Feat: add telemetry

telemetry/telemetry.go

@@ -0,0 +1,59 @@
+package telemetry
+
+import (
+	"context"
+	"log"
+	"net/http"
+
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/jaeger"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
+)
+
+// newJaegerExporter creates a new Jaeger exporter.
+func newJaegerExporter() (sdktrace.SpanExporter, error) {
+	return jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint("http://localhost:14268/api/traces")))
+}
+
+// NewTracerProvider creates a new tracer provider.
+func NewTracerProvider(exp sdktrace.SpanExporter) *sdktrace.TracerProvider {
+	res := resource.NewWithAttributes(
+		semconv.SchemaURL,
+		semconv.ServiceName("gralias"),
+		semconv.ServiceVersion("v0.1.0"),
+	)
+
+	tracerProvider := sdktrace.NewTracerProvider(
+		sdktrace.WithSampler(sdktrace.AlwaysSample()),
+		sdktrace.WithResource(res),
+		sdktrace.WithBatcher(exp),
+	)
+	return tracerProvider
+}
+
+// OtelMiddleware wraps the provided http.Handler with OpenTelemetry tracing.
+func OtelMiddleware(handler http.Handler) http.Handler {
+	return otelhttp.NewHandler(handler, "http.server")
+}
+
+func InitTracer() func() {
+	exp, err := newJaegerExporter()
+	if err != nil {
+		log.Fatalf("failed to create exporter: %v", err)
+	}
+
+	tp := NewTracerProvider(exp)
+	otel.SetTracerProvider(tp)
+
+	return func() {
+		if err := tp.Shutdown(context.Background()); err != nil {
+			log.Printf("Error shutting down tracer provider: %v", err)
+		}
+		if err := exp.Shutdown(context.Background()); err != nil {
+			log.Printf("Error shutting down exporter: %v", err)
+		}
+	}
+}