Referring to a repo file from .devcontainer/Dockerfile #80438

MichaelChirico · 2023-12-18T03:53:22Z

MichaelChirico
Dec 18, 2023

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I'm trying to set up a codespace that comes with the current repo's dependencies installed.

This is an R package; dependencies are described in a top-level file DESCRIPTION.

To get an accurate picture of what dependencies are needed for the image, then, I need to be able to read the DESCRIPTION file while building the image.

Here's what I see as options / what I've tried

Hard-code the dependencies into the Dockerfile, i.e. ignore DESCRIPTION and just write out the dependencies by hand. Obviously this requires keeping the Dockerfile in sync with the DESCRIPTION manually. Not ideal as the package is not at such a stage of maturity that the DESCRIPTION file is stable.
Hard-copy the DESCRIPTION file into .devcontainer. This works, but again is bad maintenance practice.
Refer to the parent directory within the Dockerfile, e.g. COPY ../DESCRIPTION .. This is not valid in Docker.
Use a symlink instead, i.e. ln -s .devcontainer/DESCRIPTION ../DESCRIPTION. For the same reasons, this is also not valid in Docker.
Refer to a remote copy of the DESCRIPTION file. R packages are usually (and in my case) kept on CRAN, so we could point to the CRAN copy of the DESCRIPTION file. This works, but will refer to a versioned copy of the package, which may differ from the active development version.
Keep the Dockerfile in the repo TLD alongside DESCRIPTION, then refer to ../Dockerfile in devcontainer.json. I haven't tested if this will work, but I don't want to keep the Dockerfile there. It will give the wrong impression to code readers -- keeping it in .devcontainer/ correctly shows that this Dockerfile is meant for GitHub codespaces, nothing more/less.

Is there some other way to square the circle here that I'm missing?