1.ingress controller通过和kubernetes api交互，动态的去感知集群中ingress规则变化，

2.然后读取它，按照自定义的规则，规则就是写明了哪个域名对应哪个service，生成一段nginx配置，

3.再写到nginx-ingress-control的pod里，这个Ingress controller的pod里运行着一个Nginx服务，控制器会把生成的nginx配置写入/etc/nginx.conf文件中，

4.然后reload一下使配置生效。以此达到域名分配置和动态更新的问题。

apiVersion: v1

kind: Service

metadata:

  name: myapp

  namespace: default

spec:

  selector:

    app: myapp

    release: stable

  ports:

  - name: myapp

    port: 80

    targetPort: 80

---

apiVersion: apps/v1

kind: Deployment

metadata:

  name: myapp

  namespace: default

spec:

  selector:

    matchLabels:

      app: myapp

      release: stable

   replicas: 3

   template:

     metadata:

       labels:

         app: myapp

         release: stable

      spec:

        containers:

        - name: myapp

          image: fangwenkai/kubernetes:v1.15

          imagePullPolicy: IfNotPresent

        ports:

        - name: myapp

    　　containerPort: 80   

apiVersion: v1

kind: Service

metadata:

 name: ingress-nginx

 namespace: ingress-nginx

 labels:

   app.kubernetes.io/name: ingress-nginx

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

spec:

  type: NodePort

  ports:

  - name: http

  　port: 80

  　targetPort: 80

  　nodePort: 30001                                 // 手动指定服务器端口,不指定就是默认

  　protocol: TCP

  - name: https

    port: 443

  　targetPort: 443

  　nodePort: 30443                                 // 手动指定服务器端口,不指定就是默认

    protocol: TCP

  selector:

    app.kubernetes.io/name: ingress-nginx

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

  ---

apiVersion: extensions/v1beta1

kind: Ingress

metadata:

 name: ingress-myapp

 namespace: default

 annotations:

   kubernetes.io/ingress.class: "nginx"

spec:

  rules:

  - host: myapp.kaikai.com

    http:

     paths:

     - path:

       backend:

        serviceName: myapp

        servicePort: 80