负载均衡重构: 子网感知选择 + 节点健康监控 + 节点注册上报API

- 新增 subnet-aware 负载策略: 根据客户端IP匹配最近/16子网节点
- 节点注册端点 (POST /api/nodes/register): 边缘节点自动注册
- 节点心跳端点 (POST /api/nodes/heartbeat): 上报CPU/RAM/带宽/连接数
- 健康汇总 (GET /api/nodes/health): 服务端汇总所有节点状态
- 配置节点新增subnet/is_origin字段
- 前端NodeManager: 实时健康状态/CPU/RAM进度条/带宽/连接数
- X-Forwarded-For/X-Real-IP透传支持客户端IP

backend/routes/streams.py

@@ -1,4 +1,4 @@
-from fastapi import APIRouter, HTTPException, Depends, Query
+from fastapi import APIRouter, HTTPException, Depends, Query, Request
 from sqlalchemy.ext.asyncio import AsyncSession
 from pydantic import BaseModel
 from typing import Optional
@@ -26,6 +26,18 @@ class StreamUpdate(BaseModel):
     scheduled_at: Optional[str] = None
 
 
+def _get_client_ip(request: Request) -> str | None:
+    forwarded = request.headers.get("X-Forwarded-For")
+    if forwarded:
+        return forwarded.split(",")[0].strip()
+    client = request.headers.get("X-Real-IP")
+    if client:
+        return client
+    if request.client:
+        return request.client.host
+    return None
+
+
 @router.get("")
 async def list_streams(db: AsyncSession = Depends(get_db)):
     svc = StreamService(db)
@@ -114,17 +126,19 @@ async def delete_stream(stream_id: int, db: AsyncSession = Depends(get_db),
 
 
 @router.get("/{stream_id}/watch")
-async def get_watch_urls(stream_id: int, db: AsyncSession = Depends(get_db)):
+async def get_watch_urls(stream_id: int, request: Request, db: AsyncSession = Depends(get_db)):
     svc = StreamService(db)
     stream = await svc.get_stream(stream_id)
     if not stream:
         raise HTTPException(status_code=404, detail="Stream not found")
-    urls = await svc.get_watch_urls(stream.stream_key)
+    client_ip = _get_client_ip(request)
+    urls = await svc.get_watch_urls(stream.stream_key, client_ip)
     return {
         "stream_id": stream.id,
         "title": stream.title,
         "status": stream.status.value,
         "multicast_available": urls["multicast_available"],
+        "selected_node": urls.get("selected_node"),
         "lines": urls["lines"],
         "qualities": urls["qualities"],
     }
@@ -153,12 +167,13 @@ async def stream_end(stream_id: int, db: AsyncSession = Depends(get_db),
 
 
 @router.get("/detail/{stream_key}")
-async def get_stream_by_key(stream_key: str, db: AsyncSession = Depends(get_db)):
+async def get_stream_by_key(stream_key: str, request: Request, db: AsyncSession = Depends(get_db)):
     svc = StreamService(db)
     s = await svc.get_stream_by_key(stream_key)
     if not s:
         raise HTTPException(status_code=404, detail="Stream not found")
-    urls = await svc.get_watch_urls(stream_key)
+    client_ip = _get_client_ip(request)
+    urls = await svc.get_watch_urls(stream_key, client_ip)
     return {
         "stream_id": s.id,
         "title": s.title,