django使用celery及踩坑
作者：互联网
项目结构
项目依赖
celery==5.1.2
Django==3.2.12
django-celery-beat==2.2.1
django-celery-results==2.2.0
django-redis==5.2.0
eventlet==0.33.0
greenlet==1.1.2
redis==4.1.4
安装package
- 安装celery
pip install celery
- 安装django-celery-results
用于保存celery任务结果
pip install celery
- 安装django-celery-beat
用于执行周期任务
pip install celery
- 安装eventlet
windows环境下需要
pip install eventlet
在django项目中使用
- 在项目设置文件settings.py中配置celery
settings.py
"""
Django settings for demo project.
Generated by 'django-admin startproject' using Django 3.2.12.
For more information on this file, see
https://docs.djangoproject.com/en/3.2/topics/settings/
For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.2/ref/settings/
"""
from pathlib import Path
# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent
# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.2/howto/deployment/checklist/
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'django-insecure-%8q+wpy=)*@237)o#!pgkn&^$qr9-h!w12jociuv4i^f#&z70d'
# 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',
'app1', #注册应用
'django_celery_results', #用于保存celery任务结果
'django_celery_beat', #用于执行celery周期任务
]
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',
]
ROOT_URLCONF = 'demo.urls'
TEMPLATES = [
{
'BACKEND': 'django.template.backends.django.DjangoTemplates',
'DIRS': [BASE_DIR / 'templates']
,
'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 = 'demo.wsgi.application'
# Database
# https://docs.djangoproject.com/en/3.2/ref/settings/#databases
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': BASE_DIR / 'db.sqlite3',
}
}
# Password validation
# https://docs.djangoproject.com/en/3.2/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/3.2/topics/i18n/
LANGUAGE_CODE = 'zh-hans' #语言修改为中文
TIME_ZONE = 'Asia/Shanghai' #时区修改为上海
USE_I18N = True
USE_L10N = True
USE_TZ = False
# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.2/howto/static-files/
STATIC_URL = '/static/'
# Default primary key field type
# https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field
DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
# celery配置
# 任务结果使用数据库来储存
CELERY_RESULT_BACKEND = 'django-db'
# celery 缓存
CELERY_CACHE_BACKEND = 'django-cache'
# 用了存放消息队列的位置，此处使用redis，默认使用rabbitmq
CELERY_BROKER_URL = 'redis://127.0.0.1:6379/2'
#: Only add pickle to this list if your broker is secured
#: from unwanted access (see userguide/security.html)
CELERY_ACCEPT_CONTENT = ['json']
CELERY_TASK_SERIALIZER = 'json'
# 缓存配置
CACHES = {
'default': {
'BACKEND': 'django_redis.cache.RedisCache',
'LOCATION': 'redis://127.0.0.1:6379/0',
},
'celery': {
'BACKEND': 'django_redis.cache.RedisCache',
'LOCATION': 'redis://127.0.0.1:6379/1',
},
}
- 在项目同名目录下创建celery.py文件
celery.py
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery
from celery.schedules import timedelta
# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'demo.settings')
app = Celery('demo')
app.conf.timezone = 'Asia/Shanghai'
app.conf.enable_utc = False
# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
# should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')
# 周期任务配置
app.conf.beat_schedule = {
'add-every-10-seconds': {
'task': 'app1.tasks.func2',
'schedule': timedelta(seconds=10),
'args': ()
},
}
# Load task modules from all registered Django app configs.
app.autodiscover_tasks()
- 在项目同名目录下的__init__.py中作如下配置,这样可以确保在Django启动时加载应用程序，以便@shared_task装饰器将使用该应用程序
__init__py
from .celery import app as celery_app
__all__ = ('celery_app',)
- 在app目录下新建tasks.py文件
task.py
from celery import shared_task
@shared_task
def func1():
return "异步任务"
@shared_task
def func2():
return "周期任务"
- 任务调用：异步任务为主动触发，定时和周期任务需有beat分发任务，worker去执行
views.py
from django.http import JsonResponse
from .tasks import func1
# Create your views here.
def async_task(request):
func1.delay()
return JsonResponse({"message": "这是celery异步任务！"},json_dumps_params={"ensure_ascii":False})
项目运行
- 启动django项目
python manage.py runserver 127.0.0.1:8000
- 启动celery beat（当需要执行定时任务时需要启动beat）
celery -A demo beat -l INFO
- 正确启动 celery worker
celery -A demo worker -l INFO --pool=solo
踩坑
- 不建议使用django-celery，容易出现很多包版本配合的问题
- 使用 celery -A demo worker -l INFO 启动worker会出现
ValueError: not enough values to unpack (expected 3, got 0)
- 使用 celery -A demo worker -l INFO -P eventlet 启动worker会出现
django.db.utils.DatabaseError: DatabaseWrapper objects created in a thread can only be used in that same thread
标签：settings,app,django,celery,使用,contrib,import 来源： https://blog.csdn.net/qq_29983177/article/details/123614701