Best way to .gitignore all code but my own inside a devcontainer?

[C-Loftus]

Question

What is the best way to use git inside a devcontainer if you are developing an addon for a base image where the base image should not be changed?

Background

• I write plugins for a Python server that are packaged independently of the server image
• I need to be inside the container to get the proper environment for code completion
• I mount all my work into the container so it is separated and persistent, but still accessible via the container
• I mount my .git/ folder and push my code via the git cli

Ideally I would love to be able to make the base container read only and have it be ignored by git.

Challenge

• When I develop inside the container, git tries to track changes for all the files from the base container image, not just my code
• I can use a .gitignore like the following, but then I need to manually specify each file I want to not ignore
  • I feel it is error prone and a bad practice to ignore everything by default

*

!.devcontainer/
!.vscode/
# need to use some hacky recursive unignores
!src/
!src/**

!.gitignore

• I also need to end up mounting every file I want to track, otherwise, it shows up as deleted in git when I enter the container
  • (since it wasn't mounted and thus isn't in the container filesystem)
  • this can be an issue if one if my files shares the same name as one in the container (i.e. readme.md or dockerfile)
  • this makes my devcontainer.json particularly verbose
  • combined with the verbose .gitignore, I end up having to append to two files every time I want to add a new file at the root of the workspace

[C-Loftus]

It appears that an overlay filesystem may be appropriate. However, I don't believe that overlay filesystem mounts are supported by devcontainers. Perhaps I am wrong though. Still a bit stuck on this