --nv \                              # Bind NVIDIA libraries from the host
  --env-file ~/.env \                 # Source additional environment variables (optional)
  -B /home/$USER:/home/$USER \        # Mount host file-sytem inside container 
  -B /tudelft.net/:/tudelft.net/ \    # (different for each cluster)
  $APPTAINER_ROOT/$APPTAINER_NAME \   # Path to the container to run
  python script.py                    # Command to be executed inside container

Tutorial

See the Apptainer tutorial.