Should we run the tests also with Podman

[rgaiacs]

Since #682, repo2docker can be used with Podman instead of Docker. But to the best of my knowledge, we are not regularly testing repo2docker with Podman.

We run tests using GitHub Actions, see https://github.com/jupyterhub/repo2docker/blob/314f64bfa6e032c708252fbf628ae944c3a2e72e/.github/workflows/test.yml. Our tests runs on GitHub-hosted runners, more precisely on

repo2docker/.github/workflows/test.yml

Line 49 in 314f64b

runs-on: ubuntu-${{ matrix.ubuntu_version }}

The Ubuntu based virtual machine is described in https://github.com/actions/runner-images/blob/b99fd57b68439ba9168a076f855c3097a1c63265/images/ubuntu/Ubuntu2404-Readme.md and it has installed on it

• Docker Compose v2 2.38.2
• Docker-Buildx 0.28.0
• Docker Client 28.0.4
• Docker Server 28.0.4
• Podman 4.9.3

This means that we could test repo2docker with Podman. Unfortunately, the version of Podman included in the virtual machine is very old. At the time of writing, the latest release of Podman is 5.6.1.

[manics]

Does the new buildx backend still use the standard Docker API?

[rgaiacs]

Podman documentation includes

podman buildx build command is an alias of podman build. Not all buildx build features are available in Podman. The buildx build option is provided for scripting compatibility.