Log more verbose when DisruptionController doesn't start.

cmd/kube-controller-manager/app/policy.go

@@ -23,10 +23,19 @@ package app
 import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/kubernetes/pkg/controller/disruption"
+
+	"github.com/golang/glog"
 )
 
 func startDisruptionController(ctx ControllerContext) (bool, error) {
-	if !ctx.AvailableResources[schema.GroupVersionResource{Group: "policy", Version: "v1beta1", Resource: "poddisruptionbudgets"}] {
+	var group = "policy"
+	var version = "v1beta1"
+	var resource = "poddisruptionbudgets"
+
+	if !ctx.AvailableResources[schema.GroupVersionResource{Group: group, Version: version, Resource: resource}] {
+		glog.Infof(
+			"Refusing to start disruption because resource %q in group %q is not available.",
+			resource, group+"/"+version)
 		return false, nil
 	}
 	go disruption.NewDisruptionController(