Docker input/output outside the container

Question

I created a docker container with a python script. The python script takes an input file, does some processing and saves output file at some specified location.

docker run /app/script.py --input /data/input.csv --output /data/output.csv

Since the input file can be different every time I run the script, I want it to be outside the docker container. I also would like to store the output somewhere outside the container.

docker run /app/script.py --input /my/local/location/outside/docker/input.csv --output /my/local/location/outside/docker/output.csv

Does docker support this? If so, how would one be able to achieve it?

My Dockerfile looks like the following:

FROM phusion/baseimage

RUN apt-get update
RUN apt-get install -y build-essential
RUN apt-get install -y python-dev
RUN apt-get install -y python-pip
RUN apt-get install -y python-numpy && \
    apt-get install -y python-scipy

COPY ./requirements.txt /app/requirements.txt
COPY ./src/script.py /app/script.py

WORKDIR /app
COPY . /app

Answer 1

You could mount a directory with the file inside as a Docker data volume using the -v option: https://docs.docker.com/engine/tutorials/dockervolumes/

docker run -d -P --name myapp -v /app mydir/app python script.py

This will have the added benefit of allowing you to stop the container, make changes to the file, and start the container and see the change reflected within the container.