Kubernetes Node role labeler

Description ¶

Node Role Labeler has long been sought after, a simple operator, but the task is fulfilled. The problem is that Kubernetes, specifically kubelet, cannot assign itself a label of node-role.kubernetes.io/ROLE_NAME when creating a node, because of the kubernetes.io protected prefix. Not very convenient.

Here I have Karpenter, or Cluster Autoscaler, no matter what, I want nodes to have nice roles immediately, and it does not come out of the box only by hand. Now we can attach node-role.cluster.local/NAME and the operator will create an automatically copy with a domain kubernetes.io. In reverse also works. More information - read on GitHub.

Demo ¶

Karpenter configuration ¶

Here is how we can immediately attach labels to Karpenter nodes.

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apiVersion: karpenter.k8s.aws/v1beta1
kind: EC2NodeClass
metadata:
  name: private
spec:
  amiFamily: AL2
  metadataOptions:
    httpEndpoint: enabled
    httpProtocolIPv6: disabled
    httpPutResponseHopLimit: 2
    httpTokens: required
  role: Karpenter-development-role
  securityGroupSelectorTerms:
  - tags:
      karpenter.sh/discovery: development
  subnetSelectorTerms:
  - tags:
      karpenter.sh/discovery/development/subnet: private
  tags:
    karpenter.sh/discovery: development
---
apiVersion: karpenter.sh/v1beta1
kind: NodePool
metadata:
  name: on-demand-amd64
spec:
  disruption:
    budgets:
    - nodes: 20%
    - nodes: "5"
    - duration: 20h
      nodes: "0"
      schedule: 0 5 * * *
    consolidationPolicy: WhenUnderutilized
    expireAfter: 720h
  limits:
    cpu: "200"
    memory: 400Gi
  template:
    metadata:
      labels:
        node-role.cluster.local/on-demand-amd64: ""
    spec:
      nodeClassRef:
        name: private
      requirements:
      - key: kubernetes.io/arch
        operator: In
        values:
        - amd64
      - key: node.kubernetes.io/instance-type
        operator: In
        values:
        - r5a.4xlarge
        - r5a.2xlarge
        - r5a.xlarge
        - r5a.large
        - r5a.medium
        - r5.4xlarge
        - r5.2xlarge
        - r5.xlarge
        - r5.large
        - r5.medium
        - m6i.4xlarge
        - m6i.2xlarge
        - m6i.xlarge
        - m6i.large
        - m6i.medium
        - m5a.4xlarge
        - m5a.2xlarge
        - m5a.xlarge
        - m5a.large
        - m5a.medium
        - c6a.4xlarge
        - c6a.2xlarge
        - c6a.xlarge
        - c6a.large
        - c6a.medium
        - c6.4xlarge
        - c6.2xlarge
        - c6.xlarge
        - c6.large
        - c6.medium
        - t3a.4xlarge
        - t3a.2xlarge
        - t3a.xlarge
        - t3a.large
        - t3a.medium
      - key: karpenter.sh/capacity-type
        operator: In
        values:
        - on-demand