英文:
How to watch events on a kubernetes service using its go client
问题
我希望在使用client-go时,每当Kubernetes上的服务发生更改时得到通知。
英文:
I would like to be informed when ever a service is changed on kubernetes using client-go.
答案1
得分: 20
可以这样完成:
package main
import (
"fmt"
"flag"
"time"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/pkg/fields"
)
var (
kubeconfig = flag.String("kubeconfig", "./config", "kubeconfig 文件的绝对路径")
)
func main() {
flag.Parse()
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
panic(err.Error())
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err.Error())
}
watchlist := cache.NewListWatchFromClient(clientset.Core().RESTClient(), "services", v1.NamespaceDefault,
fields.Everything())
_, controller := cache.NewInformer(
watchlist,
&v1.Service{},
time.Second * 0,
cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
fmt.Printf("service added: %s \n", obj)
},
DeleteFunc: func(obj interface{}) {
fmt.Printf("service deleted: %s \n", obj)
},
UpdateFunc:func(oldObj, newObj interface{}) {
fmt.Printf("service changed \n")
},
},
)
stop := make(chan struct{})
go controller.Run(stop)
for{
time.Sleep(time.Second)
}
}
希望对你有所帮助!
英文:
this can be done like this:
package main
import (
"fmt"
"flag"
"time"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/pkg/fields"
)
var (
kubeconfig = flag.String("kubeconfig", "./config", "absolute path to the kubeconfig file")
)
func main() {
flag.Parse()
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
panic(err.Error())
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err.Error())
}
watchlist := cache.NewListWatchFromClient(clientset.Core().RESTClient(), "services", v1.NamespaceDefault,
fields.Everything())
_, controller := cache.NewInformer(
watchlist,
&v1.Service{},
time.Second * 0,
cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
fmt.Printf("service added: %s \n", obj)
},
DeleteFunc: func(obj interface{}) {
fmt.Printf("service deleted: %s \n", obj)
},
UpdateFunc:func(oldObj, newObj interface{}) {
fmt.Printf("service changed \n")
},
},
)
stop := make(chan struct{})
go controller.Run(stop)
for{
time.Sleep(time.Second)
}
}
答案2
得分: 12
这是最新版本的client-go的用法示例,根据上面的代码。
package main
import (
"fmt"
"time"
"github.com/golang/glog"
"k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/fields"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
config, err := clientcmd.BuildConfigFromFlags("", "")
if err != nil {
glog.Errorln(err)
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
glog.Errorln(err)
}
watchlist := cache.NewListWatchFromClient(
clientset.CoreV1().RESTClient(),
string(v1.ResourceServices),
v1.NamespaceAll,
fields.Everything(),
)
_, controller := cache.NewInformer(
watchlist,
&v1.Service{},
0,
cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
fmt.Printf("service added: %s \n", obj)
},
DeleteFunc: func(obj interface{}) {
fmt.Printf("service deleted: %s \n", obj)
},
UpdateFunc: func(oldObj, newObj interface{}) {
fmt.Printf("service changed \n")
},
},
)
stop := make(chan struct{})
defer close(stop)
go controller.Run(stop)
for {
time.Sleep(time.Second)
}
}
以上是最新版本client-go的用法示例。
英文:
This is the latest version client-go's usage example. According the above code.
package main
import (
"fmt"
"time"
"github.com/golang/glog"
"k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/fields"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
config, err := clientcmd.BuildConfigFromFlags("", "")
if err != nil {
glog.Errorln(err)
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
glog.Errorln(err)
}
watchlist := cache.NewListWatchFromClient(
clientset.CoreV1().RESTClient(),
string(v1.ResourceServices),
v1.NamespaceAll,
fields.Everything(),
)
_, controller := cache.NewInformer( // also take a look at NewSharedIndexInformer
watchlist,
&v1.Service{},
0, //Duration is int64
cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
fmt.Printf("service added: %s \n", obj)
},
DeleteFunc: func(obj interface{}) {
fmt.Printf("service deleted: %s \n", obj)
},
UpdateFunc: func(oldObj, newObj interface{}) {
fmt.Printf("service changed \n")
},
},
)
// I found it in k8s scheduler module. Maybe it's help if you interested in.
// serviceInformer := cache.NewSharedIndexInformer(watchlist, &v1.Service{}, 0, cache.Indexers{
// cache.NamespaceIndex: cache.MetaNamespaceIndexFunc,
// })
// go serviceInformer.Run(stop)
stop := make(chan struct{})
defer close(stop)
go controller.Run(stop)
for {
time.Sleep(time.Second)
}
}
答案3
得分: 9
这是一个使用SharedInformerFactory的简单示例。
package main
import (
"fmt"
"time"
"github.com/golang/glog"
kubeinformers "k8s.io/client-go/informers"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
config, err := clientcmd.BuildConfigFromFlags("", "")
if err != nil {
glog.Errorln(err)
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
glog.Errorln(err)
}
kubeInformerFactory := kubeinformers.NewSharedInformerFactory(clientset, time.Second*30)
svcInformer := kubeInformerFactory.Core().V1().Services().Informer()
svcInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
fmt.Printf("service added: %s \n", obj)
},
DeleteFunc: func(obj interface{}) {
fmt.Printf("service deleted: %s \n", obj)
},
UpdateFunc: func(oldObj, newObj interface{}) {
fmt.Printf("service changed: %s \n", newObj)
},
})
stop := make(chan struct{})
defer close(stop)
kubeInformerFactory.Start(stop)
for {
time.Sleep(time.Second)
}
}
希望对你有帮助!
英文:
This is a simple one using SharedInformerFactory.
package main
import (
"fmt"
"time"
"github.com/golang/glog"
kubeinformers "k8s.io/client-go/informers"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
config, err := clientcmd.BuildConfigFromFlags("", "")
if err != nil {
glog.Errorln(err)
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
glog.Errorln(err)
}
kubeInformerFactory := kubeinformers.NewSharedInformerFactory(clientset, time.Second*30)
svcInformer := kubeInformerFactory.Core().V1().Services().Informer()
svcInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
fmt.Printf("service added: %s \n", obj)
},
DeleteFunc: func(obj interface{}) {
fmt.Printf("service deleted: %s \n", obj)
},
UpdateFunc: func(oldObj, newObj interface{}) {
fmt.Printf("service changed: %s \n", newObj)
},
},)
stop := make(chan struct{})
defer close(stop)
kubeInformerFactory.Start(stop)
for {
time.Sleep(time.Second)
}
}
答案4
得分: 9
package main
import (
"fmt"
"flag"
"time"
"log"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/pkg/fields"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/watch"
)
var (
kubeconfig = flag.String("kubeconfig", "./config", "kubeconfig文件的绝对路径")
)
func main() {
flag.Parse()
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
log.Fatal(err.Error())
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
log.Fatal(err.Error())
}
watcher, err := client.CoreV1().Services(v1.NamespaceDefault,).Watch(metav1.ListOptions{})
if err != nil {
log.Fatal(err)
}
for event := range watcher.ResultChan() {
svc := event.Object.(*v1.Service)
switch event.Type {
case watch.Added:
fmt.Printf("Service %s/%s 添加", svc.ObjectMeta.Namespace, svc.ObjectMeta.Name)
case watch.Modified:
fmt.Printf("Service %s/%s 修改", svc.ObjectMeta.Namespace, svc.ObjectMeta.Name)
case watch.Deleted:
fmt.Printf("Service %s/%s 删除", svc.ObjectMeta.Namespace, svc.ObjectMeta.Name)
}
}
}
<details>
<summary>英文:</summary>
package main
import (
"fmt"
"flag"
"time"
"log"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/pkg/fields"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/watch"
)
var (
kubeconfig = flag.String("kubeconfig", "./config", "absolute path to the kubeconfig file")
)
func main() {
flag.Parse()
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
log.Fatal(err.Error())
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
log.Fatal(err.Error())
}
watcher, err := client.CoreV1().Services(v1.NamespaceDefault,).Watch(metav1.ListOptions{})
if err != nil {
log.Fatal(err)
}
for event := range watcher.ResultChan() {
svc := event.Object.(*v1.Service)
switch event.Type {
case watch.Added:
fmt.Printf("Service %s/%s added", svc.ObjectMeta.Namespace, svc.ObjectMeta.Name)
case watch.Modified:
fmt.Printf("Service %s/%s modified", svc.ObjectMeta.Namespace, svc.ObjectMeta.Name)
case watch.Deleted:
fmt.Printf("Service %s/%s deleted", svc.ObjectMeta.Namespace, svc.ObjectMeta.Name)
}
}
}
</details>
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