Port Mapping issue

[ZAHIDSHABIR08]

Hi,
As we have mentioned port no. inside the code as 8080, now if we want to do the port mapping to expose the application publicly which port number should I use for port mapping 8080 or 5000

The second thing is when we hit this URL inside (Not publicly) we are using port 5000 why 5000? because we did not mention 5000 anywhere in the code we have used port 8080 inside the code.

[paulsweeting]

It works for me if I map the port inside the container 8080 to the host port 8080

docker run -p 8080:8080 my-custom-app

Then you can access the app in the browser using: http://localhost:8080/

With Dockerfile:

FROM ubuntu:20.04
RUN apt-get update && apt-get install -y python3 python3-pip
RUN pip3 install flask
COPY app.py /opt/
ENTRYPOINT FLASK_APP=/opt/app.py flask run --host=0.0.0.0 --port=8080