Fix CORS: proxy WebRTC requests through backend

app/main.py

@@ -7,14 +7,18 @@ import logging
 from contextlib import asynccontextmanager
 from typing import AsyncGenerator
 
+import httpx
 import aiomqtt
-from fastapi import FastAPI, Request
+from fastapi import FastAPI, Request, Response
 from fastapi.responses import HTMLResponse, StreamingResponse
 from fastapi.staticfiles import StaticFiles
 from fastapi.templating import Jinja2Templates
 
 from .config import settings
 
+# HTTP client for proxying to go2rtc
+http_client = httpx.AsyncClient(timeout=10.0)
+
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger(__name__)
 
@@ -139,6 +143,41 @@ async def events() -> StreamingResponse:
     )
 
 
+@app.post("/api/webrtc")
+async def webrtc_proxy(request: Request, src: str):
+    """Proxy WebRTC offers to go2rtc to avoid CORS issues"""
+    try:
+        body = await request.body()
+        response = await http_client.post(
+            f"http://{settings.GO2RTC_HOST}/api/webrtc?src={src}",
+            content=body,
+            headers={"Content-Type": "application/sdp"}
+        )
+        return Response(
+            content=response.content,
+            status_code=response.status_code,
+            media_type="application/sdp"
+        )
+    except Exception as e:
+        logger.error(f"WebRTC proxy error for {src}: {e}")
+        return Response(content=str(e), status_code=500)
+
+
+@app.get("/api/streams")
+async def streams_proxy():
+    """Proxy streams list from go2rtc"""
+    try:
+        response = await http_client.get(f"http://{settings.GO2RTC_HOST}/api/streams")
+        return Response(
+            content=response.content,
+            status_code=response.status_code,
+            media_type="application/json"
+        )
+    except Exception as e:
+        logger.error(f"Streams proxy error: {e}")
+        return Response(content=str(e), status_code=500)
+
+
 @app.get("/health")
 async def health():
     """Health check endpoint"""

app/templates/viewer.html

@@ -273,8 +273,8 @@
                 const offer = await pc.createOffer();
                 await pc.setLocalDescription(offer);
 
-                // Send offer to go2rtc
-                const response = await fetch(`http://${GO2RTC_HOST}/api/webrtc?src=${cameraId}`, {
+                // Send offer to go2rtc via proxy
+                const response = await fetch(`/api/webrtc?src=${cameraId}`, {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/sdp' },
                     body: offer.sdp
@@ -351,7 +351,7 @@
             await pc.setLocalDescription(offer);
 
             try {
-                const response = await fetch(`http://${GO2RTC_HOST}/api/webrtc?src=${cameraId}`, {
+                const response = await fetch(`/api/webrtc?src=${cameraId}`, {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/sdp' },
                     body: offer.sdp

requirements.txt

@@ -1,6 +1,7 @@
 fastapi>=0.109.0
 uvicorn[standard]>=0.27.0
 aiomqtt>=2.0.0
+httpx>=0.26.0
 jinja2>=3.1.0
 pydantic-settings>=2.0.0
 python-multipart>=0.0.6