utils.go

/*
Copyright 2021 The Dapr 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 utils

import (
	"flag"
	"path/filepath"
	"regexp"
	"strings"
	"time"

	corev1 "k8s.io/api/core/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"
)

var (
	clientSet  *kubernetes.Clientset
	kubeConfig *rest.Config

	envRegexp = regexp.MustCompile(`(?m)(,)\s*[a-zA-Z\_][a-zA-Z0-9\_]*=`)
)

func initKubeConfig() {
	kubeConfig = GetConfig()
	clientset, err := kubernetes.NewForConfig(kubeConfig)
	if err != nil {
		panic(err)
	}

	clientSet = clientset
}

// GetConfig gets a kubernetes rest config.
func GetConfig() *rest.Config {
	if kubeConfig != nil {
		return kubeConfig
	}

	var kubeconfig *string
	if home := homedir.HomeDir(); home != "" {
		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
	} else {
		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
	}
	flag.Parse()

	conf, err := rest.InClusterConfig()
	if err != nil {
		conf, err = clientcmd.BuildConfigFromFlags("", *kubeconfig)
		if err != nil {
			panic(err)
		}
	}

	return conf
}

// GetKubeClient gets a kubernetes client.
func GetKubeClient() *kubernetes.Clientset {
	if clientSet == nil {
		initKubeConfig()
	}

	return clientSet
}

// ToISO8601DateTimeString converts dateTime to ISO8601 Format
// ISO8601 Format: 2020-01-01T01:01:01.10101Z.
func ToISO8601DateTimeString(dateTime time.Time) string {
	return dateTime.UTC().Format("2006-01-02T15:04:05.999999Z")
}

// add env-vars from annotations.
func ParseEnvString(envStr string) []corev1.EnvVar {
	indexes := envRegexp.FindAllStringIndex(envStr, -1)
	lastEnd := len(envStr)
	parts := make([]string, len(indexes)+1)
	for i := len(indexes) - 1; i >= 0; i-- {
		parts[i+1] = strings.TrimSpace(envStr[indexes[i][0]+1 : lastEnd])
		lastEnd = indexes[i][0]
	}
	parts[0] = envStr[0:lastEnd]

	envVars := make([]corev1.EnvVar, 0)
	for _, s := range parts {
		pairs := strings.Split(strings.TrimSpace(s), "=")
		if len(pairs) != 2 {
			continue
		}
		envVars = append(envVars, corev1.EnvVar{
			Name:  pairs[0],
			Value: pairs[1],
		})
	}

	return envVars
}

// StringSliceContains return true if an array containe the "str" string.
func StringSliceContains(needle string, haystack []string) bool {
	for _, item := range haystack {
		if item == needle {
			return true
		}
	}
	return false
}