Properly using FastAPI as the shape proxy

[Lodimup]

I want to proxy using python because my backend's mostly there so I'd have db access for auth logics.
The question is am I doing this right? especially this line does not seem right. When set to default I get httpx.ReadTimeout

async with httpx.AsyncClient(timeout=3600) as client:

import os

import httpx
from fastapi import FastAPI, Request
from fastapi.responses import StreamingResponse

app = FastAPI()


@app.get("/shape-proxy")
async def shape_proxy(request: Request):
    # check header for Bearer token and get user_id, then modify the where clause to include AND user_id = $n-1, modify params[n-1] = <user_id>
    # Build the origin URL
    base_url = "http://host.docker.internal:3000/v1/shape"  # this is the electric's url
    origin_url = httpx.URL(base_url)
    # Copy query params from incoming request
    params = dict(request.query_params)
    # Add source_id and secret if present
    if "ELECTRIC_SOURCE_ID" in os.environ:
        params["source_id"] = os.environ["ELECTRIC_SOURCE_ID"]
    if "ELECTRIC_SOURCE_SECRET" in os.environ:
        params["secret"] = os.environ["ELECTRIC_SOURCE_SECRET"]
    # Make the proxied request
    async with httpx.AsyncClient(timeout=3600) as client:
        async with client.stream(
            "GET", str(origin_url), params=params, headers={}
        ) as resp:

            # Remove problematic headers
            headers = dict(resp.headers)
            headers.pop("content-encoding", None)
            headers.pop("content-length", None)

            # Stream the response body
            content = await resp.aread()
            return StreamingResponse(
                iter([content]), status_code=resp.status_code, headers=headers
            )

[icehaunter]

Hey @Lodimup, I've converted the issue to a discussion to keep the issues focused on bug/feature requests and keep usage questions to discussions.

As for your question: I'm not fluent in FastAPI, but the default httpx timeout is specified to 5s which is indeed too low for normal use. We're using long polling with 20 second window, so anything smaller than say 25s (to account for network jitter) is not a good idea for a proxy.

I can't immediately tell from this code whether you're reading the entire response into memory with the aread call, or if it'll work correctly, but you should take care to stream through the response because they can be relatively large.