Prerequisites

• Follow the getting started guide and make sure the following are installed:
  • AWS CLI
  • kubectl
  • eksctl
• https://docs.aws.amazon.com/eks/latest/userguide/getting-started.html

Initial Setup

• Set up Spring Boot.

  • Use Spring Initializr to generate a new project.
  • Select Spring Web as dependency.

• Create a Hello Controller HelloController.java.

  package com.example.fullstackbookspringbooteks;
  
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.RestController;
  
  @RestController
  public class HelloController {
      @GetMapping("/")
      public String hello() {
          return "Hello World!";
      }
  }
  
  

• Create Dockerfile.

  FROM openjdk:17
  WORKDIR /usr/src/myapp
  COPY target/fullstackbook-springboot-eks-0.0.1-SNAPSHOT.jar /usr/src/myapp
  CMD ["java", "-jar", "/usr/src/myapp/fullstackbook-springboot-eks-0.0.1-SNAPSHOT.jar"]
  

• Create an executable jar.

  ./mvnw clean package
  

• Build image.

  docker build -t myapp .
  

• Run container.

  docker run -p 8080:8080 -it --rm --name my-running-app myapp
  

Elastic Container Registry (ECR) Setup

• Go to Amazon ECR.
• Create a repository.
• Click on "View push commands".
• Follow the instructions to push image.
• Copy the image url.

Elastic Kubernetes Service (EKS) Setup

• Create EKS cluster.

  eksctl create cluster --name my-cluster --region us-west-2
  

• Confirm communication with cluster.

  kubectl get svc
  

• Create yaml configuration. k8s.yaml

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: myapp
  spec:
    selector:
      matchLabels:
        app: myapp
    template:
      metadata:
        labels:
          app: myapp
      spec:
        containers:
          - name: myapp
            image: 111111111111.dkr.ecr.us-east-2.amazonaws.com/myapp:latest
            resources:
              limits:
                memory: "128Mi"
                cpu: "500m"
            ports:
              - name: tcp
                containerPort: 8080
  ---
  apiVersion: v1
  kind: Service
  metadata:
    name: myapp
  spec:
    selector:
      app: myapp
    ports:
      - port: 80
        targetPort: 8080
    type: LoadBalancer
  

• Apply manifest.

  kubectl apply -f k8s.yaml
  

• Confirm pods.

  kubectl get pod
  

• Open shell into pod.

  kubectl exec -it myapp-7487b94844-wvfmn -- bash
  

• Confirm load balancer.

  kubectl get svc
  

• Confirm load balancer domain.

  nslookup af220a880523a491a991ecc793ae1da2-125775810.us-west-2.elb.amazonaws.com
  

  Note: This might take a few minutes.

• Confirm response from app.

  curl af220a880523a491a991ecc793ae1da2-125775810.us-west-2.elb.amazonaws.com
  

Set up AWS Load Balancer Controller

For more complex traffic routing, see how-to-set-up-aws-load-balancer-controller.md.

Delete cluster

• Delete the cluster avoid large AWS bill.

  eksctl delete cluster --name my-cluster
  

References

• https://docs.aws.amazon.com/eks/index.html
• https://docs.aws.amazon.com/ecr/index.html