Getting Started with Auto Mode

Supported Versions: EKS 1.29+, EKS Auto Mode GA Last Updated: February 19, 2026

This guide covers how to enable EKS Auto Mode on new clusters and how to convert existing clusters to use Auto Mode.

---

Enabling Auto Mode on a New Cluster

Creating a Cluster with eksctl

# cluster-auto-mode.yaml
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: my-auto-mode-cluster
  region: ap-northeast-2
  version: "1.31"

# Enable Auto Mode
autoModeConfig:
  enabled: true
  # Auto-create default NodePools
  nodePools:
    - general-purpose
    - system

vpc:
  cidr: 10.0.0.0/16
  nat:
    gateway: Single
  clusterEndpoints:
    publicAccess: true
    privateAccess: true

# Auto-create IAM OIDC Provider
iam:
  withOIDC: true

# Create cluster
eksctl create cluster -f cluster-auto-mode.yaml

# Verify creation
kubectl get nodepools

Creating a Cluster with Terraform

# main.tf
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

provider "aws" {
  region = "ap-northeast-2"
}

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

  name = "eks-auto-mode-vpc"
  cidr = "10.0.0.0/16"

  azs             = ["ap-northeast-2a", "ap-northeast-2b", "ap-northeast-2c"]
  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
  enable_dns_support     = true

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

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

# EKS Cluster with Auto Mode
module "eks" {
  source  = "terraform-aws-modules/eks/aws"
  version = "~> 20.0"

  cluster_name    = "my-auto-mode-cluster"
  cluster_version = "1.31"

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

  cluster_endpoint_public_access  = true
  cluster_endpoint_private_access = true

  # Enable Auto Mode
  cluster_compute_config = {
    enabled    = true
    node_pools = ["general-purpose", "system"]
  }

  # OIDC Provider
  enable_irsa = true

  tags = {
    Environment = "production"
    Terraform   = "true"
  }
}

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

output "cluster_name" {
  value = module.eks.cluster_name
}

# Run Terraform
terraform init
terraform plan
terraform apply

Creating a Cluster with AWS CDK

// lib/eks-auto-mode-stack.ts
import * as cdk from 'aws-cdk-lib';
import * as ec2 from 'aws-cdk-lib/aws-ec2';
import * as eks from 'aws-cdk-lib/aws-eks';
import { Construct } from 'constructs';

export class EksAutoModeStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // Create VPC
    const vpc = new ec2.Vpc(this, 'EksVpc', {
      maxAzs: 3,
      natGateways: 1,
      subnetConfiguration: [
        {
          cidrMask: 24,
          name: 'Public',
          subnetType: ec2.SubnetType.PUBLIC,
        },
        {
          cidrMask: 24,
          name: 'Private',
          subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS,
        },
      ],
    });

    // EKS Cluster with Auto Mode
    const cluster = new eks.Cluster(this, 'EksAutoModeCluster', {
      version: eks.KubernetesVersion.V1_31,
      vpc,
      vpcSubnets: [{ subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS }],
      defaultCapacity: 0, // Auto Mode disables default capacity
      clusterName: 'my-auto-mode-cluster',
      endpointAccess: eks.EndpointAccess.PUBLIC_AND_PRIVATE,
    });

    // Enable Auto Mode (using CfnCluster)
    const cfnCluster = cluster.node.defaultChild as eks.CfnCluster;
    cfnCluster.computeConfig = {
      enabled: true,
      nodePools: ['general-purpose', 'system'],
    };

    // Outputs
    new cdk.CfnOutput(this, 'ClusterName', {
      value: cluster.clusterName,
    });

    new cdk.CfnOutput(this, 'ClusterEndpoint', {
      value: cluster.clusterEndpoint,
    });
  }
}

---

Switching to Auto Mode on Existing Clusters

Here's how to switch from a cluster using existing managed node groups to Auto Mode.

# 1. Check current cluster state
aws eks describe-cluster --name my-cluster --query 'cluster.computeConfig'

# 2. Enable Auto Mode
aws eks update-cluster-config \
    --name my-cluster \
    --compute-config enabled=true,nodePools=general-purpose,nodePools=system

# 3. Check update status
aws eks describe-update \
    --name my-cluster \
    --update-id <update-id>

# 4. Verify NodePool creation
kubectl get nodepools

# 5. Verify coexistence with existing node groups
kubectl get nodes -L eks.amazonaws.com/compute-type

---

Configuration via AWS Console

1. Navigate to Amazon EKS service in AWS Console
2. Select Create Cluster or choose an existing cluster
3. Enable Auto Mode in the Compute tab
4. Select default NodePools (general-purpose, system)
5. Complete cluster creation or update

---

Verifying Auto Mode Activation

After enabling Auto Mode, verify the configuration:

# Check cluster compute configuration
aws eks describe-cluster --name my-cluster \
    --query 'cluster.computeConfig'

# List available NodePools
kubectl get nodepools

# Check NodePool details
kubectl describe nodepool general-purpose
kubectl describe nodepool system

# Verify nodes are being provisioned
kubectl get nodes -w

---

< Previous: Overview | Table of Contents | Next: NodePool Configuration >