When you run this in your Dockerfile

COPY server.py /project/

you are only copying one file, server.py, to your Docker environment. Clearly, your project needs more than one file, so you should copy what is missing.

You could fix this with

COPY . /project/

This will copy the contents of your directory . to the docker image (it won't copy the folder itself like cp would).

Or alternatively,

COPY ./CV.py /project/