I am attempting to take a working django production web app and containerize it. Every time it fails binding a port. When I check the port docker already owns it. When I do a sudo docker-compose down, the port is release. I am suspicious it is in my compose file as I use nginx and uwsgi. Here is my yml file:

version: '3.8'

services:
  web:
    build:
      context: /opt/dlnWebApplication
    volumes:
      - /opt/dlnWebApplication:/app
      - sqlite_data:/app/db  # Ensure volume for SQLite database
    ports:
      - "8081:80"  # Map the container's port 80 to the host's port 8080 (testing purpose)
    environment:
      - DJANGO_SETTINGS_MODULE=dlnWebApplication.settings

  cron:
    build:
      context: /opt/dlnEquipmentSnooper
    volumes:
      - /opt/dlnEquipmentSnooper:/app
      - sqlite_data:/app/db  # Ensure cron uses the same SQLite file
    depends_on:
      - web
    environment:
      - DJANGO_SETTINGS_MODULE=dlnWebApplication.settings

  nginx:
    image: nginx:latest
    volumes:
      - ./docker.dlnWebApplication.conf:/etc/nginx/conf.d/default.conf
      - /opt/dlnWebApplication/static:/app/static  # Match Docker paths
      - /opt/dlnWebApplication/media:/app/media    # Match Docker paths
      - ./logs:/var/log/nginx  # Optionally map logs for debugging
    ports:
      - "8081:80"  # Map container's port 80 to host's port 8080 for testing
    depends_on:
      - web

volumes:
  sqlite_data:

I believe nginx have to run on the same port as the web app.

Any help truly appreciated,
Doug