How to pass args to docker run for python?

Question

I edit my Dockerfile from the feedback I received. I run my python script with args python3 getappVotes.py --abc 116 --xyz 2 --processall This is my Dockerfile. I can build successfully but not sure how I can pass above args during docker run. Arguments are optional.

FROM python:3.7.5-slim
WORKDIR /usr/src/app
RUN python -m pip install \
        parse \
        argparse \
        datetime \
        urllib3  \
        python-dateutil \
        couchdb  \
        realpython-reader
RUN mkdir -p /var/log/appvoteslog/
COPY getappVotes.py .
ENTRYPOINT ["python", "./getappVotes.py"]
CMD ["--xx 116", "--yy 2", "--processall"]

You seem to be installing standard library packages with `pip`, that's not necessary. Typically you'd include a `requirements.txt` so you don't have to list them all out. — jonrsharpe, Jan 12 '21 at 19:54
@jonrsharpe Thanks!! I will do that once I figure out the issue. — user557657, Jan 12 '21 at 19:56
You need to use both `ENTRYPOINT` (for the program and mandatory arguments) and `CMD` (for optional arguments). Your question is certainly a duplicate, BTW ;-) — ErikMD, Jan 12 '21 at 20:06
See e.g. this SO answer: [What is the difference between CMD and ENTRYPOINT in a Dockerfile?](https://stackoverflow.com/a/39408777/9164010) — ErikMD, Jan 12 '21 at 20:08
@ErikMD I updated my Dockerfile and now I am getting this error - `error: unrecognized arguments: --xx 116 --yy 2` — user557657, Jan 13 '21 at 14:48
@user557657 OK so I'll comment on your Dockerfile in an answer below. — ErikMD, Jan 13 '21 at 15:17

ErikMD · Accepted Answer · 2021-01-13T15:23:31.537

As mentioned in the comments, for your use case, you need to use both ENTRYPOINT (for the program and mandatory arguments) and CMD (for optional arguments).

More precisely, you should edit your Dockerfile in the following way:

FROM python:3.7.5-slim
WORKDIR /usr/src/app
RUN python -m pip install \
        parse \
        argparse \
        datetime \
        urllib3  \
        python-dateutil \
        couchdb  \
        realpython-reader
RUN mkdir -p /var/log/appvoteslog/
COPY getappVotes.py .
ENTRYPOINT ["python", "./getappVotes.py"]
CMD ["--xx", "116", "--yy", "2", "--processall"]

(as from a shell perspective, --xx 116 is recognized as two separated arguments, not a single argument)

For more details:

see the answer What is the difference between CMD and ENTRYPOINT in a Dockerfile?;
see also the example from this answer: Install python package in docker file − where the "manual" command python -m pip install … is replaced with a more idiomatic command, pip install --no-cache-dir -r requirements.txt

I tried both but didnt separate the arguments and thats why it was failing. Let me try. Thanks!! — user557657, Jan 13 '21 at 15:21

How to pass args to docker run for python?

1 Answers1