Simplify and optimize Docker image

[edoardob90]

• Create a simpler Docker image starting from official Jupyter Docker Stacks
• Remove jupyter-repo2docker dependency
• Add GitHub workflow to build & push the image (as before)
• Adjust the Conda environment which is configured from docker/environment.yml

The old workflow has been renamed to .github/workflows/repo2docker.yml and Binder is still supported via the binder/ directory (unchanged).

Also: since Docker provides already the isolation, there's no need to have another virtual environment. All the tutorial dependencies are installed in the base environment, which is automatically configured by the base image.

[yakutovicha]

@edoardob90 do you need a review on this? I could give a hand.

[edoardob90]

@edoardob90 do you need a review on this? I could give a hand.

If you want, you can try to build the container from the Dockerfile. I tested the workflow in the main branch of my fork, and everything seems to work fine. But a double-check is always appreciated 😉

[yakutovicha]

Thanks, @edoardob90, I did a first pass and I would need some clarifications from your side.

[edoardob90]

Options:

Leave the COPY command

• We will have two copies of the material when using Codespaces: one in /home/jovyan/python-tutorial and another in /workspaces/python-tutorial (clone by default by GitHub)
• Docker image is larger and takes slightly longer to build

Remove COPY

• Users must clone the repository to have the materials available inside the container. On Windows, this means downloading and installing git first (here)
• Change the README accordingly: the bind-mount directory is not /home/jovyan/work but /home/jovyan/python-tutorial

[edoardob90]

@yakutovicha I think we need to resume/finalize this. It would simplify a lot the build step of the image, and solve the recent problem with the workflow run that, all of a sudden, ran out of disk space on the hosted runner.

If we're deploying only on Renkulab, the COPY instruction to have the repository available inside the container is not needed. Renku already clones the repository and mounts it inside the container at runtime.

[yakutovicha]

Great job, grazie @edoardob90!