LRN-34037 Option 1: Containerise within Makefile

[david-scarratt-lrn]

Summary

Add the ability to run make targets in a Python container. The containerising happens within the single Makefile in the directory.

Pros

• No extra files
• Make invocation the same for local vs container
• Container mode by default

Cons

• More complex Makefile with conditional sections (essentially wraps two separate makefiles into one)
• Requires opt-out flag LRN_SDK_NO_DOCKER
• Container started even for targets that don't need it (like clean)
• Will unnecessarily run Docker if invoked in a container with Docker installed (e.g., if developing in a container through an IDE). The standard Python containers do not currently include Docker, and are unlikely to in the future, though VSC gives the option when building for developing within a container.

Checklist

• [x] Feature

• [ ] Bug

• [ ] Security

• [ ] Documentation

• [ ] ChangeLog.md updated

• [ ] Tests added

• [ ] All testsuites passed

• [ ] make dist completed successfully

[shtrom]

The code looks good, but we might need to update the documentation about expected dependencies (docker) and flow. Note that there is a separate documentation overhaul effort in #56, and one thing that is specifically left out for now is the CONTRIBUTING.md, where I think this information could go.

[alangarf]

This looks great! Well done.