雖然前面有提到雖然 K8S 內建有 load balance 機制，但是建立在 L4 上。所以只有不具備真正持久連線的 HTTP 可以使用。但真正具有持久連線的 gRPC，L4 就無法進行幫忙，導致擴展 pod 之後無法將流量導過去新的 pod 上，所以我們引用 app mesh 功能。

但 AWS 有提出不需要這麼麻煩建立 app mesh 的 解法，就是直接使用 AWS ALB ，在 2020/10 ，ALB 支援了 HTTP/2 and gRPC load balancing，這邊我們就來了解內容。

準備好 gRPC application 的 ECR image

1. git clone https://github.com/grpc/grpc/tree/master/examples/python/route_guide

2. 建立 Docker file

   FROM python:3.7
   RUN pip install protobuf grpcio
   COPY ./grpc/examples/python/route_guide .
   CMD python route_guide_server.py
   EXPOSE 50051
   

3. 上傳到 ECR

   aws ecr get-login-password --region eu-north-1 | docker login --username AWS --password-stdin 123412341234.dkr.ecr.eu-north-1.amazonaws.com
   docker build -t route-guide .
   docker tag route-guide:latest 123412341234.dkr.ecr.eu-north-1.amazonaws.com/route-guide:latest
   docker push 123412341234.dkr.ecr.eu-north-1.amazonaws.com/route-guide:latest
   

建立 cluster 跟 network 環境

1. 建立 EKS cluster

2. 建立 security group，並允許自己的電腦IP位置可以 TCP 連線到此 SG

3. 建立 TG

   apiVersion: v1
   kind: Service
   metadata:
     name: route-guide
   spec:
     ports:
       - port: 50051
         targetPort: 50051
         protocol: TCP
         name: grpc
     selector:
       app: route-guide
   
   ---
   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: route-guide-ingress
     annotations:
       kubernetes.io/ingress.class: alb
       alb.ingress.kubernetes.io/scheme: internet-facing
       alb.ingress.kubernetes.io/target-type: ip
       alb.ingress.kubernetes.io/listen-ports: '[{"HTTP": 80}]'
       alb.ingress.kubernetes.io/backend-protocol-version: HTTP
       alb.ingress.kubernetes.io/group.name: route-guide
   spec:
     rules:
     - http:
         paths:
         - path: /*
           pathType: ImplementationSpecific
           backend:
             service:
               name: route-guide
               port:
                 number: 50051
   

EKS 上部署 pod

1. sevice file

   apiVersion: v1
   kind: Service
   metadata:
     name: eks-service
   spec:
     selector:
       app: your-app-name
     ports:
       - protocol: TCP
         port: 50051
         targetPort: 50051
     type: LoadBalancer
   

部署 ingress (ALB)

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: route-guide-ingress
  annotations:
    kubernetes.io/ingress.class: alb
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/target-type: ip
spec:
  rules:
  - http:
      paths:
      - path: /*
        pathType: ImplementationSpecific
        backend:
          service:
            name: route-guide
            port:
              number: 50051

ref: https://docs.aws.amazon.com/prescriptive-guidance/latest/patterns/deploy-a-grpc-based-application-on-an-amazon-eks-cluster-and-access-it-with-an-application-load-balancer.htmlrre

ref: https://aws.amazon.com/tw/blogs/aws/new-application-load-balancer-support-for-end-to-end-http-2-and-grpc/