大部分情况下，不需要指定vip，因为内部pod通过域名的方式访问service，此处只是作为演示。

# svc-vip.yaml
apiVersion: v1
kind: Service
metadata:
  name: slb-s2
  namespace: default
spec:
  selector:
    app: nginx
    release: stable
    partition: website
    tier: slb
  clusterIP: 10.100.138.12
  ports:
  - name: http
    port: 80
    targetPort: 80

[root@maxiaoke nginx-01]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.100.0.1      <none>        443/TCP   13d
slb-s1       ClusterIP   10.100.138.11   <none>        80/TCP    64m
slb-s2       ClusterIP   10.100.138.12   <none>        80/TCP    7s
[root@maxiaoke nginx-01]# kubectl describe svc slb-s2
Name:              slb-s2
Namespace:         default
Labels:            <none>
Annotations:       <none>
Selector:          app=nginx,partition=website,release=stable,tier=slb
Type:              ClusterIP
IP Families:       <none>
IP:                10.100.138.12
IPs:               10.100.138.12
Port:              http  80/TCP
TargetPort:        80/TCP
Endpoints:         10.200.3.10:80,10.200.4.8:80,10.200.4.9:80 + 2 more...
Session Affinity:  None
Events:            <none>