The problems are:
1. You can't have apptainers that use each other. The most common case was things like Make, GCC, Git etc. If Make is in a different apptainer to GCC then it won't work because as soon as you go into Make then it can't see GCC any more.
2. It doesn't work if any of your output artefacts depend on things inside the container. For example you use your GCC apptainer to compile a program. It appears to work, but when you run it you find it actually linked to something in the apptainer that isn't visible any more. This is also a problem for C headers.
3. We had constant issues with PATH getting messed up so you can't see things outside the apptainer that should have been available.
All in all it was a nice idea but ended up causing way more hassle than it was worth. It was much easier just to use an old OS (RHEL8) and get everything to work directly on that.
- Need to run more than one activity in a single container (this is an anti-pattern in other container technologies)
- HPC (and sometimes college) environments
- Want single-file distribution model (although doesn't support deltas)
- Cryptographically sign a SIF file without an external server
- Robust GPU support
We use singularity in the HPCs (like Leonardo, LUMI, Fugaku, NeSI NZ, Levante) but some devs and researchers have apptainer installed locally.
We found a timezone bug a few days ago in our Python code (matplotlib,xarray,etc.), but that didn't happen with apptainer.
As the code bases are still a bit similar, I could confirm apptainer fixed it but singularity ce was still affected by the bug -- singularity replaces the UTC timezone file by the user's timezone, Helsinki EEST in our case in LUMI HPC.
https://journals.plos.org/plosone/article?id=10.1371/journal...
If you ever use a shared cluster at a university or run by the government, Apptainer will be available, and Podman / Docker likely won't be.
In these environments, it is best not to use containers at all, and instead get to know your sysadmin and understand how he expects the cluster to be used.
On our HPC cluster, each user has a quota of inodes on the shared filesystem. This makes installing some software with lots of files problematic (like Anaconda). An Apptainer image is a single file on the filesystem though (basically squashfs) so you can have those with as many files as you want in each.
Installing the same software normally is easy and works fine though, you just exchaust your quota.
Find the code on https://github.com/evertheylen/probox or read my blog post on https://evertheylen.eu/p/probox-intro/
Some attrition using it though: is there a good in-depth book about it?
Perhaps the problems need to be addressed on a more fundamental level.
Process isolation should be the default. You should be able to opt out of certain parts of it as required by your application.
This should not be something you add on top of the OS, nor should it be something that configures existing OS functionality for you. Isolation should be the default.
Only MacOS does anything like this out of the box, that I’m aware of, and I’m not sure that it is granular enough for my liking as it is today. I often see apps asking for full disk access or local network access and deny them, because they don’t need those things, they maybe need a subset of it, but I can’t allow a subset of “full disk access” or “local network access” if the application is running as myself.
So I guess Apptainer is the solution to this use case - anyone had any experience with using it to bundle up an AI/ML application for redistribution? Thoughts/tips?
Like why should I put time into learning this instead of rootless podman? Aside from this secret management thing it sounds like same feature set
More nix less containers, btw.
E.g. docker run -ti nixery.dev/shell/cowsay bash for on-the-fly containers based on Nix.