custom-kube-scheduler/kubernetes-v1.15.4/pkg/kubectl/util/storage/storage.go

/*
Copyright 2018 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 storage

import (
	"k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"strings"
)

// TODO(yue9944882): Remove this helper package once it's copied to k/api

// IsDefaultStorageClassAnnotation represents a StorageClass annotation that
// marks a class as the default StorageClass
const IsDefaultStorageClassAnnotation = "storageclass.kubernetes.io/is-default-class"

// BetaIsDefaultStorageClassAnnotation is the beta version of IsDefaultStorageClassAnnotation.
const BetaIsDefaultStorageClassAnnotation = "storageclass.beta.kubernetes.io/is-default-class"

// IsDefaultAnnotationText returns a pretty Yes/No String if
// the annotation is set
func IsDefaultAnnotationText(obj metav1.ObjectMeta) string {
	if obj.Annotations[IsDefaultStorageClassAnnotation] == "true" {
		return "Yes"
	}
	if obj.Annotations[BetaIsDefaultStorageClassAnnotation] == "true" {
		return "Yes"
	}

	return "No"
}

// GetAccessModesAsString returns a string representation of an array of access modes.
// modes, when present, are always in the same order: RWO,ROX,RWX.
func GetAccessModesAsString(modes []v1.PersistentVolumeAccessMode) string {
	modes = removeDuplicateAccessModes(modes)
	modesStr := []string{}
	if containsAccessMode(modes, v1.ReadWriteOnce) {
		modesStr = append(modesStr, "RWO")
	}
	if containsAccessMode(modes, v1.ReadOnlyMany) {
		modesStr = append(modesStr, "ROX")
	}
	if containsAccessMode(modes, v1.ReadWriteMany) {
		modesStr = append(modesStr, "RWX")
	}
	return strings.Join(modesStr, ",")
}

// removeDuplicateAccessModes returns an array of access modes without any duplicates
func removeDuplicateAccessModes(modes []v1.PersistentVolumeAccessMode) []v1.PersistentVolumeAccessMode {
	accessModes := []v1.PersistentVolumeAccessMode{}
	for _, m := range modes {
		if !containsAccessMode(accessModes, m) {
			accessModes = append(accessModes, m)
		}
	}
	return accessModes
}

func containsAccessMode(modes []v1.PersistentVolumeAccessMode, mode v1.PersistentVolumeAccessMode) bool {
	for _, m := range modes {
		if m == mode {
			return true
		}
	}
	return false
}

// GetPersistentVolumeClass returns StorageClassName.
func GetPersistentVolumeClass(volume *v1.PersistentVolume) string {
	// Use beta annotation first
	if class, found := volume.Annotations[v1.BetaStorageClassAnnotation]; found {
		return class
	}

	return volume.Spec.StorageClassName
}

// GetPersistentVolumeClaimClass returns StorageClassName. If no storage class was
// requested, it returns "".
func GetPersistentVolumeClaimClass(claim *v1.PersistentVolumeClaim) string {
	// Use beta annotation first
	if class, found := claim.Annotations[v1.BetaStorageClassAnnotation]; found {
		return class
	}

	if claim.Spec.StorageClassName != nil {
		return *claim.Spec.StorageClassName
	}

	return ""
}