扩展 kubernetes client-go

如何解决扩展 kubernetes client-go

我正在编写一个控制器来监视 kubernetes service 对象，并在它们包含某个标签时创建 trafficsplits。

由于原生kubernetes go客户端不支持trafficsplit对象，我不得不想办法扩展客户端，让它识别自定义资源。 我发现这个 guide 很有帮助，让我可以像这样解决这个问题 -

import (
    "splitClientV1alpha1 "github.com/servicemeshinterface/smi-sdk-go/pkg/gen/client/split/clientset/versioned/typed/split/v1alpha1"
    "k8s.io/client-go/kubernetes"
    ...
)

// getting ./kube/config from file
kubehome := filepath.Join(homedir.HomeDir(),".kube","config")
// Building the config from file
kubeConfig,err = clientcmd.BuildConfigFromFlags("",kubehome)
if err != nil {
    return fmt.Errorf("error loading kubernetes configuration: %w",err)
}

// Creating the native client object
kubeClient,err := kubernetes.NewForConfig(kubeConfig)
if err != nil {
    return fmt.Errorf("error creating kubernetes client: %w",err)
}

// Creating another clientset exclusively for the custom resource
splitClient,err := splitClientV1alpha1.NewForConfig(kubeConfig)
if err != nil {
    return fmt.Errorf("error creating split client: %s",err)
}

我觉得必须有一种方法可以使用 trafficsplit 模式扩展 kubeClient 对象，而不是像我那样创建一个单独的客户端。有什么办法可以做到这一点吗？

解决方法

这绝对有可能！你想使用 go 的结构扩展特性:)

基本上，我们创建了一个扩展 kubernetes.Clientset 和 splitClientV1alpha1.SplitV1alpha1Client 的结构，并使用与您上面的代码非常相似的代码对其进行初始化。然后我们可以在该结构上使用来自任一客户端的方法。

import (
    "fmt"
    splitClientV1alpha1 "github.com/servicemeshinterface/smi-sdk-go/pkg/gen/client/split/clientset/versioned/typed/split/v1alpha1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/tools/clientcmd"
    "k8s.io/client-go/util/homedir"
    "path/filepath"
)

type MyKubeClient struct {
    kubernetes.Clientset
    splitClientV1alpha1.SplitV1alpha1Client
}

func getClient() (*MyKubeClient,error) {
    // getting ./kube/config from file
    kubehome := filepath.Join(homedir.HomeDir(),".kube","config")
    // Building the config from file
    kubeConfig,err := clientcmd.BuildConfigFromFlags("",kubehome)
    if err != nil {
        return nil,fmt.Errorf("error loading kubernetes configuration: %w",err)
    }

    // Creating the native client object
    kubeClient,err := kubernetes.NewForConfig(kubeConfig)
    if err != nil {
        return nil,fmt.Errorf("error creating kubernetes client: %w",err)
    }

    // Creating another clientset exclusively for the custom resource
    splitClient,err := splitClientV1alpha1.NewForConfig(kubeConfig)
    if err != nil {
        return nil,fmt.Errorf("error creating split client: %s",err)
    }

    return &MyKubeClient{
        Clientset:           *kubeClient,SplitV1alpha1Client: *splitClient,},nil
}

func doSomething() error {
    client,err := getClient()
    if err != nil {
        return err
    }

    client.CoreV1().Pods("").Create(...)
    client.TrafficSplits(...)
}

如果您需要将自定义客户端传递给只需要原始 kubernetes.ClientSet 的函数，您可以使用：

func doSomething() error {
    client,err := getClient()
    if err != nil {
        return err
    }

    useClientSet(&client.Clientset)
}

func useOriginalKubeClientSet(clientSet *kubernetes.Clientset) {
    # ... do things
}