Dockerize web-based Flet Application

I am not a really expert on docker but following the https://flet.dev/docs/guides/python/deploying-web-app/fly-io, I wanted to try my demo in my own computer. When I run the app from my local virtual env, the web app is displayed without problem. However, when I try to run it from a docker container, even when the container is running without issues, it give me error: (failed)net::ERR_EMPTY_RESPONSE

Docker commands used to create the image and run the container docker build --tag flet-app:latest . docker run -it -p 62590:62590 -p 8080:8080 flet-app

Source Code

import flet as ft

def main(page: ft.Page):
    page.add(ft.Text(value="Hello world from containerized Flet app!"))

ft.app(target=main, view=ft.WEB_BROWSER)

dockerfile

# syntax=docker/dockerfile:1

FROM python:3.8-slim-buster

WORKDIR /app

COPY requirements.txt requirements.txt
RUN pip3 install -r requirements.txt

COPY . . 

EXPOSE 8080 62590

CMD ["python", "./app/main.py"] 

[arminus]

I think the key here is that you start your app with

ft.app(target=main, port=8080, view=ft.WEB_BROWSER)

Then you don’t need to expose 62590 - which is pointless anyway, because unless you specify the port for ft.app(…) explicitly, fletd starts on a random port which your Docker will never know about.

At any rate, this way, my brief test worked.

[FeodorFitsner]

Try this Dockerfile which works great for Fly.io environment. Let me know if that worked.