feat(http/fiber-middleware): trace propagation

helper.go

@@ -32,7 +32,7 @@ func AddBreadcrumbToContext(c context.Context, breadcrumb *sentry.Breadcrumb) {
 	}
 }
 
-func (o *Telemetry) Trace(ctx context.Context, op string, options []ConfigureSpanStartFunc, fn func(context.Context)) {
+func (o *Telemetry) Trace(ctx context.Context, op string, options []SpanStartOpt, fn func(context.Context)) {
 	tx := o.StartSpan(ctx, op, op, options...)
 	defer tx.End()
 

tracing.go

@@ -23,9 +23,9 @@ var (
 	tracerContextKey = contextKey{"tracer"}
 )
 
-type ConfigureSpanStartFunc = func(context.Context) (context.Context, []trace.SpanStartOption, []sentry.SpanOption)
+type SpanStartOpt = func(context.Context) (context.Context, []trace.SpanStartOption, []sentry.SpanOption)
 
-func (t *Telemetry) StartSpan(ctx context.Context, operation, name string, cfgs ...ConfigureSpanStartFunc) *Span {
+func (t *Telemetry) StartSpan(ctx context.Context, operation, name string, cfgs ...SpanStartOpt) *Span {
 	otelStartOpts := make([]trace.SpanStartOption, 0)
 	sentryStartOpts := []sentry.SpanOption{sentry.WithTransactionName(name), sentry.WithDescription(name)}
 
@@ -55,7 +55,7 @@ func (t *Telemetry) StartSpan(ctx context.Context, operation, name string, cfgs
 	}
 }
 
-func WithOtelOptions(opts ...trace.SpanStartOption) ConfigureSpanStartFunc {
+func WithOtelOptions(opts ...trace.SpanStartOption) SpanStartOpt {
 	return func(ctx context.Context) (context.Context, []trace.SpanStartOption, []sentry.SpanOption) {
 		return ctx, opts, []sentry.SpanOption{}
 	}
@@ -85,7 +85,7 @@ func (t *Telemetry) InjectIntoMap(ctx context.Context, m map[string]string) {
 	}
 }
 
-func (t *Telemetry) ContinueFromHeaders(h http.Header) ConfigureSpanStartFunc {
+func (t *Telemetry) ContinueFromHeaders(h http.Header) SpanStartOpt {
 	return func(ctx context.Context) (context.Context, []trace.SpanStartOption, []sentry.SpanOption) {
 		ctx = t.Propagator.Extract(ctx, propagation.HeaderCarrier(h))
 
@@ -98,7 +98,7 @@ func (t *Telemetry) ContinueFromHeaders(h http.Header) ConfigureSpanStartFunc {
 	}
 }
 
-func (t *Telemetry) ContinueFromMap(m map[string]string) ConfigureSpanStartFunc {
+func (t *Telemetry) ContinueFromMap(m map[string]string) SpanStartOpt {
 	return func(ctx context.Context) (context.Context, []trace.SpanStartOption, []sentry.SpanOption) {
 		ctx = t.Propagator.Extract(ctx, propagation.MapCarrier(m))
 
@@ -114,7 +114,7 @@ func (t *Telemetry) ContinueFromMap(m map[string]string) ConfigureSpanStartFunc
 	}
 }
 
-func WithOtelTracer(tracer trace.Tracer) ConfigureSpanStartFunc {
+func WithOtelTracer(tracer trace.Tracer) SpanStartOpt {
 	return func(ctx context.Context) (context.Context, []trace.SpanStartOption, []sentry.SpanOption) {
 		return context.WithValue(ctx, tracerContextKey, tracer), []trace.SpanStartOption{}, []sentry.SpanOption{}
 	}

unitelhttp/fiber_middleware.go

@@ -17,7 +17,6 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/propagation"
 	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 	"go.opentelemetry.io/otel/trace"
 )
@@ -32,6 +31,7 @@ type FiberMiddlewareConfig struct {
 	TraceResponseHeaders []string
 	IgnoredRoutes        []string
 	Logger               logr.Logger
+	TracePropagator      TracePropagator
 }
 
 var fiberMiddlewareConfigDefault = FiberMiddlewareConfig{
@@ -42,6 +42,7 @@ var fiberMiddlewareConfigDefault = FiberMiddlewareConfig{
 	TraceResponseHeaders: []string{},
 	IgnoredRoutes:        []string{},
 	Logger:               logr.Discard(),
+	TracePropagator:      PropagateNoTraces,
 }
 
 func FiberMiddleware(t *unitel.Telemetry, config ...FiberMiddlewareConfig) fiber.Handler {
@@ -61,6 +62,9 @@ func FiberMiddleware(t *unitel.Telemetry, config ...FiberMiddlewareConfig) fiber
 	if cfg.IgnoredRoutes == nil {
 		cfg.IgnoredRoutes = []string{}
 	}
+	if cfg.TracePropagator == nil {
+		cfg.TracePropagator = PropagateNoTraces
+	}
 
 	meter := t.MeterProvider.Meter(fiberMwClientID, metric.WithInstrumentationVersion(unitelutils.Version))
 	tracer := t.TracerProvider.Tracer(fiberMwClientID, trace.WithInstrumentationVersion(unitelutils.Version))
@@ -128,27 +132,21 @@ func FiberMiddleware(t *unitel.Telemetry, config ...FiberMiddlewareConfig) fiber
 			return err
 		}
 
-		// FIXME: Only extract the headers from trusted servers
+		opts := []unitel.SpanStartOpt{
-		ctx = t.Propagator.Extract(ctx, propagation.HeaderCarrier(stdRequest.Header))
+			unitel.WithOtelOptions(trace.WithSpanKind(trace.SpanKindServer)),
-
+			unitel.WithOtelTracer(tracer),
-		hub := sentry.CurrentHub().Clone()
+		}
-		if client := hub.Client(); client != nil {
+		shouldPropagate := cfg.TracePropagator(&stdRequest)
-			client.SetSDKIdentifier(fiberMwClientID)
+		if shouldPropagate {
+			opts = append(opts, t.ContinueFromHeaders(stdRequest.Header))
 		}
-
-		scope := hub.Scope()
-		scope.SetRequest(&stdRequest)
-		scope.SetRequestBody(utils.CopyBytes(c.Body()))
-		ctx = sentry.SetHubOnContext(ctx, hub)
 
 		description := fmt.Sprintf("%s %s", c.Method(), c.Path())
 		span := t.StartSpan(
 			ctx,
 			"http.server",
 			description,
-			unitel.WithOtelOptions(trace.WithSpanKind(trace.SpanKindServer)),
+			opts...,
-			unitel.WithOtelTracer(tracer),
-			t.ContinueFromHeaders(stdRequest.Header),
 		)
 		defer func() {
 			if err := recover(); err != nil {
@@ -172,11 +170,17 @@ func FiberMiddleware(t *unitel.Telemetry, config ...FiberMiddlewareConfig) fiber
 		defer span.End()
 
 		defer func() {
-			h := propagation.HeaderCarrier{}
+			if !shouldPropagate {
-			t.Propagator.Inject(ctx, h)
+				return
+			}
 
-			for _, k := range h.Keys() {
+			h := http.Header{}
-				c.Set(k, h.Get(k))
+			t.InjectIntoHeaders(ctx, h)
+
+			for k, v := range h {
+				for _, vv := range v {
+					c.Response().Header.Add(k, vv)
+				}
 			}
 		}()
 
@@ -187,6 +191,17 @@ func FiberMiddleware(t *unitel.Telemetry, config ...FiberMiddlewareConfig) fiber
 			}
 		}
 		ctx = span.Context()
+
+		hub := sentry.CurrentHub().Clone()
+		if client := hub.Client(); client != nil {
+			client.SetSDKIdentifier(fiberMwClientID)
+		}
+
+		scope := hub.Scope()
+		scope.SetRequest(&stdRequest)
+		scope.SetRequestBody(utils.CopyBytes(c.Body()))
+		ctx = sentry.SetHubOnContext(ctx, hub)
+
 		c.SetUserContext(ctx)
 
 		var err error = nil