Feature Request: Add Karpenter Module for Kubernetes Node Autoscaling

[JPaiv]

Summary

Add a dedicated Karpenter module to the EKS.

Problem

The current node autoscaling approach has several limitations:

• Slow scaling response times: Current autoscaling relies on managed node groups(MNG) that have slower response time compared to Karpenter
• Limited instance flexibility: MNGs are tied to their launch templates, and one-size-fits-all is rarely a suitable approach
• Operational overhead: Managing multiple MNGs for different workload profiles adds complexity and maintenance burden
• Cost inefficiency: Karpenter is much more cost-efficient with spot instances and semi-intelligent node selection from the Node Pools

Proposed Solution

Integrate the AWS Karpenter module to the EKS.

module "karpenter" {
  source = "terraform-aws-modules/eks/aws//modules/karpenter"

  cluster_name = module.eks.cluster_name

  # Attach additional IAM policies to the Karpenter node IAM role
  node_iam_role_additional_policies = {
    AmazonSSMManagedInstanceCore = "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore"
  }

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

Reusing the existing Nodes IAM Role:

module "karpenter" {
  source = "terraform-aws-modules/eks/aws//modules/karpenter"

  cluster_name = module.eks.cluster_name

  create_node_iam_role = false
  node_iam_role_arn    = module.eks.eks_managed_node_groups["initial"].iam_role_arn

  # Since the node group role will already have an access entry
  create_access_entry = false

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