Hi there, this might rather be an issue in form of a feature request, but in the HPC world, the preferred containerisation technology is Singularity rather than Docker. There are python libraries for handling Singularity in a similar way as Docker can be handled: https://github.com/singularityhub/singularity-cli. I could try to mimic the Docker task templates that are provided in prefect with singularity instead, would such a feature be useful for the community?

It's the first time I see such a request so definitely not a common issue. And given how widespread and popular Docker is, it's basically the default. But if you would like to contribute an integration with Singularity, doing it via something like

SingularityFlowRunner

in Prefect 2.0 would make sense. Flow runners in Orion seem to be the right place for that