Running a django application on both the host machine and docker container at the same time

Question

I have created a simple django application that has one endpoint /health/live and it returns a success message upon receiving a get request.

I run the application locally with python manage.py runserver on port 8000

I also have a docker-compose and Dockerfile as below:

FROM python

ENV PYTHONUNBUFFERED 1

RUN mkdir /inventory

WORKDIR /inventory

COPY . /inventory

WORKDIR /inventory

RUN pip install -r requirements.txt

and

version: '3'

networks:
 kong-net:
  name: kong-net
  driver: bridge
  ipam:
    config:
      - subnet: 172.1.1.0/24

services:
  inventory:
    container_name: inventory
    build:
      context: .
      dockerfile: Dockerfile
    restart: unless-stopped
    networks:
      kong-net:
        ipv4_address: 172.1.1.11
    ports:
      - "8000:8000"
    environment:
      DEBUG: 'true'
    command: python manage.py runserver 0.0.0.0:8000

I then run docker-compose up (I don't detach it to be able to see the logs)

---

They both work. I send a get request to http://127.0.0.1:8000/health/live:

• based on the logs I see, the request goes through the service running directly on the system and not on the docker container
• If I stop the service running directly without docker, and send the request, the request goes through the one deployed on docker

is there a reason this is happening? why the first one takes priority? And shouldn't I see an error when trying to run the docker container or start the application locally? because they are both listening to port 8000!