replaces background tasks with celery tasks

adhocracy-plus/config/celery.py

@@ -19,3 +19,12 @@ def dummy_task():
     print(result)
 
     return result
+
+
+@celery_app.task(name="crash_task")
+def crash_task():
+    """
+    This task is for testing purposes only.
+    """
+
+    1 / 0

adhocracy-plus/config/settings/base.py

@@ -36,7 +36,6 @@
     "easy_thumbnails",
     "ckeditor",
     "ckeditor_uploader",
-    "background_task",
     "parler",
     # Wagtail cms components
     "wagtail.contrib.forms",

apps/notifications/emails.py

@@ -189,7 +189,7 @@ def send_no_object(cls, object, *args, **kwargs):
             ),
             "organisation_id": organisation.id,
         }
-        tasks.send_async_no_object(
+        tasks.send_async_no_object.delay(
             cls.__module__, cls.__name__, object_dict, args, kwargs
         )
         return []

apps/projects/tasks.py

@@ -1,9 +1,9 @@
 import importlib
 
-from background_task import background
+from celery import shared_task
 
 
-@background(schedule=1)
+@shared_task
 def send_async_no_object(email_module_name, email_class_name, object, args, kwargs):
     mod = importlib.import_module(email_module_name)
     cls = getattr(mod, email_class_name)

docs/installation_prod.md

@@ -86,11 +86,16 @@ SECURE_CONTENT_TYPE_NOSNIFF = True
 SESSION_COOKIE_HTTPONLY = True
 
 FILE_UPLOAD_PERMISSIONS = 0o644
+
+# celery configuration
+CELERY_BROKER_URL = "redis://localhost:6379"
+CELERY_RESULT_BACKEND = "redis://localhost:6379"
+CELERY_BROKER_CONNECTION_RETRY_ON_STARTUP = True
 ```
 
 #### Populate database
 
-This will create all required tables via so called **migrations**
+This will create all required tables via so-called **migrations**
 
 ```
 python manage.py migrate
@@ -117,7 +122,7 @@ Cancel the server after testing via `ctrl`+`c`
 
 ### Run the server as system daemon
 
-In order to start up the software as a regular system daemon, similar to a database or webserver, we need to create unit files.
+In order to start up the software as a regular system daemon, similar to a database or webserver, we need to create service files.
 
 `/etc/systemd/system/adhocracy-plus.service`:
 
@@ -139,26 +144,29 @@ StandardError=inherit
 WantedBy=default.target
 ```
 
-`/etc/systemd/system/adhocracy-plus-background-task.service`:
+`/etc/systemd/system/adhocracy-plus-celery-worker.service`:
 
 ```
 [Unit]
-Description=adhocracy+ background task
+Description=adhocracy+ celery worker
 After=network.target
 
 [Service]
+Type=forking
 User=aplus
 WorkingDirectory=/home/aplus/adhocracy-plus
-ExecStart=/home/aplus/.virtualenvs/aplus/bin/python manage.py process_tasks --settings adhocracy-plus.config.settings.production --sleep 5
+ExecStart=/home/aplus/.virtualenvs/aplus/bin/celery --app adhocracy-plus worker
 Restart=always
 RestartSec=3
-StandardOutput=append:/var/log/adhocracy-plus/adhocracy-plus-background-task.log
+StandardOutput=append:/var/log/adhocracy-plus/adhocracy-plus-celery-worker.log
 StandardError=inherit
 
 [Install]
 WantedBy=default.target
 ```
 
+Depending on your celery configuration you will also need to start a message broker service like redis or rabbit-mq and configure celery accordingly in `local.py` (see above). If you use redis and the default installation it should already be running, call `service redis status` to check.
+
 This will log all output to files in `/var/log/adhocracy-plus/`. You will also need to create that folder before starting the service (as `root` or using `sudo`):
 
 ```
@@ -170,14 +178,14 @@ Load and start units (as `root` or using `sudo`):
 ```
 systemctl daemon-reload
 systemctl start adhocracy-plus
-systemctl start adhocracy-plus-background-task
+systemctl start adhocracy-plus-celery-worker
 ```
 
 Enable autostart on boot:
 
 ```
 systemctl enable adhocracy-plus
-systemctl enable adhocracy-plus-background-task
+systemctl enable adhocracy-plus-celery-worker
 ```
 
 ### Setting up a proxy webserver
@@ -254,7 +262,7 @@ The landing page is managed via [wagtail](https://wagtail.io/). You can find the
 
 ```
 systemctl stop adhocracy-plus
-systemctl stop adhocracy-plus-background-task
+systemctl stop adhocracy-plus-celery-worker
 ```
 
 #### Switch to user
@@ -310,5 +318,5 @@ python manage.py runserver
 
 ```
 systemctl start adhocracy-plus
-systemctl start adhocracy-plus-background-task
+systemctl start adhocracy-plus-celery-worker
 ```

requirements/base.txt

@@ -18,7 +18,6 @@ redis==5.0.0
 Django==3.2.19
 django-allauth==0.54.0
 git+https://github.com/liqd/django-autoslug.git@liqd2212#egg=django-autoslug
-django-background-tasks==1.2.5
 django-ckeditor==6.5.1
 django-filter==22.1
 django-widget-tweaks==1.4.12

tests/conftest.py

@@ -2,30 +2,18 @@
 
 import factory
 import pytest
+from celery import Celery
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.urls import reverse
-from django.urls.base import get_resolver
 from PIL import Image
 from pytest_factoryboy import register
 from rest_framework.test import APIClient
 
 from adhocracy4.test import factories as a4_factories
 from adhocracy4.test.factories.maps import AreaSettingsFactory
-from adhocracy4.test.helpers import patch_background_task_decorator
 
 from . import factories
 
-
-def pytest_configure(config):
-    # Patch email background_task decorators for all tests
-    patch_background_task_decorator("adhocracy4.emails.tasks")
-    patch_background_task_decorator("apps.projects.tasks")
-
-    # Populate reverse dict with organisation patterns
-    resolver = get_resolver()
-    resolver.reverse_dict
-
-
 register(factories.UserFactory)
 register(factories.UserFactory, "user2")
 register(factories.AdminFactory, "admin")
@@ -48,6 +36,10 @@ def pytest_configure(config):
 register(AreaSettingsFactory)
 
 
+def pytest_configure():
+    Celery(task_always_eager=True)
+
+
 @pytest.fixture
 def apiclient():
     return APIClient()