Deploying an AWS EKS Cluster Using Terraform: A Step-by-Step Guide

Introduction

In today's cloud-native landscape, Kubernetes has become the de facto standard for container orchestration, and Amazon Elastic Kubernetes Service (EKS) provides a managed Kubernetes service that simplifies cluster management. When combined with Terraform, HashiCorp's Infrastructure as Code (IaC) tool, you can achieve reproducible, version-controlled, and automated Kubernetes infrastructure deployment.

This comprehensive guide will walk you through deploying a production-ready AWS EKS cluster using Terraform, covering everything from initial setup to operational best practices.

Prerequisites

Before beginning, ensure you have the following:

• AWS Account with appropriate IAM permissions


• AWS CLI installed and configured


• Terraform (v1.0+) installed


• kubectl for Kubernetes cluster interaction


• Basic understanding of AWS services, Kubernetes, and Terraform

Architecture Overview

Our deployment will create:

• A VPC with public and private subnets across multiple Availability Zones


• EKS control plane managed by AWS


• Managed node groups for worker nodes


• Necessary IAM roles and security groups


• Network components (NAT Gateway, Internet Gateway, Route Tables)

Efficient EKS Cluster Provisioning with Terraform's Modular Design

This implementation employs a Terraform module containing pre-defined configurations to simplify Amazon EKS cluster creation, demonstrating infrastructure-as-code efficiency.

Step 1: Prepare Your Environment - Install Terraform

Begin by installing Terraform locally to set up your development environment.

brew install terraform

Secondly, install the AWS CLI:

brew install awscli

Thirdly, install kubectl:

brew install kubernetes-cli

For installation on other operating systems, see the official documentation:

Terraform: Installation guide



AWS CLI: Installation instructions



kubectl: Installation documentation

Step 2: Configure AWS CLI Access

Run

aws configure

to set up authentication with your AWS account. You'll need to enter:

• AWS Access Key ID


• AWS Secret Access Key


• Default region: us-east-1

Terraform will use these credentials to create and manage your AWS resources.

Step 3: Prepare the Code Environment

We'll utilize the terraform-aws-modules/eks/aws Terraform module for this implementation.

data "aws_availability_zones" "available" {}



resource "aws_vpc" "main" {

 cidr_block = "10.0.0.0/16"



 tags = {

   Name = "main-vpc-eks"

 }

}



resource "aws_subnet" "public_subnet" {

 count                   = 2

 vpc_id                  = aws_vpc.main.id

 cidr_block              = cidrsubnet(aws_vpc.main.cidr_block, 8, count.index)

 availability_zone       = data.aws_availability_zones.available.names[count.index]

 map_public_ip_on_launch = true



 tags = {

   Name = "public-subnet-${count.index}"

 }

}



resource "aws_internet_gateway" "main" {

 vpc_id = aws_vpc.main.id



 tags = {

   Name = "main-igw"

 }

}



resource "aws_route_table" "public" {

 vpc_id = aws_vpc.main.id



 route {

   cidr_block = "0.0.0.0/0"

   gateway_id = aws_internet_gateway.main.id

 }



 tags = {

   Name = "main-route-table"

 }

}



resource "aws_route_table_association" "a" {

 count          = 2

 subnet_id      = aws_subnet.public_subnet.*.id[count.index]

 route_table_id = aws_route_table.public.id

}



module "eks" {

 source  = "terraform-aws-modules/eks/aws"

 version = "~> 20.31"



 cluster_name    = "sage-nodes"

 cluster_version = "1.31"



 # Optional

 cluster_endpoint_public_access = true



 # Optional: Adds the current caller identity as an administrator via cluster access entry

 enable_cluster_creator_admin_permissions = true



 eks_managed_node_groups = {

   sage-nodes = {

     instance_types = ["t3.medium"]

     min_size       = 1

     max_size       = 3

     desired_size   = 2

   }

 }



 vpc_id     = aws_vpc.main.id

 subnet_ids = aws_subnet.public_subnet.*.id



 tags = {

   Environment = "dev"

   Terraform   = "true"

 }

}

Step 4: Apply Terraform Configuration

Begin by initializing Terraform to download dependencies, then apply the configuration to create your EKS cluster infrastructure.

terraform init

Post-initialization, generate a plan to review infrastructure changes.

terraform plan

Wait a few minutes for all resources to be created.

Step 5 – Configure kubectl Access

Run the following command:

aws eks --region us-east-1 update-kubeconfig --name example

At this point, verify that the login to the cluster was successful.

kubectl config current-context

Step 6 – Manage the Cluster

Use the following command to view all nodes in the cluster:

kubectl get nodes   

To validate the cluster, deploy an NGINX instance.

kubectl run --port 80 --image nginx nginx

To see its status:

kubectl get pods          

Now, establish a tunnel from your local environment to the pod.

kubectl port-forward nginx 3000:80

Step 7 – Resource Cleanup

To destroy the resources created in this session, execute the following command:

terraform destroy

Ensure to destroy the created resources to avoid incurring huge financial bills from AWS.

Conclusion

By completing this guide, you've established a production-ready AWS EKS cluster deployment using Terraform's infrastructure-as-code approach. This foundation enables consistent, version-controlled Kubernetes infrastructure management across all environments.

Chidubem Chinwuba is a dedicated Cloud/DevOps Engineer. He possesses a deep passion for technology and its transformative potential across industries. Overall, Chidubem is driven by his passion for technology and his aspiration to make a meaningful impact in the Cloud/DevOps domain. He is excited to continue his professional growth and contribute to projects that shape the future of technology.