老師, 

不好意思, 請教您一個問題

我不大懂 6-6-ingress-nginx-controller.yaml 加 Service resource的用意是什麼呢？

不加不是也work嗎？

```

kind: Service

apiVersion: v1

metadata:

name: ingress-nginx

namespace: ingress-nginx

labels:

app.kubernetes.io/name: ingress-nginx

app.kubernetes.io/part-of: ingress-nginx

spec:

clusterIP: 10.1.211.240

externalTrafficPolicy: Cluster

ports:

- name: http

nodePort: 31686

port: 80

protocol: TCP

targetPort: http

- name: https

nodePort: 30036

port: 443

protocol: TCP

targetPort: https

selector:

app.kubernetes.io/name: ingress-nginx

app.kubernetes.io/part-of: ingress-nginx

sessionAffinity: None

type: NodePort

 ```