Docker Python Flask Gets " Do You Want To Continue" Then "executor Failed"

Trying a simple python flask web app in docker 20.10.2, build 2291f61. Doing the: docker build -t hello-world . starts out ok (please see below), but ends with: #6 2.866 After this

Solution 1:

You should change the RUN lines in the Dockerfile with apt-get in them to use the -y flag to skip asking you to confirm "yes".

The Dockerfile in the tutorial actually seems out of date or has errors in it. You need to use pip3 now to install Flask and also include the -y flag in your apt-get commands. I edited the Dockerfile from the tutorial and posted below:

FROM ubuntu

RUN apt-getupdate-y && \
    apt-get install -y python3-pip && \
    pip3 install Flask

COPY app.py /

WORKDIR /

EXPOSE 5000

CMD ["python3","app.py"]

EDIT To fix the connection issues on Windows from this answer, you can fix this by changing the main function in the Python app from:

if __name__ == '__main__':
    app.run()

to this:

if __name__ == '__main__':
    app.run('0.0.0.0')

The reason is that you need Flask to bind to 0.0.0.0 instead of the localhost interface in the container, otherwise, it won't forward outside the container. After fixing that, you should be able to access the app at localhost:5000 on your host machine.