How to proxy fastapi multipart/form-data large-file upload request to another site?

[honglei]

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Example Code

from fastapi.requests import Request
from starlette.responses import StreamingResponse
from starlette.background import BackgroundTask

import httpx
client = httpx.AsyncClient(base_url="http://localhost:8002/")

@router.post("/upload")
async def upload_files_to_channel(
    gatewayID:int,
    channelID:int,
    request:Request,
    files: list[UploadFile] = File(..., title="Add file",description="Multiple files"),
    #db: Session = Depends(deps.get_db),
    #current_user: User = Depends(deps.get_current_user),
):
    '''
    '''
    url = httpx.URL(path='/channel/upload', query=f'{channelID=}'.encode())
    rp_req = client.build_request(request.method, url,
                                  headers=request.headers.raw,
                                  content=await request.body
                                  #content=request.stream()
                                  #files=[ (f.filename,f) for f in files]
                                  )
    rp_resp = await client.send(rp_req, stream=True)
    
    return StreamingResponse(
        rp_resp.aiter_raw(),
        status_code=rp_resp.status_code,
        headers=rp_resp.headers,
        background=BackgroundTask(rp_resp.aclose),
    )

Description

like #1788 ,

from fastapi.requests import Request
from starlette.responses import StreamingResponse
from starlette.background import BackgroundTask

import httpx
client = httpx.AsyncClient(base_url="http://localhost:8002/")

@router.post("/upload")
async def upload_files_to_channel(
    gatewayID:int,
    channelID:int,
    request:Request,
    files: list[UploadFile] = File(..., title="Add file",description="Multiple files"),
    #db: Session = Depends(deps.get_db),
    #current_user: User = Depends(deps.get_current_user),
):
    '''
    '''
    url = httpx.URL(path='/channel/upload', query=f'{channelID=}'.encode())
    rp_req = client.build_request(request.method, url,
                                  headers=request.headers.raw,
                                  content=await request.body
                                  #content=request.stream()
                                  #files=[ (f.filename,f) for f in files]
                                  )
    rp_resp = await client.send(rp_req, stream=True)
    
    return StreamingResponse(
        rp_resp.aiter_raw(),
        status_code=rp_resp.status_code,
        headers=rp_resp.headers,
        background=BackgroundTask(rp_resp.aclose),
    )  

Operating System

Windows

Operating System Details

No response

FastAPI Version

0.76.0

Python Version

Python 3.10.4

Additional Context

No response

[YuriiMotov]

#1788