# Apptainer / Singularity 

If you don't have admin access to your local computer, or you simply
prefer it, you can use
[Apptainer](https://apptainer.org/docs/user/latest/quick_start.html)
instead (formerly known as
[Singularity](https://docs.sylabs.io/guides/latest/user-guide/quick_start.html)).
You still need admin access to install Apptainer, or a willing
sysadmin to do it for you.[^f108]

[^f108]: Apptainer/Singularity is already installed on all the systems in the Nevis
    particle-physics Linux cluster.

To download the container and convert it to Apptainer's .sif format:

    apptainer pull docker://wgseligman/jupyter-pyroot

After some processing, you'll have the image file
`jupyter-pyroot_latest.sif`. Then you can run Apptainer on that
container:

    apptainer run --bind=$PWD:/work jupyter-pyroot_latest.sif

Note that while you can change the mapping of the /work directory within
the container (see the Docker instructions above), you can't change
Jupyter's binding to port 8080. This might be a problem if you're
running on a shared computer system and more than one user wants to run
this container at the same time.

:::{figure-md} singularity-fig
:align: center

<img src="https://imgs.xkcd.com/comics/singularity.png" alt="xkcd singularity" width="75%">

<https://xkcd.com/1668/> by Randall Munroe
:::