EKS Auto Mode

EKS Auto Mode lets AWS fully manage the compute plane of your EKS cluster. Instead of provisioning and managing EC2 node groups yourself, you enable Auto Mode and AWS automatically provisions, scales, and terminates nodes based on workload demand. This example shows two configurations: one using the built-in general-purpose node pool, and one using only custom node pools (where you manage the NodePool and EC2NodeClass resources yourself).

Prerequisites

AWS credentials configured with permissions to create EKS clusters, IAM roles, VPCs, and EC2 resources
Terraform >= 1.5.7
AWS provider >= 6.28
The example provisions its own VPC — no pre-existing VPC is required

Due to a limitation in the EKS Auto Mode API, disabling Auto Mode requires explicitly setting compute_config = { enabled = false } and applying before you can remove the block entirely. Simply removing the compute_config block will not disable Auto Mode.

Example code

The following is the complete main.tf from examples/eks-auto-mode.

provider "aws" {
  region = local.region
}

data "aws_availability_zones" "available" {
  # Exclude local zones
  filter {
    name   = "opt-in-status"
    values = ["opt-in-not-required"]
  }
}

locals {
  name               = "ex-${basename(path.cwd)}"
  kubernetes_version = "1.33"
  region             = "us-west-2"

  vpc_cidr = "10.0.0.0/16"
  azs      = slice(data.aws_availability_zones.available.names, 0, 3)

  tags = {
    Test       = local.name
    GithubRepo = "terraform-aws-eks"
    GithubOrg  = "terraform-aws-modules"
  }
}

################################################################################
# EKS Module
################################################################################

module "eks" {
  source = "../.."  # use "terraform-aws-modules/eks/aws" version "~> 21.0" from registry

  name                   = local.name
  kubernetes_version     = local.kubernetes_version
  endpoint_public_access = true

  enable_cluster_creator_admin_permissions = true

  compute_config = {
    enabled    = true
    node_pools = ["general-purpose"]
  }

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

  tags = local.tags
}

module "eks_auto_custom_node_pools" {
  source = "../.."  # use "terraform-aws-modules/eks/aws" version "~> 21.0" from registry

  name                   = "${local.name}-custom"
  kubernetes_version     = local.kubernetes_version
  endpoint_public_access = true

  enable_cluster_creator_admin_permissions = true

  # Create just the IAM resources for EKS Auto Mode for use with custom node pools
  create_auto_mode_iam_resources = true
  compute_config = {
    enabled = true
  }

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

  tags = local.tags
}

module "disabled_eks" {
  source = "../.."  # use "terraform-aws-modules/eks/aws" version "~> 21.0" from registry

  create = false
}

################################################################################
# Supporting Resources
################################################################################

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "~> 6.0"

  name = local.name
  cidr = local.vpc_cidr

  azs             = local.azs
  private_subnets = [for k, v in local.azs : cidrsubnet(local.vpc_cidr, 4, k)]
  public_subnets  = [for k, v in local.azs : cidrsubnet(local.vpc_cidr, 8, k + 48)]
  intra_subnets   = [for k, v in local.azs : cidrsubnet(local.vpc_cidr, 8, k + 52)]

  enable_nat_gateway = true
  single_nat_gateway = true

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

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

  tags = local.tags
}

Key concepts

Built-in node pools vs. custom node pools

Configuration	When to use
`node_pools = ["general-purpose"]`	Let AWS manage a default pool; zero node-group config needed
`create_auto_mode_iam_resources = true` with no `node_pools`	You define your own `NodePool` / `EC2NodeClass` CRDs but still rely on the Auto Mode IAM setup

`compute_config` block

enabled = true — turns on EKS Auto Mode for the cluster
node_pools — list of built-in pools to activate; valid values include general-purpose and system
Omitting node_pools (with create_auto_mode_iam_resources = true) means you bring your own Karpenter-style NodePool resources

When endpoint_public_access = true, the Kubernetes API is reachable from the internet. Restrict endpoint_public_access_cidrs to your own IP range in production.

Deploy

Initialize Terraform

Download the required providers and modules.

terraform init

Review the plan

Preview what Terraform will create before applying.

terraform plan

Apply the configuration

Create the cluster and all supporting resources. Cluster creation typically takes 10–15 minutes.

terraform apply

Configure kubectl

Update your local kubeconfig so you can interact with the cluster.

aws eks update-kubeconfig --region us-west-2 --name <cluster-name>

Key outputs

After a successful apply the following outputs are available:

Output	Description
`cluster_name`	Name of the EKS cluster
`cluster_endpoint`	Kubernetes API server endpoint
`cluster_certificate_authority_data`	Base64-encoded CA data for kubectl
`cluster_iam_role_arn`	ARN of the cluster IAM role
`node_iam_role_arn`	ARN of the EKS Auto Mode node IAM role
`oidc_provider_arn`	OIDC provider ARN for IRSA

Cleanup

terraform destroy

Before destroying, ensure no external resources (load balancers, persistent volumes, etc.) were created by workloads running on the cluster. Those are not managed by this Terraform configuration and must be deleted separately.

Full example on GitHub

View the complete example including outputs.tf, variables.tf, and versions.tf.

Get Started

Compute Resources

Configuration

Sub-Modules

Examples

Operations

Prerequisites

Example code

Key concepts

Built-in node pools vs. custom node pools

`compute_config` block

Deploy

Key outputs

Cleanup

Full example on GitHub

​Prerequisites

​Example code

​Key concepts

​Built-in node pools vs. custom node pools

​compute_config block

​Deploy

​Key outputs

​Cleanup

​Full example on GitHub

Prerequisites

Example code

Key concepts

Built-in node pools vs. custom node pools

`compute_config` block

Deploy

Key outputs

Cleanup

Full example on GitHub