Tracing: Support multiple OTel propagators (#61199)

* tracing: Support multiple OTel propagators Signed-off-by: Dave Henderson <dave.henderson@grafana.com> * tracing: add TraceIDString method to fix up tests This method will be useful elsewhere if we want to log the trace ID. * improve propagation docs Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com> * doc style fix Signed-off-by: Dave Henderson <dave.henderson@grafana.com> * Use tracing.TraceIDFromContext instead of adding TraceIDString method Signed-off-by: Dave Henderson <dave.henderson@grafana.com> --------- Signed-off-by: Dave Henderson <dave.henderson@grafana.com> Co-authored-by: Bryan Boreham <bjboreham@gmail.com> Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>
2023-03-27 14:56:24 -04:00
parent a8adfe83b5
commit c0b5d2dfaa
4 changed files with 90 additions and 12 deletions
@@ -166,13 +166,17 @@ func (ots *Opentelemetry) initOTLPTracerProvider() (*tracesdk.TracerProvider, er
 		return nil, err
 	}

+	return initTracerProvider(exp, ots.customAttribs...)
+}
+
+func initTracerProvider(exp tracesdk.SpanExporter, customAttribs ...attribute.KeyValue) (*tracesdk.TracerProvider, error) {
 	res, err := resource.New(
 		context.Background(),
 		resource.WithAttributes(
 			semconv.ServiceNameKey.String("grafana"),
 			semconv.ServiceVersionKey.String(version.Version),
 		),
-		resource.WithAttributes(ots.customAttribs...),
+		resource.WithAttributes(customAttribs...),
 		resource.WithProcessRuntimeDescription(),
 		resource.WithTelemetrySDK(),
 	)
@@ -222,15 +226,34 @@ func (ots *Opentelemetry) initOpentelemetryTracer() error {
 		otel.SetTracerProvider(tp)
 	}

-	switch ots.propagation {
-	case w3cPropagator:
-		otel.SetTextMapPropagator(propagation.TraceContext{})
-	case jaegerPropagator:
-		otel.SetTextMapPropagator(jaegerpropagator.Jaeger{})
-	default:
-		otel.SetTextMapPropagator(propagation.TraceContext{})
+	propagators := []propagation.TextMapPropagator{}
+	for _, p := range strings.Split(ots.propagation, ",") {
+		switch p {
+		case w3cPropagator:
+			propagators = append(propagators, propagation.TraceContext{}, propagation.Baggage{})
+		case jaegerPropagator:
+			propagators = append(propagators, jaegerpropagator.Jaeger{})
+		case "":
+		default:
+			return fmt.Errorf("unsupported OpenTelemetry propagator: %q", p)
+		}
 	}
-	ots.tracerProvider = tp
+
+	switch len(propagators) {
+	case 0:
+		otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
+			propagation.TraceContext{}, propagation.Baggage{},
+		))
+	case 1:
+		otel.SetTextMapPropagator(propagators[0])
+	default:
+		otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagators...))
+	}
+
+	if ots.tracerProvider == nil {
+		ots.tracerProvider = tp
+	}
+
 	ots.tracer = otel.GetTracerProvider().Tracer("component-main")

 	return nil
@@ -1,7 +1,16 @@
 package tracing

+import (
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/sdk/trace/tracetest"
+)
+
 func InitializeTracerForTest() Tracer {
-	ots := &Opentelemetry{enabled: noopExporter}
+	exp := tracetest.NewInMemoryExporter()
+	tp, _ := initTracerProvider(exp)
+	otel.SetTracerProvider(tp)
+
+	ots := &Opentelemetry{propagation: "jaeger,w3c", tracerProvider: tp}
 	_ = ots.initOpentelemetryTracer()
 	return ots
 }