TODO: move predicate check into a pod admitter

pkg/kubelet/kubelet.go

@@ -102,7 +102,6 @@ import (
 	"k8s.io/kubernetes/pkg/volume/util/volumehelper"
 	"k8s.io/kubernetes/pkg/watch"
 	"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm/predicates"
-	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
 	"k8s.io/kubernetes/third_party/forked/golang/expansion"
 )
 
@@ -739,7 +738,7 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 
 	klet.appArmorValidator = apparmor.NewValidator(kubeCfg.ContainerRuntime)
 	klet.AddPodAdmitHandler(lifecycle.NewAppArmorAdmitHandler(klet.appArmorValidator))
-
+	klet.AddPodAdmitHandler(lifecycle.NewPredicateAdmitHandler(klet.getNodeAnyWay))
 	// apply functional Option's
 	for _, opt := range kubeDeps.Options {
 		opt(klet)
@@ -2155,15 +2154,9 @@ func (kl *Kubelet) rejectPod(pod *api.Pod, reason, message string) {
 // can be admitted, a brief single-word reason and a message explaining why
 // the pod cannot be admitted.
 func (kl *Kubelet) canAdmitPod(pods []*api.Pod, pod *api.Pod) (bool, string, string) {
-	node, err := kl.getNodeAnyWay()
-	if err != nil {
-		glog.Errorf("Cannot get Node info: %v", err)
-		return false, "InvalidNodeInfo", "Kubelet cannot get node info."
-	}
 
 	// the kubelet will invoke each pod admit handler in sequence
 	// if any handler rejects, the pod is rejected.
-	// TODO: move predicate check into a pod admitter
 	// TODO: move out of disk check into a pod admitter
 	// TODO: out of resource eviction should have a pod admitter call-out
 	attrs := &lifecycle.PodAdmitAttributes{Pod: pod, OtherPods: pods}
@@ -2172,44 +2165,6 @@ func (kl *Kubelet) canAdmitPod(pods []*api.Pod, pod *api.Pod) (bool, string, str
 			return false, result.Reason, result.Message
 		}
 	}
-	nodeInfo := schedulercache.NewNodeInfo(pods...)
-	nodeInfo.SetNode(node)
-	fit, reasons, err := predicates.GeneralPredicates(pod, nil, nodeInfo)
-	if err != nil {
-		message := fmt.Sprintf("GeneralPredicates failed due to %v, which is unexpected.", err)
-		glog.Warningf("Failed to admit pod %v - %s", format.Pod(pod), message)
-		return fit, "UnexpectedError", message
-	}
-	if !fit {
-		var reason string
-		var message string
-		if len(reasons) == 0 {
-			message = fmt.Sprint("GeneralPredicates failed due to unknown reason, which is unexpected.")
-			glog.Warningf("Failed to admit pod %v - %s", format.Pod(pod), message)
-			return fit, "UnknownReason", message
-		}
-		// If there are failed predicates, we only return the first one as a reason.
-		r := reasons[0]
-		switch re := r.(type) {
-		case *predicates.PredicateFailureError:
-			reason = re.PredicateName
-			message = re.Error()
-			glog.V(2).Infof("Predicate failed on Pod: %v, for reason: %v", format.Pod(pod), message)
-		case *predicates.InsufficientResourceError:
-			reason = fmt.Sprintf("OutOf%s", re.ResourceName)
-			message := re.Error()
-			glog.V(2).Infof("Predicate failed on Pod: %v, for reason: %v", format.Pod(pod), message)
-		case *predicates.FailureReason:
-			reason = re.GetReason()
-			message = fmt.Sprintf("Failure: %s", re.GetReason())
-			glog.V(2).Infof("Predicate failed on Pod: %v, for reason: %v", format.Pod(pod), message)
-		default:
-			reason = "UnexpectedPredicateFailureType"
-			message := fmt.Sprintf("GeneralPredicates failed due to %v, which is unexpected.", r)
-			glog.Warningf("Failed to admit pod %v - %s", format.Pod(pod), message)
-		}
-		return fit, reason, message
-	}
 	// TODO: When disk space scheduling is implemented (#11976), remove the out-of-disk check here and
 	// add the disk space predicate to predicates.GeneralPredicates.
 	if kl.isOutOfDisk() {

pkg/kubelet/kubelet_test.go

@@ -231,6 +231,8 @@ func newTestKubeletWithImageList(
 
 	kubelet.evictionManager = evictionManager
 	kubelet.AddPodAdmitHandler(evictionAdmitHandler)
+	// Add this as cleanup predicate pod admitter
+	kubelet.AddPodAdmitHandler(lifecycle.NewPredicateAdmitHandler(kubelet.getNodeAnyWay))
 
 	plug := &volumetest.FakeVolumePlugin{PluginName: "fake", Host: nil}
 	kubelet.volumePluginMgr, err =

pkg/kubelet/lifecycle/predicate.go

+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package lifecycle
+
+import (
+	"fmt"
+
+	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/kubelet/util/format"
+	"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm/predicates"
+	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
+)
+
+type getNodeAnyWayFuncType func() (*api.Node, error)
+type predicateAdmitHandler struct {
+	getNodeAnyWayFunc getNodeAnyWayFuncType
+}
+
+var _ PodAdmitHandler = &predicateAdmitHandler{}
+
+func NewPredicateAdmitHandler(getNodeAnyWayFunc getNodeAnyWayFuncType) *predicateAdmitHandler {
+	return &predicateAdmitHandler{
+		getNodeAnyWayFunc,
+	}
+}
+
+func (w *predicateAdmitHandler) Admit(attrs *PodAdmitAttributes) PodAdmitResult {
+	node, err := w.getNodeAnyWayFunc()
+	if err != nil {
+		glog.Errorf("Cannot get Node info: %v", err)
+		return PodAdmitResult{
+			Admit:   false,
+			Reason:  "InvalidNodeInfo",
+			Message: "Kubelet cannot get node info.",
+		}
+	}
+	pod := attrs.Pod
+	pods := attrs.OtherPods
+	nodeInfo := schedulercache.NewNodeInfo(pods...)
+	nodeInfo.SetNode(node)
+	fit, reasons, err := predicates.GeneralPredicates(pod, nil, nodeInfo)
+	if err != nil {
+		message := fmt.Sprintf("GeneralPredicates failed due to %v, which is unexpected.", err)
+		glog.Warningf("Failed to admit pod %v - %s", format.Pod(pod), message)
+		return PodAdmitResult{
+			Admit:   fit,
+			Reason:  "UnexpectedError",
+			Message: message,
+		}
+	}
+	if !fit {
+		var reason string
+		var message string
+		if len(reasons) == 0 {
+			message = fmt.Sprint("GeneralPredicates failed due to unknown reason, which is unexpected.")
+			glog.Warningf("Failed to admit pod %v - %s", format.Pod(pod), message)
+			return PodAdmitResult{
+				Admit:   fit,
+				Reason:  "UnknownReason",
+				Message: message,
+			}
+		}
+		// If there are failed predicates, we only return the first one as a reason.
+		r := reasons[0]
+		switch re := r.(type) {
+		case *predicates.PredicateFailureError:
+			reason = re.PredicateName
+			message = re.Error()
+			glog.V(2).Infof("Predicate failed on Pod: %v, for reason: %v", format.Pod(pod), message)
+		case *predicates.InsufficientResourceError:
+			reason = fmt.Sprintf("OutOf%s", re.ResourceName)
+			message := re.Error()
+			glog.V(2).Infof("Predicate failed on Pod: %v, for reason: %v", format.Pod(pod), message)
+		case *predicates.FailureReason:
+			reason = re.GetReason()
+			message = fmt.Sprintf("Failure: %s", re.GetReason())
+			glog.V(2).Infof("Predicate failed on Pod: %v, for reason: %v", format.Pod(pod), message)
+		default:
+			reason = "UnexpectedPredicateFailureType"
+			message := fmt.Sprintf("GeneralPredicates failed due to %v, which is unexpected.", r)
+			glog.Warningf("Failed to admit pod %v - %s", format.Pod(pod), message)
+		}
+		return PodAdmitResult{
+			Admit:   fit,
+			Reason:  reason,
+			Message: message,
+		}
+	}
+	return PodAdmitResult{
+		Admit: true,
+	}
+}