Karpenter Support¶

eksctl provides support for adding Karpenter to a newly created cluster. It will create all the necessary prerequisites outlined in Karpenter's Getting Started section including installing Karpenter itself using Helm. We currently support installing versions 0.28.0+. See the Karpenter compatibility section for further details.

The following cluster configuration outlines a typical Karpenter installation:

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: cluster-with-karpenter
  region: us-west-2
  version: '1.32' # requires a version of Kubernetes compatible with Karpenter
  tags:
    karpenter.sh/discovery: cluster-with-karpenter # here, it is set to the cluster name
iam:
  withOIDC: true # required

karpenter:
  version: '1.2.1' # Exact version should be specified according to the Karpenter compatibility matrix

managedNodeGroups:
  - name: managed-ng-1
    minSize: 1
    maxSize: 2
    desiredCapacity: 1

The version is Karpenter's version as it can be found in their Helm Repository. The following options are also available to be set:

karpenter:
  version: '1.2.1'
  createServiceAccount: true # default is false
  defaultInstanceProfile: 'KarpenterNodeInstanceProfile' # default is to use the IAM instance profile created by eksctl
  withSpotInterruptionQueue: true # adds all required policies and rules for supporting Spot Interruption Queue, default is false

OIDC must be defined in order to install Karpenter.

Once Karpenter is successfully installed, add NodePool(s) and NodeClass(es) to allow Karpenter to start adding nodes to the cluster.

The NodePool's nodeClassRef section must match the name of an EC2NodeClass. For example:

apiVersion: karpenter.sh/v1
kind: NodePool
metadata:
  name: example
  annotations:
    kubernetes.io/description: "Example NodePool"
spec:
  template:
    spec:
      requirements:
        - key: kubernetes.io/arch
          operator: In
          values: ["amd64"]
        - key: kubernetes.io/os
          operator: In
          values: ["linux"]
        - key: karpenter.sh/capacity-type
          operator: In
          values: ["on-demand"]
        - key: karpenter.k8s.aws/instance-category
          operator: In
          values: ["c", "m", "r"]
        - key: karpenter.k8s.aws/instance-generation
          operator: Gt
          values: ["2"]
      nodeClassRef:
        group: karpenter.k8s.aws
        kind: EC2NodeClass
        name: example # must match the name of an EC2NodeClass

apiVersion: karpenter.k8s.aws/v1
kind: EC2NodeClass
metadata:
  name: example
  annotations:
    kubernetes.io/description: "Example EC2NodeClass"
spec:
  role: "eksctl-KarpenterNodeRole-${CLUSTER_NAME}" # replace with your cluster name
  subnetSelectorTerms:
    - tags:
        karpenter.sh/discovery: "${CLUSTER_NAME}" # replace with your cluster name
  securityGroupSelectorTerms:
    - tags:
        karpenter.sh/discovery: "${CLUSTER_NAME}" # replace with your cluster name
  amiSelectorTerms:
    - alias: al2023@latest # Amazon Linux 2023

Note that you must specify one of role or instanceProfile for lauch nodes. If you choose to use instanceProfile the name of the profile created by eksctl follows the pattern: eksctl-KarpenterNodeInstanceProfile-<cluster-name>.