在 Go 中创建自定义 Kubernetes 控制器

apiversion: apiextensions.k8s.io/v1

kind: customresourcedefinition

Metadata:

  name: my-crds.com.shivam.kumar

spec:

  group: com.shivam.kumar

  names:

    kind: my-crd

    plural: my-crds

  scope: namespaced

  versions:

    - name: v1

      served: true

      storage: true

      schema:

        openapiv3schema:

          type: object

          properties:

            apiversion:

              type: string

            kind:

              type: string

            metadata:

              type: object

            spec:

              type: object

              properties:

                descrIPtion:

                  type: string

apiversion: com.shivam.kumar/v1

kind: my-crd

metadata:

  name: my-custom-resource

spec:

  description: "my crd instance"

package main

import (

    "context"

    "fmt"

    "path/filepath"

    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

    "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"

    "k8s.io/apimachinery/pkg/runtime"

    "k8s.io/apimachinery/pkg/runtime/schema"

    "k8s.io/apimachinery/pkg/watch"

    "k8s.io/client-go/dynamic"

    "k8s.io/client-go/rest"

    "k8s.io/client-go/tools/cache"

    "k8s.io/client-go/tools/clientcmd"

    "k8s.io/client-go/util/homedir"

)

func main() {

    var kubeconfig string

    if home := homedir.HomeDir(); home != "" {

        kubeconfig = filepath.Join(home, ".kube", "config")

    }

    config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)

    if err != nil {

        fmt.Println("Falling back to in-cluster config")

        config, err = rest.InClusterConfig()

        if err != nil {

            panic(err.Error())

        }

    }

    dynClient, err := dynamic.NewForConfig(config)

    if err != nil {

        panic(err.Error())

    }

    thefoothebar := schema.GroupVersionResource{Group: "com.shivam.kumar", Version: "v1", Resource: "my-crds"}

    infORMer := cache.NewSharedIndexInformer(

        &cache.ListWatch{

            ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {

                return dynClient.Resource(thefoothebar).Namespace("").List(context.TODO(), options)

            },

            WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {

                return dynClient.Resource(thefoothebar).Namespace("").Watch(context.TODO(), options)

            },

        },

        &unstructured.Unstructured{},

        0,

        cache.Indexers{},

    )

    informer.AddEventHandler(cache.ResourceEventHandlerFuncs{

        AddFunc: func(obj interface{}) {

            fmt.Println("Add event detected:", obj)

        },

        UpdateFunc: func(oldObj, newObj interface{}) {

            fmt.Println("Update event detected:", newObj)

        },

        DeleteFunc: func(obj interface{}) {

            fmt.Println("Delete event detected:", obj)

        },

    })

    stop := make(chan struct{})

    defer close(stop)

    go informer.Run(stop)

    if !cache.WaitForCacheSync(stop, informer.HasSynced) {

        panic("Timeout waiting for cache sync")

    }

    fmt.Println("Custom Resource Controller started successfully")

<p>现在当我们构建这个 go 程序并运行它时 -<br>

go build -o k8s-controller .<br>

./k8s-控制器</p>

<p>现在，每当我们添加、更新或删除上面创建的自定义资源时，我们都会在终端中获取它的活动日志。所以这意味着我们的控制器正在监视我们的 crd。</p>