Ingress-Nginx

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