kubernetes/cmd/kube-controller-manager/app/autoscaling.go

func newHorizontalPodAutoscalerControllerDescriptor() *ControllerDescriptor { … }

func startHorizontalPodAutoscalerControllerWithRESTClient(ctx context.Context, controllerContext ControllerContext, controllerName string) (controller.Interface, bool, error) { … }

func startHPAControllerWithMetricsClient(ctx context.Context, controllerContext ControllerContext, metricsClient metrics.MetricsClient) (controller.Interface, bool, error) { … }