chore: refactor gateway http context

gateway/server.go

@@ -185,13 +185,15 @@ func (s *Server) buildHttpHandler(target *HttpClientConf) http.HandlerFunc {
 			return
 		}
 
+		// accept the context from the original request, including the deadline
+		req = req.WithContext(r.Context())
+		// set the timeout if it's configured, take effect only if it's greater than 0
+		// and less than the deadline of the original request
 		if target.Timeout > 0 {
 			timeout := time.Duration(target.Timeout) * time.Millisecond
 			ctx, cancel := context.WithTimeout(r.Context(), timeout)
 			defer cancel()
 			req = req.WithContext(ctx)
-		} else {
-			req = req.WithContext(r.Context())
 		}
 
 		resp, err := httpc.DoRequest(req)