feature:基本框架

utils/request_id.py

@@ -0,0 +1,32 @@
+"""每请求 trace_id：contextvar 存链路号，中间件生成 / 透传并回写响应头。"""
+import contextvars
+import uuid
+
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.requests import Request
+from starlette.responses import Response
+
+_request_id: contextvars.ContextVar[str | None] = contextvars.ContextVar("request_id", default=None)
+
+
+def get_request_id() -> str | None:
+    """获取当前请求的 trace_id（请求上下文外返回 None）。"""
+    return _request_id.get()
+
+
+def new_request_id() -> str:
+    return uuid.uuid4().hex[:16]
+
+
+class RequestIdMiddleware(BaseHTTPMiddleware):
+    """透传客户端 X-Trace-Id（无则生成），供日志/响应头/审计链路关联。"""
+
+    async def dispatch(self, request: Request, call_next):
+        rid = request.headers.get("X-Trace-Id") or new_request_id()
+        token = _request_id.set(rid)
+        try:
+            response: Response = await call_next(request)
+            response.headers["X-Trace-Id"] = rid
+            return response
+        finally:
+            _request_id.reset(token)