Can't open localhost in the browser on port given in docker-compose

Question

I am trying to build and run django application with docker and docker-compose. docker-compose build example_app and docker-compose run example_app run without errors, but when I go to http://127.0.0.1:8000/ page doesn't open, I'm just getting "page is unavailable" error in the browser. Here is my Dockeffile, docker-compose.yml and project structure

Dockerfile

FROM python:3.9-buster

RUN mkdir app
WORKDIR /app
COPY ./requirements.txt /app/requirements.txt
COPY ./requirements_dev.txt /app/requirements_dev.txt
RUN pip install --upgrade pip
RUN pip install -r /app/requirements.txt

docker-compose.yml

version: '3'

services:
  example_app:
    image: example_app
    build:
      context: ../
      dockerfile: ./docker/Dockerfile
    command: bash -c "cd app_examples/drf_example && python manage.py runserver"
    volumes:
      - ..:/app
    ports:
      - 8000:8000

project structure:

──app
──app_examples/drf_example/
  ────manage.py
  ────api
  ────drf_example
──requirements.txt
──requirements_dev.txt
──docker/
  ────docker-compose.yml
  ────Dockerfile

Answer 1

By default, Django apps bind to 127.0.0.1 meaning that they'll only accept connections from the local machine. In a container context, the local machine is the container, so your app won't accept connections from outside the container.

To get it to accept connections from anywhere, you add the bind address to the runserver command. In your case, you'd change the command in your docker-compose.yml file to

command: bash -c "cd app_examples/drf_example && python manage.py runserver 0.0.0.0:8000"