How to Create an EKS Cluster Using Terraform

 

How to Create an EKS Cluster Using Terraform – Step-by-Step Guide

Amazon Elastic Kubernetes Service (EKS) is a fully managed service that simplifies running Kubernetes on AWS without managing the control plane yourself. If you’re a DevOps engineer or cloud enthusiast, knowing how to create an EKS cluster using Terraform is a must.

In this guide, we’ll cover everything you need — from prerequisites to deployment — so you can quickly set up a production-ready EKS cluster on AWS.

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Why Use Terraform for EKS?

Terraform helps automate AWS infrastructure creation. Instead of manually creating resources, you write declarative code, making deployments repeatable, scalable, and version-controlled.

Key benefits include:

• Infrastructure as Code (IaC): Easy versioning and collaboration

• Reusable Modules: Write once, use anywhere

• Cost Management: Automate cleanup to avoid surprises

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Prerequisites

Before we begin, make sure you have:

• An AWS account with admin access

• AWS CLI installed and configured

• Terraform installed (v1.5+ recommended)

• A code editor like VS Code

• Basic knowledge of AWS and Kubernetes

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Step 1: Create a Terraform Project

Create a folder for your project:

mkdir eks-terraform
cd eks-terraform

Inside this folder, create three files:

• main.tf → Core infrastructure code

• variables.tf → Variables for customization

• outputs.tf → Outputs for easy access

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Step 2: Configure Provider

In main.tf, start with the AWS provider:

provider "aws" {
  region = "us-east-1"
}

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Step 3: Use the EKS Terraform Module

HashiCorp provides a ready-made EKS module, making things easier. Add this code to main.tf:

module "eks" {
  source          = "terraform-aws-modules/eks/aws"
  cluster_name    = "my-eks-cluster"
  cluster_version = "1.30"
  subnets         = ["subnet-123456", "subnet-654321"]
  vpc_id          = "vpc-123456"

  node_groups = {
    default = {
      desired_capacity = 2
      max_capacity     = 3
      min_capacity     = 1
      instance_types   = ["t3.medium"]
    }
  }
}

Tip: Replace vpc_id and subnets with your real values.

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Step 4: Variables and Outputs

In variables.tf, define variables:

variable "region" {
  default = "us-east-1"
}

In outputs.tf, print the EKS cluster endpoint:

output "eks_cluster_endpoint" {
  value = module.eks.cluster_endpoint
}

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Step 5: Initialize and Apply

Run the following commands:

terraform init
terraform plan
terraform apply

When prompted, type yes to confirm.

Terraform will now create:

• EKS Control Plane

• Worker Nodes

• Required IAM Roles

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Step 6: Configure kubectl

Once the cluster is ready, update your kubeconfig:

aws eks --region us-east-1 update-kubeconfig --name my-eks-cluster

Check your nodes:

kubectl get nodes

If everything works, you have a running EKS cluster! 🎉

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Step 7: Deploy a Test Application

To confirm, deploy an NGINX pod:

kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=LoadBalancer

After a few minutes, get the external IP:

kubectl get svc

Open it in your browser — you should see the NGINX welcome page.

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Best Practices for EKS with Terraform

• Store state remotely: Use S3 + DynamoDB for Terraform state

• Enable logging & monitoring: Integrate CloudWatch or Prometheus

• Use modules: Keep your Terraform code modular and clean

• Automate CI/CD: Use GitLab or GitHub Actions for deployments

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Conclusion

That’s it! You’ve learned how to create an EKS cluster using Terraform step by step. With this setup, you can easily scale your infrastructure and deploy applications faster.

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