How to configure docker to use redis with celery - django

Question

docker-compose.yml
version: '3.1'
services:
redis:
image: redis:latest
container_name: rd01
ports:
- '6379:6379'
webapp:
image: webapp
container_name: wa01
ports:
- "8000:8000"
links:
- redis
depends_on:
- redis
celery:
build: .
container_name: cl01
command: celery -A server worker -l info
depends_on:
- redis
I also don't feel I understand links and depends_on, I tried different combinations.
Celery cannot connect to redis. I get the following error -
[2018-08-01 13:59:42,249: ERROR/MainProcess] consumer: Cannot connect to amqp://guest:**#127.0.0.1:5672//: [Errno 111] Connection refused.
I believe I have set broker URLs correctly in settings.py in my django application (webapp image)
CELERY_BROKER_URL = 'redis://redis:6379/0'
CELERY_RESULT_BACKEND = 'redis://redis:6379/0'
What is the right way to dockerize a django project with celery and redis? TIA.
EDITS
celery.py
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'server.settings')
app = Celery('server')
app.config_from_object('django.conf:settings', namespace='CELERY')
app.autodiscover_tasks()
#app.task(bind=True)
def debug_task(self):
print('Request: {0!r}'.format(self.request))
This is my django project to it's simplest form to reproduce the error.

Answer 1

You have to add the redis url while initialize the Celery classas,
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'server.settings')
app = Celery('server', broker='redis://redis:6379/0') # Change is here <<<<
app.config_from_object('django.conf:settings', namespace='CELERY')
app.autodiscover_tasks()
#app.task(bind=True)
def debug_task(self):
print('Request: {0!r}'.format(self.request))
UPDATE
[After a long discussion]
Change your docker-compose.yml as
version: '3.1'
services:
redis:
image: redis:latest
container_name: rd01
webapp:
build: .
container_name: wa01
ports:
- "8000:8000"
links:
- redis
depends_on:
- redis
celery:
build: .
volumes:
- .:/src
container_name: cl01
command: celery -A server worker -l info
links:
- redis
and Dockerfile as
FROM python:3.6
RUN mkdir /webapp
WORKDIR /webapp
COPY . /webapp
RUN pip install -r requirements.txt
EXPOSE 8000
CMD ["/start.sh"]