k8sapi.go

/*
 Copyright (c) 2022 Dell Inc. or its subsidiaries. All Rights Reserved.

 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 k8s

import (
	"context"
	"sync"

	corev1 "k8s.io/api/core/v1"
	v1 "k8s.io/api/storage/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
)

// API holds data used to access the K8S API
type API struct {
	Client kubernetes.Interface
	Lock   sync.Mutex
}

// GetPersistentVolumes will return a list of persistent volumes in the kubernetes cluster
func (api *API) GetPersistentVolumes() (*corev1.PersistentVolumeList, error) {
	api.Lock.Lock()
	defer api.Lock.Unlock()
	if api.Client == nil {
		err := ConnectFn(api)
		if err != nil {
			return nil, err
		}
	}
	return api.Client.CoreV1().PersistentVolumes().List(context.Background(), metav1.ListOptions{})
}

// GetStorageClasses will return a list of storage classes in the kubernetes clusteer
func (api *API) GetStorageClasses() (*v1.StorageClassList, error) {
	api.Lock.Lock()
	defer api.Lock.Unlock()
	if api.Client == nil {
		err := ConnectFn(api)
		if err != nil {
			return nil, err
		}
	}
	return api.Client.StorageV1().StorageClasses().List(context.Background(), metav1.ListOptions{})
}

// ConnectFn will connect the client to the k8s API
var ConnectFn = func(api *API) error {
	config, err := getConfig()
	if err != nil {
		return err
	}
	api.Client, err = NewConfigFn(config)
	if err != nil {
		return err
	}
	return nil
}

// InClusterConfigFn will return a valid configuration if we are running in a Pod on a kubernetes cluster
var InClusterConfigFn = func() (*rest.Config, error) {
	return rest.InClusterConfig()
}

// NewConfigFn will return a valid kubernetes.Clientset
var NewConfigFn = func(config *rest.Config) (*kubernetes.Clientset, error) {
	return kubernetes.NewForConfig(config)
}

func getConfig() (*rest.Config, error) {
	config, err := InClusterConfigFn()
	if err != nil {
		return nil, err
	}
	return config, nil
}