K8s: Add tracing to apiserver startup (#95744)

Co-authored-by: Stephanie Hingtgen <stephanie.hingtgen@grafana.com>

pkg/modules/tracing/service.go

@@ -0,0 +1,35 @@
+package tracing
+
+import (
+	"context"
+
+	"github.com/grafana/dskit/services"
+	"github.com/grafana/grafana/pkg/semconv"
+	"go.opentelemetry.io/otel/trace"
+)
+
+var _ services.NamedService = &ServiceTracer{}
+
+// ServiceTracer wraps service.NamedService and adds tracing.
+// Currently it is limited to the starting -> running state transition.
+type ServiceTracer struct {
+	services.NamedService
+	tracer trace.Tracer
+}
+
+// NewServiceTracer creates a new ServiceTracer.
+func NewServiceTracer(tracerProvider trace.TracerProvider, service services.NamedService) *ServiceTracer {
+	tracer := tracerProvider.Tracer("pkg/modules/tracing")
+	return &ServiceTracer{NamedService: service, tracer: tracer}
+}
+
+func (s *ServiceTracer) StartAsync(ctx context.Context) error {
+	spanCtx, span := s.tracer.Start(ctx, "Service Start", trace.WithAttributes(semconv.GrafanaServiceName(s.ServiceName())))
+	go func() {
+		if err := s.AwaitRunning(spanCtx); err != nil {
+			span.RecordError(err)
+		}
+		span.End()
+	}()
+	return s.NamedService.StartAsync(ctx)
+}