I have such middleware
class RequestContext(BaseHTTPMiddleware): async def dispatch(self, request: Request, call_next: RequestResponseEndpoint): request_id = request_ctx.set(str(uuid4())) # generate uuid to request body = await request.body() if body: logger.info(...) # log request with body else: logger.info(...) # log request without body response = await call_next(request) response.headers['X-Request-ID'] = request_ctx.get() logger.info("%s" % (response.status_code)) request_ctx.reset(request_id) return response
So the line body = await request.body()
freezes all requests that have body and I have 504 from all of them. How can I safely read the request body in this context? I just want to log request parameters.
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Answer
I would not create a Middleware that inherits from BaseHTTPMiddleware since it has some issues, FastAPI gives you a opportunity to create your own routers, in my experience this approach is way better.
from fastapi import APIRouter, FastAPI, Request, Response, Body from fastapi.routing import APIRoute from typing import Callable, List from uuid import uuid4 class ContextIncludedRoute(APIRoute): def get_route_handler(self) -> Callable: original_route_handler = super().get_route_handler() async def custom_route_handler(request: Request) -> Response: request_id = str(uuid4()) response: Response = await original_route_handler(request) if await request.body(): print(await request.body()) response.headers["Request-ID"] = request_id return response return custom_route_handler app = FastAPI() router = APIRouter(route_class=ContextIncludedRoute) @router.post("/context") async def non_default_router(bod: List[str] = Body(...)): return bod app.include_router(router)
Works as expected.
b'["string"]' INFO: 127.0.0.1:49784 - "POST /context HTTP/1.1" 200 OK