FastAPI Background Task Not Executing with Dependency Injection
I'm confused about I've been researching this but I'm integrating two systems and I'm working on a FastAPI application (version 0.68) and I'm trying to use background tasks to process an item after an HTTP request. However, the background task isn't executing as expected when I use dependency injection. I've defined a background task using `BackgroundTasks` and tried to pass a dependency that fetches some configuration data from the database. Here’s the simplified version of my code: ```python from fastapi import FastAPI, BackgroundTasks, Depends from sqlalchemy.orm import Session app = FastAPI() def get_db(): # Assuming there's some logic here to create and yield a database session pass def process_item(item_id: int, db: Session): # Perform some database operations # Simulating a processing time import time time.sleep(5) print(f"Processed item {item_id}") @app.post("/items/{item_id}") async def create_item(item_id: int, background_tasks: BackgroundTasks, db: Session = Depends(get_db)): background_tasks.add_task(process_item, item_id, db) return {"message": "Item processing started"} ``` When I make a POST request to `/items/1`, I get the response immediately, but the `process_item` function doesn't seem to execute. I tried logging within the function to see if it gets called, but there’s no output. I also verified that the `get_db` function is working correctly, as I can interact with the database outside of this context. I suspect it might be an issue with how FastAPI is managing background tasks when a dependency is involved. I've also checked the FastAPI documentation, but I couldn't find anything addressing this specific use case. Could it be that the database session is getting closed before the background task executes? If so, how can I ensure that the database session remains open for the duration of the background task? Any insights or solutions would be greatly appreciated! This is happening in both development and production on macOS. Am I approaching this the right way? The project is a microservice built with Python. Thanks, I really appreciate it!