fix CORS headers for traces (#8458)

Author: adameat

ydb/core/mon/async_http_mon.cpp

@@ -247,8 +247,9 @@ class THttpMonLegacyActorRequest : public TActorBootstrapped<THttpMonLegacyActor
         response << "HTTP/1.1 204 No Content\r\n"
                     "Access-Control-Allow-Origin: " << origin << "\r\n"
                     "Access-Control-Allow-Credentials: true\r\n"
-                    "Access-Control-Allow-Headers: Content-Type,Authorization,Origin,Accept,X-Trace-Verbosity,X-Want-Trace\r\n"
-                    "Access-Control-Allow-Methods: OPTIONS, GET, POST, PUT, DELETE\r\n"
+                    "Access-Control-Allow-Headers: Content-Type,Authorization,Origin,Accept,X-Trace-Verbosity,X-Want-Trace,traceparent\r\n"
+                    "Access-Control-Expose-Headers: traceresponse,X-Worker-Name\r\n"
+                    "Access-Control-Allow-Methods: OPTIONS,GET,POST,PUT,DELETE\r\n"
                     "Content-Type: " << type << "\r\n"
                     "Connection: keep-alive\r\n\r\n";
         ReplyWith(request->CreateResponseString(response));

ydb/core/viewer/viewer.cpp

@@ -595,8 +595,9 @@ void TViewer::FillCORS(TStringBuilder& stream, const TRequestState& request) {
     if (origin) {
         stream << "Access-Control-Allow-Origin: " << origin << "\r\n"
                << "Access-Control-Allow-Credentials: true\r\n"
-               << "Access-Control-Allow-Headers: Content-Type,Authorization,Origin,Accept,X-Trace-Verbosity,X-Want-Trace\r\n"
-               << "Access-Control-Allow-Methods: OPTIONS, GET, POST, DELETE\r\n"
+               << "Access-Control-Allow-Headers: Content-Type,Authorization,Origin,Accept,X-Trace-Verbosity,X-Want-Trace,traceparent\r\n"
+               << "Access-Control-Expose-Headers: traceresponse,X-Worker-Name\r\n"
+               << "Access-Control-Allow-Methods: OPTIONS,GET,POST,PUT,DELETE\r\n"
                << "Allow: OPTIONS, GET, POST, DELETE\r\n";
     }
 }