How to list all pods in k8s cluster using client-go in golang program?

Question

I want to list all pods in k8s cluster using client-go in go program. A go program that list all pods in k8s cluster using client-go?

Answer 1

Assuming you are running the program inside the cluster use InClusterConfig as below and call clientset.CoreV1().Pods("").List(context.TODO(), metav1.ListOptions{}). Since we are not passing any value for namespace it will list all pods in all namespaces.

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())
    }
    for {
        // get pods in all the namespaces by omitting namespace
        // Or specify namespace to get pods in particular namespace
        pods, err := clientset.CoreV1().Pods("").List(context.TODO(), metav1.ListOptions{})
        if err != nil {
            panic(err.Error())
        }
        fmt.Printf("There are %d pods in the cluster\n", len(pods.Items))

        // Examples for error handling:
        // - Use helper functions e.g. errors.IsNotFound()
        // - And/or cast to StatusError and use its properties like e.g. ErrStatus.Message
        _, err = clientset.CoreV1().Pods("default").Get(context.TODO(), "example-xxxxx", metav1.GetOptions{})
        if errors.IsNotFound(err) {
            fmt.Printf("Pod example-xxxxx not found in default namespace\n")
        } else if statusError, isStatus := err.(*errors.StatusError); isStatus {
            fmt.Printf("Error getting pod %v\n", statusError.ErrStatus.Message)
        } else if err != nil {
            panic(err.Error())
        } else {
            fmt.Printf("Found example-xxxxx pod in default namespace\n")
        }

        time.Sleep(10 * time.Second)
    }
}