start reworking exporters to be more composable

pkg/fiber_tracing/fiber_tracing.go

@@ -0,0 +1,73 @@
+package fiber_tracing
+
+import (
+	"context"
+	"log"
+
+	"github.com/gofiber/fiber/v2"
+	fiberOpentelemetry "github.com/psmarcin/fiber-opentelemetry/pkg/fiber-otel"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/resource"
+	trc "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.25.0"
+	trace "go.opentelemetry.io/otel/trace"
+)
+
+var (
+	TracingError error = nil
+	TP           trc.TracerProvider
+)
+
+type Config struct {
+	AppName         string
+	Version         string
+	ServiceProvider string
+	Exporter        trc.SpanExporter
+}
+
+func newResource(config Config) *resource.Resource {
+	r := resource.NewWithAttributes(
+		semconv.SchemaURL,
+		semconv.ServiceNameKey.String(config.AppName),
+		semconv.ServiceVersionKey.String(config.Version),
+		attribute.String("service.provider", config.ServiceProvider),
+	)
+	return r
+}
+
+func NewMiddleware(config Config) func(*fiber.Ctx) error {
+	var tracerProviders []trc.TracerProviderOption
+
+	tracerProviders = append(tracerProviders, trc.WithBatcher(config.Exporter))
+	tracerProviders = append(tracerProviders, trc.WithResource(newResource(config)))
+
+	TP = *trc.NewTracerProvider(tracerProviders...)
+
+	otel.SetTracerProvider(&TP)
+	otel.SetErrorHandler(otel.ErrorHandlerFunc(func(err error) {
+		if err != TracingError {
+			TracingError = err
+			log.Println(err)
+		}
+	}))
+
+	tracer := TP.Tracer("_maal-fiber-otel_")
+
+	return fiberOpentelemetry.New(
+		fiberOpentelemetry.Config{
+			Tracer:   tracer,
+			SpanName: "{{ .Method }} {{ .Path }}",
+			TracerStartAttributes: []trace.SpanStartOption{
+				trace.WithSpanKind(trace.SpanKindServer),
+				trace.WithNewRoot(),
+			},
+		},
+	)
+}
+
+func ShutdownTracer() {
+	if err := TP.Shutdown(context.Background()); err != nil {
+		log.Fatal(err)
+	}
+}