/*
Copyright 2015 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 e2e

import (
	"fmt"
	"reflect"
	"strings"
	"time"

	apierrs "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/v1"
	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
	extensionsinternal "k8s.io/kubernetes/pkg/apis/extensions"
	extensions "k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
	"k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
	"k8s.io/kubernetes/pkg/controller"
	"k8s.io/kubernetes/pkg/controller/daemon"
	"k8s.io/kubernetes/pkg/kubectl"
	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
	"k8s.io/kubernetes/test/e2e/framework"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

const (
	// this should not be a multiple of 5, because node status updates
	// every 5 seconds. See https://github.com/kubernetes/kubernetes/pull/14915.
	dsRetryPeriod  = 1 * time.Second
	dsRetryTimeout = 5 * time.Minute

	daemonsetLabelPrefix = "daemonset-"
	daemonsetNameLabel   = daemonsetLabelPrefix + "name"
	daemonsetColorLabel  = daemonsetLabelPrefix + "color"
)

// This test must be run in serial because it assumes the Daemon Set pods will
// always get scheduled.  If we run other tests in parallel, this may not
// happen.  In the future, running in parallel may work if we have an eviction
// model which lets the DS controller kick out other pods to make room.
// See http://issues.k8s.io/21767 for more details
var _ = framework.KubeDescribe("Daemon set [Serial]", func() {
	var f *framework.Framework

	AfterEach(func() {
		// Clean up
		daemonsets, err := f.ClientSet.Extensions().DaemonSets(f.Namespace.Name).List(metav1.ListOptions{})
		Expect(err).NotTo(HaveOccurred(), "unable to dump DaemonSets")
		if daemonsets != nil && len(daemonsets.Items) > 0 {
			for _, ds := range daemonsets.Items {
				By(fmt.Sprintf("Deleting DaemonSet %q with reaper", ds.Name))
				dsReaper, err := kubectl.ReaperFor(extensionsinternal.Kind("DaemonSet"), f.InternalClientset)
				Expect(err).NotTo(HaveOccurred())
				err = dsReaper.Stop(f.Namespace.Name, ds.Name, 0, nil)
				Expect(err).NotTo(HaveOccurred())
				err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnNoNodes(f, &ds))
				Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to be reaped")
			}
		}
		if daemonsets, err := f.ClientSet.Extensions().DaemonSets(f.Namespace.Name).List(metav1.ListOptions{}); err == nil {
			framework.Logf("daemonset: %s", runtime.EncodeOrDie(api.Codecs.LegacyCodec(api.Registry.EnabledVersions()...), daemonsets))
		} else {
			framework.Logf("unable to dump daemonsets: %v", err)
		}
		if pods, err := f.ClientSet.Core().Pods(f.Namespace.Name).List(metav1.ListOptions{}); err == nil {
			framework.Logf("pods: %s", runtime.EncodeOrDie(api.Codecs.LegacyCodec(api.Registry.EnabledVersions()...), pods))
		} else {
			framework.Logf("unable to dump pods: %v", err)
		}
		err = clearDaemonSetNodeLabels(f.ClientSet)
		Expect(err).NotTo(HaveOccurred())
	})

	f = framework.NewDefaultFramework("daemonsets")

	image := framework.ServeHostnameImage
	dsName := "daemon-set"

	var ns string
	var c clientset.Interface

	BeforeEach(func() {
		ns = f.Namespace.Name

		c = f.ClientSet
		err := clearDaemonSetNodeLabels(c)
		Expect(err).NotTo(HaveOccurred())
	})

	It("should run and stop simple daemon", func() {
		label := map[string]string{daemonsetNameLabel: dsName}

		By(fmt.Sprintf("Creating simple DaemonSet %q", dsName))
		ds, err := c.Extensions().DaemonSets(ns).Create(newDaemonSet(dsName, image, label))
		Expect(err).NotTo(HaveOccurred())

		By("Check that daemon pods launch on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")
		err = checkDaemonStatus(f, dsName)
		Expect(err).NotTo(HaveOccurred())

		By("Stop a daemon pod, check that the daemon pod is revived.")
		podList := listDaemonPods(c, ns, label)
		pod := podList.Items[0]
		err = c.Core().Pods(ns).Delete(pod.Name, nil)
		Expect(err).NotTo(HaveOccurred())
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to revive")
	})

	It("should run and stop complex daemon", func() {
		complexLabel := map[string]string{daemonsetNameLabel: dsName}
		nodeSelector := map[string]string{daemonsetColorLabel: "blue"}
		framework.Logf("Creating daemon %q with a node selector", dsName)
		ds := newDaemonSet(dsName, image, complexLabel)
		ds.Spec.Template.Spec.NodeSelector = nodeSelector
		ds, err := c.Extensions().DaemonSets(ns).Create(ds)
		Expect(err).NotTo(HaveOccurred())

		By("Initially, daemon pods should not be running on any nodes.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnNoNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pods to be running on no nodes")

		By("Change node label to blue, check that daemon pod is launched.")
		nodeList := framework.GetReadySchedulableNodesOrDie(f.ClientSet)
		Expect(len(nodeList.Items)).To(BeNumerically(">", 0))
		newNode, err := setDaemonSetNodeLabels(c, nodeList.Items[0].Name, nodeSelector)
		Expect(err).NotTo(HaveOccurred(), "error setting labels on node")
		daemonSetLabels, _ := separateDaemonSetNodeLabels(newNode.Labels)
		Expect(len(daemonSetLabels)).To(Equal(1))
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonPodOnNodes(f, ds, []string{newNode.Name}))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pods to be running on new nodes")
		err = checkDaemonStatus(f, dsName)
		Expect(err).NotTo(HaveOccurred())

		By("Update the node label to green, and wait for daemons to be unscheduled")
		nodeSelector[daemonsetColorLabel] = "green"
		greenNode, err := setDaemonSetNodeLabels(c, nodeList.Items[0].Name, nodeSelector)
		Expect(err).NotTo(HaveOccurred(), "error removing labels on node")
		Expect(wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnNoNodes(f, ds))).
			NotTo(HaveOccurred(), "error waiting for daemon pod to not be running on nodes")

		By("Update DaemonSet node selector to green, and change its update strategy to RollingUpdate")
		patch := fmt.Sprintf(`{"spec":{"template":{"spec":{"nodeSelector":{"%s":"%s"}}},"updateStrategy":{"type":"RollingUpdate"}}}`,
			daemonsetColorLabel, greenNode.Labels[daemonsetColorLabel])
		ds, err = c.Extensions().DaemonSets(ns).Patch(dsName, types.StrategicMergePatchType, []byte(patch))
		Expect(err).NotTo(HaveOccurred(), "error patching daemon set")
		daemonSetLabels, _ = separateDaemonSetNodeLabels(greenNode.Labels)
		Expect(len(daemonSetLabels)).To(Equal(1))
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonPodOnNodes(f, ds, []string{greenNode.Name}))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pods to be running on new nodes")
		err = checkDaemonStatus(f, dsName)
		Expect(err).NotTo(HaveOccurred())
	})

	It("should run and stop complex daemon with node affinity", func() {
		complexLabel := map[string]string{daemonsetNameLabel: dsName}
		nodeSelector := map[string]string{daemonsetColorLabel: "blue"}
		framework.Logf("Creating daemon %q with a node affinity", dsName)
		ds := newDaemonSet(dsName, image, complexLabel)
		ds.Spec.Template.Spec.Affinity = &v1.Affinity{
			NodeAffinity: &v1.NodeAffinity{
				RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
					NodeSelectorTerms: []v1.NodeSelectorTerm{
						{
							MatchExpressions: []v1.NodeSelectorRequirement{
								{
									Key:      daemonsetColorLabel,
									Operator: v1.NodeSelectorOpIn,
									Values:   []string{nodeSelector[daemonsetColorLabel]},
								},
							},
						},
					},
				},
			},
		}
		ds, err := c.Extensions().DaemonSets(ns).Create(ds)
		Expect(err).NotTo(HaveOccurred())

		By("Initially, daemon pods should not be running on any nodes.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnNoNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pods to be running on no nodes")

		By("Change node label to blue, check that daemon pod is launched.")
		nodeList := framework.GetReadySchedulableNodesOrDie(f.ClientSet)
		Expect(len(nodeList.Items)).To(BeNumerically(">", 0))
		newNode, err := setDaemonSetNodeLabels(c, nodeList.Items[0].Name, nodeSelector)
		Expect(err).NotTo(HaveOccurred(), "error setting labels on node")
		daemonSetLabels, _ := separateDaemonSetNodeLabels(newNode.Labels)
		Expect(len(daemonSetLabels)).To(Equal(1))
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonPodOnNodes(f, ds, []string{newNode.Name}))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pods to be running on new nodes")
		err = checkDaemonStatus(f, dsName)
		Expect(err).NotTo(HaveOccurred())

		By("Remove the node label and wait for daemons to be unscheduled")
		_, err = setDaemonSetNodeLabels(c, nodeList.Items[0].Name, map[string]string{})
		Expect(err).NotTo(HaveOccurred(), "error removing labels on node")
		Expect(wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnNoNodes(f, ds))).
			NotTo(HaveOccurred(), "error waiting for daemon pod to not be running on nodes")
	})

	It("should retry creating failed daemon pods", func() {
		label := map[string]string{daemonsetNameLabel: dsName}

		By(fmt.Sprintf("Creating a simple DaemonSet %q", dsName))
		ds, err := c.Extensions().DaemonSets(ns).Create(newDaemonSet(dsName, image, label))
		Expect(err).NotTo(HaveOccurred())

		By("Check that daemon pods launch on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")
		err = checkDaemonStatus(f, dsName)
		Expect(err).NotTo(HaveOccurred())

		By("Set a daemon pod's phase to 'Failed', check that the daemon pod is revived.")
		podList := listDaemonPods(c, ns, label)
		pod := podList.Items[0]
		pod.ResourceVersion = ""
		pod.Status.Phase = v1.PodFailed
		_, err = c.Core().Pods(ns).UpdateStatus(&pod)
		Expect(err).NotTo(HaveOccurred(), "error failing a daemon pod")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to revive")
	})

	It("Should not update pod when spec was updated and update strategy is OnDelete", func() {
		label := map[string]string{daemonsetNameLabel: dsName}

		framework.Logf("Creating simple daemon set %s", dsName)
		ds, err := c.Extensions().DaemonSets(ns).Create(newDaemonSet(dsName, image, label))
		Expect(err).NotTo(HaveOccurred())
		Expect(ds.Spec.TemplateGeneration).To(Equal(int64(1)))

		By("Check that daemon pods launch on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")

		By("Make sure all daemon pods have correct template generation 1")
		err = checkDaemonPodsTemplateGeneration(c, ns, label, "1")
		Expect(err).NotTo(HaveOccurred())

		By("Update daemon pods image.")
		patch := getDaemonSetImagePatch(ds.Spec.Template.Spec.Containers[0].Name, redisImage)
		ds, err = c.Extensions().DaemonSets(ns).Patch(dsName, types.StrategicMergePatchType, []byte(patch))
		Expect(err).NotTo(HaveOccurred())
		Expect(ds.Spec.TemplateGeneration).To(Equal(int64(2)))

		By("Check that daemon pods images aren't updated.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonPodsImageAndAvailability(c, ds, image, 0))
		Expect(err).NotTo(HaveOccurred())

		By("Make sure all daemon pods have correct template generation 1")
		err = checkDaemonPodsTemplateGeneration(c, ns, label, "1")
		Expect(err).NotTo(HaveOccurred())

		By("Check that daemon pods are still running on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")
	})

	It("Should update pod when spec was updated and update strategy is RollingUpdate", func() {
		label := map[string]string{daemonsetNameLabel: dsName}

		templateGeneration := int64(999)
		framework.Logf("Creating simple daemon set %s with templateGeneration %d", dsName, templateGeneration)
		ds := newDaemonSet(dsName, image, label)
		ds.Spec.TemplateGeneration = templateGeneration
		ds.Spec.UpdateStrategy = extensions.DaemonSetUpdateStrategy{Type: extensions.RollingUpdateDaemonSetStrategyType}
		ds, err := c.Extensions().DaemonSets(ns).Create(ds)
		Expect(err).NotTo(HaveOccurred())
		Expect(ds.Spec.TemplateGeneration).To(Equal(templateGeneration))

		By("Check that daemon pods launch on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")

		By(fmt.Sprintf("Make sure all daemon pods have correct template generation %d", templateGeneration))
		err = checkDaemonPodsTemplateGeneration(c, ns, label, fmt.Sprint(templateGeneration))
		Expect(err).NotTo(HaveOccurred())

		By("Update daemon pods image.")
		patch := getDaemonSetImagePatch(ds.Spec.Template.Spec.Containers[0].Name, redisImage)
		ds, err = c.Extensions().DaemonSets(ns).Patch(dsName, types.StrategicMergePatchType, []byte(patch))
		Expect(err).NotTo(HaveOccurred())
		Expect(ds.Spec.TemplateGeneration).To(Equal(templateGeneration + 1))

		By("Check that daemon pods images are updated.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonPodsImageAndAvailability(c, ds, redisImage, 1))
		Expect(err).NotTo(HaveOccurred())

		By(fmt.Sprintf("Make sure all daemon pods have correct template generation %d", templateGeneration+1))
		err = checkDaemonPodsTemplateGeneration(c, ns, label, fmt.Sprint(templateGeneration+1))
		Expect(err).NotTo(HaveOccurred())

		By("Check that daemon pods are still running on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")
	})

	It("Should adopt or recreate existing pods when creating a RollingUpdate DaemonSet with matching or mismatching templateGeneration", func() {
		label := map[string]string{daemonsetNameLabel: dsName}

		// 1. Create a RollingUpdate DaemonSet
		templateGeneration := int64(999)
		framework.Logf("Creating simple RollingUpdate DaemonSet %s with templateGeneration %d", dsName, templateGeneration)
		ds := newDaemonSet(dsName, image, label)
		ds.Spec.TemplateGeneration = templateGeneration
		ds.Spec.UpdateStrategy = extensions.DaemonSetUpdateStrategy{Type: extensions.RollingUpdateDaemonSetStrategyType}
		ds, err := c.Extensions().DaemonSets(ns).Create(ds)
		Expect(err).NotTo(HaveOccurred())
		Expect(ds.Spec.TemplateGeneration).To(Equal(templateGeneration))

		By("Check that daemon pods launch on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkRunningOnAllNodes(f, ds))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to start")

		By(fmt.Sprintf("Make sure all daemon pods have correct template generation %d", templateGeneration))
		err = checkDaemonPodsTemplateGeneration(c, ns, label, fmt.Sprint(templateGeneration))
		Expect(err).NotTo(HaveOccurred())

		// 2. Orphan DaemonSet pods
		By(fmt.Sprintf("Deleting DaemonSet %s and orphaning its pods", dsName))
		err = orphanDaemonSetPods(c, ds)
		Expect(err).NotTo(HaveOccurred())
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonSetPodsOrphaned(c, ns, label))
		Expect(err).NotTo(HaveOccurred(), "error waiting for DaemonSet pods to be orphaned")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonSetDeleted(f, ns, ds.Name))
		Expect(err).NotTo(HaveOccurred(), "error waiting for DaemonSet to be deleted")

		// 3. Adopt DaemonSet pods (no restart)
		newDSName := "adopt"
		By(fmt.Sprintf("Creating a new RollingUpdate DaemonSet %s to adopt pods", newDSName))
		newDS := newDaemonSet(newDSName, image, label)
		newDS.Spec.TemplateGeneration = templateGeneration
		newDS.Spec.UpdateStrategy = extensions.DaemonSetUpdateStrategy{Type: extensions.RollingUpdateDaemonSetStrategyType}
		newDS, err = c.Extensions().DaemonSets(ns).Create(newDS)
		Expect(err).NotTo(HaveOccurred())
		Expect(newDS.Spec.TemplateGeneration).To(Equal(templateGeneration))

		By(fmt.Sprintf("Wait for all pods to be adopted by DaemonSet %s", newDSName))
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonSetPodsAdopted(c, ns, newDS.UID, label))
		Expect(err).NotTo(HaveOccurred(), "error waiting for DaemonSet pods to be orphaned")

		By(fmt.Sprintf("Make sure no daemon pod updated its template generation %d", templateGeneration))
		err = checkDaemonPodsTemplateGeneration(c, ns, label, fmt.Sprint(templateGeneration))
		Expect(err).NotTo(HaveOccurred())

		By("Make sure no pods are recreated by looking at their names")
		err = checkDaemonSetPodsName(c, ns, dsName, label)
		Expect(err).NotTo(HaveOccurred())

		// 4. Orphan DaemonSet pods again
		By(fmt.Sprintf("Deleting DaemonSet %s and orphaning its pods", newDSName))
		err = orphanDaemonSetPods(c, newDS)
		Expect(err).NotTo(HaveOccurred())
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonSetPodsOrphaned(c, ns, label))
		Expect(err).NotTo(HaveOccurred(), "error waiting for DaemonSet pods to be orphaned")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonSetDeleted(f, ns, newDSName))
		Expect(err).NotTo(HaveOccurred(), "error waiting for DaemonSet to be deleted")

		// 4. Adopt DaemonSet pods (should kill and restart those pods)
		newRestartDSName := "restart"
		By(fmt.Sprintf("Creating a new RollingUpdate DaemonSet %s to restart adopted pods", newRestartDSName))
		newRestartDS := newDaemonSet(newRestartDSName, image, label)
		newRestartDS.Spec.UpdateStrategy = extensions.DaemonSetUpdateStrategy{Type: extensions.RollingUpdateDaemonSetStrategyType}
		newRestartDS, err = c.Extensions().DaemonSets(ns).Create(newRestartDS)
		Expect(err).NotTo(HaveOccurred())
		Expect(newRestartDS.Spec.TemplateGeneration).To(Equal(int64(1)))

		By("Wait for restarted DaemonSet pods launch on every node of the cluster.")
		err = wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, checkDaemonSetPodsNameMatch(c, ns, newRestartDSName, label))
		Expect(err).NotTo(HaveOccurred(), "error waiting for daemon pod to restart")

		By("Make sure restarted DaemonSet pods have correct template generation 1")
		err = checkDaemonPodsTemplateGeneration(c, ns, label, "1")
		Expect(err).NotTo(HaveOccurred())
	})
})

// getDaemonSetImagePatch generates a patch for updating a DaemonSet's container image
func getDaemonSetImagePatch(containerName, containerImage string) string {
	return fmt.Sprintf(`{"spec":{"template":{"spec":{"containers":[{"name":"%s","image":"%s"}]}}}}`, containerName, containerImage)
}

func orphanDaemonSetPods(c clientset.Interface, ds *extensions.DaemonSet) error {
	trueVar := true
	deleteOptions := &metav1.DeleteOptions{OrphanDependents: &trueVar}
	deleteOptions.Preconditions = metav1.NewUIDPreconditions(string(ds.UID))
	return c.Extensions().DaemonSets(ds.Namespace).Delete(ds.Name, deleteOptions)
}

func newDaemonSet(dsName, image string, label map[string]string) *extensions.DaemonSet {
	return &extensions.DaemonSet{
		ObjectMeta: metav1.ObjectMeta{
			Name: dsName,
		},
		Spec: extensions.DaemonSetSpec{
			Template: v1.PodTemplateSpec{
				ObjectMeta: metav1.ObjectMeta{
					Labels: label,
				},
				Spec: v1.PodSpec{
					Containers: []v1.Container{
						{
							Name:  dsName,
							Image: image,
							Ports: []v1.ContainerPort{{ContainerPort: 9376}},
						},
					},
				},
			},
		},
	}
}

func listDaemonPods(c clientset.Interface, ns string, label map[string]string) *v1.PodList {
	selector := labels.Set(label).AsSelector()
	options := metav1.ListOptions{LabelSelector: selector.String()}
	podList, err := c.Core().Pods(ns).List(options)
	Expect(err).NotTo(HaveOccurred())
	Expect(len(podList.Items)).To(BeNumerically(">", 0))
	return podList
}

func separateDaemonSetNodeLabels(labels map[string]string) (map[string]string, map[string]string) {
	daemonSetLabels := map[string]string{}
	otherLabels := map[string]string{}
	for k, v := range labels {
		if strings.HasPrefix(k, daemonsetLabelPrefix) {
			daemonSetLabels[k] = v
		} else {
			otherLabels[k] = v
		}
	}
	return daemonSetLabels, otherLabels
}

func clearDaemonSetNodeLabels(c clientset.Interface) error {
	nodeList := framework.GetReadySchedulableNodesOrDie(c)
	for _, node := range nodeList.Items {
		_, err := setDaemonSetNodeLabels(c, node.Name, map[string]string{})
		if err != nil {
			return err
		}
	}
	return nil
}

func setDaemonSetNodeLabels(c clientset.Interface, nodeName string, labels map[string]string) (*v1.Node, error) {
	nodeClient := c.Core().Nodes()
	var newNode *v1.Node
	var newLabels map[string]string
	err := wait.PollImmediate(dsRetryPeriod, dsRetryTimeout, func() (bool, error) {
		node, err := nodeClient.Get(nodeName, metav1.GetOptions{})
		if err != nil {
			return false, err
		}

		// remove all labels this test is creating
		daemonSetLabels, otherLabels := separateDaemonSetNodeLabels(node.Labels)
		if reflect.DeepEqual(daemonSetLabels, labels) {
			newNode = node
			return true, nil
		}
		node.Labels = otherLabels
		for k, v := range labels {
			node.Labels[k] = v
		}
		newNode, err = nodeClient.Update(node)
		if err == nil {
			newLabels, _ = separateDaemonSetNodeLabels(newNode.Labels)
			return true, err
		}
		if se, ok := err.(*apierrs.StatusError); ok && se.ErrStatus.Reason == metav1.StatusReasonConflict {
			framework.Logf("failed to update node due to resource version conflict")
			return false, nil
		}
		return false, err
	})
	if err != nil {
		return nil, err
	} else if len(newLabels) != len(labels) {
		return nil, fmt.Errorf("Could not set daemon set test labels as expected.")
	}

	return newNode, nil
}

func checkDaemonPodOnNodes(f *framework.Framework, ds *extensions.DaemonSet, nodeNames []string) func() (bool, error) {
	return func() (bool, error) {
		podList, err := f.ClientSet.Core().Pods(f.Namespace.Name).List(metav1.ListOptions{})
		if err != nil {
			framework.Logf("could not get the pod list: %v", err)
			return false, nil
		}
		pods := podList.Items

		nodesToPodCount := make(map[string]int)
		for _, pod := range pods {
			if controllerRef := controller.GetControllerOf(&pod); controllerRef == nil || controllerRef.UID != ds.UID {
				continue
			}
			if pod.DeletionTimestamp != nil {
				continue
			}
			if podutil.IsPodAvailable(&pod, ds.Spec.MinReadySeconds, metav1.Now()) {
				nodesToPodCount[pod.Spec.NodeName] += 1
			}
		}
		framework.Logf("Number of nodes with available pods: %d", len(nodesToPodCount))

		// Ensure that exactly 1 pod is running on all nodes in nodeNames.
		for _, nodeName := range nodeNames {
			if nodesToPodCount[nodeName] != 1 {
				framework.Logf("Node %s is running more than one daemon pod", nodeName)
				return false, nil
			}
		}

		framework.Logf("Number of running nodes: %d, number of available pods: %d", len(nodeNames), len(nodesToPodCount))
		// Ensure that sizes of the lists are the same. We've verified that every element of nodeNames is in
		// nodesToPodCount, so verifying the lengths are equal ensures that there aren't pods running on any
		// other nodes.
		return len(nodesToPodCount) == len(nodeNames), nil
	}
}

func checkRunningOnAllNodes(f *framework.Framework, ds *extensions.DaemonSet) func() (bool, error) {
	return func() (bool, error) {
		nodeList, err := f.ClientSet.Core().Nodes().List(metav1.ListOptions{})
		framework.ExpectNoError(err)
		nodeNames := make([]string, 0)
		for _, node := range nodeList.Items {
			if !canScheduleOnNode(node, ds) {
				framework.Logf("DaemonSet pods can't tolerate node %s with taints %+v, skip checking this node", node.Name, node.Spec.Taints)
				continue
			}
			nodeNames = append(nodeNames, node.Name)
		}
		return checkDaemonPodOnNodes(f, ds, nodeNames)()
	}
}

// canScheduleOnNode checks if a given DaemonSet can schedule pods on the given node
func canScheduleOnNode(node v1.Node, ds *extensions.DaemonSet) bool {
	newPod := daemon.NewPod(ds, node.Name)
	nodeInfo := schedulercache.NewNodeInfo()
	nodeInfo.SetNode(&node)
	fit, _, err := daemon.Predicates(newPod, nodeInfo)
	if err != nil {
		framework.Failf("Can't test DaemonSet predicates for node %s: %v", node.Name, err)
		return false
	}
	return fit
}

func checkRunningOnNoNodes(f *framework.Framework, ds *extensions.DaemonSet) func() (bool, error) {
	return checkDaemonPodOnNodes(f, ds, make([]string, 0))
}

func checkDaemonStatus(f *framework.Framework, dsName string) error {
	ds, err := f.ClientSet.Extensions().DaemonSets(f.Namespace.Name).Get(dsName, metav1.GetOptions{})
	if err != nil {
		return fmt.Errorf("Could not get daemon set from v1.")
	}
	desired, scheduled, ready := ds.Status.DesiredNumberScheduled, ds.Status.CurrentNumberScheduled, ds.Status.NumberReady
	if desired != scheduled && desired != ready {
		return fmt.Errorf("Error in daemon status. DesiredScheduled: %d, CurrentScheduled: %d, Ready: %d", desired, scheduled, ready)
	}
	return nil
}

func checkDaemonPodsImageAndAvailability(c clientset.Interface, ds *extensions.DaemonSet, image string, maxUnavailable int) func() (bool, error) {
	return func() (bool, error) {
		podList, err := c.Core().Pods(ds.Namespace).List(metav1.ListOptions{})
		if err != nil {
			return false, err
		}
		pods := podList.Items

		unavailablePods := 0
		allImagesUpdated := true
		for _, pod := range pods {
			if controllerRef := controller.GetControllerOf(&pod); controllerRef == nil || controllerRef.UID != ds.UID {
				continue
			}
			podImage := pod.Spec.Containers[0].Image
			if podImage != image {
				allImagesUpdated = false
				framework.Logf("Wrong image for pod: %s. Expected: %s, got: %s.", pod.Name, image, podImage)
			}
			if !podutil.IsPodAvailable(&pod, ds.Spec.MinReadySeconds, metav1.Now()) {
				framework.Logf("Pod %s is not available", pod.Name)
				unavailablePods++
			}
		}
		if unavailablePods > maxUnavailable {
			return false, fmt.Errorf("number of unavailable pods: %d is greater than maxUnavailable: %d", unavailablePods, maxUnavailable)
		}
		if !allImagesUpdated {
			return false, nil
		}
		return true, nil
	}
}

func checkDaemonPodsTemplateGeneration(c clientset.Interface, ns string, label map[string]string, templateGeneration string) error {
	pods := listDaemonPods(c, ns, label)
	for _, pod := range pods.Items {
		// We don't care about inactive pods
		if !controller.IsPodActive(&pod) {
			continue
		}
		podTemplateGeneration := pod.Labels[extensions.DaemonSetTemplateGenerationKey]
		if podTemplateGeneration != templateGeneration {
			return fmt.Errorf("expected pod %s/%s template generation %s, but got %s", pod.Namespace, pod.Name, templateGeneration, podTemplateGeneration)
		}
	}
	return nil
}

func checkDaemonSetDeleted(f *framework.Framework, ns, name string) func() (bool, error) {
	return func() (bool, error) {
		_, err := f.ClientSet.Extensions().DaemonSets(ns).Get(name, metav1.GetOptions{})
		if !apierrs.IsNotFound(err) {
			return false, err
		}
		return true, nil
	}
}

func checkDaemonSetPodsOrphaned(c clientset.Interface, ns string, label map[string]string) func() (bool, error) {
	return func() (bool, error) {
		pods := listDaemonPods(c, ns, label)
		for _, pod := range pods.Items {
			// This pod is orphaned only when controller ref is cleared
			if controllerRef := controller.GetControllerOf(&pod); controllerRef != nil {
				return false, nil
			}
		}
		return true, nil
	}
}

func checkDaemonSetPodsAdopted(c clientset.Interface, ns string, dsUID types.UID, label map[string]string) func() (bool, error) {
	return func() (bool, error) {
		pods := listDaemonPods(c, ns, label)
		for _, pod := range pods.Items {
			// This pod is adopted only when its controller ref is update
			if controllerRef := controller.GetControllerOf(&pod); controllerRef == nil || controllerRef.UID != dsUID {
				return false, nil
			}
		}
		return true, nil
	}
}

func checkDaemonSetPodsNameMatch(c clientset.Interface, ns, prefix string, label map[string]string) func() (bool, error) {
	return func() (bool, error) {
		if err := checkDaemonSetPodsName(c, ns, prefix, label); err != nil {
			framework.Logf("%v", err)
			return false, nil
		}
		return true, nil
	}
}

func checkDaemonSetPodsName(c clientset.Interface, ns, prefix string, label map[string]string) error {
	pods := listDaemonPods(c, ns, label)
	for _, pod := range pods.Items {
		if !strings.HasPrefix(pod.Name, prefix) {
			return fmt.Errorf("expected pod %s name to be prefixed %q", pod.Name, prefix)
		}
	}
	return nil
}