Getting Started with Karpenter

export KARPENTER_NAMESPACE="kube-system"
export KARPENTER_VERSION="1.1.0"
export K8S_VERSION="1.31"

export AWS_PARTITION="aws" # if you are not using standard partitions, you may need to configure to aws-cn / aws-us-gov
export CLUSTER_NAME="${USER}-karpenter-demo"
export AWS_DEFAULT_REGION="us-west-2"
export AWS_ACCOUNT_ID="$(aws sts get-caller-identity --query Account --output text)"
export TEMPOUT="$(mktemp)"
export ARM_AMI_ID="$(aws ssm get-parameter --name /aws/service/eks/optimized-ami/${K8S_VERSION}/amazon-linux-2-arm64/recommended/image_id --query Parameter.Value --output text)"
export AMD_AMI_ID="$(aws ssm get-parameter --name /aws/service/eks/optimized-ami/${K8S_VERSION}/amazon-linux-2/recommended/image_id --query Parameter.Value --output text)"
export GPU_AMI_ID="$(aws ssm get-parameter --name /aws/service/eks/optimized-ami/${K8S_VERSION}/amazon-linux-2-gpu/recommended/image_id --query Parameter.Value --output text)"

aws iam create-service-linked-role --aws-service-name spot.amazonaws.com || true
# If the role has already been successfully created, you will see:
# An error occurred (InvalidInput) when calling the CreateServiceLinkedRole operation: Service role name AWSServiceRoleForEC2Spot has been taken in this account, please try a different suffix.

cosign verify public.ecr.aws/karpenter/karpenter:1.1.0 \
  --certificate-oidc-issuer=https://token.actions.githubusercontent.com \
  --certificate-identity-regexp='https://github\.com/aws/karpenter-provider-aws/\.github/workflows/release\.yaml@.+' \
  --certificate-github-workflow-repository=aws/karpenter-provider-aws \
  --certificate-github-workflow-name=Release \
  --certificate-github-workflow-ref=refs/tags/v1.1.0 \
  --annotations version=1.1.0

cat <<EOF | envsubst | kubectl apply -f -
apiVersion: karpenter.sh/v1
kind: NodePool
metadata:
  name: default
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: default
      expireAfter: 720h # 30 * 24h = 720h
  limits:
    cpu: 1000
  disruption:
    consolidationPolicy: WhenEmptyOrUnderutilized
    consolidateAfter: 1m
---
apiVersion: karpenter.k8s.aws/v1
kind: EC2NodeClass
metadata:
  name: default
spec:
  amiFamily: AL2 # Amazon Linux 2
  role: "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: "${CLUSTER_NAME}" # replace with your cluster name
  amiSelectorTerms:
    - id: "${ARM_AMI_ID}"
    - id: "${AMD_AMI_ID}"
#   - id: "${GPU_AMI_ID}" # <- GPU Optimized AMD AMI 
#   - name: "amazon-eks-node-${K8S_VERSION}-*" # <- automatically upgrade when a new AL2 EKS Optimized AMI is released. This is unsafe for production workloads. Validate AMIs in lower environments before deploying them to production.
EOF

cat <<EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: inflate
spec:
  replicas: 0
  selector:
    matchLabels:
      app: inflate
  template:
    metadata:
      labels:
        app: inflate
    spec:
      terminationGracePeriodSeconds: 0
      securityContext:
        runAsUser: 1000
        runAsGroup: 3000
        fsGroup: 2000
      containers:
      - name: inflate
        image: public.ecr.aws/eks-distro/kubernetes/pause:3.7
        resources:
          requests:
            cpu: 1
        securityContext:
          allowPrivilegeEscalation: false
EOF

kubectl scale deployment inflate --replicas 5
kubectl logs -f -n "${KARPENTER_NAMESPACE}" -l app.kubernetes.io/name=karpenter -c controller

kubectl delete deployment inflate
kubectl logs -f -n "${KARPENTER_NAMESPACE}" -l app.kubernetes.io/name=karpenter -c controller

kubectl delete node "${NODE_NAME}"

helm uninstall karpenter --namespace "${KARPENTER_NAMESPACE}"
aws cloudformation delete-stack --stack-name "Karpenter-${CLUSTER_NAME}"
aws ec2 describe-launch-templates --filters "Name=tag:karpenter.k8s.aws/cluster,Values=${CLUSTER_NAME}" |
    jq -r ".LaunchTemplates[].LaunchTemplateName" |
    xargs -I{} aws ec2 delete-launch-template --launch-template-name {}
eksctl delete cluster --name "${CLUSTER_NAME}"

helm repo add grafana-charts https://grafana.github.io/helm-charts
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update

kubectl create namespace monitoring

curl -fsSL https://raw.githubusercontent.com/aws/karpenter-provider-aws/v"${KARPENTER_VERSION}"/website/content/en/preview/getting-started/getting-started-with-karpenter/prometheus-values.yaml | envsubst | tee prometheus-values.yaml
helm install --namespace monitoring prometheus prometheus-community/prometheus --values prometheus-values.yaml

curl -fsSL https://raw.githubusercontent.com/aws/karpenter-provider-aws/v"${KARPENTER_VERSION}"/website/content/en/preview/getting-started/getting-started-with-karpenter/grafana-values.yaml | tee grafana-values.yaml
helm install --namespace monitoring grafana grafana-charts/grafana --values grafana-values.yaml

kubectl port-forward --namespace monitoring svc/grafana 3000:80

kubectl get secret --namespace monitoring grafana -o jsonpath="{.data.admin-password}" | base64 --decode

privateCluster:
  enabled: true

com.amazonaws.<region>.ec2
com.amazonaws.<region>.ecr.api
com.amazonaws.<region>.ecr.dkr
com.amazonaws.<region>.s3 – For pulling container images
com.amazonaws.<region>.sts – For IAM roles for service accounts
com.amazonaws.<region>.ssm - For resolving default AMIs
com.amazonaws.<region>.sqs - For accessing SQS if using interruption handling
com.amazonaws.<region>.eks - For Karpenter to discover the cluster endpoint

aws ec2 create-vpc-endpoint --vpc-id ${VPC_ID} --service-name ${SERVICE_NAME} --vpc-endpoint-type Interface --subnet-ids ${SUBNET_IDS} --security-group-ids ${SECURITY_GROUP_IDS}

cat <<EOF | envsubst | kubectl apply -f -
---
apiVersion: flowcontrol.apiserver.k8s.io/v1
kind: FlowSchema
metadata:
  name: karpenter-leader-election
spec:
  distinguisherMethod:
    type: ByUser
  matchingPrecedence: 200
  priorityLevelConfiguration:
    name: leader-election
  rules:
  - resourceRules:
    - apiGroups:
      - coordination.k8s.io
      namespaces:
      - '*'
      resources:
      - leases
      verbs:
      - get
      - create
      - update
    subjects:
    - kind: ServiceAccount
      serviceAccount:
        name: karpenter
        namespace: "${KARPENTER_NAMESPACE}"

---
apiVersion: flowcontrol.apiserver.k8s.io/v1
kind: FlowSchema
metadata:
  name: karpenter-workload
spec:
  distinguisherMethod:
    type: ByUser
  matchingPrecedence: 1000
  priorityLevelConfiguration:
    name: workload-high
  rules:
  - nonResourceRules:
    - nonResourceURLs:
      - '*'
      verbs:
      - '*'
    resourceRules:
    - apiGroups:
      - '*'
      clusterScope: true
      namespaces:
      - '*'
      resources:
      - '*'
      verbs:
      - '*'
    subjects:
    - kind: ServiceAccount
      serviceAccount:
        name: karpenter
        namespace: "${KARPENTER_NAMESPACE}"
EOF