Predefining systems

To make cotainr easier to use, you can predefine systems. This currently means specifying a base image for a part of your HPC system. This can be done by creating a JSON <https://www.json.org/>_ file named systems.json in the project root folder.

Why should I do this?

If it is not trivial for the users to get MPI or GPU access working in containers on your system, then a predefined base image with support for this will help your users tremendously.

File format

The file format is relatively simple. For each you give it a name and then add a base image. The base image path can be one of the support targets for apptainer/singularity build.

{
  "system-name": {
    "base-image": "docker://ubuntu:22.04"
  },
  "another-system-name": {
    "base-image": "/path/to/file/on/system"
  }
}