Django Celery Beat 无法从 docker 容器内连接到 postgres 数据库

Question

我的 docker contianer django 服务器、postgres、celery worker 和 celery beat。单独运行应用程序连接到数据库没有问题，但是当运行更新数据库的定时任务时出现错误

celery_1       | django.db.utils.OperationalError: could not connect to server: No such file or directory

celery_1       |        Is the server running locally and accepting
celery_1       |        connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

以下是我的文件

docker-compose.yaml

version: "3"

services:
  redis:
    image: redis:alpine
  db:
    image: postgres:10-alpine
    environment:
      - POSTGRES_DB=app
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=supersecretpassword
    ports:
      - "5432:5432"
    volumes:
      - "db:/var/lib/postgresql/data"

  pgadmin:
    image: dpage/pgadmin4
    depends_on:
      - db
    ports:
      - "5555:80"
    environment:
      - PGADMIN_DEFAULT_EMAIL=dev@localhost
      - PGADMIN_DEFAULT_PASSWORD=password

  dj-dividend:
    container_name: dividend
    build: backend
    command: sh -c "python manage.py wait_for_db && python manage.py makemigrations && python manage.py migrate && python manage.py runserver 0.0.0.0:80"
    environment:
      - DB_HOST=db
      - DB_NAME=app
      - DB_USER=postgres
      - DB_PASS=supersecretpassword
    volumes:
      - ./backend:/code
    ports:
      - "80:80"
    depends_on:
      - db
      - redis
  celery:
    build: backend
    command: celery -A backend worker -l info
    volumes:
      - ./backend:/code
    depends_on:
      - db
      - redis
  celery-beat:
    build: backend
    command: celery -A backend beat -l info
    volumes:
      - ./backend:/code
    depends_on:
      - db
      - redis
      - celery
volumes:
  db:

settings.py

import os
from celery.schedules import crontab

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/2.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '1a0@6lsfxtfrt0n=#q1&up6hf$px-$ug^n%^v!n)^iwp_n*7c%'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = ['*']


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'dividends',
    'rest_framework',
    'django_celery_beat',
    'core'

]
CORS_ORIGIN_ALLOW_ALL = True


MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'corsheaders.middleware.CorsMiddleware',
]

ROOT_URLCONF = 'backend.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'backend.wsgi.application'


# Database
# https://docs.djangoproject.com/en/2.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'HOST': os.environ.get('DB_HOST'),
        'NAME': os.environ.get('DB_NAME'),
        'USER': os.environ.get('DB_USER'),
        'PASSWORD': os.environ.get('DB_PASS'),
    }
}


# Password validation
# https://docs.djangoproject.com/en/2.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/2.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/2.2/howto/static-files/

STATIC_URL = '/static/'

#Celery

CELERY_BROKER_URL = "redis://redis:6379"
CELERY_RESULT_BACKEND = "redis://redis:6379"
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'
CELERY_BEAT_SCHEDULE = {
    "get_stocks": {
        'task': 'dividends.tasks.get_stocks',
        'schedule': crontab(minute="*/1") #every minute
    }
}

Dockerfile

FROM python:3.7

# Set environment variables
ENV PYTHONUNBUFFERED 1

COPY requirements.txt /

# Install dependencies.
RUN pip install -r /requirements.txt

# Set work directory.
RUN mkdir /code
WORKDIR /code

# Copy project code.
COPY . /code/

EXPOSE 80

tasks.py

from celery import shared_task
from .utils import get_stock_data

from .models import Stock


@shared_task(default_retry_delay=5, max_retries=3)
def get_stocks():
    for stock in Stock.objects.all().values_list('ticker'):
        try:
            get_stock_data(stock[0])
        except:
            continue

芹菜.py

from celery import Celery
import os

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'backend.settings')

app = Celery('backend')
app.config_from_object('django.conf:settings', namespace='CELERY')

app.autodiscover_tasks()

Answer 1

你需要将postgresql的环境变量添加到celery-beat