Creating model in task leads cannot connect to postgres database - tries to use socket instead of network port

I am at wits end. I researched for sometime, and maybe I don't know the correct keywords, but I couldn't find a solution that worked.

I have dockerized a Django app (custom link shortener) with a Postgres backend that uses Celery, RabbitMQ for a single task - to create and save an object to the database when a GET request is made.

The idea is this: when a shortlink is requested (GET request), the app simply redirects the request to another URL, but also creates a task using Celery. That task is supposed to add an analytics record to the Postgres database. The redirect works fine. I can create new shortlinks just fine. The django app connects to the postgres container fine. But Celery, in a different container tries to connect upon creating and saving the new object to the postgres container via a socket. This is the main error:

celery | django.db.utils.OperationalError: could not connect to server: No such file or directory
celery | Is the server running locally and accepting
celery | connections on Unix domain socket "/tmp/.s.PGSQL.5432"?


The following are what I think is the relevant, code, but if I didn't include something, please let me know. Thank you.

docker-compose.yml:

version: '3.6'

services:

pgdb:
container_name: postgres
restart: unless-stopped
environment:
- POSTGRES_DB=postgres
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=password
image: postgres:10-alpine
ports:
- 5432:5432
volumes:
- postgres_data:/var/lib/postgres/data
networks:
- net1

rabbitmq:
container_name: rabbitmq
restart: always
image: rabbitmq:3.7-alpine
environment:
- RABBITMQ_DEFAULT_USER=slinky
- RABBITMQ_DEFAULT_PASS=pwd
depends_on:
- pgdb
networks:
- net1
ports:
- 5672:5672

django:
container_name: django
restart: unless-stopped
environment:
- DB_NAME=postgres
- DB_USER=postgres
- DB_PASSWORD=password
- DB_HOST=pgdb
- DB_PORT=5432
build:
context: .
dockerfile: docker/django.dockerfile
command: sh -c "/usr/local/bin/gunicorn slinky.wsgi -w 2 -b 0.0.0.0:8000 --log-file gunicorn.log"
volumes:
- .:/code
- /tmp
networks:
- net1
ports:
- 8000:8000
depends_on:
- pgdb
- rabbitmq

celery:
container_name: celery
restart: unless-stopped
build:
context: .
dockerfile: docker/django.dockerfile
command: celery -A slinky worker -l info
volumes:
- .:/code
depends_on:
- rabbitmq
networks:
- net1

nginx:
container_name: nginx
restart: unless-stopped
build:
context: .
dockerfile: docker/nginx.dockerfile
volumes:
- .:/code
ports:
- 80:80
networks:
- net1
depends_on:
- django

volumes:
postgres_data:

networks:
net1:
driver: bridge
name: net1


tasks.py:

from __future__ import absolute_import, unicode_literals
from celery import shared_task
from django.conf import settings
from django.db import models
from .utils import ip2country


@shared_task
def redirect_event(url, slink, label, ip):
country = "Switzerland" # ip2country(ip)
print("Saving redirect event object: ", country)
obj = RedirectEvent(url=url, slink=slink, label=label, country=country)
obj.save()


utils.py:

from django.conf import settings
from django.db import models

import random
import string
import requests

SLINK_LENGTH = getattr(settings, "SLINK_LENGTH", 6)

def code_gen(size=SLINK_LENGTH, chars = string.ascii_lowercase + string.digits):
return ''.join(random.choice(chars) for _ in range(size))

def create_code(instance, size=SLINK_LENGTH):
new_code = code_gen(size=size)
Klass = instance.__class__
qs_exists = Klass.objects.filter(shortcode=new_code).exists()
if qs_exists:
return create_code(size=size)
return new_code

def ip2country(ip):
url = "http://api.ipaddress.com/iptocountry?format=json&ip=" + ip
print("IP2 country API call: ", url)
r = requests.get(url)
data = r.json()
return data['country_name']


views.py:

from django.conf import settings
from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import render, get_object_or_404
from django.views import View
from .models import Slink, SlinkBaseDomain, RedirectEvent
from shortener.tasks import redirect_event

SLINK_BASE = getattr(settings, "SLINK_BASE", "www.meydan.tv")

class SlinkRedirectView(View):
def get(self, request, slink=None, *args, **kwargs):
obj = get_object_or_404(Slink, shortcode=slink)
latest_domain_obj = SlinkBaseDomain.objects.latest()
latest_domain = latest_domain_obj.domain
url = latest_domain + obj.url
ip = request.META['REMOTE_ADDR']

# celery task (delayed job)
redirect_event.delay(obj.url, slink, obj.label, ip)

print("================= Redirecting user to external URL: ", url)
return HttpResponseRedirect(url)


from app models.py:

class RedirectEvent(models.Model):
url = models.CharField(max_length=255)
slink = models.CharField(max_length=SLINK_LENGTH)
country = models.CharField(max_length=255, blank=True)
label = models.CharField(max_length=25, blank=True)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)

def __str__(self):
return str(self.slink)

class Meta:
verbose_name = "Redirect Analytic"


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