Populate NodeAffinity on top of labels for cloud based PersistentVolumes

Signed-off-by: Deep Debroy <ddebroy@docker.com>

pkg/apis/core/v1/helper/helpers.go

@@ -283,6 +283,20 @@ func NodeSelectorRequirementsAsFieldSelector(nsm []v1.NodeSelectorRequirement) (
 	return fields.AndSelectors(selectors...), nil
 }
 
+// NodeSelectorRequirementKeysExistInNodeSelectorTerms checks if a NodeSelectorTerm with key is already specified in terms
+func NodeSelectorRequirementKeysExistInNodeSelectorTerms(reqs []v1.NodeSelectorRequirement, terms []v1.NodeSelectorTerm) bool {
+	for _, req := range reqs {
+		for _, term := range terms {
+			for _, r := range term.MatchExpressions {
+				if r.Key == req.Key {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}
+
 // MatchNodeSelectorTerms checks whether the node labels and fields match node selector terms in ORed;
 // nil or empty term matches no objects.
 func MatchNodeSelectorTerms(

pkg/apis/core/v1/helper/helpers_test.go

@@ -968,3 +968,193 @@ func TestMatchTopologySelectorTerms(t *testing.T) {
 		})
 	}
 }
+
+func TestNodeSelectorRequirementKeyExistsInNodeSelectorTerms(t *testing.T) {
+	tests := []struct {
+		name   string
+		reqs   []v1.NodeSelectorRequirement
+		terms  []v1.NodeSelectorTerm
+		exists bool
+	}{
+		{
+			name:   "empty set of keys in empty set of terms",
+			reqs:   []v1.NodeSelectorRequirement{},
+			terms:  []v1.NodeSelectorTerm{},
+			exists: false,
+		},
+		{
+			name: "key existence in terms with all keys specified",
+			reqs: []v1.NodeSelectorRequirement{
+				{
+					Key:      "key1",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value1"},
+				},
+				{
+					Key:      "key2",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value2"},
+				},
+			},
+			terms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key2",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value2"},
+						},
+						{
+							Key:      "key3",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value3"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key1",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value11, test-value12"},
+						},
+						{
+							Key:      "key4",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value41, test-value42"},
+						},
+					},
+				},
+			},
+			exists: true,
+		},
+		{
+			name: "key existence in terms with one of the keys specfied",
+			reqs: []v1.NodeSelectorRequirement{
+				{
+					Key:      "key1",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value1"},
+				},
+				{
+					Key:      "key2",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value2"},
+				},
+				{
+					Key:      "key3",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value3"},
+				},
+				{
+					Key:      "key6",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value6"},
+				},
+			},
+			terms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key2",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value2"},
+						}, {
+							Key:      "key4",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value4"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key5",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value5"},
+						},
+					},
+				},
+			},
+			exists: true,
+		},
+		{
+			name: "key existence in terms without any of the keys specified",
+			reqs: []v1.NodeSelectorRequirement{
+				{
+					Key:      "key2",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value2"},
+				},
+				{
+					Key:      "key3",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value3"},
+				},
+			},
+			terms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key4",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value"},
+						},
+						{
+							Key:      "key5",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key6",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "key7",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value"},
+						},
+						{
+							Key:      "key8",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"test-value"},
+						},
+					},
+				},
+			},
+			exists: false,
+		},
+		{
+			name: "key existence in empty set of terms",
+			reqs: []v1.NodeSelectorRequirement{
+				{
+					Key:      "key2",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value2"},
+				},
+				{
+					Key:      "key3",
+					Operator: v1.NodeSelectorOpIn,
+					Values:   []string{"test-value3"},
+				},
+			},
+			terms:  []v1.NodeSelectorTerm{},
+			exists: false,
+		},
+	}
+	for _, test := range tests {
+		keyExists := NodeSelectorRequirementKeysExistInNodeSelectorTerms(test.reqs, test.terms)
+		if test.exists != keyExists {
+			t.Errorf("test %s failed. Expected %v but got %v", test.name, test.exists, keyExists)
+		}
+	}
+}

pkg/controller/cloud/BUILD

@@ -15,12 +15,15 @@ go_library(
     importpath = "k8s.io/kubernetes/pkg/controller/cloud",
     deps = [
         "//pkg/api/v1/node:go_default_library",
+        "//pkg/apis/core/v1/helper:go_default_library",
         "//pkg/cloudprovider:go_default_library",
         "//pkg/controller:go_default_library",
         "//pkg/controller/util/node:go_default_library",
+        "//pkg/features:go_default_library",
         "//pkg/kubelet/apis:go_default_library",
         "//pkg/scheduler/algorithm:go_default_library",
         "//pkg/util/node:go_default_library",
+        "//pkg/volume/util:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
@@ -30,6 +33,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/util/strategicpatch:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/watch:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//staging/src/k8s.io/client-go/informers/core/v1:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes/scheme:go_default_library",
@@ -57,11 +61,13 @@ go_test(
         "//pkg/controller/testutil:go_default_library",
         "//pkg/kubelet/apis:go_default_library",
         "//pkg/scheduler/algorithm:go_default_library",
+        "//pkg/volume/util:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/types:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//staging/src/k8s.io/client-go/informers:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes/fake:go_default_library",
         "//staging/src/k8s.io/client-go/kubernetes/scheme:go_default_library",

pkg/controller/cloud/pvlcontroller.go

@@ -34,6 +34,11 @@ import (
 	"k8s.io/apimachinery/pkg/util/strategicpatch"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apimachinery/pkg/watch"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	v1helper "k8s.io/kubernetes/pkg/apis/core/v1/helper"
+	"k8s.io/kubernetes/pkg/features"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
+	volumeutil "k8s.io/kubernetes/pkg/volume/util"
 
 	"k8s.io/client-go/kubernetes"
 	corelisters "k8s.io/client-go/listers/core/v1"
@@ -70,7 +75,7 @@ func NewPersistentVolumeLabelController(
 		kubeClient: kubeClient,
 		queue:      workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "pvLabels"),
 	}
-	pvlc.syncHandler = pvlc.addLabels
+	pvlc.syncHandler = pvlc.addLabelsAndAffinity
 	pvlc.pvlIndexer, pvlc.pvlController = cache.NewIndexerInformer(
 		&cache.ListWatch{
 			ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
@@ -166,7 +171,7 @@ func (pvlc *PersistentVolumeLabelController) processNextWorkItem() bool {
 
 // AddLabels adds appropriate labels to persistent volumes and sets the
 // volume as available if successful.
-func (pvlc *PersistentVolumeLabelController) addLabels(key string) error {
+func (pvlc *PersistentVolumeLabelController) addLabelsAndAffinity(key string) error {
 	_, name, err := cache.SplitMetaNamespaceKey(key)
 	if err != nil {
 		return fmt.Errorf("error getting name of volume %q to get volume from informer: %v", key, err)
@@ -178,10 +183,10 @@ func (pvlc *PersistentVolumeLabelController) addLabels(key string) error {
 		return fmt.Errorf("error getting volume %s from informer: %v", name, err)
 	}
 
-	return pvlc.addLabelsToVolume(volume)
+	return pvlc.addLabelsAndAffinityToVolume(volume)
 }
 
-func (pvlc *PersistentVolumeLabelController) addLabelsToVolume(vol *v1.PersistentVolume) error {
+func (pvlc *PersistentVolumeLabelController) addLabelsAndAffinityToVolume(vol *v1.PersistentVolume) error {
 	var volumeLabels map[string]string
 	// Only add labels if the next pending initializer.
 	if needsInitialization(vol.Initializers, initializerName) {
@@ -202,11 +207,52 @@ func (pvlc *PersistentVolumeLabelController) addLabelsToVolume(vol *v1.Persisten
 func (pvlc *PersistentVolumeLabelController) createPatch(vol *v1.PersistentVolume, volLabels map[string]string) ([]byte, error) {
 	volName := vol.Name
 	newVolume := vol.DeepCopyObject().(*v1.PersistentVolume)
+	populateAffinity := utilfeature.DefaultFeatureGate.Enabled(features.VolumeScheduling) && len(volLabels) != 0
+
 	if newVolume.Labels == nil {
 		newVolume.Labels = make(map[string]string)
 	}
+
+	requirements := make([]v1.NodeSelectorRequirement, 0)
 	for k, v := range volLabels {
 		newVolume.Labels[k] = v
+		// Set NodeSelectorRequirements based on the labels
+		if populateAffinity {
+			var values []string
+			if k == kubeletapis.LabelZoneFailureDomain {
+				zones, err := volumeutil.LabelZonesToSet(v)
+				if err != nil {
+					return nil, fmt.Errorf("failed to convert label string for Zone: %s to a Set", v)
+				}
+				values = zones.List()
+			} else {
+				values = []string{v}
+			}
+			requirements = append(requirements, v1.NodeSelectorRequirement{Key: k, Operator: v1.NodeSelectorOpIn, Values: values})
+		}
+	}
+	if populateAffinity {
+		if newVolume.Spec.NodeAffinity == nil {
+			newVolume.Spec.NodeAffinity = new(v1.VolumeNodeAffinity)
+		}
+		if newVolume.Spec.NodeAffinity.Required == nil {
+			newVolume.Spec.NodeAffinity.Required = new(v1.NodeSelector)
+		}
+		if len(newVolume.Spec.NodeAffinity.Required.NodeSelectorTerms) == 0 {
+			// Need atleast one term pre-allocated whose MatchExpressions can be appended to
+			newVolume.Spec.NodeAffinity.Required.NodeSelectorTerms = make([]v1.NodeSelectorTerm, 1)
+		}
+		// Populate NodeAffinity with requirements if there are no conflicting keys found
+		if v1helper.NodeSelectorRequirementKeysExistInNodeSelectorTerms(requirements, newVolume.Spec.NodeAffinity.Required.NodeSelectorTerms) {
+			glog.V(4).Info("NodeSelectorRequirements for cloud labels %v conflict with existing NodeAffinity %v. Skipping addition of NodeSelectorRequirements for cloud labels.",
+				requirements, newVolume.Spec.NodeAffinity)
+		} else {
+			for _, req := range requirements {
+				for i := range newVolume.Spec.NodeAffinity.Required.NodeSelectorTerms {
+					newVolume.Spec.NodeAffinity.Required.NodeSelectorTerms[i].MatchExpressions = append(newVolume.Spec.NodeAffinity.Required.NodeSelectorTerms[i].MatchExpressions, req)
+				}
+			}
+		}
 	}
 	newVolume.Initializers = removeInitializer(newVolume.Initializers, initializerName)
 	glog.V(4).Infof("removed initializer on PersistentVolume %s", newVolume.Name)

pkg/controller/cloud/pvlcontroller_test.go

@@ -18,6 +18,7 @@ package cloud
 
 import (
 	"encoding/json"
+	"reflect"
 	"testing"
 	"time"
 
@@ -26,8 +27,11 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/kubernetes/fake"
 	core "k8s.io/client-go/testing"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
+	volumeutil "k8s.io/kubernetes/pkg/volume/util"
 
 	fakecloud "k8s.io/kubernetes/pkg/cloudprovider/providers/fake"
 )
@@ -71,29 +75,292 @@ func TestCreatePatch(t *testing.T) {
 			},
 		},
 	}
-
-	testCases := map[string]struct {
-		vol    v1.PersistentVolume
-		labels map[string]string
-	}{
-		"non-cloud PV": {
-			vol:    ignoredPV,
-			labels: nil,
+	expectedAffinitya1b2MergedWithAWSPV := v1.VolumeNodeAffinity{
+		Required: &v1.NodeSelector{
+			NodeSelectorTerms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "a",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1"},
+						},
+						{
+							Key:      "b",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"2"},
+						},
+					},
+				},
+			},
 		},
-		"no labels": {
-			vol:    awsPV,
-			labels: nil,
+	}
+	expectedAffinityZone1MergedWithAWSPV := v1.VolumeNodeAffinity{
+		Required: &v1.NodeSelector{
+			NodeSelectorTerms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      kubeletapis.LabelZoneFailureDomain,
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1"},
+						},
+					},
+				},
+			},
 		},
-		"cloudprovider returns nil, nil": {
-			vol:    awsPV,
-			labels: nil,
+	}
+	expectedAffinityZonesMergedWithAWSPV := v1.VolumeNodeAffinity{
+		Required: &v1.NodeSelector{
+			NodeSelectorTerms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      kubeletapis.LabelZoneFailureDomain,
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1", "2", "3"},
+						},
+					},
+				},
+			},
 		},
-		"cloudprovider labels": {
-			vol:    awsPV,
-			labels: map[string]string{"a": "1", "b": "2"},
+	}
+	awsPVWithAffinity := v1.PersistentVolume{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "awsPV",
+			Initializers: &metav1.Initializers{
+				Pending: []metav1.Initializer{
+					{
+						Name: initializerName,
+					},
+				},
+			},
+		},
+		Spec: v1.PersistentVolumeSpec{
+			PersistentVolumeSource: v1.PersistentVolumeSource{
+				AWSElasticBlockStore: &v1.AWSElasticBlockStoreVolumeSource{
+					VolumeID: "123",
+				},
+			},
+			NodeAffinity: &v1.VolumeNodeAffinity{
+				Required: &v1.NodeSelector{
+					NodeSelectorTerms: []v1.NodeSelectorTerm{
+						{
+							MatchExpressions: []v1.NodeSelectorRequirement{
+								{
+									Key:      "c",
+									Operator: v1.NodeSelectorOpIn,
+									Values:   []string{"val1", "val2"},
+								},
+								{
+									Key:      "d",
+									Operator: v1.NodeSelectorOpIn,
+									Values:   []string{"val3"},
+								},
+							},
+						},
+						{
+							MatchExpressions: []v1.NodeSelectorRequirement{
+								{
+									Key:      "e",
+									Operator: v1.NodeSelectorOpIn,
+									Values:   []string{"val4", "val5"},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+	expectedAffinitya1b2MergedWithAWSPVWithAffinity := v1.VolumeNodeAffinity{
+		Required: &v1.NodeSelector{
+			NodeSelectorTerms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "c",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val1", "val2"},
+						},
+						{
+							Key:      "d",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val3"},
+						},
+						{
+							Key:      "a",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1"},
+						},
+						{
+							Key:      "b",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"2"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "e",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val4", "val5"},
+						},
+						{
+							Key:      "a",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1"},
+						},
+						{
+							Key:      "b",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"2"},
+						},
+					},
+				},
+			},
+		},
+	}
+	expectedAffinityZone1MergedWithAWSPVWithAffinity := v1.VolumeNodeAffinity{
+		Required: &v1.NodeSelector{
+			NodeSelectorTerms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "c",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val1", "val2"},
+						},
+						{
+							Key:      "d",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val3"},
+						},
+						{
+							Key:      kubeletapis.LabelZoneFailureDomain,
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "e",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val4", "val5"},
+						},
+						{
+							Key:      kubeletapis.LabelZoneFailureDomain,
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1"},
+						},
+					},
+				},
+			},
+		},
+	}
+	expectedAffinityZonesMergedWithAWSPVWithAffinity := v1.VolumeNodeAffinity{
+		Required: &v1.NodeSelector{
+			NodeSelectorTerms: []v1.NodeSelectorTerm{
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "c",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val1", "val2"},
+						},
+						{
+							Key:      "d",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val3"},
+						},
+						{
+							Key:      kubeletapis.LabelZoneFailureDomain,
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1", "2", "3"},
+						},
+					},
+				},
+				{
+					MatchExpressions: []v1.NodeSelectorRequirement{
+						{
+							Key:      "e",
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"val4", "val5"},
+						},
+						{
+							Key:      kubeletapis.LabelZoneFailureDomain,
+							Operator: v1.NodeSelectorOpIn,
+							Values:   []string{"1", "2", "3"},
+						},
+					},
+				},
+			},
 		},
 	}
 
+	zones, _ := volumeutil.ZonesToSet("1,2,3")
+	testCases := map[string]struct {
+		vol              v1.PersistentVolume
+		labels           map[string]string
+		expectedAffinity *v1.VolumeNodeAffinity
+	}{
+		"non-cloud PV": {
+			vol:              ignoredPV,
+			labels:           nil,
+			expectedAffinity: nil,
+		},
+		"no labels": {
+			vol:              awsPV,
+			labels:           nil,
+			expectedAffinity: nil,
+		},
+		"cloudprovider returns nil, nil": {
+			vol:              awsPV,
+			labels:           nil,
+			expectedAffinity: nil,
+		},
+		"cloudprovider labels": {
+			vol:              awsPV,
+			labels:           map[string]string{"a": "1", "b": "2"},
+			expectedAffinity: &expectedAffinitya1b2MergedWithAWSPV,
+		},
+		"cloudprovider labels pre-existing affinity non-conflicting": {
+			vol:              awsPVWithAffinity,
+			labels:           map[string]string{"a": "1", "b": "2"},
+			expectedAffinity: &expectedAffinitya1b2MergedWithAWSPVWithAffinity,
+		},
+		"cloudprovider labels pre-existing affinity conflicting": {
+			vol:              awsPVWithAffinity,
+			labels:           map[string]string{"a": "1", "c": "2"},
+			expectedAffinity: nil,
+		},
+		"cloudprovider singlezone": {
+			vol:              awsPV,
+			labels:           map[string]string{kubeletapis.LabelZoneFailureDomain: "1"},
+			expectedAffinity: &expectedAffinityZone1MergedWithAWSPV,
+		},
+		"cloudprovider singlezone pre-existing affinity non-conflicting": {
+			vol:              awsPVWithAffinity,
+			labels:           map[string]string{kubeletapis.LabelZoneFailureDomain: "1"},
+			expectedAffinity: &expectedAffinityZone1MergedWithAWSPVWithAffinity,
+		},
+		"cloudprovider multizone": {
+			vol:              awsPV,
+			labels:           map[string]string{kubeletapis.LabelZoneFailureDomain: volumeutil.ZonesSetToLabelValue(zones)},
+			expectedAffinity: &expectedAffinityZonesMergedWithAWSPV,
+		},
+		"cloudprovider multizone pre-existing affinity non-conflicting": {
+			vol:              awsPVWithAffinity,
+			labels:           map[string]string{kubeletapis.LabelZoneFailureDomain: volumeutil.ZonesSetToLabelValue(zones)},
+			expectedAffinity: &expectedAffinityZonesMergedWithAWSPVWithAffinity,
+		},
+	}
+
+	utilfeature.DefaultFeatureGate.Set("VolumeScheduling=true")
+	defer utilfeature.DefaultFeatureGate.Set("VolumeScheduling=false")
 	for d, tc := range testCases {
 		cloud := &fakecloud.FakeCloud{}
 		client := fake.NewSimpleClientset()
@@ -104,16 +371,20 @@ func TestCreatePatch(t *testing.T) {
 		}
 		obj := &v1.PersistentVolume{}
 		json.Unmarshal(patch, obj)
-		if tc.labels != nil {
-			for k, v := range tc.labels {
-				if obj.ObjectMeta.Labels[k] != v {
-					t.Errorf("%s: label %s expected %s got %s", d, k, v, obj.ObjectMeta.Labels[k])
-				}
-			}
-		}
 		if obj.ObjectMeta.Initializers != nil {
 			t.Errorf("%s: initializer wasn't removed: %v", d, obj.ObjectMeta.Initializers)
 		}
+		if tc.labels == nil {
+			continue
+		}
+		for k, v := range tc.labels {
+			if obj.ObjectMeta.Labels[k] != v {
+				t.Errorf("%s: label %s expected %s got %s", d, k, v, obj.ObjectMeta.Labels[k])
+			}
+		}
+		if !reflect.DeepEqual(tc.expectedAffinity, obj.Spec.NodeAffinity) {
+			t.Errorf("Expected affinity %v does not match target affinity %v", tc.expectedAffinity, obj.Spec.NodeAffinity)
+		}
 	}
 }
 
@@ -132,32 +403,35 @@ func TestAddLabelsToVolume(t *testing.T) {
 	}
 
 	testCases := map[string]struct {
-		vol          v1.PersistentVolume
-		initializers *metav1.Initializers
-		shouldLabel  bool
+		vol                       v1.PersistentVolume
+		initializers              *metav1.Initializers
+		shouldLabelAndSetAffinity bool
 	}{
 		"PV without initializer": {
-			vol:          pv,
-			initializers: nil,
-			shouldLabel:  false,
+			vol:                       pv,
+			initializers:              nil,
+			shouldLabelAndSetAffinity: false,
 		},
 		"PV with initializer to remove": {
-			vol:          pv,
-			initializers: &metav1.Initializers{Pending: []metav1.Initializer{{Name: initializerName}}},
-			shouldLabel:  true,
+			vol:                       pv,
+			initializers:              &metav1.Initializers{Pending: []metav1.Initializer{{Name: initializerName}}},
+			shouldLabelAndSetAffinity: true,
 		},
 		"PV with other initializers only": {
-			vol:          pv,
-			initializers: &metav1.Initializers{Pending: []metav1.Initializer{{Name: "OtherInit"}}},
-			shouldLabel:  false,
+			vol:                       pv,
+			initializers:              &metav1.Initializers{Pending: []metav1.Initializer{{Name: "OtherInit"}}},
+			shouldLabelAndSetAffinity: false,
 		},
 		"PV with other initializers first": {
-			vol:          pv,
-			initializers: &metav1.Initializers{Pending: []metav1.Initializer{{Name: "OtherInit"}, {Name: initializerName}}},
-			shouldLabel:  false,
+			vol:                       pv,
+			initializers:              &metav1.Initializers{Pending: []metav1.Initializer{{Name: "OtherInit"}, {Name: initializerName}}},
+			shouldLabelAndSetAffinity: false,
 		},
 	}
 
+	utilfeature.DefaultFeatureGate.Set("VolumeScheduling=true")
+	defer utilfeature.DefaultFeatureGate.Set("VolumeScheduling=false")
+
 	for d, tc := range testCases {
 		labeledCh := make(chan bool, 1)
 		client := fake.NewSimpleClientset()
@@ -168,6 +442,22 @@ func TestAddLabelsToVolume(t *testing.T) {
 			if obj.ObjectMeta.Labels["a"] != "1" {
 				return false, nil, nil
 			}
+			if obj.Spec.NodeAffinity == nil {
+				return false, nil, nil
+			}
+			if obj.Spec.NodeAffinity.Required == nil {
+				return false, nil, nil
+			}
+			if len(obj.Spec.NodeAffinity.Required.NodeSelectorTerms) == 0 {
+				return false, nil, nil
+			}
+			reqs := obj.Spec.NodeAffinity.Required.NodeSelectorTerms[0].MatchExpressions
+			if len(reqs) != 1 {
+				return false, nil, nil
+			}
+			if reqs[0].Key != "a" || reqs[0].Values[0] != "1" || reqs[0].Operator != v1.NodeSelectorOpIn {
+				return false, nil, nil
+			}
 			labeledCh <- true
 			return true, nil, nil
 		})
@@ -177,16 +467,16 @@ func TestAddLabelsToVolume(t *testing.T) {
 		}
 		pvlController := &PersistentVolumeLabelController{kubeClient: client, cloud: fakeCloud}
 		tc.vol.ObjectMeta.Initializers = tc.initializers
-		pvlController.addLabelsToVolume(&tc.vol)
+		pvlController.addLabelsAndAffinityToVolume(&tc.vol)
 
 		select {
 		case l := <-labeledCh:
-			if l != tc.shouldLabel {
-				t.Errorf("%s: label of pv failed.  expected %t got %t", d, tc.shouldLabel, l)
+			if l != tc.shouldLabelAndSetAffinity {
+				t.Errorf("%s: label and affinity setting of pv failed.  expected %t got %t", d, tc.shouldLabelAndSetAffinity, l)
 			}
 		case <-time.After(500 * time.Millisecond):
-			if tc.shouldLabel != false {
-				t.Errorf("%s: timed out waiting for label notification", d)
+			if tc.shouldLabelAndSetAffinity != false {
+				t.Errorf("%s: timed out waiting for label and affinity setting notification", d)
 			}
 		}
 	}

plugin/pkg/admission/storage/persistentvolume/label/BUILD

@@ -18,10 +18,13 @@ go_library(
         "//pkg/cloudprovider:go_default_library",
         "//pkg/cloudprovider/providers/aws:go_default_library",
         "//pkg/cloudprovider/providers/gce:go_default_library",
+        "//pkg/features:go_default_library",
         "//pkg/kubeapiserver/admission:go_default_library",
         "//pkg/kubelet/apis:go_default_library",
         "//pkg/volume:go_default_library",
+        "//pkg/volume/util:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/admission:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
     ],
 )
@@ -33,10 +36,13 @@ go_test(
     deps = [
         "//pkg/apis/core:go_default_library",
         "//pkg/cloudprovider/providers/aws:go_default_library",
+        "//pkg/kubelet/apis:go_default_library",
+        "//pkg/volume/util:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/resource:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/types:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/admission:go_default_library",
+        "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
     ],
 )
 

plugin/pkg/admission/storage/persistentvolume/label/admission.go

@@ -24,13 +24,16 @@ import (
 
 	"github.com/golang/glog"
 	"k8s.io/apiserver/pkg/admission"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/aws"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/gce"
+	"k8s.io/kubernetes/pkg/features"
 	kubeapiserveradmission "k8s.io/kubernetes/pkg/kubeapiserver/admission"
 	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 	vol "k8s.io/kubernetes/pkg/volume"
+	volumeutil "k8s.io/kubernetes/pkg/volume/util"
 )
 
 const (
@@ -79,6 +82,19 @@ func (l *persistentVolumeLabel) SetCloudConfig(cloudConfig []byte) {
 	l.cloudConfig = cloudConfig
 }
 
+func nodeSelectorRequirementKeysExistInNodeSelectorTerms(reqs []api.NodeSelectorRequirement, terms []api.NodeSelectorTerm) bool {
+	for _, req := range reqs {
+		for _, term := range terms {
+			for _, r := range term.MatchExpressions {
+				if r.Key == req.Key {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}
+
 func (l *persistentVolumeLabel) Admit(a admission.Attributes) (err error) {
 	if a.GetResource().GroupResource() != api.Resource("persistentvolumes") {
 		return nil
@@ -108,6 +124,7 @@ func (l *persistentVolumeLabel) Admit(a admission.Attributes) (err error) {
 		volumeLabels = labels
 	}
 
+	requirements := make([]api.NodeSelectorRequirement, 0)
 	if len(volumeLabels) != 0 {
 		if volume.Labels == nil {
 			volume.Labels = make(map[string]string)
@@ -117,6 +134,42 @@ func (l *persistentVolumeLabel) Admit(a admission.Attributes) (err error) {
 			// This should be OK because they are in the kubernetes.io namespace
 			// i.e. we own them
 			volume.Labels[k] = v
+
+			// Set NodeSelectorRequirements based on the labels
+			var values []string
+			if k == kubeletapis.LabelZoneFailureDomain {
+				zones, err := volumeutil.LabelZonesToSet(v)
+				if err != nil {
+					return admission.NewForbidden(a, fmt.Errorf("failed to convert label string for Zone: %s to a Set", v))
+				}
+				values = zones.UnsortedList()
+			} else {
+				values = []string{v}
+			}
+			requirements = append(requirements, api.NodeSelectorRequirement{Key: k, Operator: api.NodeSelectorOpIn, Values: values})
+		}
+
+		if utilfeature.DefaultFeatureGate.Enabled(features.VolumeScheduling) {
+			if volume.Spec.NodeAffinity == nil {
+				volume.Spec.NodeAffinity = new(api.VolumeNodeAffinity)
+			}
+			if volume.Spec.NodeAffinity.Required == nil {
+				volume.Spec.NodeAffinity.Required = new(api.NodeSelector)
+			}
+			if len(volume.Spec.NodeAffinity.Required.NodeSelectorTerms) == 0 {
+				// Need atleast one term pre-allocated whose MatchExpressions can be appended to
+				volume.Spec.NodeAffinity.Required.NodeSelectorTerms = make([]api.NodeSelectorTerm, 1)
+			}
+			if nodeSelectorRequirementKeysExistInNodeSelectorTerms(requirements, volume.Spec.NodeAffinity.Required.NodeSelectorTerms) {
+				glog.V(4).Info("NodeSelectorRequirements for cloud labels %v conflict with existing NodeAffinity %v. Skipping addition of NodeSelectorRequirements for cloud labels.",
+					requirements, volume.Spec.NodeAffinity)
+			} else {
+				for _, req := range requirements {
+					for i := range volume.Spec.NodeAffinity.Required.NodeSelectorTerms {
+						volume.Spec.NodeAffinity.Required.NodeSelectorTerms[i].MatchExpressions = append(volume.Spec.NodeAffinity.Required.NodeSelectorTerms[i].MatchExpressions, req)
+					}
+				}
+			}
 		}
 	}
 

plugin/pkg/admission/storage/persistentvolume/label/admission_test.go

@@ -20,13 +20,18 @@ import (
 	"testing"
 
 	"fmt"
+	"reflect"
+	"sort"
 
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apiserver/pkg/admission"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/aws"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
+	volumeutil "k8s.io/kubernetes/pkg/volume/util"
 )
 
 type mockVolumes struct {
@@ -83,6 +88,16 @@ func mockVolumeLabels(labels map[string]string) *mockVolumes {
 	return &mockVolumes{volumeLabels: labels}
 }
 
+func getNodeSelectorRequirementWithKey(key string, term api.NodeSelectorTerm) (*api.NodeSelectorRequirement, error) {
+	for _, r := range term.MatchExpressions {
+		if r.Key != key {
+			continue
+		}
+		return &r, nil
+	}
+	return nil, fmt.Errorf("key %s not found", key)
+}
+
 // TestAdmission
 func TestAdmission(t *testing.T) {
 	pvHandler := newPersistentVolumeLabel()
@@ -107,6 +122,8 @@ func TestAdmission(t *testing.T) {
 			},
 		},
 	}
+	utilfeature.DefaultFeatureGate.Set("VolumeScheduling=true")
+	defer utilfeature.DefaultFeatureGate.Set("VolumeScheduling=false")
 
 	// Non-cloud PVs are ignored
 	err := handler.Admit(admission.NewAttributesRecord(&ignoredPV, nil, api.Kind("PersistentVolume").WithVersion("version"), ignoredPV.Namespace, ignoredPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
@@ -137,6 +154,9 @@ func TestAdmission(t *testing.T) {
 	if len(awsPV.ObjectMeta.Labels) != 0 {
 		t.Errorf("Unexpected number of labels")
 	}
+	if awsPV.Spec.NodeAffinity != nil {
+		t.Errorf("Unexpected NodeAffinity found")
+	}
 
 	// Don't panic if the cloudprovider returns nil, nil
 	pvHandler.ebsVolumes = mockVolumeFailure(nil)
@@ -145,17 +165,45 @@ func TestAdmission(t *testing.T) {
 		t.Errorf("Expected no error when cloud provider returns empty labels")
 	}
 
-	// Labels from the cloudprovider should be applied to the volume
+	// Labels from the cloudprovider should be applied to the volume as labels and node affinity expressions
 	labels = make(map[string]string)
 	labels["a"] = "1"
 	labels["b"] = "2"
+	zones, _ := volumeutil.ZonesToSet("1,2,3")
+	labels[kubeletapis.LabelZoneFailureDomain] = volumeutil.ZonesSetToLabelValue(zones)
 	pvHandler.ebsVolumes = mockVolumeLabels(labels)
 	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
 	if err != nil {
 		t.Errorf("Expected no error when creating aws pv")
 	}
 	if awsPV.Labels["a"] != "1" || awsPV.Labels["b"] != "2" {
-		t.Errorf("Expected label a to be added when creating aws pv")
+		t.Errorf("Expected label a and b to be added when creating aws pv")
+	}
+	if awsPV.Spec.NodeAffinity == nil {
+		t.Errorf("Unexpected nil NodeAffinity found")
+	}
+	if len(awsPV.Spec.NodeAffinity.Required.NodeSelectorTerms) != 1 {
+		t.Errorf("Unexpected number of NodeSelectorTerms")
+	}
+	term := awsPV.Spec.NodeAffinity.Required.NodeSelectorTerms[0]
+	if len(term.MatchExpressions) != 3 {
+		t.Errorf("Unexpected number of NodeSelectorRequirements in volume NodeAffinity: %d", len(term.MatchExpressions))
+	}
+	r, _ := getNodeSelectorRequirementWithKey("a", term)
+	if r == nil || r.Values[0] != "1" || r.Operator != api.NodeSelectorOpIn {
+		t.Errorf("NodeSelectorRequirement a-in-1 not found in volume NodeAffinity")
+	}
+	r, _ = getNodeSelectorRequirementWithKey("b", term)
+	if r == nil || r.Values[0] != "2" || r.Operator != api.NodeSelectorOpIn {
+		t.Errorf("NodeSelectorRequirement b-in-2 not found in volume NodeAffinity")
+	}
+	r, _ = getNodeSelectorRequirementWithKey(kubeletapis.LabelZoneFailureDomain, term)
+	if r == nil {
+		t.Errorf("NodeSelectorRequirement %s-in-%v not found in volume NodeAffinity", kubeletapis.LabelZoneFailureDomain, zones)
+	}
+	sort.Strings(r.Values)
+	if !reflect.DeepEqual(r.Values, zones.List()) {
+		t.Errorf("ZoneFailureDomain elements %v does not match zone labels %v", r.Values, zones)
 	}
 
 	// User-provided labels should be honored, but cloudprovider labels replace them when they overlap
@@ -173,4 +221,50 @@ func TestAdmission(t *testing.T) {
 		t.Errorf("Expected (non-conflicting) user provided labels to be honored when creating aws pv")
 	}
 
+	// if a conflicting affinity is already specified, leave affinity in-tact
+	labels = make(map[string]string)
+	labels["a"] = "1"
+	labels["b"] = "2"
+	labels["c"] = "3"
+	pvHandler.ebsVolumes = mockVolumeLabels(labels)
+	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
+	if err != nil {
+		t.Errorf("Expected no error when creating aws pv")
+	}
+	if awsPV.Spec.NodeAffinity == nil {
+		t.Errorf("Unexpected nil NodeAffinity found")
+	}
+	if awsPV.Spec.NodeAffinity.Required == nil {
+		t.Errorf("Unexpected nil NodeAffinity.Required %v", awsPV.Spec.NodeAffinity.Required)
+	}
+	r, _ = getNodeSelectorRequirementWithKey("c", awsPV.Spec.NodeAffinity.Required.NodeSelectorTerms[0])
+	if r != nil {
+		t.Errorf("NodeSelectorRequirement c not expected  in volume NodeAffinity")
+	}
+
+	// if a non-conflicting affinity is specified, check for new affinity being added
+	labels = make(map[string]string)
+	labels["e"] = "1"
+	labels["f"] = "2"
+	labels["g"] = "3"
+	pvHandler.ebsVolumes = mockVolumeLabels(labels)
+	err = handler.Admit(admission.NewAttributesRecord(&awsPV, nil, api.Kind("PersistentVolume").WithVersion("version"), awsPV.Namespace, awsPV.Name, api.Resource("persistentvolumes").WithVersion("version"), "", admission.Create, nil))
+	if err != nil {
+		t.Errorf("Expected no error when creating aws pv")
+	}
+	if awsPV.Spec.NodeAffinity == nil {
+		t.Errorf("Unexpected nil NodeAffinity found")
+	}
+	if awsPV.Spec.NodeAffinity.Required == nil {
+		t.Errorf("Unexpected nil NodeAffinity.Required %v", awsPV.Spec.NodeAffinity.Required)
+	}
+	// populate old entries
+	labels["a"] = "1"
+	labels["b"] = "2"
+	for k, v := range labels {
+		r, _ = getNodeSelectorRequirementWithKey(k, awsPV.Spec.NodeAffinity.Required.NodeSelectorTerms[0])
+		if r == nil || r.Values[0] != v || r.Operator != api.NodeSelectorOpIn {
+			t.Errorf("NodeSelectorRequirement %s-in-%v not found in volume NodeAffinity", k, v)
+		}
+	}
 }