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

Question

My docker contianer django server， postgres， celery worker and celery beat.自行运行应用程序，连接到数据库没有问题，但是当更新数据库的定时任务运行时，我收到错误

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

celery.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

在数据库容器中，您设置：

environment:
- POSTGRES_DB=app
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=supersecretpassword

然后，您需要将这些行复制并粘贴到celery_beat容器中，以便它可以连接到您的数据库。

然后你会得到：

celery-beat:
build: backend
command: celery -A backend beat -l info
volumes:
- ./backend:/code
depends_on:
- db
- redis
- celery
environment:
- POSTGRES_DB=app
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=supersecretpassword

Answer 2

你需要将 postgreSQL 的环境变量添加到 celery-beat 中