AWS EKS Automation with Terraform

The golden rule of managing cloud infrastructures: "Don't click in the console, write Code!" The Infrastructure as Code (IaC) approach ensures your infrastructure is reproducible, versionable, and auditable. Using Terraform when setting up a complex service like AWS EKS is almost a necessity.

In this guide, we will examine how to set up a production-ready EKS cluster using Terraform. You can check our Terraform Consultancy services for professional support on Terraform.

Why Terraform?

• Modularity: You avoid writing hundreds of lines of code by using ready-made modules for EKS.
• State Management: Tracks the current state of your infrastructure and updates only the changed parts.
• Dependency Management: Knows that EKS cannot be created before VPC is created and sets the order automatically.

EKS Setup Steps with Terraform

1. Provider Settings

First, define the AWS provider.

provider "aws" {
  region = "eu-central-1"
}

2. VPC Module

EKS requires a specific network structure. The AWS VPC module makes our job easier.

module "vpc" {
  source = "terraform-aws-modules/vpc/aws"
  name   = "my-eks-vpc"
  cidr   = "10.0.0.0/16"

  azs             = ["eu-central-1a", "eu-central-1b"]
  private_subnets = ["10.0.1.0/24", "10.0.2.0/24"]
  public_subnets  = ["10.0.101.0/24", "10.0.102.0/24"]

  enable_nat_gateway = true
  enable_vpn_gateway = true

  tags = {
    "kubernetes.io/cluster/my-cluster" = "shared"
  }
}

3. EKS Module

The community-supported terraform-aws-modules/eks/aws module incredibly simplifies EKS setup.

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

  cluster_name    = "my-cluster"
  cluster_version = "1.30"

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

  eks_managed_node_groups = {
    general = {
      min_size     = 1
      max_size     = 3
      desired_size = 2
      instance_types = ["t3.medium"]
    }
  }

  enable_cluster_creator_admin_permissions = true
}

Execution

terraform init
terraform apply

After these commands, you will have a ready EKS cluster with its VPC, Security Groups, IAM Roles, and Worker Nodes in about 15-20 minutes.

Conclusion

Managing EKS with Terraform eliminates manual errors and allows you to make infrastructure changes (such as increasing node count or upgrading version) with just a code change and an apply command.