Add custom attributes to tracing

Author: urdarinda

extra/redisotel/tracing.go

@@ -116,6 +116,7 @@ func (th *tracingHook) ProcessHook(hook redis.ProcessHook) redis.ProcessHook {
 		}
 
 		opts := th.spanOpts
+		opts = append(opts, trace.WithAttributes(th.conf.attrsFunc(ctx)...))
 		opts = append(opts, trace.WithAttributes(attrs...))
 
 		ctx, span := th.conf.tracer.Start(ctx, cmd.FullName(), opts...)
@@ -149,6 +150,7 @@ func (th *tracingHook) ProcessPipelineHook(
 		}
 
 		opts := th.spanOpts
+		opts = append(opts, trace.WithAttributes(th.conf.attrsFunc(ctx)...))
 		opts = append(opts, trace.WithAttributes(attrs...))
 
 		ctx, span := th.conf.tracer.Start(ctx, "redis.pipeline "+summary, opts...)

extra/redisotel/tracing_test.go

@@ -117,12 +117,23 @@ func TestTracingHook_DialHook(t *testing.T) {
 	}
 }
 
+func customAttrFn(ctx context.Context) []attribute.KeyValue {
+
+	attributes := make([]attribute.KeyValue, 0)
+
+	if method, ok := ctx.Value(semconv.RPCMethodKey).(string); ok {
+		attributes = append(attributes, semconv.RPCMethodKey.String(method))
+	}
+
+	return attributes
+}
 func TestTracingHook_ProcessHook(t *testing.T) {
 	imsb := tracetest.NewInMemoryExporter()
 	provider := sdktrace.NewTracerProvider(sdktrace.WithSyncer(imsb))
 	hook := newTracingHook(
 		"redis://localhost:6379",
 		WithTracerProvider(provider),
+		WithAttributesFunc(customAttrFn),
 	)
 
 	tests := []struct {
@@ -141,7 +152,9 @@ func TestTracingHook_ProcessHook(t *testing.T) {
 			processHook := hook.ProcessHook(func(ctx context.Context, cmd redis.Cmder) error {
 				return tt.errTest
 			})
-			assertEqual(t, tt.errTest, processHook(context.Background(), cmd))
+
+			ctx := context.WithValue(context.Background(), semconv.RPCMethodKey, "ping")
+			assertEqual(t, tt.errTest, processHook(ctx, cmd))
 			assertEqual(t, 1, len(imsb.GetSpans()))
 
 			spanData := imsb.GetSpans()[0]
@@ -151,6 +164,8 @@ func TestTracingHook_ProcessHook(t *testing.T) {
 			assertAttributeContains(t, spanData.Attributes, semconv.DBSystemRedis)
 			assertAttributeContains(t, spanData.Attributes, semconv.DBConnectionStringKey.String("redis://localhost:6379"))
 			assertAttributeContains(t, spanData.Attributes, semconv.DBStatementKey.String("ping"))
+			// check for custom attribute
+			assertAttributeContains(t, spanData.Attributes, semconv.RPCMethodKey.String("ping"))
 
 			if tt.errTest == nil {
 				assertEqual(t, 0, len(spanData.Events))