Deploying and Scaling an Amazon EKS Cluster

In this lab, i will show you how i deployed an Amazon EKS cluster, deployed a sample application, and scaled the cluster using the Kubernetes Horizontal Pod Autoscaler (HPA).

Step 1: Installing the required tools

1. Install and configure the AWS CLI

2. Install [kubectl]

   curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
   sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl

3. Install the [eksctl] command-line tool.

   # for ARM systems, set ARCH to: `arm64`, `armv6` or `armv7`
   ARCH=amd64
   PLATFORM=$(uname -s)_$ARCH
   
   curl -sLO "https://github.com/weaveworks/eksctl/releases/latest/download/eksctl_$PLATFORM.tar.gz"
   
   # (Optional) Verify checksum
   curl -sL "https://github.com/weaveworks/eksctl/releases/latest/download/eksctl_checksums.txt" | grep $PLATFORM | sha256sum --check
   
   tar -xzf eksctl_$PLATFORM.tar.gz -C /tmp && rm eksctl_$PLATFORM.tar.gz
   
   sudo mv /tmp/eksctl /usr/local/bin

   Save the above script as eksctl.sh then run chmod +x eksctl.sh and sudo sh eksctl.sh

Step 2: Creating an EKS Cluster

1. Create a new Amazon EKS cluster using the eksctl command:

   eksctl create cluster --name my-eks-cluster --region us-east-1 --nodegroup-name my-nodegroup --node-type t2.small --nodes 3 --nodes-min 1 --nodes-max 5 --managed

   Replace my-eks-cluster and us-east-1 with your preferred cluster name and AWS region.

Step 3: Deploying a Sample Application

1. Create a new file named deployment.yaml with the following content:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx-deployment
   spec:
     selector:
       matchLabels:
         app: nginx
     replicas: 3
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: nginx:1.14.2
           ports:
           - containerPort: 80

2. Deploy the sample application to your EKS cluster:

   kubectl apply -f deployment.yaml

Step 4: Exposing the Application

1. Expose the application using a Kubernetes service:

   kubectl expose deployment nginx-deployment --type=LoadBalancer --name=my-service

2. Get the external IP address of the LoadBalancer:

   kubectl get services my-service

Step 5: Setting up Horizontal Pod Autoscaler (HPA)

1. Create a new file named hpa.yaml with the following content:

   apiVersion: autoscaling/v1
   kind: HorizontalPodAutoscaler
   metadata:
     name: nginx-deployment-hpa
   spec:
     scaleTargetRef:
       apiVersion: apps/v1
       kind: Deployment
       name: nginx-deployment
     minReplicas: 3
     maxReplicas: 10
     targetCPUUtilizationPercentage: 50

2. Apply the HPA configuration:

   kubectl apply -f hpa.yaml

   Now, your EKS cluster will automatically scale the number of pods based on the CPU utilization.

3. Configure permissions for your IAM user account

   kubectl get configmap aws-auth -n kube-system -o yaml > aws-auth.yaml

   Edit the aws-auth.yaml file and add the mapUsers section (as per the below example)

   apiVersion: v1
   data:
     mapRoles: |
       - groups:
         - system:bootstrappers
         - system:nodes
         rolearn: arn:aws:iam::<account-number>:role/eksctl-my-eks-cluster-nodegroup-m-NodeInstanceRole-ZKA8ZSWLC7Z2
         username: system:node:{{EC2PrivateDNSName}}
     mapUsers: |
       - userarn: <your-iam-user-arn>
         username: <your-iam-user-name>
         groups:
           - system:masters
   
   kind: ConfigMap
   metadata:
     creationTimestamp: "2024-07-27T10:41:25Z"
     name: aws-auth
     namespace: kube-system
     resourceVersion: "1215"
     uid: 54d885a3-3484-41d4-b032-41959915d8b6

   Then, run:

   kubectl apply -f aws-auth.yaml

   You should now have access to view all objects in the cluster.

Delete the service and cluster

kubectl delete svc my-service
eksctl delete cluster --name my-eks-cluster