The docker build worked just fine for me. There is one suggestion however, I see why you did RUN pip install -r requirements.txt rather than including each pip install directly in the Dockerfile. Makes total sense to have just one set of dependencies. However, thought should be spent on how to do this caching. Putting RUN pip install -r requirements.txt before the cache bust means that if requirements.txt is updated in the repo then the pip install -r requirements.txt won't rerun. While if cache bust is placed before the pip install -r requirements.txt, then there will be a lengthy install with every build.

I feel there must be a better way of managing the cache in Docker.

I'm going to merge this now. Works great. Thank you! Can look into caching more in general.

That's true!
Sounds good, I will get back to you about cacheing soon - thank you!