main.py

import os
from starlette.applications import Starlette
from starlette.middleware import Middleware
from starlette.middleware.cors import CORSMiddleware
from starlette.routing import Route
from starlette.requests import Request
from starlette.responses import JSONResponse
import httpx

TARGET_SERVER_HOST = os.environ.get("TARGET_SERVER_HOST")

middleware = [
    Middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )
]

app = Starlette(middleware=middleware)


async def forward_request(request: Request):
    try:
        async with httpx.AsyncClient() as client:
            target_url = f"{TARGET_SERVER_HOST}{request.url.path}"
            method = request.method
            headers = dict(request.headers)
            if "host" in headers:
                del headers["host"]
            if "content-length" in headers:
                del headers["content-length"]
            if request.method in ["POST", "PUT", "PATCH"]:
                request_body = await request.json()
            else:
                request_body = None
            response = await client.request(
                method, target_url, headers=headers, json=request_body
            )
            return JSONResponse(response.json(), status_code=response.status_code)
    except httpx.HTTPError as e:
        return JSONResponse({"error": str(e)}, status_code=500)


app.add_route(
    "/{path:path}", forward_request, methods=["GET", "POST", "PUT", "PATCH", "DELETE"]
)

if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app, host="0.0.0.0", port=8000)