Docker Django could not connect to server: Connection refused

Question

I'm new to Docker, and I'm trying to put my Django rest API in a container with Nginx, Gunicorn and Postgres, using docker-compose and docker-machine. Following this tutorial: https://realpython.com/blog/python/django-development-with-docker-compose-and-machine/

Most of my code is the same as the tutorial's ( https://github.com/realpython/dockerizing-django ). with some minor name changes.

this my docker-compose.yml (I changed the gunicorn command to runserver for debugging purposes)

web:
  restart: always
  build: ./web
  expose:
    - "8000"
  links:
    - postgres:postgres
    - redis:redis
  volumes:
    - /usr/src/app
    - /usr/src/app/static
  env_file: .env
  environment:
    DEBUG: 'true'
  command: /usr/local/bin/python manage.py runserver

nginx:
  restart: always
  build: ./nginx/
  ports:
    - "80:80"
  volumes:
    - /www/static
  volumes_from:
    - web
  links:
    - web:web

postgres:
  restart: always
  image: postgres:latest
  ports:
    - "5432:5432"
  volumes:
    - pgdata:/var/lib/postgresql/data/

redis:
  restart: always
  image: redis:latest
  ports:
    - "6379:6379"
  volumes:
    - redisdata:/data

And this is in my settings.py of Django:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'postgres',
        'USER': 'postgres',
        'PASSWORD': 'postgres',
        'HOST': 'postgres',
        'PORT': '5432',
    }
}

Nginx and postgres (and redis) are up and running, however my django server wont start, by this error:

web_1       | django.db.utils.OperationalError: could not connect to server: Connection refused
web_1       |   Is the server running on host "localhost" (::1) and accepting
web_1       |   TCP/IP connections on port 5432?
web_1       | could not connect to server: Connection refused
web_1       |   Is the server running on host "localhost" (127.0.0.1) and accepting
web_1       |   TCP/IP connections on port 5432?

I've googled a lot and I've verified that postgres is running, on port 5432, I can connect to it using psql command .

I am lost. What is my mistake?

EDIT: It appears that it is not using my settings.py file or something, since it's asking if the server is running on localhost, while settings should be looking for postgres.

Answer 1

When those who have this problem please check your settings.py :

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'dbname',
        'USER': 'user',
        'PASSWORD': 'password',
        'HOST': 'db'
    }
}

Your HOST:'db' and docker-compose file db name should be same. If you want to rename from db, make sure that you change in docker-compose file and setting.py :

db:
  restart: always
  image: postgres:latest
  ports:
    - "5432:5432"
  volumes:
    - pgdata:/var/lib/postgresql/data/

Answer 2

Checkout your manage.py, there should be a line

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myproject.settings")

if there is no such line, put it

set your DJANGO_SETTINGS_MODULE with respect to PYTHONPATH .

UPD i cloned your repo and launched the web service by changing command in docker-compose.yml

-  command: /usr/local/bin/gunicorn docker_django.wsgi:application -w 2 -b :8000
+  command: python manage.py runserver 0.0.0.0:8000

I'm sure DJANGO_SETTINGS_MODULE is correct.

Answer 3

I'm exactly facing the same issue, while runing my django app with docker on aws ec2 instance.

I noticed that this error only happend for the first time the docker image is build, so to fix i juste ran :

CTRL + C then docker-compose up again and everything worked fine.