How to pass json file as an argument using docker run command

Question

Below is my Dockerfile content:

FROM python:2.7-slim

# Set the working directory to /app
WORKDIR /app

# Copy the current directory contents into the container at /app
ADD . /app

RUN pip install numpy==1.12.0

CMD ["python", "t_1.py", "t_1.json"]

I want to pass this file(t_1.sjon) as argument with docker run command at runtime so that CMD ["python", "t_1.py", "RUN TIME ARGUMENT"]. I tried mounting volumes but fails as json file is independent and I want as argument.

Please help.

Answer 1

What you should use is ENTRYPOINT

FROM python:2.7-slim

# Set the working directory to /app
WORKDIR /app

# Copy the current directory contents into the container at /app
ADD . /app

RUN pip install numpy==1.12.0

ENTRYPOINT ["python", "t_1.py"]

Now when you run the docker command

docker run -v ./t_1.json:/data/t_1.json <dockerimage> /data/t_1.json

This will make it equivalent to python t_1.py /data/t_1.json