simple-module-background-tasks 0.0.16

Celery + Redis task queue with admin UI for monitoring and retrying failed/stuck tasks

simple_module_background_tasks

Celery + Redis background-task module for simple_module apps. Provides a pre-configured Celery instance, a task registration hook, and an admin UI for monitoring + retrying failed/stuck tasks.

Install

pip install simple_module_background_tasks

Requires a Redis broker — set SM_CELERY_BROKER_URL (default redis://localhost:6379/0).

What it provides

• register_background_tasks() module hook — modules declare tasks here; the registry wires them into the Celery app at boot.
• Admin UI at /background-tasks/admin — list recent runs, retry failed, inspect tracebacks.
• Shared Celery app accessible via from background_tasks import celery_app (import name background_tasks, distribution name simple_module_background_tasks).

Usage

Declare a task in a module:

# modules/reports/reports/tasks.py
from background_tasks import celery_app   # type: ignore[import-not-found]


@celery_app.task(name="reports.generate")
def generate_report(report_id: int) -> None:
    ...

Register it:

class ReportsModule(ModuleBase):
    meta = ModuleMeta(name="reports", depends_on=["background_tasks"])

    def register_background_tasks(self):
        from . import tasks  # noqa: F401 — side-effect: registers tasks

Enqueue from an endpoint:

generate_report.delay(report_id=42)

Run a worker locally:

uv run celery -A background_tasks.celery_app worker --loglevel=info

Worker log context

Every worker log line automatically carries the Celery task identifiers that fired it. A LogContextFilter is attached when the Celery app is built (build_celery) and the task_prerun / task_postrun signals bind task_id + task_name into contextvars for the task's duration:

{"level": "INFO", "logger": "reports.tasks", "message": "ingest done",
 "task_id": "9c2a…", "task_name": "reports.generate"}

Use bind_task_context(...) to attach app-level identifiers (the domain job_id that named a Celery task is the canonical example):

from background_tasks import bind_task_context

@celery_app.task
def process_dataset(job_id: int) -> None:
    with bind_task_context(job_id=job_id):
        logger.info("starting ingest")   # now carries job_id too

Bindings nest cleanly and restore on exit. structlog users can mount the same contextvars directly via structlog.contextvars.merge_contextvars.

Depends on

• simple_module_core, simple_module_db, simple_module_hosting
• celery[redis]>=5.4, redis>=5

License

MIT — see LICENSE.