From 247982bda05f4a1a1fb96961096e77bf34cd80e1 Mon Sep 17 00:00:00 2001
From: Zach Montoya <zach.montoya@datadoghq.com>
Date: Fri, 17 Jan 2025 16:14:34 -0800
Subject: [PATCH] Run tests against Go. This one differs specifically because
 we don't run automatic instrumentation in the typical dd-trace-go setup, so
 the user is expected to set the default propagator. This test simply tests
 that using the API `otel.GetTextMapPropagator()` works as expected

---
 manifests/golang.yml                          |   3 +
 .../build/docker/golang/app/net-http/main.go  | 112 ++++++++++++++++++
 2 files changed, 115 insertions(+)

diff --git a/manifests/golang.yml b/manifests/golang.yml
index 49cbe414b1..57bd0f6292 100644
--- a/manifests/golang.yml
+++ b/manifests/golang.yml
@@ -509,6 +509,9 @@ tests/:
       Test_AWS_API_Gateway_Inferred_Span_Creation: missing_feature
     test_otel_drop_in.py:
       Test_Otel_Drop_In: missing_feature
+      Test_Otel_Drop_In_Default_Propagator:
+        '*': irrelevant
+        net-http: v1.70.1
   parametric/:
     test_config_consistency.py:
       Test_Config_Dogstatsd: missing_feature
diff --git a/utils/build/docker/golang/app/net-http/main.go b/utils/build/docker/golang/app/net-http/main.go
index ebbfd3dff2..497d05f01e 100644
--- a/utils/build/docker/golang/app/net-http/main.go
+++ b/utils/build/docker/golang/app/net-http/main.go
@@ -32,6 +32,7 @@ import (
 	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
 	oteltrace "go.opentelemetry.io/otel/trace"
+	otelbaggage "go.opentelemetry.io/otel/baggage"
 
 	"gopkg.in/DataDog/dd-trace-go.v1/appsec"
 	httptrace "gopkg.in/DataDog/dd-trace-go.v1/contrib/net/http"
@@ -537,6 +538,79 @@ func main() {
 		w.Write([]byte("ok"))
 	})
 
+	mux.HandleFunc("/otel_drop_in_default_propagator_extract", func(w http.ResponseWriter, r *http.Request) {
+		// Differing from other languages, the user must set the text map propagator because dd-trace-go
+		// doesn't automatically instrument at runtime (not including Orchestrion)
+		otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
+
+		httpCarrier := HttpCarrier{header: r.Header}
+
+		propagator := otel.GetTextMapPropagator()
+		ctx := propagator.Extract(r.Context(), httpCarrier)
+
+		spanContext := oteltrace.SpanContextFromContext(ctx)
+		baggage := otelbaggage.FromContext(ctx)
+		
+		base := 16
+		bitSize := 64
+		result := make(map[string]any, 4)
+
+		num, err := strconv.ParseInt(spanContext.TraceID().String()[16:], base, bitSize)
+		if err == nil {
+			result["trace_id"] = num
+		}
+
+		num, err = strconv.ParseInt(spanContext.SpanID().String(), base, bitSize)
+		if err == nil {
+			result["span_id"] = num
+		}
+
+		result["tracestate"] = spanContext.TraceState().String()
+		result["baggage"] = baggage.String()
+		
+		jsonData, err := json.Marshal(result)
+		if err != nil {
+			w.WriteHeader(422)
+			w.Write([]byte("failed to convert carrier to JSON"))
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(jsonData)
+	})
+
+	mux.HandleFunc("/otel_drop_in_default_propagator_inject", func(w http.ResponseWriter, r *http.Request) {
+		// Differing from other languages, the user must set the text map propagator because dd-trace-go
+		// doesn't automatically instrument at runtime (not including Orchestrion)
+		otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
+
+		ctx := context.Background()
+		p := ddotel.NewTracerProvider()
+		tracer := p.Tracer("")
+		otel.SetTracerProvider(p)
+
+		_, span := tracer.Start(ddotel.ContextWithStartOptions(ctx), "main")
+		newCtx := oteltrace.ContextWithSpan(ctx, span)
+
+		propagator := otel.GetTextMapPropagator()
+		mapCarrier := make(MapCarrier)
+		propagator.Inject(newCtx, mapCarrier)
+
+		jsonData, err := json.Marshal(mapCarrier)
+		span.End()
+
+		if err != nil {
+			w.WriteHeader(422)
+			w.Write([]byte("failed to convert carrier to JSON"))
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		w.Write(jsonData)
+	})
+
 	mux.HandleFunc("/session/new", func(w http.ResponseWriter, r *http.Request) {
 		sessionID := strconv.Itoa(rand.Int())
 		w.Header().Add("Set-Cookie", "session="+sessionID+"; Path=/; Max-Age=3600; Secure; HttpOnly")
@@ -598,6 +672,44 @@ func (c carrier) ForeachKey(handler func(key, val string) error) error {
 	return nil
 }
 
+type MapCarrier map[string]string
+
+func (c MapCarrier) Get(key string) string {
+	return c[key]
+}
+
+func (c MapCarrier) Set(key, val string) {
+	c[key] = val
+}
+
+func (c MapCarrier) Keys() []string {
+	keys := make([]string, 0, len(c))
+	for k := range c {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+type HttpCarrier struct {
+	header http.Header
+}
+
+func (c HttpCarrier) Get(key string) string {
+	return c.header.Get(key)
+}
+
+func (c HttpCarrier) Set(key, val string) {
+	c.header.Set(key, val)
+}
+
+func (c HttpCarrier) Keys() []string {
+	keys := make([]string, 0, len(c.header))
+	for k := range c.header {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
 func write(w http.ResponseWriter, r *http.Request, d []byte) {
 	span, _ := ddtracer.StartSpanFromContext(r.Context(), "child.span")
 	defer span.Finish()