Unable to run vscode's debugger with dockerized django project

Every time when I run a debugger there happen many things but not what I expect.

I'm running a project with docker-compose up

Checking the localhost if backend backend is okay. It's down. What's funny the container is running because I'm attached to this with vscode's remote containers.

The debugpy library is installed.

The first approach to run a debugger end with such info in debug console:

Attached!
System check identified some issues:

WARNINGS:
workflow.State.additional_values: (fields.W904) django.contrib.postgres.fields.JSONField is deprecated. Support for it (except in historical migrations) will be removed in Django 4.0.
    HINT: Use django.db.models.JSONField instead.
Operations to perform:
  Apply all migrations: accounts, auth, contenttypes, files, mambu, otp_totp, sessions, token_blacklist, workflow, zoho
Running migrations:
  No migrations to apply.

and it's down. Backend is also down.

Second try:

Attached!
System check identified some issues:

WARNINGS:
workflow.State.additional_values: (fields.W904) django.contrib.postgres.fields.JSONField is deprecated. Support for it (except in historical migrations) will be removed in Django 4.0.
    HINT: Use django.db.models.JSONField instead.
Zoho Configuration failed, check that you have all variables ZOHO_TOKEN_URL, ZOHO_REST_API_KEY, ZOHO_CURRENT_USER_EMAIL

and it's down but backend is up - I'm able to login etc.

The third try ends with such an error connect ECONNREFUSED 127.0.0.1:5678.

Any tips?

Code:

manage.py

#!/usr/bin/env python
"""Django's command-line utility for administrative tasks."""
import os
import sys

def initialize_debugger():
    import debugpy

    debugpy.listen(("0.0.0.0", 5678))
    debugpy.wait_for_client()
    print('Attached!')

def main():
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "xxx.settings")
    try:
        from django.core.management import execute_from_command_line
    except ImportError as exc:
        raise ImportError(
            "Couldn't import Django. Are you sure it's installed and "
            "available on your PYTHONPATH environment variable? Did you "
            "forget to activate a virtual environment?"
        ) from exc
    execute_from_command_line(sys.argv)

if __name__ == "__main__":
    initialize_debugger()
    main()

The local docker-compose.yml

version: "3.2"

services:
  backend:
    container_name: xxx
    build:
      context: ./backend
      dockerfile: ../build/backend.Dockerfile
    volumes:
      - ./backend:/opt/app
    command: ./run.sh
    ports:
      - "8000:8000"
      - "5678:5678"
    env_file:
      - build/.env-local
    links:
      - db:db
      - rabbit:rabbit
      - memcached:memcached
  celery:
    container_name: xxx
    restart: always
    build:
      dockerfile: ../build/backend.Dockerfile
      context: ./backend
    command: ./run_celery.sh
    env_file:
      - build/.env-local
    working_dir: /opt/app/
    volumes:
      - ./backend/:/opt/app
    links:
      - db:db
      - rabbit:rabbit
  frontend:
    container_name: xxx
    build:
      context: frontend
      dockerfile: ../build/frontend.Dockerfile
    environment:
      - BROWSER=none
      - CI=true
    volumes:
      - ./frontend/src/:/frontend/src
      - ./frontend/public/:/frontend/public
  nginx:
    container_name: xxx
    build:
      dockerfile: build/nginx.Dockerfile
      context: .
      args:
        REACT_APP_GOOGLE_ANALYTICS_TOKEN: $REACT_APP_GOOGLE_ANALYTICS_TOKEN
        REACT_APP_PAGESENSE_LINK: $REACT_APP_PAGESENSE_LINK
        REACT_APP_CHATBOT_TOKEN: $REACT_APP_CHATBOT_TOKEN
        REACT_APP_SENTRY_DSN: $REACT_APP_SENTRY_DSN
        REACT_APP_SENTRY_ENVIRONMENT: $REACT_APP_SENTRY_ENVIRONMENT
        REACT_APP_SENTRY_TRACES_SAMPLE_RATE: $REACT_APP_SENTRY_TRACES_SAMPLE_RATE
        REACT_APP_THIRD_PARTY_API_URL: $REACT_APP_THIRD_PARTY_API_URL
    ports:
      - "5000:80"
    depends_on:
      - backend
      - frontend
    env_file:
      - build/.env-local
    volumes:
      - ./build/nginx/nginx.conf:/etc/nginx.conf
  db:
    container_name: xxx
    image: postgres:12
    ports:
      - "5432:5432"
    restart: on-failure
    environment:
      POSTGRES_DB: postgres
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
  rabbit:
    container_name: xxx
    image: rabbitmq
    ports:
      - "5672:5672"
  memcached:
    container_name: xxx
    image: memcached
    ports:
      - "11211:11211"
    restart: always
  flower:
    image: mher/flower:0.9.5
    environment:
      - CELERY_BROKER_URL=amqp://xxx-rabbitmq//
      - FLOWER_PORT=8888
    ports:
      - 8888:8888

and the launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "CF: Remote Attach",
            "type": "python",
            "request": "attach",
            "connect": {
                "host": "localhost",
                "port": 5678
            },
            "pathMappings": [
                {
                    "localRoot": "${workspaceFolder}/backend",
                    "remoteRoot": "/opt/app/"
                }
            ],
            "django": true
        }
    ]
}

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