Deploy an EKS Cluster with Terraform

This tutorial was originally published on devopsstart.com. Learn how to automate the deployment of a production-ready EKS cluster using Terraform modules!

This tutorial walks you through deploying a production-ready Amazon EKS cluster using Terraform.

Step 1: Set Up the Project Structure

Create a new Terraform project:

mkdir eks-cluster && cd eks-cluster
touch main.tf variables.tf outputs.tf

Step 2: Configure the AWS Provider

terraform {
  required_version = ">= 1.5"
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

provider "aws" {
  region = var.region
}

variable "region" {
  default = "us-west-2"
}

variable "cluster_name" {
  default = "my-eks-cluster"
}

Step 3: Create the VPC

EKS needs a VPC with public and private subnets:

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "~> 5.0"

  name = "${var.cluster_name}-vpc"
  cidr = "10.0.0.0/16"

  azs             = ["${var.region}a", "${var.region}b", "${var.region}c"]
  private_subnets = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
  public_subnets  = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]

  enable_nat_gateway   = true
  single_nat_gateway   = true
  enable_dns_hostnames = true

  public_subnet_tags = {
    "kubernetes.io/role/elb" = 1
  }

  private_subnet_tags = {
    "kubernetes.io/role/internal-elb" = 1
  }
}

Step 4: Deploy the EKS Cluster

module "eks" {
  source  = "terraform-aws-modules/eks/aws"
  version = "~> 20.0"

  cluster_name    = var.cluster_name
  cluster_version = "1.30"

  vpc_id     = module.vpc.vpc_id
  subnet_ids = module.vpc.private_subnets

  eks_managed_node_groups = {
    default = {
      instance_types = ["t3.medium"]
      min_size       = 2
      max_size       = 4
      desired_size   = 2
    }
  }
}

Step 5: Apply and Connect

terraform init
terraform plan
terraform apply

aws eks update-kubeconfig --name my-eks-cluster --region us-west-2
kubectl get nodes

You should see your two worker nodes in Ready state.

Cleanup

To avoid ongoing costs:

terraform destroy

Troubleshooting

Nodes not joining the cluster? Check that the node group subnets have NAT gateway access and the correct IAM roles are attached.

kubectl connection refused? Run aws eks update-kubeconfig again and verify your AWS credentials.