在 Docker 容器内传递 python arguments (argparse)

Question

I have a python script that i run with the following command: python3 scan.py --api_token 5563ff177863e97a70a45dd4 --base_api_url http://101.102.34.66:4242/scanjob/ --base_report_url http://101.102.33.66:4242/ --job_id 42 This works perfectly when I run it on the command line

IN my Dockerfile, I have tried ARG and ENV. none seem to work

#ARG api_token
#ARG username
#ARG password

# Configure AWS arguments
#RUN aws configure set aws_access_key_id $AWS_KEY \
 #   && aws configure set aws_secret_access_key $AWS_SECRET_KEY \
  #  && aws configure set default.region $AWS_REGION

### copy bash script and change permission
RUN mkdir workspace
COPY scan-api.sh /workspace
RUN chmod +x  /workspace/scan-api.py
CMD ["/python3", "/workspace/scan-api.py"]

so how do i define this flagged argument in docker file? And whats the command run when running the image?

Answer 1

You can do this in two ways as you want to override at run time.

• As args to Docker run command
• As an ENV to Docker run command

1st is simplest and you will not need to change anything Dockerfile

docker run --rm my_image python3 /workspace/scan-api.py --bar tet --api_token 5563ff177863e97a70a45dd4 --base_api_url http://101.102.34.66:4242/scanjob/ --base_report_url http://101.102.33.66:4242/ --job_id

and my simple script

import sys
print  ("All ARGs",sys.argv[1:])

Using ENV you will need to change Dockerfile

I am posting the way for one, you can do this for all args

FROM python:3.7-alpine3.9 
ENV API_TOKEN=default_token
CMD ["sh", "-c", "python /workspace/scan-api.py $API_TOKEN"]

So you can override them during run time or have the ability to run with some default value.

docker run -it --rm -e API_TOKEN=new_token my_image

Answer 2

CMD takes exactly the same arguments you used from the command line.

CMD ["/python3", "scan.py", "--api_token", "5563ff177863e97a70a45dd4", "--base_api_url", "http://101.102.34.66:4242/scanjob/", "--base_report_url", "http://101.102.33.66:4242/", "--job_id", "42"]

Answer 3

It's confusing.

You will need to use the SHELL form of ENTRYPOINT (or CMD ) in order to have environment variable substitution, eg

ENTRYPOINT "/python3","/workspace/scan-api.py","--api-token=${TOKEN}" ...

And then run the container using something of the form:

docker run --interactive --tty --env=TOKEN=${TOKEN} ...

HTH!