docker port exposing issue

Question

I have a flask application that I'm trying to dockerize but the ports are not getting exposed properly.

DockerFile

FROM tiangolo/uwsgi-nginx-flask:python3.7

LABEL Name=testAPP Version=0.0.1
EXPOSE 5000

ADD . /app
WORKDIR /app

# Using pip:
RUN python3 -m pip install -r requirements.txt

ENTRYPOINT [ "python3" ]
CMD ["application.py" ,"runserver","-h 0.0.0.0"]

Docker Build is successful:

docker build --rm -f "Dockerfile" -t testAPP .

Docker Run is building the image successfully

docker run -device -expose 5000:5000 testAPP

Also tried,

docker run --rm -d -p 443:443/tcp -p 5000:5000/tcp -p 80:80/tcp testAPP

But when I try to access the site it throws an error

site can't be reached error

Flask App(Inside the APP)

if __name__ == '__main__':
    app.run(host='127.0.0.1', port=5000)

On Execution of the command

Docker container ps

CONTAINER ID     IMAGE        COMMAND      CREATED          STATUS    PORTS      NAMES
 8724cdb38e14    testAPP   "/entrypoint.sh pyth…" 15 seconds ago   Up 13 seconds    80/tcp, 443/tcp, 0.0.0.0:5000->5000/tcp  funny_galois

Answer 1

Defining a port as exposed doesn't publish the port by itself. Try with the flag -p , like:

-p container_port:local_port

example:

docker run -p 8080:8080 -v ~/Code/PYTHON/ttftt-recipes-manager:/app python_dev

But before running try to check if there is something else that already running on the specified port like:

lsof -i :PORTNUM 

and after with something like:

docker logs my_container

Answer 2

Make sure you're mapping your localhost port to the container's port

docker run -p 127.0.0.1:8000:8000 your_image

And once you're application is in the container, you want to run your app with the host set to 0.0.0.0