Add utility for determining qos of a pod

pkg/kubelet/qos/util/qos.go

@@ -18,6 +18,7 @@ package util
 
 import (
 	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/util/sets"
 )
 
 const (
@@ -46,6 +47,25 @@ func isResourceBestEffort(container *api.Container, resource api.ResourceName) b
 	return !hasReq || req.Value() == 0
 }
 
+// GetPodQos returns the QoS class of a pod.
+// The QoS class of a pod is the lowest QoS class for each resource in each container.
+func GetPodQos(pod *api.Pod) string {
+	qosValues := sets.NewString()
+	for _, container := range pod.Spec.Containers {
+		qosPerResource := GetQoS(&container)
+		for _, qosValue := range qosPerResource {
+			qosValues.Insert(qosValue)
+		}
+	}
+	if qosValues.Has(BestEffort) {
+		return BestEffort
+	}
+	if qosValues.Has(Burstable) {
+		return Burstable
+	}
+	return Guaranteed
+}
+
 // GetQos returns a mapping of resource name to QoS class of a container
 func GetQoS(container *api.Container) map[api.ResourceName]string {
 	resourceToQoS := map[api.ResourceName]string{}