Django, Docker-compose and PostgreSQL

docker-compose-prod.yml

version: '3.8'

services:
  web:
    build: .
#    command: python /code/manage.py runserver 0.0.0.0:8000
    command: gunicorn config.wsgi -b 0.0.0.0:8000
    environment:
      - ENVIRONMENT=production
      - SECRET_KEY=YOUR-DJANGO-SECRET-KEY
    volumes:
      - .:/code
    ports:
      - 8000:8000
    depends_on:
      - db
  db:
    image: postgres:11
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      - "POSTGRES_HOST_AUTH_METHOD=trust"

volumes:
  postgres_data:

docker-compose.yml

version: '3.8'

services:
  web:
    build: .
#    command: python /code/manage.py runserver 0.0.0.0:8000
    command: gunicorn config.wsgi -b 0.0.0.0:8000
    environment:
      - ENVIRONMENT=development
      - SECRET_KEY=YOUR-DJANGO-SECRET-KEY
      - DEBUG=1
    volumes:
      - .:/code
    ports:
      - 8000:8000
    depends_on:
      - db
  db:
    image: postgres:11
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      - "POSTGRES_HOST_AUTH_METHOD=trust"

volumes:
  postgres_data:

Dockerfile

# Pull base image
FROM python:3.8

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1

# Set work directory
WORKDIR /code

# Install dependencies
COPY Pipfile Pipfile.lock /code/
RUN pip install pipenv && pipenv install --system

# Copy project
COPY . /code/

settings.py

# Database
# https://docs.djangoproject.com/en/2.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'postgres',
        'USER': 'postgres',
        'PASSWORD': 'postgres',
        'HOST': 'db',
        'PORT': 5432
    }
}