Undefined error in go-client when listing the nodes

Question

I am new to golang and I am trying to list the nodes in my minikube cluster with the client-go. And I encounter the following issue:

nodeList.Items undefined (type *invalid type has no field or method Items)compilerMissingFieldOrMethod

And here's my code snippet for this:

package main

import (
    "context"
    "fmt"

    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/tools/clientcmd"
)

func main() {
    rules := clientcmd.NewDefaultClientConfigLoadingRules()
    kubeconfig := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(rules, &clientcmd.ConfigOverrides{})
    config, err := kubeconfig.ClientConfig()
    if err != nil {
        panic(err)
    }
    clientset := kubernetes.NewForConfigOrDie(config)

    nodeList, err := clientset.CoreV1().Nodes().List(context.Background(), metav1.ListOptions{})

    if err != nil {
        panic(err)
    }

    for _, node := range nodeList.Items {
        fmt.Printf("%s\n", node.Name)
    }
}

Can someone help me what is the problem here?

Thank you!

score 1 · Answer 1 · answered Nov 18 '22 at 12:40

It looks like the clientset is not created from your kubeconfig. I would suggest you to create the clientset in the following way. I have used out of cluster config here to create the clientset. You can also create it using InclusterConfig.

package main

import (
    "context"
    "flag"
    "fmt"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/util/homedir"
    "path/filepath"

    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/tools/clientcmd"
)

func main() {
    // parse the .kubeconfig file
    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()

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

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

    nodeList, err := clientset.CoreV1().Nodes().List(context.Background(), metav1.ListOptions{})

    if err != nil {
        panic(err)
    }

    for _, node := range nodeList.Items {
        fmt.Printf("%s\n", node.Name)
    }
}

Undefined error in go-client when listing the nodes

1 Answers1