---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: busy
spec:
  serviceName: busy
  selector:
    matchLabels:
      app: busy
  replicas: 3
  template:
    metadata:
      name: busy
      labels:
        app: busy
    spec:
      containers:
        - name: busy
          image: busybox:1.28
          imagePullPolicy: IfNotPresent
          command:
            - sleep
            - "3600"
      restartPolicy: Always

---
kind: Service
apiVersion: v1
metadata:
  name: busy-headless
spec:
  clusterIP: None
  publishNotReadyAddresses: true
  selector:
    app: busy

17:00 $ kubectl exec -ti busy-0 -- nslookup busy-headless.default.svc.cluster.local
Server:    10.233.0.3
Address 1: 10.233.0.3 coredns.kube-system.svc.cluster.local

Name:      busy-headless.default.svc.cluster.local
Address 1: 10.233.67.10 10-233-67-10.busy-headless.default.svc.cluster.local
Address 2: 10.233.68.27 10-233-68-27.busy-headless.default.svc.cluster.local
Address 3: 10.233.68.26 10-233-68-26.busy-headless.default.svc.cluster.local
Address 4: 10.233.69.11 busy-0.busy.default.svc.cluster.local