Fix missing requestID due to empty traceID

internal/rpc/server/server.go

@@ -7,6 +7,8 @@ import (
 	"log"
 	"net"
 
+	"github.com/chain4travel/camino-messenger-bot/internal/tracing"
+
 	"buf.build/gen/go/chain4travel/camino-messenger-protocol/grpc/go/cmp/services/activity/v1alpha/activityv1alphagrpc"
 	"buf.build/gen/go/chain4travel/camino-messenger-protocol/grpc/go/cmp/services/book/v1alpha/bookv1alphagrpc"
 	bookv1alpha "buf.build/gen/go/chain4travel/camino-messenger-protocol/protocolbuffers/go/cmp/services/book/v1alpha"
@@ -59,7 +61,7 @@ type server struct {
 	grpcServer      *grpc.Server
 	cfg             *config.RPCServerConfig
 	logger          *zap.SugaredLogger
-	tracer          trace.Tracer
+	tracer          tracing.Tracer
 	processor       messaging.Processor
 	serviceRegistry *messaging.ServiceRegistry
 }
@@ -68,7 +70,7 @@ func (s *server) Checkpoint() string {
 	return "request-gateway"
 }
 
-func NewServer(cfg *config.RPCServerConfig, logger *zap.SugaredLogger, tracer trace.Tracer, processor messaging.Processor, serviceRegistry *messaging.ServiceRegistry) *server {
+func NewServer(cfg *config.RPCServerConfig, logger *zap.SugaredLogger, tracer tracing.Tracer, processor messaging.Processor, serviceRegistry *messaging.ServiceRegistry) *server {
 	var opts []grpc.ServerOption
 	if cfg.Unencrypted {
 		logger.Warn("Running gRPC server without TLS!")
@@ -182,7 +184,7 @@ func (s *server) processInternalRequest(ctx context.Context, requestType messagi
 func (s *server) processExternalRequest(ctx context.Context, requestType messaging.MessageType, request *messaging.RequestContent) (messaging.ResponseContent, error) {
 	ctx, span := s.tracer.Start(ctx, "server.processExternalRequest", trace.WithSpanKind(trace.SpanKindServer))
 	defer span.End()
-	err, md := s.processMetadata(ctx, span.SpanContext().TraceID())
+	err, md := s.processMetadata(ctx, s.tracer.TraceIDForSpan(span))
 	if err != nil {
 		return messaging.ResponseContent{}, fmt.Errorf("error processing metadata: %v", err)
 	}

internal/tracing/nooptracer.go

@@ -7,6 +7,8 @@ package tracing
 
 import (
 	"context"
+	"crypto/rand"
+
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -19,9 +21,18 @@ type noopTracer struct {
 func NewNoOpTracer() (Tracer, error) {
 	return &noopTracer{tp: trace.NewNoopTracerProvider()}, nil
 }
+
 func (n *noopTracer) Start(ctx context.Context, spanName string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {
 	return n.tp.Tracer("").Start(ctx, spanName, opts...)
 }
+
 func (n *noopTracer) Shutdown() error {
 	return nil // nothing to do here
 }
+
+// TraceIDForSpan returns a random trace ID in tha case of noopTracer. A non-empty trace ID is required for the span to be exported.
+func (n *noopTracer) TraceIDForSpan(trace.Span) trace.TraceID {
+	traceID := trace.TraceID{}
+	rand.Read(traceID[:])
+	return traceID
+}

internal/tracing/nooptracer_test.go

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2024, Chain4Travel AG. All rights reserved.
+ * See the file LICENSE for licensing terms.
+ */
+
+package tracing
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.opentelemetry.io/otel/trace"
+)
+
+func TestNoopTraceIDForSpan(t *testing.T) {
+	tracer, err := NewNoOpTracer()
+	require.NoError(t, err)
+	_, span := tracer.Start(context.Background(), "test")
+	got := tracer.TraceIDForSpan(span)
+	emptyTraceID := trace.TraceID{}
+	require.NotEqual(t, emptyTraceID, got)
+}

internal/tracing/tracer.go

@@ -7,13 +7,14 @@ package tracing
 
 import (
 	"context"
+	"time"
+
 	"github.com/chain4travel/camino-messenger-bot/config"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/sdk/resource"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
 	"go.opentelemetry.io/otel/trace"
-	"time"
 )
 
 const tracerProviderShutdownTimeout = exportTimeout + 5*time.Second
@@ -22,6 +23,7 @@ var _ Tracer = (*tracer)(nil)
 
 type Tracer interface {
 	trace.Tracer
+	TraceIDForSpan(trace.Span) trace.TraceID // TraceIDForSpan returns the trace ID of the given span.
 	Shutdown() error
 }
 
@@ -38,6 +40,10 @@ func (t *tracer) Shutdown() error {
 	return t.tp.Shutdown(ctx)
 }
 
+func (t *tracer) TraceIDForSpan(span trace.Span) trace.TraceID {
+	return span.SpanContext().TraceID()
+}
+
 func NewTracer(tracingConfig *config.TracingConfig, name string) (Tracer, error) {
 	exporter, err := newExporter(tracingConfig)
 	if err != nil {

internal/tracing/tracer_test.go

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2024, Chain4Travel AG. All rights reserved.
+ * See the file LICENSE for licensing terms.
+ */
+
+package tracing
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestTraceIDForSpan(t *testing.T) {
+	tracer, err := NewNoOpTracer()
+	require.NoError(t, err)
+	_, span := tracer.Start(context.Background(), "test")
+	got := tracer.TraceIDForSpan(span)
+	require.NotEqual(t, span.SpanContext().TraceID(), got)
+}