client-go集群外认证k8s

除了认证外，还判断了操作系统。

且根据不同的系统，生成不同的文件。

在集群外认证时，使用的是k8s官方的方式，

而不是第三方库。

package main

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"runtime"

	//"time"
	"strings"

	//"k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/api/core/v1"
	//"k8s.io/apimachinery/pkg/labels"
	//"k8s.io/apimachinery/pkg/watch"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"

	//"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	//
	// Uncomment to load all auth plugins
	// _ "k8s.io/client-go/plugin/pkg/client/auth"
	//
	// Or uncomment to load specific auth plugins
	// _ "k8s.io/client-go/plugin/pkg/client/auth/azure"
	// _ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
	// _ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
	// _ "k8s.io/client-go/plugin/pkg/client/auth/openstack"
)

func main() {
	// creates the in-cluster config
	//config, err := rest.InClusterConfig()
	//if err != nil {
	//	panic(err.Error())
	//}
	// creates the clientset
	//clientset, err := kubernetes.NewForConfig(config)
	//if err != nil {
	//	panic(err.Error())
	//}

	// creates the out-cluster config
	var kubeconfig *string
	if home := 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()

	// use the current context in kubeconfig
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil {
		panic(err.Error())
	}

	// create the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}

	// get pods in all the namespaces by omitting namespace
	// Or specify namespace to get pods in particular namespace
	services, err := clientset.CoreV1().Services("").List(metav1.ListOptions{})
	if err != nil {
		panic(err.Error())
	}
	for i := 0; i < len(services.Items); i++ {
		item := services.Items[i].Annotations
		for k, v := range item {
			if strings.Contains(k, "getambassador") && strings.Contains(v, "ambassador") && strings.Contains(v, "Mapping") {
				fmt.Println(v)
				fmt.Println("@@@@@@@@@@@@@@@@@@@@@@@")
			}
		}
	}

	//time.Sleep(10 * time.Second)
	handleNewServices(clientset)

}

func handleNewServices(clientset *kubernetes.Clientset) {
	for {
		serviceStreamWatcher, err := clientset.CoreV1().Services("").Watch(metav1.ListOptions{})
		if err != nil {
			panic(err.Error())
		}
		fmt.Printf("%T\n", serviceStreamWatcher)
		for {
			select {
			case event := <-serviceStreamWatcher.ResultChan():

				service := event.Object.(*v1.Service)

				for key, value := range service.Annotations {
					if strings.Contains(key, "getambassador") && strings.Contains(value, "ambassador") && strings.Contains(value, "Mapping") {
						toFileStr := fmt.Sprintf("%s\n%s\n=============\n", event.Type, value)
						//fmt.Println(toFileStr)
						sysType := runtime.GOOS
						absFilePath := ""
						if sysType == "linux" {
							absFilePath = "/app/k8s-ambassador"
						} else {
							absFilePath = "k8s-ambassador"
						}
						_appendToFile(absFilePath, toFileStr)
					}
				}
			}
		}
	}
}

func _appendToFile(file, str string) {
	f, err := os.OpenFile(file, os.O_CREATE|os.O_APPEND|os.O_RDWR, 0664)
	if err != nil {
		fmt.Printf("Cannot open file %s!\n", file)
		return
	}
	defer f.Close()
	f.WriteString(str)
}

func homeDir() string {
	if h := os.Getenv("HOME"); h != "" {
		return h
	}
	return os.Getenv("USERPROFILE") // windows
}

client-go集群外认证k8s的相关教程结束。