fix(otelgrpc): correctly assign grpc status code

CHANGELOG.md

@@ -28,6 +28,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Fixed
 
 - The `go.opentelemetry.io/contrib/samplers/jaegerremote` sampler does not panic when the default HTTP round-tripper (`http.DefaultTransport`) is not `*http.Transport`. (#4045)
+- The `UnaryServerInterceptor` in `go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc` now sets gRPC status code correctly for the `rpc.server.duration` metric. (#4481)
 
 ## [1.20.0/0.45.0/0.14.0] - 2023-09-28
 

instrumentation/google.golang.org/grpc/otelgrpc/interceptor.go

@@ -366,31 +366,32 @@ func UnaryServerInterceptor(opts ...Option) grpc.UnaryServerInterceptor {
 			messageReceived.Event(ctx, 1, req)
 		}
 
-		var statusCode grpc_codes.Code
-		defer func(t time.Time) {
-			elapsedTime := time.Since(t) / time.Millisecond
-			attr = append(attr, semconv.RPCGRPCStatusCodeKey.Int64(int64(statusCode)))
-			o := metric.WithAttributes(attr...)
-			cfg.rpcServerDuration.Record(ctx, int64(elapsedTime), o)
-		}(time.Now())
+		before := time.Now()
+		var grpcStatusCode grpc_codes.Code
 
 		resp, err := handler(ctx, req)
 		if err != nil {
 			s, _ := status.FromError(err)
+			grpcStatusCode = s.Code()
 			statusCode, msg := serverStatus(s)
 			span.SetStatus(statusCode, msg)
 			span.SetAttributes(statusCodeAttr(s.Code()))
 			if cfg.SentEvent {
 				messageSent.Event(ctx, 1, s.Proto())
 			}
 		} else {
-			statusCode = grpc_codes.OK
+			grpcStatusCode = grpc_codes.OK
 			span.SetAttributes(statusCodeAttr(grpc_codes.OK))
 			if cfg.SentEvent {
 				messageSent.Event(ctx, 1, resp)
 			}
 		}
 
+		elapsedTime := time.Since(before).Milliseconds()
+		attr = append(attr, semconv.RPCGRPCStatusCodeKey.Int64(int64(grpcStatusCode)))
+		o := metric.WithAttributes(attr...)
+		cfg.rpcServerDuration.Record(ctx, elapsedTime, o)
+
 		return resp, err
 	}
 }

instrumentation/google.golang.org/grpc/otelgrpc/test/interceptor_test.go

@@ -26,6 +26,8 @@ import (
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	"go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/sdk/trace/tracetest"
 	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
@@ -52,6 +54,19 @@ func getSpanFromRecorder(sr *tracetest.SpanRecorder, name string) (trace.ReadOnl
 	return nil, false
 }
 
+func getMetricFromData(data metricdata.Histogram[int64], name string) (*metricdata.HistogramDataPoint[int64], bool) {
+	for _, d := range data.DataPoints {
+		v, ok := d.Attributes.Value(semconv.RPCMethodKey)
+		if !ok {
+			return nil, false
+		}
+		if semconv.RPCMethod(name).Value == v {
+			return &d, true
+		}
+	}
+	return nil, false
+}
+
 type mockUICInvoker struct {
 	ctx context.Context
 }
@@ -867,24 +882,34 @@ func assertServerSpan(t *testing.T, wantSpanCode codes.Code, wantSpanStatusDescr
 func TestUnaryServerInterceptor(t *testing.T) {
 	sr := tracetest.NewSpanRecorder()
 	tp := trace.NewTracerProvider(trace.WithSpanProcessor(sr))
+	mr := metric.NewManualReader()
+	mp := metric.NewMeterProvider(metric.WithReader(mr))
 	usi := otelgrpc.UnaryServerInterceptor(
 		otelgrpc.WithTracerProvider(tp),
+		otelgrpc.WithMeterProvider(mp),
 	)
+
 	for _, check := range serverChecks {
 		name := check.grpcCode.String()
 		t.Run(name, func(t *testing.T) {
+			serviceName := "TestGrpcService"
+			methodName := serviceName + "/" + name
+			fullMethodName := "/" + methodName
 			// call the unary interceptor
 			grpcErr := status.Error(check.grpcCode, check.grpcCode.String())
 			handler := func(_ context.Context, _ interface{}) (interface{}, error) {
 				return nil, grpcErr
 			}
-			_, err := usi(context.Background(), &grpc_testing.SimpleRequest{}, &grpc.UnaryServerInfo{FullMethod: name}, handler)
+			_, err := usi(context.Background(), &grpc_testing.SimpleRequest{}, &grpc.UnaryServerInfo{FullMethod: fullMethodName}, handler)
 			assert.Equal(t, grpcErr, err)
 
 			// validate span
-			span, ok := getSpanFromRecorder(sr, name)
-			require.True(t, ok, "missing span %s", name)
+			span, ok := getSpanFromRecorder(sr, methodName)
+			require.True(t, ok, "missing span %s", methodName)
 			assertServerSpan(t, check.wantSpanCode, check.wantSpanStatusDescription, check.grpcCode, span)
+
+			// validate metric
+			checkManualReaderRecords(t, mr, serviceName, name, check.grpcCode)
 		})
 	}
 }
@@ -1069,3 +1094,22 @@ func TestStreamServerInterceptorEvents(t *testing.T) {
 		})
 	}
 }
+
+func checkManualReaderRecords(t *testing.T, reader metric.Reader, serviceName, name string, code grpc_codes.Code) {
+	rm := metricdata.ResourceMetrics{}
+	err := reader.Collect(context.Background(), &rm)
+	assert.NoError(t, err)
+	require.Len(t, rm.ScopeMetrics, 1)
+	require.Len(t, rm.ScopeMetrics[0].Metrics, 1)
+	require.IsType(t, rm.ScopeMetrics[0].Metrics[0].Data, metricdata.Histogram[int64]{})
+	data := rm.ScopeMetrics[0].Metrics[0].Data.(metricdata.Histogram[int64])
+	dpt, ok := getMetricFromData(data, name)
+	assert.True(t, ok)
+	attr := dpt.Attributes.ToSlice()
+	assert.ElementsMatch(t, []attribute.KeyValue{
+		semconv.RPCMethod(name),
+		semconv.RPCService(serviceName),
+		otelgrpc.RPCSystemGRPC,
+		otelgrpc.GRPCStatusCodeKey.Int64(int64(code)),
+	}, attr)
+}