Apptainer User Guide

Welcome to the Apptainer User Guide!

This guide aims to give an introduction to Apptainer, brief installation instructions, and cover topics relevant to users building and running containers.

For a detailed guide to installation and configuration, please see the separate Admin Guide for this version of Apptainer.

Building Containers

Learn how to write a definition file that can be used to build a container. Understand the environment within a build and how to build as a non-root user.

Container Signing & Encryption

Apptainer allows containers to be signed using a PGP key. The signature travels with the container image, allowing you to verify that the image is unmodified at any time. Encryption of containers using LUKS2 is also supported. Encrypted containers can be run without decrypting them to disk first. Using encrypted containers currently requires a setuid installation of Apptainer.

Advanced Usage

Once you’ve understood the basics, explore all the options which Apptainer provides for accessing data, running persistent services in containers, manipulating the container environment, and applying networking and security configuration.

Compatibility

Apptainer has unique benefits and supports easy access to GPUs and other hardware. It also strives for compatibility with Docker/OCI container formats. Understand the differences between Apptainer and Docker, as well as how to use containerized MPI and GPU applications.

Get Involved

We’d love you to get involved in the Apptainer community! Whether through contributing feature and fixes, helping to answer questions from other users, or simply testing new releases.

Contributing

Reference

Appendix
- Apptainer’s environment variables
- Build Modules