Task 2: Schedule DaemonSet Pods by default scheduler.

pkg/controller/daemon/BUILD

@@ -68,6 +68,8 @@ go_test(
         "//pkg/api/v1/pod:go_default_library",
         "//pkg/apis/core:go_default_library",
         "//pkg/controller:go_default_library",
+        "//pkg/features:go_default_library",
+        "//pkg/kubelet/apis:go_default_library",
         "//pkg/kubelet/types:go_default_library",
         "//pkg/scheduler/algorithm:go_default_library",
         "//pkg/securitycontext:go_default_library",

pkg/controller/daemon/daemon_controller.go

@@ -934,7 +934,22 @@ func (dsc *DaemonSetsController) syncNodes(ds *apps.DaemonSet, podsToDelete, nod
 		for i := pos; i < pos+batchSize; i++ {
 			go func(ix int) {
 				defer createWait.Done()
-				err := dsc.podControl.CreatePodsOnNode(nodesNeedingDaemonPods[ix], ds.Namespace, &template, ds, metav1.NewControllerRef(ds, controllerKind))
+				var err error
+
+				podTemplate := &template
+
+				if utilfeature.DefaultFeatureGate.Enabled(features.ScheduleDaemonSetPods) {
+					podTemplate = template.DeepCopy()
+					podTemplate.Spec.Affinity = util.ReplaceDaemonSetPodHostnameNodeAffinity(
+						podTemplate.Spec.Affinity, nodesNeedingDaemonPods[ix])
+
+					err = dsc.podControl.CreatePodsWithControllerRef(ds.Namespace, podTemplate,
+						ds, metav1.NewControllerRef(ds, controllerKind))
+				} else {
+					err = dsc.podControl.CreatePodsOnNode(nodesNeedingDaemonPods[ix], ds.Namespace, podTemplate,
+						ds, metav1.NewControllerRef(ds, controllerKind))
+				}
+
 				if err != nil && errors.IsTimeout(err) {
 					// Pod is created but its initialization has timed out.
 					// If the initialization is successful eventually, the
@@ -1267,6 +1282,9 @@ func (dsc *DaemonSetsController) nodeShouldRunDaemonPod(node *v1.Node, ds *apps.
 		return false, false, false, err
 	}
 
+	// TODO(k82cn): When 'ScheduleDaemonSetPods' upgrade to beta or GA, remove unnecessary check on failure reason,
+	//              e.g. InsufficientResourceError; and simplify "wantToRun, shouldSchedule, shouldContinueRunning"
+	//              into one result, e.g. selectedNode.
 	var insufficientResourceErr error
 	for _, r := range reasons {
 		glog.V(4).Infof("DaemonSet Predicates failed on node %s for ds '%s/%s' for reason: %v", node.Name, ds.ObjectMeta.Namespace, ds.ObjectMeta.Name, r.GetReason())
@@ -1341,11 +1359,50 @@ func NewPod(ds *apps.DaemonSet, nodeName string) *v1.Pod {
 	return newPod
 }
 
+// nodeSelectionPredicates runs a set of predicates that select candidate nodes for the DaemonSet;
+// the predicates include:
+//   - PodFitsHost: checks pod's NodeName against node
+//   - PodMatchNodeSelector: checks pod's NodeSelector and NodeAffinity against node
+func nodeSelectionPredicates(pod *v1.Pod, meta algorithm.PredicateMetadata, nodeInfo *schedulercache.NodeInfo) (bool, []algorithm.PredicateFailureReason, error) {
+	var predicateFails []algorithm.PredicateFailureReason
+	fit, reasons, err := predicates.PodFitsHost(pod, meta, nodeInfo)
+	if err != nil {
+		return false, predicateFails, err
+	}
+	if !fit {
+		predicateFails = append(predicateFails, reasons...)
+	}
+
+	fit, reasons, err = predicates.PodMatchNodeSelector(pod, meta, nodeInfo)
+	if err != nil {
+		return false, predicateFails, err
+	}
+	if !fit {
+		predicateFails = append(predicateFails, reasons...)
+	}
+	return len(predicateFails) == 0, predicateFails, nil
+}
+
 // Predicates checks if a DaemonSet's pod can be scheduled on a node using GeneralPredicates
 // and PodToleratesNodeTaints predicate
 func Predicates(pod *v1.Pod, nodeInfo *schedulercache.NodeInfo) (bool, []algorithm.PredicateFailureReason, error) {
 	var predicateFails []algorithm.PredicateFailureReason
-	critical := utilfeature.DefaultFeatureGate.Enabled(features.ExperimentalCriticalPodAnnotation) && kubelettypes.IsCriticalPod(pod)
+
+	// If ScheduleDaemonSetPods is enabled, only check nodeSelector and nodeAffinity.
+	if utilfeature.DefaultFeatureGate.Enabled(features.ScheduleDaemonSetPods) {
+		fit, reasons, err := nodeSelectionPredicates(pod, nil, nodeInfo)
+		if err != nil {
+			return false, predicateFails, err
+		}
+		if !fit {
+			predicateFails = append(predicateFails, reasons...)
+		}
+
+		return len(predicateFails) == 0, predicateFails, nil
+	}
+
+	critical := utilfeature.DefaultFeatureGate.Enabled(features.ExperimentalCriticalPodAnnotation) &&
+		kubelettypes.IsCriticalPod(pod)
 
 	fit, reasons, err := predicates.PodToleratesNodeTaints(pod, nil, nodeInfo)
 	if err != nil {

pkg/controller/daemon/daemon_controller_test.go

@@ -43,6 +43,8 @@ import (
 	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/controller"
+	"k8s.io/kubernetes/pkg/features"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 	kubelettypes "k8s.io/kubernetes/pkg/kubelet/types"
 	"k8s.io/kubernetes/pkg/scheduler/algorithm"
 	"k8s.io/kubernetes/pkg/securitycontext"
@@ -267,6 +269,31 @@ func (f *fakePodControl) CreatePodsOnNode(nodeName, namespace string, template *
 	return nil
 }
 
+func (f *fakePodControl) CreatePodsWithControllerRef(namespace string, template *v1.PodTemplateSpec, object runtime.Object, controllerRef *metav1.OwnerReference) error {
+	f.Lock()
+	defer f.Unlock()
+	if err := f.FakePodControl.CreatePodsWithControllerRef(namespace, template, object, controllerRef); err != nil {
+		return fmt.Errorf("failed to create pod for DaemonSet")
+	}
+
+	pod := &v1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Labels:    template.Labels,
+			Namespace: namespace,
+		},
+	}
+
+	pod.Name = names.SimpleNameGenerator.GenerateName(fmt.Sprintf("%p-", pod))
+
+	if err := legacyscheme.Scheme.Convert(&template.Spec, &pod.Spec, nil); err != nil {
+		return fmt.Errorf("unable to convert pod template: %v", err)
+	}
+
+	f.podStore.Update(pod)
+	f.podIDMap[pod.Name] = pod
+	return nil
+}
+
 func (f *fakePodControl) DeletePod(namespace string, podID string, object runtime.Object) error {
 	f.Lock()
 	defer f.Unlock()
@@ -423,6 +450,95 @@ func TestSimpleDaemonSetLaunchesPods(t *testing.T) {
 	}
 }
 
+// When ScheduleDaemonSetPods is enabled, DaemonSets without node selectors should
+// launch pods on every node by NodeAffinity.
+func TestSimpleDaemonSetScheduleDaemonSetPodsLaunchesPods(t *testing.T) {
+	enabled := utilfeature.DefaultFeatureGate.Enabled(features.ScheduleDaemonSetPods)
+	// Rollback feature gate.
+	defer func() {
+		if !enabled {
+			utilfeature.DefaultFeatureGate.Set("ScheduleDaemonSetPods=false")
+		}
+	}()
+
+	utilfeature.DefaultFeatureGate.Set("ScheduleDaemonSetPods=true")
+
+	nodeNum := 5
+
+	for _, strategy := range updateStrategies() {
+		ds := newDaemonSet("foo")
+		ds.Spec.UpdateStrategy = *strategy
+		manager, podControl, _, err := newTestController(ds)
+		if err != nil {
+			t.Fatalf("error creating DaemonSets controller: %v", err)
+		}
+		addNodes(manager.nodeStore, 0, nodeNum, nil)
+		manager.dsStore.Add(ds)
+		syncAndValidateDaemonSets(t, manager, ds, podControl, nodeNum, 0, 0)
+
+		// Check for ScheduleDaemonSetPods feature
+		if len(podControl.podIDMap) != nodeNum {
+			t.Fatalf("failed to create pods for DaemonSet when enabled ScheduleDaemonSetPods.")
+		}
+
+		nodeMap := make(map[string]*v1.Node)
+		for _, node := range manager.nodeStore.List() {
+			n := node.(*v1.Node)
+			nodeMap[n.Name] = n
+		}
+
+		if len(nodeMap) != nodeNum {
+			t.Fatalf("not enough nodes in the store, expected: %v, got: %v",
+				nodeNum, len(nodeMap))
+		}
+
+		for _, pod := range podControl.podIDMap {
+			if len(pod.Spec.NodeName) != 0 {
+				t.Fatalf("the hostname of pod %v should be empty, but got %s",
+					pod.Name, pod.Spec.NodeName)
+			}
+			if pod.Spec.Affinity == nil {
+				t.Fatalf("the Affinity of pod %s is nil.", pod.Name)
+			}
+			if pod.Spec.Affinity.NodeAffinity == nil {
+				t.Fatalf("the NodeAffinity of pod %s is nil.", pod.Name)
+			}
+
+			nodeSelector := pod.Spec.Affinity.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution
+			if nodeSelector == nil {
+				t.Fatalf("the node selector of pod %s is nil.", pod.Name)
+			}
+			if len(nodeSelector.NodeSelectorTerms) != 1 {
+				t.Fatalf("incorrect node selector terms number of pod %s, expected: 1, got: %d.",
+					pod.Name, len(nodeSelector.NodeSelectorTerms))
+			}
+
+			if len(nodeSelector.NodeSelectorTerms[0].MatchExpressions) != 1 {
+				t.Fatalf("incorrect expression number of pod %s node selector term, expected: 1, got: %d.",
+					pod.Name, len(nodeSelector.NodeSelectorTerms[0].MatchExpressions))
+			}
+
+			exp := nodeSelector.NodeSelectorTerms[0].MatchExpressions[0]
+			if exp.Key == kubeletapis.LabelHostname {
+				if exp.Operator != v1.NodeSelectorOpIn {
+					t.Fatalf("the operation of hostname NodeAffinity is not %v", v1.NodeSelectorOpIn)
+				}
+
+				if len(exp.Values) != 1 {
+					t.Fatalf("incorrect hostname in node affinity: expected 1, got %v", len(exp.Values))
+				}
+
+				delete(nodeMap, exp.Values[0])
+			}
+		}
+
+		if len(nodeMap) != 0 {
+			t.Fatalf("did not foud pods on nodes %+v", nodeMap)
+		}
+	}
+
+}
+
 // Simulate a cluster with 100 nodes, but simulate a limit (like a quota limit)
 // of 10 pods, and verify that the ds doesn't make 100 create calls per sync pass
 func TestSimpleDaemonSetPodCreateErrors(t *testing.T) {

pkg/controller/daemon/util/BUILD

@@ -14,6 +14,7 @@ go_library(
         "//pkg/api/v1/pod:go_default_library",
         "//pkg/apis/core/v1/helper:go_default_library",
         "//pkg/features:go_default_library",
+        "//pkg/kubelet/apis:go_default_library",
         "//pkg/kubelet/types:go_default_library",
         "//pkg/scheduler/algorithm:go_default_library",
         "//vendor/k8s.io/api/apps/v1:go_default_library",
@@ -43,6 +44,7 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//pkg/api/testapi:go_default_library",
+        "//pkg/kubelet/apis:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/api/extensions/v1beta1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",

pkg/controller/daemon/util/daemonset_util.go

@@ -28,6 +28,7 @@ import (
 	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
 	v1helper "k8s.io/kubernetes/pkg/apis/core/v1/helper"
 	"k8s.io/kubernetes/pkg/features"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 	kubelettypes "k8s.io/kubernetes/pkg/kubelet/types"
 	"k8s.io/kubernetes/pkg/scheduler/algorithm"
 )
@@ -133,3 +134,68 @@ func SplitByAvailablePods(minReadySeconds int32, pods []*v1.Pod) ([]*v1.Pod, []*
 	}
 	return availablePods, unavailablePods
 }
+
+// ReplaceDaemonSetPodHostnameNodeAffinity replaces the 'kubernetes.io/hostname' NodeAffinity term with
+// the given "nodeName" in the "affinity" terms.
+func ReplaceDaemonSetPodHostnameNodeAffinity(affinity *v1.Affinity, nodename string) *v1.Affinity {
+	nodeSelector := &v1.NodeSelector{
+		NodeSelectorTerms: []v1.NodeSelectorTerm{
+			{
+				MatchExpressions: []v1.NodeSelectorRequirement{
+					{
+						Key:      kubeletapis.LabelHostname,
+						Operator: v1.NodeSelectorOpIn,
+						Values:   []string{nodename},
+					},
+				},
+			},
+		},
+	}
+
+	if affinity == nil {
+		return &v1.Affinity{
+			NodeAffinity: &v1.NodeAffinity{
+				RequiredDuringSchedulingIgnoredDuringExecution: nodeSelector,
+			},
+		}
+	}
+
+	if affinity.NodeAffinity == nil {
+		affinity.NodeAffinity = &v1.NodeAffinity{
+			RequiredDuringSchedulingIgnoredDuringExecution: nodeSelector,
+		}
+		return affinity
+	}
+
+	nodeAffinity := affinity.NodeAffinity
+
+	if nodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution == nil {
+		nodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution = nodeSelector
+		return affinity
+	}
+
+	nodeSelectorTerms := []v1.NodeSelectorTerm{}
+
+	// Removes hostname node selector, as only the target hostname will take effect.
+	for _, term := range nodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms {
+		exps := []v1.NodeSelectorRequirement{}
+		for _, exp := range term.MatchExpressions {
+			if exp.Key != kubeletapis.LabelHostname {
+				exps = append(exps, exp)
+			}
+		}
+
+		if len(exps) > 0 {
+			term.MatchExpressions = exps
+			nodeSelectorTerms = append(nodeSelectorTerms, term)
+		}
+	}
+
+	// Adds target hostname NodeAffinity term.
+	nodeSelectorTerms = append(nodeSelectorTerms, nodeSelector.NodeSelectorTerms[0])
+
+	// Replace node selector with the new one.
+	nodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms = nodeSelectorTerms
+
+	return affinity
+}

pkg/controller/daemon/util/daemonset_util_test.go

@@ -18,12 +18,14 @@ package util
 
 import (
 	"fmt"
+	"reflect"
 	"testing"
 
 	"k8s.io/api/core/v1"
 	extensions "k8s.io/api/extensions/v1beta1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/kubernetes/pkg/api/testapi"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 )
 
 func newPod(podName string, nodeName string, label map[string]string) *v1.Pod {
@@ -168,3 +170,173 @@ func int64Ptr(i int) *int64 {
 	li := int64(i)
 	return &li
 }
+
+func TestReplaceDaemonSetPodHostnameNodeAffinity(t *testing.T) {
+	tests := []struct {
+		affinity *v1.Affinity
+		hostname string
+		expected *v1.Affinity
+	}{
+		{
+			affinity: nil,
+			hostname: "host_1",
+			expected: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+						NodeSelectorTerms: []v1.NodeSelectorTerm{
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			affinity: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					PreferredDuringSchedulingIgnoredDuringExecution: []v1.PreferredSchedulingTerm{
+						{
+							Preference: v1.NodeSelectorTerm{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			hostname: "host_1",
+			expected: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					PreferredDuringSchedulingIgnoredDuringExecution: []v1.PreferredSchedulingTerm{
+						{
+							Preference: v1.NodeSelectorTerm{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1"},
+									},
+								},
+							},
+						},
+					},
+					RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+						NodeSelectorTerms: []v1.NodeSelectorTerm{
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			affinity: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+						NodeSelectorTerms: []v1.NodeSelectorTerm{
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      "not-host-label",
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"label_value_1", "label_value_2"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			hostname: "host_1",
+			expected: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+						NodeSelectorTerms: []v1.NodeSelectorTerm{
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      "not-host-label",
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"label_value_1", "label_value_2"},
+									},
+								},
+							},
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			affinity: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+						NodeSelectorTerms: []v1.NodeSelectorTerm{
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1", "host_2"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			hostname: "host_1",
+			expected: &v1.Affinity{
+				NodeAffinity: &v1.NodeAffinity{
+					RequiredDuringSchedulingIgnoredDuringExecution: &v1.NodeSelector{
+						NodeSelectorTerms: []v1.NodeSelectorTerm{
+							{
+								MatchExpressions: []v1.NodeSelectorRequirement{
+									{
+										Key:      kubeletapis.LabelHostname,
+										Operator: v1.NodeSelectorOpIn,
+										Values:   []string{"host_1"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		got := ReplaceDaemonSetPodHostnameNodeAffinity(test.affinity, test.hostname)
+		if !reflect.DeepEqual(test.expected, got) {
+			t.Errorf("Failed to append NodeAffinity, got: %v, expected: %v", got, test.expected)
+		}
+	}
+}

pkg/features/kube_features.go

@@ -242,7 +242,7 @@ const (
 	// alpha: v1.10
 	//
 	// Schedule DaemonSet Pods by default scheduler instead of DaemonSet controller
-	NoDaemonSetScheduler utilfeature.Feature = "NoDaemonSetScheduler"
+	ScheduleDaemonSetPods utilfeature.Feature = "ScheduleDaemonSetPods"
 
 	// owner: @mikedanese
 	// alpha: v1.10
@@ -308,7 +308,7 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	SupportIPVSProxyMode:                        {Default: true, PreRelease: utilfeature.Beta},
 	SupportPodPidsLimit:                         {Default: false, PreRelease: utilfeature.Alpha},
 	HyperVContainer:                             {Default: false, PreRelease: utilfeature.Alpha},
-	NoDaemonSetScheduler:                        {Default: false, PreRelease: utilfeature.Alpha},
+	ScheduleDaemonSetPods:                       {Default: false, PreRelease: utilfeature.Alpha},
 	TokenRequest:                                {Default: false, PreRelease: utilfeature.Alpha},
 	CRIContainerLogRotation:                     {Default: false, PreRelease: utilfeature.Alpha},
 	GCERegionalPersistentDisk:                   {Default: true, PreRelease: utilfeature.Beta},