Add Server and Traceparent http headers

geoipapi.go

@@ -15,11 +15,13 @@ import (
 	"time"
 
 	"github.com/oschwald/geoip2-golang"
-	"go.ntppool.org/common/logger"
-	"go.ntppool.org/common/tracing"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
+
+	"go.ntppool.org/common/logger"
+	"go.ntppool.org/common/tracing"
+	"go.ntppool.org/common/version"
 )
 
 type geoType uint8
@@ -86,12 +88,24 @@ func setupHTTP(ctx context.Context) error {
 	mux.HandleFunc("/api/json", handleJSON)
 	mux.HandleFunc("/healthz", handleHealth)
 
+	versionHandler := func(next http.Handler) http.Handler {
+		vinfo := version.VersionInfo()
+		v := "geoipapi/" + vinfo.Version + "+" + vinfo.GitRevShort
+		return http.HandlerFunc(
+			func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Set("Server", v)
+				span := trace.SpanFromContext(r.Context())
+				w.Header().Set("Traceparent", span.SpanContext().TraceID().String())
+				next.ServeHTTP(w, r)
+			})
+	}
+
 	srv := &http.Server{
 		Addr:         ":8009",
 		BaseContext:  func(_ net.Listener) context.Context { return ctx },
 		ReadTimeout:  time.Second,
 		WriteTimeout: 10 * time.Second,
-		Handler:      otelhttp.NewHandler(mux, "geoipapi"),
+		Handler:      otelhttp.NewHandler(versionHandler(mux), "geoipapi"),
 	}
 	srvErr := make(chan error, 1)
 	go func() {