AKS (12) Application Gateway后端指向Azure AKS

　　《Windows Azure Platform 系列文章目录》

　　我们在使用Azure AKS的时候，会通过Azure Application Gateway进行服务暴露，主要有三种实现方式：

　　(1)推荐做法：通过AGIC (Application Gateway Ingress Controller)配置

　　(2)AKS服务，通过Node Port暴露。然后Application Gateway后端池指向到Azure AKS Node Port内网IP地址

　　(3)AKS服务，通过Internal Load Balancer暴露。然后Application Gateway后端池，指向到Azure AKS Internal Load Balancer负载均衡器内网IP

　　第一种配置方式，可以参考：https://learn.microsoft.com/en-us/azure/application-gateway/ingress-controller-install-existing

　　第二种配置方式，具体部署步骤如下：

　　1.手动创建Azure application Gateway，步骤略。

　　2.创建Azure AKS SVC，服务暴露通过Nodeport暴露，如下：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: scnginx-deployment
  labels:
    app: scnginx
spec:
  replicas: 9
  selector:
    matchLabels:
      app: scnginx
  template:
    metadata:
      labels:
        app: scnginx
    spec:
      containers:
      - name: nginx
        image: nginx
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: scnginx-service
spec:
  type: NodePort    
  selector:
    app: scnginx
  ports:
  - name: nginx-svc-nodeport
    protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30009

　　3.通过执行kubectl get node -o wide，查看AKS Node的内网IP地址。具体截图略

　　4.Application Gateway的后端IP地址，指向到AKS Node 的内网IP

　　第三种配置方式，具体部署步骤如下：

　　1.创建Azure AKS SVC，服务暴露通过Azure内网负载均衡器实现。文件名指定为：2.azure_svc_internal_lb.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 9
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service-lb
  annotations:
    #指定负载均衡器的内网IP，请按照实际场景修改
    service.beta.kubernetes.io/azure-load-balancer-ipv4: 10.0.4.4
    #指定负载均衡器的类型，为内网
    service.beta.kubernetes.io/azure-load-balancer-internal: "true"
    #指定负载均衡器所在的子网
    service.beta.kubernetes.io/azure-load-balancer-internal-subnet: "internal-lb-subnet"
spec:
  type: LoadBalancer    
  selector:
    app: nginx
  ports:
  - name: nginx-svc-intenral-lb
    protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30009