scheduler: integration test for ReadWriteOncePod alpha

Tests scheduler enforcement of the ReadWriteOncePod PVC access mode.

- Creates a pod using a PVC with ReadWriteOncePod
- Creates a second pod using the same PVC
- Observes the second pod fails to schedule because PVC is in-use
- Deletes the first pod
- Observes the second pod successfully schedules

pkg/scheduler/testing/wrappers.go

@@ -581,10 +581,7 @@ func (p *PodWrapper) Labels(labels map[string]string) *PodWrapper {
 
 // Annotation sets a {k,v} pair to the inner pod annotation.
 func (p *PodWrapper) Annotation(key, value string) *PodWrapper {
-	if p.ObjectMeta.Annotations == nil {
-		p.ObjectMeta.Annotations = make(map[string]string)
-	}
-	p.ObjectMeta.Annotations[key] = value
+	metav1.SetMetaDataAnnotation(&p.ObjectMeta, key, value)
 	return p
 }
 
@@ -695,3 +692,94 @@ func (n *NodeWrapper) Taints(taints []v1.Taint) *NodeWrapper {
 	n.Spec.Taints = taints
 	return n
 }
+
+// PersistentVolumeClaimWrapper wraps a PersistentVolumeClaim inside.
+type PersistentVolumeClaimWrapper struct{ v1.PersistentVolumeClaim }
+
+// MakePersistentVolumeClaim creates a PersistentVolumeClaim wrapper.
+func MakePersistentVolumeClaim() *PersistentVolumeClaimWrapper {
+	return &PersistentVolumeClaimWrapper{}
+}
+
+// Obj returns the inner PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) Obj() *v1.PersistentVolumeClaim {
+	return &p.PersistentVolumeClaim
+}
+
+// Name sets `s` as the name of the inner PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) Name(s string) *PersistentVolumeClaimWrapper {
+	p.SetName(s)
+	return p
+}
+
+// Namespace sets `s` as the namespace of the inner PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) Namespace(s string) *PersistentVolumeClaimWrapper {
+	p.SetNamespace(s)
+	return p
+}
+
+// Annotation sets a {k,v} pair to the inner PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) Annotation(key, value string) *PersistentVolumeClaimWrapper {
+	metav1.SetMetaDataAnnotation(&p.ObjectMeta, key, value)
+	return p
+}
+
+// VolumeName sets `name` as the volume name of the inner
+// PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) VolumeName(name string) *PersistentVolumeClaimWrapper {
+	p.PersistentVolumeClaim.Spec.VolumeName = name
+	return p
+}
+
+// AccessModes sets `accessModes` as the access modes of the inner
+// PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) AccessModes(accessModes []v1.PersistentVolumeAccessMode) *PersistentVolumeClaimWrapper {
+	p.PersistentVolumeClaim.Spec.AccessModes = accessModes
+	return p
+}
+
+// Resources sets `resources` as the resource requirements of the inner
+// PersistentVolumeClaim.
+func (p *PersistentVolumeClaimWrapper) Resources(resources v1.ResourceRequirements) *PersistentVolumeClaimWrapper {
+	p.PersistentVolumeClaim.Spec.Resources = resources
+	return p
+}
+
+// PersistentVolumeWrapper wraps a PersistentVolume inside.
+type PersistentVolumeWrapper struct{ v1.PersistentVolume }
+
+// MakePersistentVolume creates a PersistentVolume wrapper.
+func MakePersistentVolume() *PersistentVolumeWrapper {
+	return &PersistentVolumeWrapper{}
+}
+
+// Obj returns the inner PersistentVolume.
+func (p *PersistentVolumeWrapper) Obj() *v1.PersistentVolume {
+	return &p.PersistentVolume
+}
+
+// Name sets `s` as the name of the inner PersistentVolume.
+func (p *PersistentVolumeWrapper) Name(s string) *PersistentVolumeWrapper {
+	p.SetName(s)
+	return p
+}
+
+// AccessModes sets `accessModes` as the access modes of the inner
+// PersistentVolume.
+func (p *PersistentVolumeWrapper) AccessModes(accessModes []v1.PersistentVolumeAccessMode) *PersistentVolumeWrapper {
+	p.PersistentVolume.Spec.AccessModes = accessModes
+	return p
+}
+
+// Capacity sets `capacity` as the resource list of the inner PersistentVolume.
+func (p *PersistentVolumeWrapper) Capacity(capacity v1.ResourceList) *PersistentVolumeWrapper {
+	p.PersistentVolume.Spec.Capacity = capacity
+	return p
+}
+
+// HostPathVolumeSource sets `src` as the host path volume source of the inner
+// PersistentVolume.
+func (p *PersistentVolumeWrapper) HostPathVolumeSource(src *v1.HostPathVolumeSource) *PersistentVolumeWrapper {
+	p.PersistentVolume.Spec.HostPath = src
+	return p
+}

test/integration/scheduler/filters/filters_test.go

@@ -24,11 +24,13 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/wait"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/kubernetes"
 	featuregatetesting "k8s.io/component-base/featuregate/testing"
+	"k8s.io/component-helpers/storage/volume"
 	"k8s.io/kubernetes/pkg/features"
 	st "k8s.io/kubernetes/pkg/scheduler/testing"
 	testutils "k8s.io/kubernetes/test/integration/util"
@@ -1540,10 +1542,11 @@ var (
 
 func TestUnschedulablePodBecomesSchedulable(t *testing.T) {
 	tests := []struct {
-		name   string
-		init   func(kubernetes.Interface, string) error
-		pod    *testutils.PausePodConfig
-		update func(kubernetes.Interface, string) error
+		name                   string
+		init                   func(kubernetes.Interface, string) error
+		pod                    *testutils.PausePodConfig
+		update                 func(kubernetes.Interface, string) error
+		enableReadWriteOncePod bool
 	}{
 		{
 			name: "node gets added",
@@ -1687,9 +1690,76 @@ func TestUnschedulablePodBecomesSchedulable(t *testing.T) {
 				return nil
 			},
 		},
+		{
+			name: "scheduled pod uses read-write-once-pod pvc",
+			init: func(cs kubernetes.Interface, ns string) error {
+				_, err := createNode(cs, st.MakeNode().Name("node").Obj())
+				if err != nil {
+					return fmt.Errorf("cannot create node: %v", err)
+				}
+
+				storage := v1.ResourceRequirements{Requests: v1.ResourceList{v1.ResourceStorage: resource.MustParse("1Mi")}}
+				volType := v1.HostPathDirectoryOrCreate
+				pv, err := testutils.CreatePV(cs, st.MakePersistentVolume().
+					Name("pv-with-read-write-once-pod").
+					AccessModes([]v1.PersistentVolumeAccessMode{v1.ReadWriteOncePod}).
+					Capacity(storage.Requests).
+					HostPathVolumeSource(&v1.HostPathVolumeSource{Path: "/mnt", Type: &volType}).
+					Obj())
+				if err != nil {
+					return fmt.Errorf("cannot create pv: %v", err)
+				}
+				pvc, err := testutils.CreatePVC(cs, st.MakePersistentVolumeClaim().
+					Name("pvc-with-read-write-once-pod").
+					Namespace(ns).
+					// Annotation and volume name required for PVC to be considered bound.
+					Annotation(volume.AnnBindCompleted, "true").
+					VolumeName(pv.Name).
+					AccessModes([]v1.PersistentVolumeAccessMode{v1.ReadWriteOncePod}).
+					Resources(storage).
+					Obj())
+				if err != nil {
+					return fmt.Errorf("cannot create pvc: %v", err)
+				}
+
+				pod := initPausePod(&testutils.PausePodConfig{
+					Name:      "pod-to-be-deleted",
+					Namespace: ns,
+					Volumes: []v1.Volume{{
+						Name: "volume",
+						VolumeSource: v1.VolumeSource{
+							PersistentVolumeClaim: &v1.PersistentVolumeClaimVolumeSource{
+								ClaimName: pvc.Name,
+							},
+						},
+					}},
+				})
+				if _, err := createPausePod(cs, pod); err != nil {
+					return fmt.Errorf("cannot create pod: %v", err)
+				}
+				return nil
+			},
+			pod: &testutils.PausePodConfig{
+				Name: "pod-to-take-over-pvc",
+				Volumes: []v1.Volume{{
+					Name: "volume",
+					VolumeSource: v1.VolumeSource{
+						PersistentVolumeClaim: &v1.PersistentVolumeClaimVolumeSource{
+							ClaimName: "pvc-with-read-write-once-pod",
+						},
+					},
+				}},
+			},
+			update: func(cs kubernetes.Interface, ns string) error {
+				return deletePod(cs, "pod-to-be-deleted", ns)
+			},
+			enableReadWriteOncePod: true,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.ReadWriteOncePod, tt.enableReadWriteOncePod)()
+
 			testCtx := initTest(t, "scheduler-informer")
 			defer testutils.CleanupTest(t, testCtx)
 

test/integration/util/util.go

@@ -610,6 +610,7 @@ type PausePodConfig struct {
 	Priority                          *int32
 	PreemptionPolicy                  *v1.PreemptionPolicy
 	PriorityClassName                 string
+	Volumes                           []v1.Volume
 }
 
 // InitPausePod initializes a pod API object from the given config. It is used
@@ -637,6 +638,7 @@ func InitPausePod(conf *PausePodConfig) *v1.Pod {
 			Priority:          conf.Priority,
 			PreemptionPolicy:  conf.PreemptionPolicy,
 			PriorityClassName: conf.PriorityClassName,
+			Volumes:           conf.Volumes,
 		},
 	}
 	if conf.Resources != nil {
@@ -674,6 +676,18 @@ func CreatePausePodWithResource(cs clientset.Interface, podName string,
 	return CreatePausePod(cs, InitPausePod(&conf))
 }
 
+// CreatePVC creates a PersistentVolumeClaim with the given config and returns
+// its pointer and error status.
+func CreatePVC(cs clientset.Interface, pvc *v1.PersistentVolumeClaim) (*v1.PersistentVolumeClaim, error) {
+	return cs.CoreV1().PersistentVolumeClaims(pvc.Namespace).Create(context.TODO(), pvc, metav1.CreateOptions{})
+}
+
+// CreatePV creates a PersistentVolume with the given config and returns its
+// pointer and error status.
+func CreatePV(cs clientset.Interface, pv *v1.PersistentVolume) (*v1.PersistentVolume, error) {
+	return cs.CoreV1().PersistentVolumes().Create(context.TODO(), pv, metav1.CreateOptions{})
+}
+
 // RunPausePod creates a pod with "Pause" image and the given config and waits
 // until it is scheduled. It returns its pointer and error status.
 func RunPausePod(cs clientset.Interface, pod *v1.Pod) (*v1.Pod, error) {