create custom node condition

main.go

package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"

	"github.com/prometheus/common/log"
	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
)

func newK8SClient() (*kubernetes.Clientset, error) {
	userHomeDir, err := os.UserHomeDir()

	if err != nil {
		userHomeDir = ""
	}

	kubeConfig := filepath.Join(userHomeDir, ".kube", "config")
	k8sConfig, err := clientcmd.BuildConfigFromFlags("", kubeConfig)
	if err != nil {
		log.Fatalf("cannot build k8s config from file %s, err: %v", kubeConfig, err)
	}

	return kubernetes.NewForConfig(k8sConfig)
}

func main() {
	k8sClient, err := newK8SClient()
	if err != nil {
		log.Fatalf("cannot create k8s clientset, err: %v", err)
	}
	var samplecondition = []v1.NodeCondition{
		{
			Type:               v1.NodeConditionType("SampleCondition"),
			Status:             v1.ConditionStatus(v1.ConditionTrue),
			LastHeartbeatTime:  metav1.Now(),
			LastTransitionTime: metav1.Now(),
			Reason:             "Sample Reason",
			Message:            "Sample Messsage",
		},
	}
	raw, err := json.Marshal(&samplecondition)
	patch := []byte(fmt.Sprintf(`{"status":{"conditions":%s}}`, raw))
	nodename := "kind-control-plane"
	err = k8sClient.RESTClient().Patch(types.StrategicMergePatchType).RequestURI("/api/v1/nodes/" + nodename + "/status").Body(patch).Do().Error()
	if err != nil {
		log.Fatalf("cannot set node condition, err: %v", err)
	}

}