How To Deploy Express With Amazon EKS

• GitHub: https://github.com/travisluong/fullstackbook-express-eks
• YouTube: https://www.youtube.com/watch?v=4NUrGJXt1cw

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

• Install Express.

  npm init
  npm install express --save

• Create express app. app.js

  const express = require('express')
  const app = express()
  const port = 3000
  
  app.get('/', (req, res) => {
    res.send('Hello World!')
  })
  
  app.listen(port, () => {
    console.log(`Example app listening on port ${port}`)
  })

• Create Dockerfile.

  FROM node:16
  WORKDIR /usr/src/app
  COPY package.json ./
  RUN npm install
  COPY . .
  CMD [ "node", "app.js" ]

• Build image.

  docker build -t express-eks .

• Run container.

  docker run -p 3000:3000 -it --rm --name express-eks-run express-eks

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: 3000
  ---
  apiVersion: v1
  kind: Service
  metadata:
    name: myapp
  spec:
    selector:
      app: myapp
    ports:
      - port: 80
        targetPort: 3000
    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

Deploy Script

• Use this script to deploy latest commits.

LATEST_SHA=$(git rev-parse HEAD)
docker build -t express-eks:$LATEST_SHA .
docker tag express-eks:$LATEST_SHA 207100238581.dkr.ecr.us-east-2.amazonaws.com/express-eks:$LATEST_SHA
docker push 207100238581.dkr.ecr.us-east-2.amazonaws.com/express-eks:$LATEST_SHA
kubectl set image deployment/myapp myapp=207100238581.dkr.ecr.us-east-2.amazonaws.com/express-eks:$LATEST_SHA -n default

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