add context.routing_error_reason to report attributes

include/istio/control/http/report_data.h

@@ -40,6 +40,7 @@ class ReportData {
     uint64_t response_body_size;
     std::chrono::nanoseconds duration;
     int response_code;
+    std::string response_flags;
   };
   virtual void GetReportInfo(ReportInfo* info) const = 0;
 

include/istio/utils/attribute_names.h

@@ -75,6 +75,7 @@ struct AttributeName {
   // Context attributes
   static const char kContextProtocol[];
   static const char kContextTime[];
+  static const char kContextRoutingErrorReason[];
 
   // Check error code and message.
   static const char kCheckErrorCode[];

src/envoy/http/mixer/report_data.h

@@ -88,6 +88,8 @@ class ReportData : public ::istio::control::http::ReportData {
     // responseCode is for the backend response. If it is not valid, the request
     // is rejected by Envoy. Set the response code for such requests as 500.
     data->response_code = info_.responseCode().value_or(500);
+
+    data->response_flags = RequestInfo::ResponseFlagUtils::toShortString(info_);
   }
 
   bool GetDestinationIpPort(std::string *str_ip, int *port) const override {

src/istio/control/http/attributes_builder.cc

@@ -226,6 +226,9 @@ void AttributesBuilder::ExtractReportAttributes(ReportData *report_data) {
     builder.AddString(utils::AttributeName::kResponseGrpcMessage,
                       grpc_status.message);
   }
+
+  builder.AddString(utils::AttributeName::kContextRoutingErrorReason,
+                    info.response_flags);
 }
 
 }  // namespace http

src/istio/control/http/attributes_builder_test.cc

@@ -65,6 +65,12 @@ attributes {
     string_value: "http"
   }
 }
+attributes {
+  key: "context.routing_error_reason"
+  value {
+    string_value: "NR"
+  }
+}
 attributes {
   key: "destination.principal"
   value {
@@ -547,6 +553,7 @@ TEST(AttributesBuilderTest, TestReportAttributes) {
         info->request_total_size = 240;
         info->duration = std::chrono::nanoseconds(1);
         info->response_code = 404;
+        info->response_flags = "NR";
       }));
   EXPECT_CALL(mock_data, GetGrpcStatus(_))
       .WillOnce(Invoke([](ReportData::GrpcStatus *status) -> bool {

src/istio/utils/attribute_names.cc

@@ -70,6 +70,8 @@ const char AttributeName::kConnectionEvent[] = "connection.event";
 // Context attributes
 const char AttributeName::kContextProtocol[] = "context.protocol";
 const char AttributeName::kContextTime[] = "context.time";
+const char AttributeName::kContextRoutingErrorReason[] =
+    "context.routing_error_reason";
 
 // Check error code and message.
 const char AttributeName::kCheckErrorCode[] = "check.error_code";