How can I correct this Dockerfile to take arguments properly? - dockerfile

Question

I have this dockerfile content:
FROM python:latest
ARG b=8
ARG r=False
ARG p=1
ENV b=${b}
ENV r=${r}
ENV p=${p}
# many lines of successful setup
ENTRYPOINT python analyze_all.py /analysispath -b $b -p $p -r $r
My intention was to take three arguments at the command line like so:
docker run -it -v c:\analyze containername -e b=16 -e p=22 -e r=False
But unfortunately, I'm misunderstanding something fundamental and simple here instead of something complicated, so I'm helpless :).

Answer 1

If I understood the question correctly, this Dockerfile should do what is required:
FROM python:latest
# test script that prints argv
COPY analyze_all.py /
ENTRYPOINT ["python", "analyze_all.py", "/analysispath"]
Launch:
$ docker run -it test:latest -b 16 -p 22 -r False
sys.argv=['analyze_all.py', '/analysispath', '-b', '16', '-p', '22', '-r', 'False']
Looks like your Dockerfile is designed to build and run a container on Windows. I tested my Dockerfile on Linux, it probably won't be much different to use this approach on Windows.
I think ARG instructions isn't needed in this case because it defines a variable that users can pass at build-time using the docker build command. I would also suggest that you take a look at the Dockerfile reference for the ENTRYPOINT instruction:
Command line arguments to docker run will be appended after all elements in an exec form ENTRYPOINT, and will override all elements specified using CMD. This allows arguments to be passed to the entry point, i.e., docker run -d will pass the -d argument to the entry point.
Also, this question will probably be useful for you: How do I use Docker environment variable in ENTRYPOINT array?