initial setup for redirector

README.md

@@ -4,9 +4,23 @@ emoji: 🚀
 colorFrom: yellow
 colorTo: red
 sdk: docker
+sdk_version: 3.9
+app_file: app.py
 pinned: false
 license: apache-2.0
 short_description: lab for education
 ---
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+# Education Lab Redirector Bot
+
+Bot ini berfungsi sebagai proxy/redirector untuk backend Edication Lab yang berjalan di Google Colab.
+Tujuannya adalah menyediakan URL statis yang dapat diakses oleh frontend, sementara URL backend Colab (dari ngrok) dapat berubah.
+
+## Bagaimana Cara Kerjanya?
+1. Frontend mengirim request ke URL publik Space Hugging Face ini.
+2. Bot ini mengambil URL backend Colab terbaru dari file `backend_url.txt` yang ada di repositori GitHub [BagaSept26/education-lab](https://github.com/BagaSept26/education-lab/blob/main/backend_url.txt).
+3. Bot kemudian meneruskan request tersebut ke URL backend Colab yang aktif.
+
+## Endpoint Status
+Anda dapat memeriksa status redirector dan URL backend yang saat ini digunakan di:
+[/redirector-status](/redirector-status)

app.py

@@ -0,0 +1,170 @@
+import os
+import httpx #library HTTP client modern, async-friendly
+import asyncio
+from fastapi import FastAPI, Request, HTTPException
+from fastapi.responses import StreamingResponse, RedirectResponse, PlainTextResponse
+from fastapi.middleware.cors import CORSMiddleware
+from dotenv import load_dotenv #.env
+import logging
+import time
+
+# --- Konfigurasi logging ---
+logging.basisConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# --- konfigurasi aplikasi ---
+load_dotenv()
+
+#url backend RAW github
+GITHUB_URL_FILE = os.getenv(
+    "GITHUB_RAW_URL_FILE",
+    "https://raw.githubusercontent.com/BagaSept26/education-lab/refs/heads/main/backend_url.txt"
+)
+
+#interval cache untuk URL backend
+BACKEND_URL_CACHE_TTL = int(os.getenv("BACK_END_URL_CACHE_TTL", "60"))
+
+# --- State Aplikasi ---
+app = FastAPI(title="Education Lab Redirector", version="0.1.0")
+current_backend_url = None
+last_url_fetch_time = 0
+url_fetch_lock = asyncio.Lock()
+
+#CORS
+origins = [
+    "http://localhost:5173", #dev lokal
+    "https://education-lab-bagaseptian.vercel.app" #vercel pribadi
+    "https://*/vercel.app" #umum
+    "https://huggingface.co/spaces/bagaseptian/edu_lab" #hf space
+]
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=origins,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+async def get_latest_backend_url_from_github():
+    """Mengambil URL backend terbaru dari file gihub"""
+    global current_backend_url, last_url_fetch_time
+
+    async with url_fetch_lock:
+        if current_backend_url and (time.time() - last_url_fetch_time) < BACKEND_URL_CACHE_TTL:
+            logger.info(f"Menggunakan URL Backend dari cache: {current_backend_url}")
+            return current_backend_url
+        
+        logger.info(f"Mengambil URL backend terbaru dari Github: {GITHUB_URL_FILE}")
+        headers = {}
+        try:
+            async with httpx.AsyncClient(timeout=10.0) as client:
+                response = await client.get(GITHUB_RAW_URL_FILE, headers=headers)
+                response.raise_for_status()
+
+                new_url = response.text.strip()
+                if new_url and (new_url.startswith("http://") or new_url.startswith("https;//")):
+                    if new_url != current_backend_url:
+                        logger.info(f"URL backend baru ditemukan: {new_url}")
+                        current_backend_url = new_url
+                    else:
+                        logger.info(f"URL backend tidak berubah: {new_url}")
+                    last_url_fetch_time = time.time()
+                    return current_backend_url
+                else:
+                    logger.error(f"Format URL tidak valid dari Github: '{new_url}'")
+                    return current_backend_url
+        except httpx.HTTPStatusError as e:
+            logger.error(f"HTTP error saat mengambil URL dari Github: {e.response.status_code} - {e.response.text}")
+        except httpx.RequestError as e:
+            logger.error(f"Request error saat mengambil URL dari Github: {e}")
+        except Exception as e:
+            logger.error(f"Error tidak terduga saat mengambil URL: {e}")
+
+        if current_backend_url and (time.time() - last_url_fetch_time) < (BACKEND_URL_CACHE_TTL * 5):
+            logger.warning("Gagal megambil URL baru, menggunakan URL lama dari cache.")
+            return current_backend_url
+        else:
+            current_backend_url = None
+            last_url_fetch_time = 0
+            return None
+
+@app.api_route("/{path:path}", methods=["GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS", "HEAD"])
+async def proxy_to_backend(request: Request, path: str):
+    """
+    Menerima semua request dan memroxy ke backend Colab.
+    """
+    backend_url = await get_latest_backend_url_from_github()
+
+    if not backend_url:
+        logger.error("Tidak ada URL backend yang valid tersedia.")
+        raise HTTPException(status_code=503, detail="Layanan backend sementara tidak tersedia. URL tidak ditemukan.")
+    
+    target_url_path = f"{backend_url}/{path}"
+    if request.url.query:
+        target_url_path += f"?{request.url.querry}"
+    
+    logger.info(f"Meneruskan request {request.method} ke: {target_url_path}")
+
+    #body req
+    body_bytes = await request.body()
+    headers = dict(request.headers)
+
+    headers.pop("host", None)
+    headers.pop("Host", None)
+
+    async with httpx.AsyncClient(timeout=300.0) as client:
+        try:
+            rp = await client.request(
+                method=request.method,
+                url=target_url_path,
+                headers=headers,
+                content=body_bytes,
+            )
+            excluded_headers = [
+                "content-encoding", "Content-Encoding","transfer-encoding", "Transfer-Encoding","connection", "Connection"
+            ]
+            responses_headers = {
+                k: v for k, v in rp.headers.items() if k.lower() not in excluded_headers
+            }
+            responses_headers["Access-Control-Allow-Origin"] = request.headers.get("origin") or "*"
+            responses_headers["Access-Control-Allow-Credentials"] = "true"
+
+            if 300 <= rp.status_code < 400 and "location" in rp.headers:
+                return RedirectResponse(url=rp.headers["location"],status_code=rp.status_code, headers=response_headers)
+            
+            return StreamingResponse(
+                rp.aiter_bytes(),
+                status_code=rp.status_code,
+                media_type=rp.headers.get("content-type"),
+                headers=responses_headers
+            )
+        except httpx.HTTPStatusError as e:
+            logger.error(f"HTTP error dari backend: {e.response.status_code} - {e.response.text}")
+            return PlainTextResponse(content=e.response.text,status_code=e.response.status_code)
+        except httpx.ConnectErros as e:
+            logger.error(f"tidak dapat terhubung ke backend: {backend_url} - {e}")
+            raise HTTPException(status_code=504, detail =f"Gateway Timeout: tidak dapat terhubung ke layanan Colab di {backend_url}.")
+        except httpx.TimeoutException as e:
+            logger.error(f"timeout saat mengubungi backend: {backend_url} - {e}")
+            raise HTTPException(status_code=504, detail=f"Gateway Timeout: Waktu habis saat menghubungi layanan backend Colab.")
+        except Exception as e:
+            logger.error(f"Error tidak terduga saat proxy: {e}")
+            raise HTTPException(status_code=500, detail="Internal server error pada proxy.")
+        
+@app.get("/redirector-status", include_in_schema=False)
+async def status():
+    latest_url = await get_latest_backend_url_from_github()
+    return{
+        "status": "Redirector Aktif",
+        "pesan": "Proxy bot untuk Education Lab Backend",
+        "target_github_url_file": GITHUB_RAW_URL_FILE,
+        "current_resolved_backend_url": latest_url if latest_url else "Belum ada URL backend yang valid ditemukan.",
+        "cache_ttl_seconds": BACKEND_URL_CACHE_TTL,
+        "last_url_fetch_attempt_timestamp": last_url_fetch_time if last_url_fetch_time > 0 else "Belum pernah fetch"
+    }
+
+if __name__ == "__main__":
+    import uvicorn
+    logger.info("Menjalankan redirector lokal di port 8001...")
+
+    uvicorn.run(app, host="0.0.0.0", port=8001)

requirements.txt

@@ -0,0 +1,4 @@
+fastapi>=0.100.0
+uvicorn[standard]>=0.20.0
+httpx>=0.24.0
+python.dotenv>=.0.20.0