An error in setting up the Database upon dockerizing my website

Using Django Deployment
1

I am trying to dockarize my django app but I have a problem in configuring the database:

docker-compose.yaml:

services:

  db:
    image: postgres:13
    container_name: db
    # networks:
    #           - djangonetwork
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      # - POSTGRES_HOST_AUTH_METHOD=trust
      - POSTGRES_NAME=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres
  es:
    image: elasticsearch:7.9.1
    environment:
      - xpack.security.enabled=false
      - discovery.type=single-node
    ports:
      - "9200:9200"
      - "9300:9300"
    networks:
      - elastic
    volumes:
      - ./data/elastic:/var/lib/elasticsearch/data

  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    ports:
      - "8000:8000"
    environment:
      - POSTGRES_NAME= postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres
    volumes:
      - .:/app
    #   - /tmp/app/mysqld:/run/mysqld
    depends_on:
      - db
      - es
    networks:
      - elastic
      # - postdata
  


  thesearchable:
      build: ./thesearchable
      ports:
        - "3000:3000"
      volumes:
        - ./frontend:/frontend

volumes:
  postgres_data:

networks:
  elastic:
    driver: bridge

in settings.py:

'default': {
        "ENGINE": "django.db.backends.postgresql",
        "NAME": "postgres",
        "USER": "postgres",
        "PASSWORD": "postgres",
        "HOST": "db",  # set in docker-compose.yml
        "PORT": 5432,  # default postgres port
    }

I have found that many people faced this problem but none of the answers solved my problem and I always find this message

error django.db.utils.OperationalError: could not translate host name "db" to address: Temporary failure in name resolution

so how can I solve this?

2

I don’t know if this is critical, but in your definition for web (and in your es container), you have:

But you don’t have that network entry in your db definition. I would think you would want all your containers running in the same docker network.