Replace celery with django_q, adjust code

Pipfile

@@ -20,9 +20,7 @@ gunicorn = "*"
 django-environ = "*"
 django-storages = "*"
 boto3 = "*"
-celery = "*"
-django-celery-results = "*"
-django-celery-beat = "*"
+django-q2 = "*"
 flower = "*"
 django-friendship = "*"
 django-jsonform = "*"

README.md

@@ -2,7 +2,6 @@
     <h1>VibeLink</h1>
     <img src="https://img.shields.io/badge/Python-14354C?style=for-the-badge&logo=python&logoColor=white" alt=""/>
     <img src="https://img.shields.io/badge/Django-092E20?style=for-the-badge&logo=django&logoColor=white" alt=""/>
-    <img src="https://img.shields.io/badge/Celery-8C9A41?&style=for-the-badge&logo=celery&logoColor=white" alt=""/>
     <img src="https://img.shields.io/badge/PostgreSQL-316192?style=for-the-badge&logo=postgresql&logoColor=white" alt=""/>
     <img src="https://img.shields.io/badge/Redis-%23DD0031.svg?&style=for-the-badge&logo=redis&logoColor=white" alt=""/>
     <img src="https://img.shields.io/badge/Docker-008FCC?style=for-the-badge&logo=docker&logoColor=white" alt=""/>

core/__init__.py

@@ -1,3 +0,0 @@
-from .celery import app as celery_app
-
-__all__ = ('celery_app',)

core/settings/base.py

@@ -19,7 +19,7 @@
 BASE_DIR = Path(__file__).resolve().parent.parent.parent
 
 env = Env()
-env.read_env(BASE_DIR / 'env/backend.env')
+env.read_env()
 
 # Quick-start development settings - unsuitable for production
 # See https://docs.djangoproject.com/en/4.2/howto/deployment/checklist/
@@ -59,8 +59,7 @@
     'allauth.socialaccount',
     'dj_rest_auth.registration',
 
-    'django_celery_results',
-    'django_celery_beat',
+    'django_q',
 
     'friendship',
 
@@ -69,6 +68,7 @@
     'accounts',
     'links',
     'tracks',
+    'emails',
 ]
 
 MIDDLEWARE = [
@@ -250,7 +250,7 @@
 }
 
 # Authentication backends
-# https://django-allauth.readthedocs.io/en/latest/configuration.html
+# https://docs.allauth.org/en/latest/account/configuration.html
 
 AUTHENTICATION_BACKENDS = [
     'django.contrib.auth.backends.ModelBackend',
@@ -307,11 +307,12 @@
 SPECTACULAR_SETTINGS = {
     'TITLE': 'VibeLink API',
     'DESCRIPTION': 'VibeLink REST API provided by Alschn',
-    'VERSION': '1.0.0',
+    'VERSION': '0.1.0',
     'CONTACT': {
         'name': 'Alschn',
         'url': 'https://github.com/Alschn/',
     },
+    'SCHEMA_PATH_PREFIX': '/api/',
     'SERVE_PERMISSIONS': ['rest_framework.permissions.AllowAny'],
 }
 
@@ -326,31 +327,56 @@
 
 CORS_ORIGIN_REGEX_WHITELIST = env.list('CORS_ORIGIN_REGEX_WHITELIST', default=[])
 
-# Redis settings
+# Django Q configuration
+# https://django-q2.readthedocs.io/en/master/configure.html
+
+REDIS_HOST = env('REDIS_HOST', default='redis_db')
+REDIS_PORT = env.int('REDIS_PORT', default=6379)
+
+# default values taken from the documentation
+Q_CLUSTER_NAME = env('Q_CLUSTER_NAME', default='vibelink')
+Q_CLUSTER_WORKERS = env.int('Q_CLUSTER_WORKERS', default=4)
+Q_CLUSTER_DAEMONIZE_WORKERS = env.bool('Q_CLUSTER_DAEMONIZE_WORKERS', default=False)
+Q_CLUSTER_RECYCLE = env.int('Q_CLUSTER_RECYCLE', default=500)
+Q_CLUSTER_TIMEOUT = env.int('Q_CLUSTER_TIMEOUT', default=60)
+Q_CLUSTER_COMPRESS = env.bool('Q_CLUSTER_COMPRESS', default=True)
+Q_CLUSTER_MAX_ATTEMPTS = env.int('Q_CLUSTER_MAX_ATTEMPTS', default=0)
+Q_CLUSTER_RETRY = env.int('Q_CLUSTER_RETRY', default=60)
+Q_CLUSTER_SAVE_LIMIT = env.int('Q_CLUSTER_SAVE_LIMIT', default=250)
+Q_CLUSTER_QUEUE_LIMIT = env.int('Q_CLUSTER_QUEUE_LIMIT', default=500)
+Q_CLUSTER_CPU_AFFINITY = env.int('Q_CLUSTER_CPU_AFFINITY', default=1)
+Q_CLUSTER_SYNC = False
+Q_CLUSTER_CATCH_UP = True
+
+Q_CLUSTER = {
+    'name': Q_CLUSTER_NAME,
+    'workers': Q_CLUSTER_WORKERS,
+    'daemonize_workers': Q_CLUSTER_DAEMONIZE_WORKERS,
+    'recycle': Q_CLUSTER_RECYCLE,
+    'timeout': Q_CLUSTER_TIMEOUT,
+    'compress': Q_CLUSTER_COMPRESS,
+    'max_attempts': Q_CLUSTER_MAX_ATTEMPTS,
+    'retry': Q_CLUSTER_RETRY,
+    'save_limit': Q_CLUSTER_SAVE_LIMIT,
+    'queue_limit': Q_CLUSTER_QUEUE_LIMIT,
+    'cpu_affinity': Q_CLUSTER_CPU_AFFINITY,
+    'sync': Q_CLUSTER_SYNC,
+    'catch_up': Q_CLUSTER_CATCH_UP,
+    'label': 'Django Q2',
+    'redis': {
+        'host': REDIS_HOST,
+        'port': REDIS_PORT,
+        'db': 0,
+    }
+}
 
 # Django cache settings
 # https://docs.djangoproject.com/en/4.2/topics/cache/
 
-REDIS_HOST = env('REDIS_HOST', default=None)
-
-REDIS_PORT = env('REDIS_PORT', cast=int, default=None)
-
-REDIS_URL = env('REDIS_URL', default=None)
-
-CELERY_TIMEZONE = TIME_ZONE
-
-CELERY_BROKER_URL = REDIS_URL or f'redis://{REDIS_HOST}:{REDIS_PORT}'
-
-CELERY_RESULT_BACKEND = 'django-db'
-
-CELERY_CACHE_BACKEND = 'default'
-
-CELERY_BEAT_SCHEDULER = 'django_celery_beat.schedulers:DatabaseScheduler'
-
 CACHES = {
     'default': {
         'BACKEND': 'django.core.cache.backends.redis.RedisCache',
-        'LOCATION': CELERY_BROKER_URL,
+        'LOCATION': f'redis://{REDIS_HOST}:{REDIS_PORT}',
     },
 }
 

core/shared/tasks.py

@@ -1,6 +1,13 @@
 import inspect
+from datetime import timedelta, datetime
+from typing import Any
 from typing import Callable
 
+from django.db import connection
+from django.utils import timezone
+from django_q.models import Schedule
+from django_q.tasks import async_task
+
 
 def get_function_module_path(func: Callable) -> str:
     """
@@ -18,3 +25,62 @@ def get_function_module_path(func: Callable) -> str:
     """
 
     return f"{inspect.getmodule(func).__name__}.{func.__name__}"
+
+
+def create_async_task(func: Callable, *args: Any, **kwargs: Any):
+    """
+    Wrapper around `django_q.tasks.async_task` function
+    that automatically resolves a path to the given callable.
+    """
+
+    return async_task(
+        get_function_module_path(func),
+        *args,
+        **kwargs
+    )
+
+
+def assure_scheduled(
+    schedule_func: Callable[..., Schedule],
+    name: str,
+    recreate: bool = False,
+    *args,
+    **kwargs
+) -> Schedule | None:
+    """
+    Checks if a schedule with given name exists and if not, creates it.
+    If it exists, then it is deleted and recreated to ensure its details are up-to-date.
+    """
+    tables = connection.introspection.table_names()
+
+    if Schedule._meta.db_table not in tables:
+        print(
+            f'Schedule table not in database, "{schedule_func.__name__}" not scheduled, '
+            f'please run migrations and restart the app'
+        )
+        return
+
+    queryset = Schedule.objects.filter(name=name)
+
+    if queryset.exists():
+        if recreate:
+            print(f"Schedule with name `{name}` already exists. Recreating...")
+            queryset.delete()
+            return schedule_func(*args, **kwargs, name=name)
+
+        print(f"Schedule with name `{name}` already exists. Skipping...")
+        return queryset.first()
+
+    print(f"Creating schedule with name `{name}`...")
+    return schedule_func(*args, **kwargs, name=name)
+
+
+def get_daily_schedule_next_run_time(
+    *, hour: int, minute: int,
+    second: int = 0, microsecond: int = 0
+) -> datetime:
+    now = timezone.now()
+    return now.replace(
+        hour=hour, minute=minute,
+        second=second, microsecond=microsecond
+    ) + timedelta(days=1)

docker-compose.yml

@@ -34,49 +34,17 @@ services:
       - "8000:8000"
     command: python manage.py runserver 0.0.0.0:8000
 
-  celery_worker:
-    container_name: vibe-link-celery-worker
+  django_q:
+    container_name: vibe-link-django_q
     build: .
     env_file:
       - env/backend.env
-    stdin_open: true
-    tty: true
-    depends_on:
-      - postgres_db
-      - redis_db
     volumes:
       - .:/app/
-    command: celery -A core.celery.app worker -l INFO
-
-  celery_beat:
-    container_name: vibe-link-celery-beat
-    build: .
-    env_file:
-      - env/backend.env
-    stdin_open: true
-    tty: true
     depends_on:
       - postgres_db
       - redis_db
-    volumes:
-      - .:/app/
-    command: celery -A core.celery.app beat -l INFO
-
-  flower:
-    container_name: vibe-link-flower
-    build: .
-    env_file:
-      - env/backend.env
-    stdin_open: true
-    tty: true
-    depends_on:
-      - postgres_db
-      - redis_db
-    volumes:
-      - .:/app/
-    ports:
-      - "5555:5555"
-    command: celery -A core.celery.app flower -l INFO
+    command: python manage.py qcluster
 
 volumes:
   postgres-data:

links/apps.py

@@ -4,3 +4,12 @@
 class LinksConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'links'
+
+    def ready(self) -> None:
+        from core.shared.tasks import assure_scheduled
+        from links.queue.schedules import schedule_daily_generate_link_requests
+
+        assure_scheduled(
+            schedule_daily_generate_link_requests,
+            name='schedule_daily_generate_link_requests'
+        )

links/emails.py

@@ -1,9 +1,10 @@
-from typing import Iterable
+import typing
 
-from accounts.models import User
+if typing.TYPE_CHECKING:
+    from accounts.models import User
 
 
-def send_link_requests_email_notifications(users: Iterable[User]) -> None:
+def send_link_requests_email_notifications(users: typing.Iterable['User']) -> None:
     """Send email notifications to users about newly created link requests."""
 
     # todo: implement

links/queue/schedules.py

@@ -1,16 +1,28 @@
 import random
 
-from celery import shared_task
 from django.utils import timezone
+from django_q.models import Schedule
+from django_q.tasks import schedule
 
-from core.shared.tasks import get_function_module_path
+from core.shared.tasks import (
+    get_function_module_path,
+    get_daily_schedule_next_run_time
+)
 from links.queue.tasks import generate_link_requests
 
 
-@shared_task
-def schedule_generate_link_requests() -> str:
-    from django_celery_beat.models import PeriodicTask, ClockedSchedule
+def schedule_daily_generate_link_requests(*args, **kwargs) -> Schedule:
+    return schedule(
+        get_function_module_path(schedule_generate_link_requests),
+        *args,
+        schedule_type=Schedule.DAILY,
+        repeats=-1,
+        next_run=get_daily_schedule_next_run_time(hour=0, minute=0),
+        **kwargs,
+    )
+
 
+def schedule_generate_link_requests() -> Schedule:
     now = timezone.now()
     end_of_today = now.replace(hour=23, minute=59, second=59)
 
@@ -21,16 +33,9 @@ def schedule_generate_link_requests() -> str:
 
     task_name = 'generate-link-requests-' + random_time.strftime('%Y-%m-%d-%H-%M-%S')
 
-    # create a new schedule required by periodic task
-    clocked, _ = ClockedSchedule.objects.get_or_create(clocked_time=random_time)
-
-    # schedule one-off task at random time
-    PeriodicTask.objects.create(
+    return schedule(
+        get_function_module_path(generate_link_requests),
         name=task_name,
-        task=get_function_module_path(generate_link_requests),
-        one_off=True,
-        clocked=clocked,
-        start_time=random_time,
+        schedule_type=Schedule.ONCE,
+        next_run=random_time
     )
-
-    return task_name