WSL2 Docker Flask container doesn't connects

Question

I'm trying to create a simple web application container within Ubuntu-WSL2 with the help of the Docker. So I've built my container creating my-simple-webapp folder and within that folder, I've created Dockerfile and app.py files;

Dockerfile

FROM ubuntu:16.04
RUN apt-get update && apt-get install -y python python-pip
RUN pip install flask
COPY app.py /opt/
ENTRYPOINT FLASK_APP=/opt/app.py flask run --host=0.0.0.0 --port=8080

app.py

import os
from flask import Flask
app = Flask(__name__)

@app.route("/")
def main():
    return "Welcome!"

@app.route('/how are you')
def hello():
    return 'I am good, how about you?'

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8080)

When I run the command docker build ./my-simple-webapp it works without error. However when I use my browser to connect my container typing 172.17.0.2:8080, o.o.o.o:8080 or localhost:8080 connection times out.

Resource : https://github.com/mmumshad/simple-webapp-flask

Answer 1

If you want to deploy your flask application, you need to choose from the following options: https://flask.palletsprojects.com/en/1.1.x/deploying/

The way you are trying to do it, can be used only for development purposes.

Answer 2

If all you run is docker build... then you still need to start your container with docker run....

You can open the docker dashboard (in your Windows tray) to see if your container is actually running.

Answer 3

To actually run your app you need to start a container. First, build the image:

docker build -t simple-webapp-flask .

Then start a container using the image, with 8080:8080 mapping from container to your host:

docker run -p 8080:8080 simple-webapp-flask