'Connection refused' when running django/postgres project in docker

Question

I'm working on a Django/Postgres project and currently trying to dockerize. Postgresql has always worked fine on my pc, but now I'm having trouble spinning it up on docker. I get this error:

web_1 | django.db.utils.OperationalError: could not connect to server: Connection refused

Is the server running on host "localhost" (127.0.0.1) and accepting

TCP/IP connections on port 5432?

I've tried a lot of solutions suggested online, but none have solved my problem.

Here's all the relevant code:

.yml file

version: '3.8'

services:
  web:
    build:
      context: ./web
      network: host
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - ./web/:/usr/src/web/
    ports:
      - 8000:8000
    env_file:
      - ./.env.dev

    depends_on:
      - web_db

  web_db:
    image: postgres:12.5-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      - POSTGRES_USER=username
      - POSTGRES_PASSWORD=password 
      - POSTGRES_DB=db_name

volumes:
  postgres_data:

env file

SECRET_KEY=secret
DEBUG=1
DJANGO_ALLOWED_HOSTS=localhost 127.0.0.1 [::1]
SQL_ENGINE=django.db.backends.postgresql_psycopg2
SQL_DATABASE=db_name
SQL_USER=username
SQL_PASSWORD=password
SQL_HOST=localhost
SQL_PORT=5432

settings.py

DATABASES = {
    "default": {
        "ENGINE": os.environ.get("SQL_ENGINE", "django.db.backends.postgresql_psycopg2"),
        "NAME": os.environ.get("SQL_DATABASE", "db_name"),
        "USER": os.environ.get("SQL_USER", "username"),
        "PASSWORD": os.environ.get("SQL_PASSWORD", "password"),
        "HOST": os.environ.get("SQL_HOST", "localhost"),
        "PORT": os.environ.get("SQL_PORT", ""),
    }
}

And here are my configs:

sudo nano /var/lib/docker/volumes/project_postgres_data/_data/pg_hba.conf

#TYPE  DATABASE        USER            ADDRESS                 METHOD

local   all             all                                     trust

#IPv4 local connections:

host    all             all             127.0.0.1/32            trust

#IPv6 local connections:

host    all             all             ::1/128                 trust

local   replication     all                                     trust

host    replication     all             127.0.0.1/32            trust

host    replication     all             ::1/128                 trust


host all all all md5 

sudo nano /var/lib/docker/volumes/project_postgres_data/_data/postgresql.conf

listen_addresses = '*'

#port = 5432

All the configs seem to check out, so I have no idea why connection fails. Any ideas?

PS: I'll update the question with any extra info needed.

Answer 1

Use SQL_HOST=web_db instead of SQL_HOST=localhost in your env file