Apptainer, previously known as Singularity, is an open-source project under the Linux Foundation since November 2021.

Apptainer containers provide an application virtualization layer enabling mobility of compute via both application and environment portability. With Apptainer, you can build a user-defined software stack including an application and all its dependencies (libraries, etc.) that runs on any other Linux system where Apptainer is installed.

Note: Apptainer retains the look and feel of Singularity and uses the same Singularity Image Format (SIF) for the container images.

Main Apptainer commands include:

apptainer help

To find help on available options and commands.

apptainer build

To build an Apptainer image.

apptainer shell

To run a shell within a container.

apptainer exec

To run a command within a container.

apptainer run

To run a user-defined default command within a container.

Many ready-to-use Apptainer images from multiple sources are available for you to grab with the apptainer build command and use on your workstation or on NAS systems. Introduction to Using Apptainer Build provides some basic information on using the apptainer build command.

If you have an existing Apptainer image that is ready to run, you should be able to run it on any platform where Apptainer is installed.

Apptainer is installed for use on NAS systems with either x86_64 or aarch64 architecture, and with either the TOSS4 or TOSS5 operating system. You can use Apptainer after loading one of these modules:

apptainer/x86-toss4

For use on older NAS systems with x86_64 architecture and the TOSS4 operating system, including Electra (bro_ele, sky_ele), Aitken (rom_ait, mil_ait) and some Cabeus systems (mil_a100).

apptainer/x86-toss5

For use on the latest NAS Athena system (tur_ath) with x86_64 architecture and the TOSS5 operating system.

apptainer/arm-toss5

For use on the Cabeus GH200 system (gh200) with aarch64 architecture and the TOSS5 operating system.

See Running an Apptainer Container Image on NAS Systems to learn how to run your image on NAS systems.

References

For more information about using Apptainer, see the official Apptainer Container Documentation.