Can't start django project in docker

Question

At startup Redis does not work, therefore caching does not work, as I realized there is no connection to the database. I can't make loaddata fixtures and Celery can't connect to Redis either. In general, nothing works. No matter how many examples I found on how to create these files, everywhere it is done like this.

1. Dockerfile:

FROM python:3.11

WORKDIR /app

COPY . .

RUN pip install -r requirements.txt

CMD python manage.py migrate \
    && python manage.py loaddata site_blog/fixtures/posts.json \
    && python manage.py loaddata site_blog/fixtures/post_category.json \
    && python manage.py loaddata site_blog/fixtures/comments.json \
    && python manage.py loaddata users/fixtures/users.json \
    && python manage.py makemigrations \
    && python manage.py migrate \
    && python manage.py runserver 0.0.0.0:8000

2. docker-compose.yml:

version: '3'
services:
  postgres-db:
    image: postgres
    environment:
      POSTGRES_USER: db_mp_blog_username
      POSTGRES_PASSWORD: db_mp_blog_password
      POSTGRES_DB: db_mp_blog
    ports:
      - "5432:5432"
    restart: always

  redis:
    image: redis
    restart: always
    ports:
      - "6379:6379"

  site:
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - "8000:8000"
    depends_on:
      - postgres-db
      - redis
    environment:
      DB_NAME: "db_mp_blog"
      DB_USER: "db_mp_blog_username"
      DB_PASSWORD: "db_mp_blog_password"
      DB_HOST: "postgres-db"
      DB_PORT: 5432
      CELERY_BROKER_URL: 'redis://127.0.0.1:6379'
      CELERY_RESULT_BACKEND: 'redis://127.0.0.1:6379'
      SECRET_KEY: 'django-insecure-c467_p2n3g4ni%yq_ebaqe1j2=!ozmn=zvgh8i23uzos&9p3pc'
    restart: always

  celery:
    build: .
    command: celery -A blog worker --loglevel=info
    depends_on:
      - site
      - redis
      - postgres-db
    environment:
      DB_NAME: "db_mp_blog"
      DB_USER: "db_mp_blog_username"
      DB_PASSWORD: "db_mp_blog_password"
      DB_HOST: "postgres-db"
      DB_PORT: 5432
      CELERY_BROKER_URL: 'redis://127.0.0.1:6379'
      CELERY_RESULT_BACKEND: 'redis://127.0.0.1:6379'
      SECRET_KEY: 'django-insecure-c467_p2n3g4ni%yq_ebaqe1j2=!ozmn=zvgh8i23uzos&9p3pc'

Answer 1

You should create a network in your Docker Compose file and add all of your services to that network. Then, modify the addresses in your Docker Compose according to the service. For example, change

CELERY_BROKER_URL: 'redis://127.0.0.1:6379'

to

CELERY_BROKER_URL: 'redis://redis:6379'