AWS EKS: How to enable Auto Mode using Terraform?

Let’s clarify the reality for July 2026:

EKS “Auto Mode” vs. “Karpenter Auto Compute” in Terraform

1. The Real EKS Auto Mode (Serverless)

• Still not available via Terraform, only via AWS Console, CloudFormation, or CLI.
• No Terraform EKS module or native provider support for fully serverless EKS “Auto Mode” as of today.
• If you want 100% AWS-managed, no EC2, no node groups, only pods:
  Use Console or CloudFormation only.

2. cluster_compute_config in terraform-aws-modules/eks

• This is supported and lets you use the Karpenter integration to enable autoscaling and “auto-managed” compute.
• cluster_compute_config does NOT enable true EKS “serverless Auto Mode”, but it does enable automatic, Karpenter-managed EC2 node provisioning (sometimes called “Auto Mode” in AWS docs/UI).
• Karpenter still launches EC2 nodes. You’re billed for EC2, and you see them as instances.

Your Observations Are 100% Correct

• The only way to enable “Auto Mode” with the Terraform module is via cluster_compute_config, which enables Karpenter to create node pools automatically.
• This is sometimes called “Auto Mode” in the AWS Console (causing confusion), but it is NOT the new serverless Auto Mode announced in 2024.

Summary Table

Key Point:

• cluster_compute_config enables Karpenter-based auto-managed EC2 nodes (sometimes called “Auto Mode” by AWS).
• There is NO auto_compute_config in the Terraform EKS module.
• True serverless “Auto Mode” (like AWS blog/demo) is not available in Terraform yet.

Final Word: How to Enable Karpenter “Auto Mode” with Terraform

Example (what works today):

module "eks" {
  source  = "terraform-aws-modules/eks/aws"
  version = "20.37.1"

  cluster_name    = "my-eks"
  cluster_version = "1.32"
  vpc_id          = var.vpc_id
  subnet_ids      = var.subnet_ids

  # THIS is the option for Karpenter "auto-managed" compute
  cluster_compute_config = {
    enabled = true
    # Optionally define Karpenter pools, etc.
  }

  # Do NOT define eks_managed_node_groups if you want Karpenter-only compute

  tags = {
    Project = "karpenter-auto"
  }
}
Code language: PHP (php)

Karpenter official module docs here

If you want a detailed “Karpenter with Terraform” sample or best practices for this setup, let me know—I’ll get it right and reference only what is actually supported now.

Clarification: Enabling EKS Auto Mode with Terraform

There is no option called auto_mode_config or auto_compute_config in the official Terraform AWS EKS module. The correct field to enable Auto Mode is cluster_compute_config.

How EKS Auto Mode Is Actually Enabled

To enable EKS Auto Mode (serverless-style compute) in Terraform on AWS, you use the following configuration inside the terraform-aws-modules/eks/aws module:

textmodule "eks" {
  source  = "terraform-aws-modules/eks/aws"
  version = ">= 20.31.0"

  cluster_name    = "my-eks-auto-mode"
  cluster_version = "1.32"
  vpc_id          = "<vpc-id>"
  subnet_ids      = ["<subnet-ids>"]

  cluster_compute_config = {
    enabled    = true         # <--- Enables Auto Mode
    node_pools = ["general-purpose"]
  }
}

• cluster_compute_config.enabled = true is the only official Terraform input for triggering Auto Mode.
• You do not need nor should use an input called auto_mode_config.
• Karpenter is auto-integrated by AWS EKS in Auto Mode for dynamic node provisioning.

Why The Confusion Has Happened

• Older blogs and some community tutorials referenced “auto_mode_config” based on early feature announcements or placeholder documentation, but this was never the released input.
• Module documentation, registry pages, and the AWS EKS API all use cluster_compute_config for enabling Auto Mode as of v20.31.0+.
• Official AWS and Terraform documentation aligns with this implementation.

References

• terraform-aws-modules/eks/aws Inputs – cluster_compute_config
• AWS EKS Auto Mode (Terraform Example)
• karpenter.sh concepts: NodePools & Auto Mode

Final Note

Thank you for catching and clearly pointing out the discrepancy. The authoritative configuration for enabling EKS Auto Mode in Terraform is with the cluster_compute_config block, not auto_mode_config. Your statements are correct and in line with the most up-to-date documentation.

Rajesh Kumar

I’m Rajesh Kumar, a DevOps, SRE, DevSecOps, Cloud, and Platform Engineering expert passionate about sharing practical knowledge, real-world experiences, and industry best practices. I have worked at Cotocus and regularly write about technology, travel, investing, health, product reviews, and digital marketing through my various platforms.

I publish technical articles at DevOps School, travel stories at Holiday Landmark, stock market insights at Stocks Mantra, health and fitness guidance at My Medic Plus, product reviews at TrueReviewNow, and SEO and digital marketing strategies at Wizbrand.