testdriven.io: The Definitive Guide to Celery and Django. All containers logs are "Waiting for PostgreSQL to become available..."

Question

I've followed each step of part 1 chapter 4 and literally copy pasted the code as shown.

docker-compose is able to build the containers but I always get the Waiting for PostgresSQL to become available being logged from all the other containers as shown below. docker-compose logs

Following is the output of docker ps -a. From which I can see that all containers are running in their respective ports. docker ps -a logs

I checked the docker container logs of the db and it shows to be running. postgres container logs

But, I'm unable to open the Django server on port 8010 nor able to view the flower server on port 5557 because in the container logs I'm getting the message "Waiting for PostgreSQL to become available..."

Someone please help. This issue is killing me. I've tried to view the logs of each container and it's showing it's running, yet I'm not able to view the Django and flower server.

Let me know if you guys need more info.

Thanks!

Tried checking if the DB is up and running at the correct port. checked if Redis is running. checked the logs of each running container which points to the same message "Waiting for PostgreSQL to become available..."

Answer 1

psycopg2-binary package was used. Using psycopg2 instead worked for me. This issue maybe related to Mac M1

Answer 2

I had the same problem with this tutorial (on mac M1) and it took me many hours. The solution for me was finally to use "alpine" instead of "buster", here is my Dockerfile:

FROM alpine:3.17.1

ENV PYTHONUNBUFFERED 1
ENV PYTHONDONTWRITEBYTECODE 1

RUN apk update \
    && apk add postgresql-dev gcc python3-dev musl-dev py3-pip bash

# Requirements are installed here to ensure they will be cached.
COPY ./requirements.txt /requirements.txt
RUN pip install -r /requirements.txt

COPY ./compose/local/django/entrypoint /entrypoint
RUN sed -i 's/\r$//g' /entrypoint
RUN chmod +x /entrypoint

COPY ./compose/local/django/start /start
RUN sed -i 's/\r$//g' /start
RUN chmod +x /start

COPY ./compose/local/django/celery/worker/start /start-celeryworker
RUN sed -i 's/\r$//g' /start-celeryworker
RUN chmod +x /start-celeryworker

COPY ./compose/local/django/celery/beat/start /start-celerybeat
RUN sed -i 's/\r$//g' /start-celerybeat
RUN chmod +x /start-celerybeat

COPY ./compose/local/django/celery/flower/start /start-flower
RUN sed -i 's/\r$//g' /start-flower
RUN chmod +x /start-flower

WORKDIR /app

ENTRYPOINT ["/entrypoint"]

requirements.txt:

django==4.1.4
celery==5.2.7
redis==4.3.4
flower==1.2.0
psycopg2-binary==2.9.5

And may not directly related, I added start and health checks to the docker compose file, so you don’t need the postgres "ready" polling in the entrypoint script.

Here my docker-compose.yml:

version: '3.8'

services:
  web:
    build:
      context: .
      dockerfile: ./compose/local/django/Dockerfile
    image: django_celery_example_web
    command: /start
    volumes:
      - .:/app
    ports:
      - 8010:8000
    env_file:
      - ./.env/.dev-sample
    depends_on:
      redis:
        condition: service_started
      db:
        condition: service_healthy

  db:
    image: postgres:14.6-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      - POSTGRES_DB=hello_django
      - POSTGRES_USER=hello_django
      - POSTGRES_PASSWORD=hello_django
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U hello_django"]
      interval: 5s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    networks:
      - default

  celery_worker:
    build:
      context: .
      dockerfile: ./compose/local/django/Dockerfile
    image: django_celery_example_celery_worker
    command: /start-celeryworker
    volumes:
      - .:/app
    env_file:
      - ./.env/.dev-sample
    networks:
      - default
    depends_on:
      redis:
        condition: service_started
      db:
        condition: service_healthy

  celery_beat:
    build:
      context: .
      dockerfile: ./compose/local/django/Dockerfile
    image: django_celery_example_celery_beat
    command: /start-celerybeat
    volumes:
      - .:/app
    env_file:
      - ./.env/.dev-sample
    depends_on:
      redis:
        condition: service_started
      db:
        condition: service_healthy

  flower:
    build:
      context: .
      dockerfile: ./compose/local/django/Dockerfile
    image: django_celery_example_celery_flower
    command: /start-flower
    volumes:
      - .:/app
    env_file:
      - ./.env/.dev-sample
    ports:
      - 5557:5555
    depends_on:
      redis:
        condition: service_started
      db:
        condition: service_healthy

volumes:
  postgres_data: