How Can I Log Raw HTTP Request and Response Bodies in Python FastAPI?

Logging Raw HTTP Request/Response Bodies in Python FastAPI

In Python FastAPI, you can log the raw JSON bodies of specific request/response routes by employing middleware or custom APIRoute classes.

Option 1: Using Middleware

Middleware allows you to handle requests and responses before they are processed by endpoints. To create middleware:

@app.middleware("http")
async def middleware(request: Request, call_next):
    # ...
    return await call_next(request)

Use the request.body() or request.stream() methods to consume the request body. Store the body in a BackgroundTask for logging later.

For the response body, use custom code to read and store it:

res_body = b''
async for chunk in response.body_iterator:
    res_body += chunk

You can then log both the request and response bodies within the BackgroundTask to avoid impacting response time.

Option 2: Using Custom APIRoute Class

Create a custom APIRoute class to handle request and response bodies:

class LoggingRoute(APIRoute):
    # ...
    async def custom_route_handler(request: Request) -> Response:
        # ...
        return response

In the custom route handler, consume the request body and handle the response body similarly to Option 1. By using this approach, you can limit logging to specific routes using APIRouters.

Considerations

• Large request/response bodies (> server RAM) can cause memory issues.
• Streaming responses may encounter issues or delays on the client side due to the entire response being read before returning.
• Consider usage limits or alternative logging strategies for endpoints returning large or streaming responses.

The above is the detailed content of How Can I Log Raw HTTP Request and Response Bodies in Python FastAPI?. For more information, please follow other related articles on the PHP Chinese website!