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[aws] EKS Autoscaling

Hayley Shim 2025. 3. 9. 01:35

안녕하세요. AWS EKS Workshop Study (=AEWS) 3기 모임에서 스터디한 내용을 정리했습니다. 해당 글에서는 Amzaon EKS Observability에 대해 자세히 알아보겠습니다.

 

 

실습 환경

# YAML 파일 다운로드
curl -O https://s3.ap-northeast-2.amazonaws.com/cloudformation.cloudneta.net/K8S/myeks-5week.yaml

# 변수 지정
CLUSTER_NAME=myeks
SSHKEYNAME=<SSH 키 페이 이름>
MYACCESSKEY=<IAM Uesr 액세스 키>
MYSECRETKEY=<IAM Uesr 시크릿 키>

# CloudFormation 스택 배포
aws cloudformation deploy --template-file myeks-5week.yaml --stack-name $CLUSTER_NAME --parameter-overrides KeyName=$SSHKEYNAME SgIngressSshCidr=$(curl -s ipinfo.io/ip)/32  MyIamUserAccessKeyID=$MYACCESSKEY MyIamUserSecretAccessKey=$MYSECRETKEY ClusterBaseName=$CLUSTER_NAME --region ap-northeast-2

# CloudFormation 스택 배포 완료 후 작업용 EC2 IP 출력
aws cloudformation describe-stacks --stack-name myeks --query 'Stacks[*].Outputs[0].OutputValue' --output text

# 작업용 EC2 SSH 접속
$ ssh -i ~/.ssh/kp-hayley.pem ec2-user@$(aws cloudformation describe-stacks --stack-name myeks --query 'Stacks[*].Outputs[0].OutputValue' --output text)

 

 

기본 설정

# default 네임스페이스 적용
$ kubectl ns default

# AWS LB Controller
$ helm repo add eks https://aws.github.io/eks-charts
$ helm repo update
$ helm install aws-load-balancer-controller eks/aws-load-balancer-controller -n kube-system --set clusterName=$CLUSTER_NAME \
  --set serviceAccount.create=false --set serviceAccount.name=aws-load-balancer-controller


# ExternalDNS
echo $MyDomain
curl -s https://raw.githubusercontent.com/gasida/PKOS/main/aews/externaldns.yaml | MyDomain=$MyDomain MyDnzHostedZoneId=$MyDnzHostedZoneId envsubst | kubectl apply -f -


# kube-ops-view
helm repo add geek-cookbook https://geek-cookbook.github.io/charts/
helm install kube-ops-view geek-cookbook/kube-ops-view --version 1.2.2 --set service.main.type=ClusterIP  --set env.TZ="Asia/Seoul" --namespace kube-system

# kubeopsview 용 Ingress 설정 : group 설정으로 1대의 ALB를 여러개의 ingress 에서 공용 사용
echo $CERT_ARN
cat <<EOF | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    alb.ingress.kubernetes.io/certificate-arn: $CERT_ARN
    alb.ingress.kubernetes.io/group.name: study
    alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS":443}, {"HTTP":80}]'
    alb.ingress.kubernetes.io/load-balancer-name: $CLUSTER_NAME-ingress-alb
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/ssl-redirect: "443"
    alb.ingress.kubernetes.io/success-codes: 200-399
    alb.ingress.kubernetes.io/target-type: ip
  labels:
    app.kubernetes.io/name: kubeopsview
  name: kubeopsview
  namespace: kube-system
spec:
  ingressClassName: alb
  rules:
  - host: kubeopsview.$MyDomain
    http:
      paths:
      - backend:
          service:
            name: kube-ops-view
            port:
              number: 8080  # name: http
        path: /
        pathType: Prefix
EOF

 

 

프로메테우스 & 그라파나(admin / prom-operator) 설치

# repo 추가
$ helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

# 파라미터 파일 생성
$ cat <<EOT > monitor-values.yaml
prometheus:
  prometheusSpec:
    podMonitorSelectorNilUsesHelmValues: false
    serviceMonitorSelectorNilUsesHelmValues: false
    retention: 5d
    retentionSize: "10GiB"

  verticalPodAutoscaler:
    enabled: true

  ingress:
    enabled: true
    ingressClassName: alb
    hosts: 
      - prometheus.$MyDomain
    paths: 
      - /*
    annotations:
      alb.ingress.kubernetes.io/scheme: internet-facing
      alb.ingress.kubernetes.io/target-type: ip
      alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS":443}, {"HTTP":80}]'
      alb.ingress.kubernetes.io/certificate-arn: $CERT_ARN
      alb.ingress.kubernetes.io/success-codes: 200-399
      alb.ingress.kubernetes.io/load-balancer-name: myeks-ingress-alb
      alb.ingress.kubernetes.io/group.name: study
      alb.ingress.kubernetes.io/ssl-redirect: '443'

grafana:
  defaultDashboardsTimezone: Asia/Seoul
  adminPassword: prom-operator

  ingress:
    enabled: true
    ingressClassName: alb
    hosts: 
      - grafana.$MyDomain
    paths: 
      - /*
    annotations:
      alb.ingress.kubernetes.io/scheme: internet-facing
      alb.ingress.kubernetes.io/target-type: ip
      alb.ingress.kubernetes.io/listen-ports: '[{"HTTPS":443}, {"HTTP":80}]'
      alb.ingress.kubernetes.io/certificate-arn: $CERT_ARN
      alb.ingress.kubernetes.io/success-codes: 200-399
      alb.ingress.kubernetes.io/load-balancer-name: myeks-ingress-alb
      alb.ingress.kubernetes.io/group.name: study
      alb.ingress.kubernetes.io/ssl-redirect: '443'

defaultRules:
  create: false
kubeControllerManager:
  enabled: false
kubeEtcd:
  enabled: false
kubeScheduler:
  enabled: false
alertmanager:
  enabled: false
EOT

# 배포
$ kubectl create ns monitoring
$ helm install kube-prometheus-stack prometheus-community/kube-prometheus-stack --version 45.27.2 \
--set prometheus.prometheusSpec.scrapeInterval='15s' --set prometheus.prometheusSpec.evaluationInterval='15s' \
-f monitor-values.yaml --namespace monitoring

# Metrics-server 배포
$ kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

 

EKS Node Viewer 설치 : 노드 할당 가능 용량과 요청 request 리소스 표시, 실제 파드 리소스 사용량 X

# macOS 설치
brew tap aws/tap
brew install eks-node-viewer

# 운영서버 EC2에 설치 : userdata 통해 golang이미 설치 되어 있음
go install github.com/awslabs/eks-node-viewer/cmd/eks-node-viewer@latest  # 설치 시 2~3분 정도 소요

 

Kubernetes autoscaling overview

참고: AWS re:Invent 2022 — Optimizing Amazon EKS for performance and cost on AWS (CON324)

HPA — Horizontal Pod Autoscaler

  • kube-ops-view 와 그라파나 (22128 , 22251) 에서 모니터링 실습
# Run and expose php-apache server
cat << EOF > php-apache.yaml
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: php-apache
spec: 
  selector: 
    matchLabels: 
      run: php-apache
  template: 
    metadata: 
      labels: 
        run: php-apache
    spec: 
      containers: 
      - name: php-apache
        image: registry.k8s.io/hpa-example
        ports: 
        - containerPort: 80
        resources: 
          limits: 
            cpu: 500m
          requests: 
            cpu: 200m
---
apiVersion: v1
kind: Service
metadata: 
  name: php-apache
  labels: 
    run: php-apache
spec: 
  ports: 
  - port: 80
  selector: 
    run: php-apache
EOF
$ kubectl apply -f php-apache.yaml


# 확인
$ kubectl exec -it deploy/php-apache -- cat /var/www/html/index.php
<?php
$x = 0.0001;
for ($i = 0; $i <= 1000000; $i++) {
 $x += sqrt($x);
}
echo "OK!";
?>
...

# 모니터링 : 터미널2개 사용
$ watch -d 'kubectl get hpa,pod;echo;kubectl top pod;echo;kubectl top node'
$ kubectl exec -it deploy/php-apache -- top

# 접속
$ PODIP=$(kubectl get pod -l run=php-apache -o jsonpath={.items[0].status.podIP})
$ curl -s $PODIP; echo
OK!

 

HPA 생성 및 부하 발생 후 오토 스케일링 테스트

# Create the HorizontalPodAutoscaler : requests.cpu=200m - 알고리즘
# Since each pod requests 200 milli-cores by kubectl run, this means an average CPU usage of 100 milli-cores.
$ kubectl autoscale deployment php-apache --cpu-percent=50 --min=1 --max=10
$ kubectl describe hpa
...
Metrics:                                               ( current / target )
  resource cpu on pods  (as a percentage of request):  0% (1m) / 50%
Min replicas:                                          1
Max replicas:                                          10
Deployment pods:                                       1 current / 1 desired

# HPA 설정 확인
$ kubectl krew install neat
$ kubectl get hpa php-apache -o yaml
$ kubectl get hpa php-apache -o yaml | kubectl neat | yh
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata: 
  name: php-apache
  namespace: default
spec: 
  maxReplicas: 10
  metrics: 
  - resource: 
      name: cpu
      target: 
        averageUtilization: 50
        type: Utilization
    type: Resource
  minReplicas: 1
  scaleTargetRef: 
    apiVersion: apps/v1
    kind: Deployment
    name: php-apache

# 반복 접속 1 (파드1 IP로 접속) >> 증가 확인 후 중지
$ while true;do curl -s $PODIP; sleep 0.5; done
OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!^C

# 반복 접속 2 (서비스명 도메인으로 접속) >> 증가 확인 후 중지 >> 중지 5분 후 파드 갯수 감소 확인
# Run this in a separate terminal
# so that the load generation continues and you can carry on with the rest of the steps
$ kubectl run -i --tty load-generator --rm --image=busybox:1.28 --restart=Never -- /bin/sh -c "while sleep 0.01; do wget -q -O- http://php-apache; done"
OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!OK!O
.....

pod/php-apache-698db99f59-4l6ch   1/1     Running   0          4m9s
pod/php-apache-698db99f59-6rc55   1/1     Running   0          3m24s
pod/php-apache-698db99f59-crnjh   1/1     Running   0          21m
pod/php-apache-698db99f59-h8tss   1/1     Running   0          3m24s
pod/php-apache-698db99f59-m5hzr   1/1     Running   0          4m24s
pod/php-apache-698db99f59-srjr7   1/1     Running   0          4m9s
pod/php-apache-698db99f59-xqv2b   1/1     Running   0          4m24s
...

 

KEDA — Kubernetes based Event Driven Autoscaler

  • 기존의 HPA(Horizontal Pod Autoscaler)는 리소스(CPU, Memory) 메트릭을 기반으로 스케일 여부를 결정하게 됩니다.
  • KEDA 특정 이벤트를 기반으로 스케일 여부를 결정할 수 있습니다.
# KEDA 설치
$ cat <<EOT > keda-values.yaml
metricsServer:
  useHostNetwork: true

prometheus:
  metricServer:
    enabled: true
    port: 9022
    portName: metrics
    path: /metrics
    serviceMonitor:
      # Enables ServiceMonitor creation for the Prometheus Operator
      enabled: true
    podMonitor:
      # Enables PodMonitor creation for the Prometheus Operator
      enabled: true
  operator:
    enabled: true
    port: 8080
    serviceMonitor:
      # Enables ServiceMonitor creation for the Prometheus Operator
      enabled: true
    podMonitor:
      # Enables PodMonitor creation for the Prometheus Operator
      enabled: true

  webhooks:
    enabled: true
    port: 8080
    serviceMonitor:
      # Enables ServiceMonitor creation for the Prometheus webhooks
      enabled: true
EOT

$ kubectl create namespace keda
$ helm repo add kedacore https://kedacore.github.io/charts
$ helm install keda kedacore/keda --version 2.10.2 --namespace keda -f keda-values.yaml

# KEDA 설치 확인
$ kubectl get-all -n keda
$ kubectl get all -n keda
$ kubectl get crd | grep keda


# keda 네임스페이스에 디플로이먼트 생성
$ kubectl apply -f php-apache.yaml -n keda
$ kubectl get pod -n keda

# ScaledObject 정책 생성 : cron
$ cat <<EOT > keda-cron.yaml
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: php-apache-cron-scaled
spec:
  minReplicaCount: 0
  maxReplicaCount: 2
  pollingInterval: 30
  cooldownPeriod: 300
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: php-apache
  triggers:
  - type: cron
    metadata:
      timezone: Asia/Seoul
      start: 00,15,30,45 * * * *
      end: 05,20,35,50 * * * *
      desiredReplicas: "1"
EOT
$ kubectl apply -f keda-cron.yaml -n keda

# 그라파나 대시보드 추가
# 모니터링
$ watch -d 'kubectl get ScaledObject,hpa,pod -n keda'
$ kubectl get ScaledObject -w

# 확인
$ kubectl get ScaledObject,hpa,pod -n keda
NAME                                          SCALETARGETKIND      SCALETARGETNAME   MIN   MAX   TRIGGERS   AUTHENTICATION   READY   ACTIVE   FALLBACK   AGE
scaledobject.keda.sh/php-apache-cron-scaled   apps/v1.Deployment   php-apache        0     2     cron                        True    True     Unknown    77s

NAME                                                                  REFERENCE               TARGETS             MINPODS   MAXPODS   REPLICAS   AGE
horizontalpodautoscaler.autoscaling/keda-hpa-php-apache-cron-scaled   Deployment/php-apache   <unknown>/1 (avg)   1         2         0          77s

NAME                                                   READY   STATUS    RESTARTS        AGE
pod/keda-admission-webhooks-68cf687cbf-szj68           1/1     Running   0               3m7s
pod/keda-operator-656478d687-nn4x2                     1/1     Running   1 (2m57s ago)   3m7s
pod/keda-operator-metrics-apiserver-7fd585f657-lph24   1/1     Running   0               3m7s
pod/php-apache-698db99f59-4jzgr                        1/1     Running   0               16s

$ kubectl get hpa -o jsonpath={.items[0].spec} -n keda | jq
{
  "maxReplicas": 2,
  "metrics": [
    {
      "external": {
        "metric": {
          "name": "s0-cron-Asia-Seoul-00,15,30,45xxxx-05,20,35,50xxxx",
          "selector": {
            "matchLabels": {
              "scaledobject.keda.sh/name": "php-apache-cron-scaled"
            }
          }
        },
        "target": {
          "averageValue": "1",
          "type": "AverageValue"
        }
      },
      "type": "External"
    }
  ],
  "minReplicas": 1,
  "scaleTargetRef": {
    "apiVersion": "apps/v1",
    "kind": "Deployment",
    "name": "php-apache"
  }
}

# KEDA 및 deployment 등 삭제
$ kubectl delete -f keda-cron.yaml -n keda && kubectl delete deploy php-apache -n keda && helm uninstall keda -n keda
$ kubectl delete namespace keda

 

KEDA 활용 : Karpenter + KEDA로 특정 시간에 AutoScaling

  • CA는 ASG 설정을 통해 일정 시간에 노드를 증설하고 감소시킬 수 있으나 Karpenter는 ASG를 사용하지 않기 때문에 불가능하다.

실습 :

  1. KEDA 사용 (cron을 사용해서 일정 시간에 파드 증가/감소)
  2. Pod에 affinity.podAntiAffinity 를 사용하고 cpu request 1m으로 설정
  3. Karpenter가 파드안티어피니티를 확인하고 Pod가 없는 새로운 노드를 증설 → 오버 프로비저닝 Pod의 개수만큼 노드 증설이 보장된다.
# KEDA 설치
$ helm repo add kedacore https://kedacore.github.io/charts
$ helm repo update
$ helm install keda kedacore/keda -n keda --create-namespace

# Karpenter Provisioner
apiVersion: karpenter.sh/v1alpha5
kind: Provisioner
metadata:
  name: karpenter-provisioner
spec:    
  requirements:
    - key: node.kubernetes.io/instance-type
      operator: In
      values: ["t3.medium", "t3.large", "t3.xlarge"]  
    - key: "topology.kubernetes.io/zone"
      operator: In
      values: ["ap-northeast-2a", "ap-northeast-2c"]      
    - key: karpenter.sh/capacity-type
      operator: In
      values: ["on-demand"]  
  limits:
    resources:
      cpu: "1000"
      memory: 1000Gi
  ttlSecondsAfterEmpty: 30
  labels:
    role: ops
    provision: karpenter
  provider:
    securityGroupSelector:
      karpenter.sh/discovery: ${CLUSTER_NAME}
    subnetSelector:
      karpenter.sh/discovery: ${CLUSTER_NAME}
    tags:
      Name: karpenter.sh/provisioner-name/karpenter-provisioner
      karpenter.sh/discovery: ${CLUSTER_NAME}

# 오버 프로비저닝 Pod
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
spec:
  replicas: 0
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      terminationGracePeriodSeconds: 0
      containers:
        - name: nginx
          image: nginx
          resources:
            requests:  
              cpu: 1m         
      affinity:
        nodeAffinity:  # karpenter node 증설을 위한 노드어피니티.
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: provision
                operator: In
                values:
                - karpenter 
        podAntiAffinity:  # 파드 개수만큼 node 증설하기 위한 파드안티어피니티.
          requiredDuringSchedulingIgnoredDuringExecution:
          - labelSelector:
              matchExpressions:
              - key: app
                operator: In
                values:
                - nginx
            topologyKey: "kubernetes.io/hostname"


# KEDA ScaledObject
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: keda-over-provioning
spec:
  # min / max count
  minReplicaCount: 1
  maxReplicaCount: 10

  # target
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: nginx

  triggers:
  - type: cron
    metadata:
      timezone: Asia/Seoul
      start: 00 13 * * *
      end: 00 21 * * *
      desiredReplicas: "5"



# HPA 생성
$ kubectl get hpa
NAME                            REFERENCE               TARGETS     MINPODS   MAXPODS   REPLICAS   AGE
keda-hpa-keda-over-provioning   Deployment/nginx        1/1 (avg)   1         10        1          17s


# 지정시간이 되면 Karpenter가 Pod, Node 개수 증설함 

 

VPA — Vertical Pod Autoscaler

  • pod resources.request을 최대한 최적값으로 수정, HPA와 같이 사용 불가능, 수정 시 파드 재실행
$ cd ~/autoscaler/vertical-pod-autoscaler/
$ tree hack
hack
├── boilerplate.go.txt
├── convert-alpha-objects.sh
├── deploy-for-e2e.sh
├── generate-crd-yaml.sh
├── run-e2e.sh
├── run-e2e-tests.sh
├── update-codegen.sh
├── update-kubernetes-deps-in-e2e.sh
├── update-kubernetes-deps.sh
├── verify-codegen.sh
├── vpa-apply-upgrade.sh
├── vpa-down.sh
├── vpa-process-yaml.sh
├── vpa-process-yamls.sh
├── vpa-up.sh
└── warn-obsolete-vpa-objects.sh

0 directories, 16 files

# openssl 버전 확인
$ openssl version
OpenSSL 1.0.2k-fips  26 Jan 2017

# openssl 1.1.1 이상 버전 확인
$ yum install openssl11 -y
$ openssl11 version
OpenSSL 1.1.1g FIPS  21 Apr 2020

# 스크립트파일내에 openssl11 수정
$ sed -i 's/openssl/openssl11/g' ~/autoscaler/vertical-pod-autoscaler/pkg/admission-controller/gencerts.sh

# Deploy the Vertical Pod Autoscaler to your cluster with the following command.
$ watch -d kubectl get pod -n kube-system
$ cat hack/vpa-up.sh
#!/bin/bash

# Copyright 2018 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

set -o errexit
set -o nounset
set -o pipefail

SCRIPT_ROOT=$(dirname ${BASH_SOURCE})/..

$SCRIPT_ROOT/hack/vpa-process-yamls.sh create

$ ./hack/vpa-up.sh
$ kubectl get crd | grep autoscaling
kubectl get mutatingwebhookconfigurations vpa-webhook-config
kubectl get mutatingwebhookconfigurations vpa-webhook-config -o json | jq
# 모니터링
$ watch -d kubectl top pod

# 공식 예제 배포
$ cd ~/autoscaler/vertical-pod-autoscaler/
$ cat examples/hamster.yaml | yh
---
apiVersion: "autoscaling.k8s.io/v1"
kind: VerticalPodAutoscaler
metadata: 
  name: hamster-vpa
spec: 
 
 
 
  # recommenders 
  #   - name 'alternative'
  targetRef: 
    apiVersion: "apps/v1"
    kind: Deployment
    name: hamster
  resourcePolicy: 
    containerPolicies: 
      - containerName: '*'
        minAllowed: 
          cpu: 100m
          memory: 50Mi
        maxAllowed: 
          cpu: 1
          memory: 500Mi
        controlledResources: ["cpu", "memory"]
---
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: hamster
spec: 
  selector: 
    matchLabels: 
      app: hamster
  replicas: 2
  template: 
    metadata: 
      labels: 
        app: hamster
    spec: 
      securityContext: 
        runAsNonRoot: true
        runAsUser: 65534 # nobody
      containers: 
        - name: hamster
          image: registry.k8s.io/ubuntu-slim:0.1
          resources: 
            requests: 
              cpu: 100m
              memory: 50Mi
          command: ["/bin/sh"]
          args: 
            - "-c"
            - "while true; do timeout 0.5s yes >/dev/null; sleep 0.5s; done"

$ kubectl apply -f examples/hamster.yaml && kubectl get vpa -w
NAME          MODE   CPU    MEM       PROVIDED   AGE
hamster-vpa          587m   262144k   True       2m18s

# 파드 리소스 Requestes 확인
$ kubectl describe pod | grep Requests: -A2
    Requests:
      cpu:        100m
      memory:     50Mi
--
    Requests:
      cpu:        100m
      memory:     50Mi
--
    Requests:
      cpu:        1m
    Environment:  <none>
--
    Requests:
      cpu:        200m
    Environment:  <none>

# VPA에 의해 기존 파드 삭제되고 신규 파드가 생성됨
$ kubectl get events --sort-by=".metadata.creationTimestamp" | grep VPA
2m16s       Normal    EvictedByVPA             pod/hamster-5bccbb88c6-s6jkp         Pod was evicted by VPA Updater to apply resource recommendation.
76s         Normal    EvictedByVPA             pod/hamster-5bccbb88c6-jc6gq         Pod was evicted by VPA Updater to apply resource recommendation.


# 삭제
$ kubectl delete -f examples/hamster.yaml && cd ~/autoscaler/vertical-pod-autoscaler/ && ./hack/vpa-down.sh

 

CA — Cluster Autoscaler

  • Cluster Autoscale 동작을 하기 위한 cluster-autoscaler 파드(디플로이먼트)를 배치합니다.
  • Cluster Autoscaler(CA)는 pending 상태인 파드가 존재할 경우, 워커 노드 스케일 아웃합니다.
  • 특정 시간을 간격으로 사용률을 확인하여 스케일 인/아웃을 수행합니다. 그리고 AWS에서는 Auto Scaling Group(ASG)을 사용하여 Cluster Autoscaler를 적용합니다.

Cluster Autoscaler(CA) 설정

# EKS 노드에 이미 아래 tag가 들어가 있음
# k8s.io/cluster-autoscaler/enabled : true
# k8s.io/cluster-autoscaler/myeks : owned
$ aws ec2 describe-instances  --filters Name=tag:Name,Values=$CLUSTER_NAME-ng1-Node --query "Reservations[*].Instances[*].Tags[*]" --output yaml | yh
...
- Key: k8s.io/cluster-autoscaler/myeks
      Value: owned
- Key: k8s.io/cluster-autoscaler/enabled
      Value: 'true'
...
# 현재 autoscaling(ASG) 정보 확인
# aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='클러스터이름']].[AutoScalingGroupName, MinSize, MaxSize,DesiredCapacity]" --output table
$ aws autoscaling describe-auto-scaling-groups \
    --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='myeks']].[AutoScalingGroupName, MinSize, MaxSize,DesiredCapacity]" \
    --output table
-----------------------------------------------------------------
|                   DescribeAutoScalingGroups                   |
+------------------------------------------------+----+----+----+
|  eks-ng1-d8c42e9a-525d-ab54-5ddf-e8be5d85ff28  |  3 |  3 |  3 |
+------------------------------------------------+----+----+----+

# MaxSize 6개로 수정
$ export ASG_NAME=$(aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='eks-hayley']].AutoScalingGroupName" --output text)
$ aws autoscaling update-auto-scaling-group --auto-scaling-group-name ${ASG_NAME} --min-size 3 --desired-capacity 3 --max-size 6

# 확인
$ aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='eks-hayley']].[AutoScalingGroupName, MinSize, MaxSize,DesiredCapacity]" --output table
-----------------------------------------------------------------
|                   DescribeAutoScalingGroups                   |
+------------------------------------------------+----+----+----+
|  eks-ng1-c2c41e26-6213-a429-9a58-02374389d5c3  |  3 |  6 |  3 |
+------------------------------------------------+----+----+----+

# 배포 : Deploy the Cluster Autoscaler (CA)
$ curl -s -O https://raw.githubusercontent.com/kubernetes/autoscaler/master/cluster-autoscaler/cloudprovider/aws/examples/cluster-autoscaler-autodiscover.yaml
$ sed -i "s/<YOUR CLUSTER NAME>/$CLUSTER_NAME/g" cluster-autoscaler-autodiscover.yaml
$ kubectl apply -f cluster-autoscaler-autodiscover.yaml

# 확인
$ kubectl get pod -n kube-system | grep cluster-autoscaler
cluster-autoscaler-799b44d94-hv5cz             1/1     Running   0          17s

$ kubectl describe deployments.apps -n kube-system cluster-autoscaler

# (옵션) cluster-autoscaler 파드가 동작하는 워커 노드가 퇴출(evict) 되지 않게 설정
$ kubectl -n kube-system annotate deployment.apps/cluster-autoscaler cluster-autoscaler.kubernetes.io/safe-to-evict="false"
deployment.apps/cluster-autoscaler annotated

 

SCALE A CLUSTER WITH Cluster Autoscaler(CA)

# 모니터링 
$ kubectl get nodes -w
$ while true; do kubectl get node; echo "------------------------------" ; date ; sleep 1; done
$ while true; do aws ec2 describe-instances --query "Reservations[*].Instances[*].{PrivateIPAdd:PrivateIpAddress,InstanceName:Tags[?Key=='Name']|[0].Value,Status:State.Name}" --filters Name=instance-state-name,Values=running --output text ; echo "------------------------------"; date; sleep 1; done

# Deploy a Sample App
# We will deploy an sample nginx application as a ReplicaSet of 1 Pod
$ cat <<EoF> nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-to-scaleout
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        service: nginx
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx-to-scaleout
        resources:
          limits:
            cpu: 500m
            memory: 512Mi
          requests:
            cpu: 500m
            memory: 512Mi
EoF

$ kubectl apply -f nginx.yaml
$ kubectl get deployment/nginx-to-scaleout
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
nginx-to-scaleout   1/1     1            1           9s

# Scale our ReplicaSet
# Let’s scale out the replicaset to 15
$ kubectl scale --replicas=15 deployment/nginx-to-scaleout && date
Sun May 28 00:33:16 KST 2023

# 확인
$ kubectl get pods -l app=nginx -o wide --watch
$ kubectl -n kube-system logs -f deployment/cluster-autoscaler

# 노드 자동 증가 확인
$ kubectl get nodes
NAME                                               STATUS   ROLES    AGE    VERSION
ip-192-168-1-152.ap-northeast-2.compute.internal   Ready    <none>   177m   v1.24.13-eks-0a21954
ip-192-168-2-83.ap-northeast-2.compute.internal    Ready    <none>   177m   v1.24.13-eks-0a21954
ip-192-168-3-108.ap-northeast-2.compute.internal   Ready    <none>   177m   v1.24.13-eks-0a21954

$ aws autoscaling describe-auto-scaling-groups \
    --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='myeks']].[AutoScalingGroupName, MinSize, MaxSize,DesiredCapacity]" \
    --output table

Sun May 28 00:34:23 KST 2023
NAME                                               STATUS   ROLES    AGE    VERSION
ip-192-168-1-152.ap-northeast-2.compute.internal   Ready    <none>   178m   v1.24.13-eks-0a21954
ip-192-168-1-197.ap-northeast-2.compute.internal   Ready    <none>   14s    v1.24.13-eks-0a21954
ip-192-168-2-174.ap-northeast-2.compute.internal   Ready    <none>   20s    v1.24.13-eks-0a21954
ip-192-168-2-83.ap-northeast-2.compute.internal    Ready    <none>   178m   v1.24.13-eks-0a21954
ip-192-168-3-108.ap-northeast-2.compute.internal   Ready    <none>   178m   v1.24.13-eks-0a21954
ip-192-168-3-210.ap-northeast-2.compute.internal   Ready    <none>   13s    v1.24.13-eks-0a21954


# 디플로이먼트 삭제
$ kubectl delete -f nginx.yaml && date

# 노드 갯수 축소 : 기본은 10분 후 scale down 됨, 물론 아래 flag 로 시간 수정 가능 >> 그러니 디플로이먼트 삭제 후 10분 기다리고 나서 보자!
# By default, cluster autoscaler will wait 10 minutes between scale down operations, 
# you can adjust this using the --scale-down-delay-after-add, --scale-down-delay-after-delete, 
# and --scale-down-delay-after-failure flag. 
# E.g. --scale-down-delay-after-add=5m to decrease the scale down delay to 5 minutes after a node has been added.

# 터미널1
$ watch -d kubectl get node
  • CA 문제점 : 하나의 자원에 대해 두군데 (AWS ASG vs AWS EKS)에서 각자의 방식으로 관리해서 관리 정보가 서로 동기화되지 않아 다양한 문제 발생

 

CPA — Cluster Proportional Autoscaler

  • 노드 수 증가에 비례하여 성능 처리가 필요한 애플리케이션(컨테이너/파드)를 수평으로 자동 확장합니다. ex. coredns — Github Workshop
$ helm repo add cluster-proportional-autoscaler https://kubernetes-sigs.github.io/cluster-proportional-autoscaler

# CPA규칙을 설정하고 helm차트를 릴리즈 필요
$ helm upgrade --install cluster-proportional-autoscaler cluster-proportional-autoscaler/cluster-proportional-autoscaler

# nginx 디플로이먼트 배포
$ cat <<EOT > cpa-nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        resources:
          limits:
            cpu: "100m"
            memory: "64Mi"
          requests:
            cpu: "100m"
            memory: "64Mi"
        ports:
        - containerPort: 80
EOT
$ kubectl apply -f cpa-nginx.yaml

# CPA 규칙 설정
$ cat <<EOF > cpa-values.yaml
config:
  ladder:
    nodesToReplicas:
      - [1, 1]
      - [2, 2]
      - [3, 3]
      - [4, 3]
      - [5, 5]
options:
  namespace: default
  target: "deployment/nginx-deployment"
EOF

# 모니터링
$ watch -d kubectl get pod

# helm 업그레이드
$ helm upgrade --install cluster-proportional-autoscaler -f cpa-values.yaml cluster-proportional-autoscaler/cluster-proportional-autoscaler

# 노드 5개로 증가
# export ASG_NAME=$(aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='eks-hayley']].AutoScalingGroupName" --output text)
# aws autoscaling update-auto-scaling-group --auto-scaling-group-name ${ASG_NAME} --min-size 5 --desired-capacity 5 --max-size 5
$ aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='eks-hayley']].[AutoScalingGroupName, MinSize, MaxSize,DesiredCapacity]" --output table
-----------------------------------------------------------------
|                   DescribeAutoScalingGroups                   |
+------------------------------------------------+----+----+----+
|  eks-ng1-d8c42e9a-525d-ab54-5ddf-e8be5d85ff28  |  5 |  5 |  5 |
+------------------------------------------------+----+----+----+

# 노드 4개로 축소
$ aws autoscaling update-auto-scaling-group --auto-scaling-group-name ${ASG_NAME} --min-size 4 --desired-capacity 4 --max-size 4
$ aws autoscaling describe-auto-scaling-groups --query "AutoScalingGroups[? Tags[? (Key=='eks:cluster-name') && Value=='eks-hayley']].[AutoScalingGroupName, MinSize, MaxSize,DesiredCapacity]" --output table
-----------------------------------------------------------------
|                   DescribeAutoScalingGroups                   |
+------------------------------------------------+----+----+----+
|  eks-ng1-d8c42e9a-525d-ab54-5ddf-e8be5d85ff28  |  4 |  4 |  4 |
+------------------------------------------------+----+----+----+


# 삭제
$ helm uninstall cluster-proportional-autoscaler && kubectl delete -f cpa-nginx.yaml

 

Karpenter : K8S Native AutoScaler & Fargate

  • 참고 영상 : [영상] Karpenter로 쿠버네티스 클러스터 최적화: 비용 절감과 효율성 향상* - Youtube , 원본영상*
  • 작동 방식

— 모니터링 → (스케줄링 안된 Pod 발견) → 스펙 평가 → 생성 ⇒ Provisioning

— 모니터링 → (비어있는 노드 발견) → 제거 ⇒ Deprovisioning

 

  • Getting Started with Karpenter 실습 : Docs Intro 
# 변수 설정
export KARPENTER_NAMESPACE="kube-system"
export KARPENTER_VERSION="1.2.1"
export K8S_VERSION="1.32"

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="gasida-karpenter-demo" # ${USER}-karpenter-demo
export AWS_DEFAULT_REGION="ap-northeast-2"
export AWS_ACCOUNT_ID="$(aws sts get-caller-identity --query Account --output text)"
export TEMPOUT="$(mktemp)"
export ALIAS_VERSION="$(aws ssm get-parameter --name "/aws/service/eks/optimized-ami/${K8S_VERSION}/amazon-linux-2023/x86_64/standard/recommended/image_id" --query Parameter.Value | xargs aws ec2 describe-images --query 'Images[0].Name' --image-ids | sed -r 's/^.*(v[[:digit:]]+).*$/\1/')"

# 확인
echo "${KARPENTER_NAMESPACE}" "${KARPENTER_VERSION}" "${K8S_VERSION}" "${CLUSTER_NAME}" "${AWS_DEFAULT_REGION}" "${AWS_ACCOUNT_ID}" "${TEMPOUT}" "${ALIAS_VERSION}"

# CloudFormation 스택으로 IAM Policy/Role, SQS, Event/Rule 생성 : 3분 정도 소요
## IAM Policy : KarpenterControllerPolicy-gasida-karpenter-demo
## IAM Role : KarpenterNodeRole-gasida-karpenter-demo
curl -fsSL https://raw.githubusercontent.com/aws/karpenter-provider-aws/v"${KARPENTER_VERSION}"/website/content/en/preview/getting-started/getting-started-with-karpenter/cloudformation.yaml  > "${TEMPOUT}" \
&& aws cloudformation deploy \
  --stack-name "Karpenter-${CLUSTER_NAME}" \
  --template-file "${TEMPOUT}" \
  --capabilities CAPABILITY_NAMED_IAM \
  --parameter-overrides "ClusterName=${CLUSTER_NAME}"
  
  
  # 클러스터 생성 : EKS 클러스터 생성 15분 정도 소요
eksctl create cluster -f - <<EOF
---
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig
metadata:
  name: ${CLUSTER_NAME}
  region: ${AWS_DEFAULT_REGION}
  version: "${K8S_VERSION}"
  tags:
    karpenter.sh/discovery: ${CLUSTER_NAME}

iam:
  withOIDC: true
  podIdentityAssociations:
  - namespace: "${KARPENTER_NAMESPACE}"
    serviceAccountName: karpenter
    roleName: ${CLUSTER_NAME}-karpenter
    permissionPolicyARNs:
    - arn:${AWS_PARTITION}:iam::${AWS_ACCOUNT_ID}:policy/KarpenterControllerPolicy-${CLUSTER_NAME}

iamIdentityMappings:
- arn: "arn:${AWS_PARTITION}:iam::${AWS_ACCOUNT_ID}:role/KarpenterNodeRole-${CLUSTER_NAME}"
  username: system:node:{{EC2PrivateDNSName}}
  groups:
  - system:bootstrappers
  - system:nodes
  ## If you intend to run Windows workloads, the kube-proxy group should be specified.
  # For more information, see https://github.com/aws/karpenter/issues/5099.
  # - eks:kube-proxy-windows

managedNodeGroups:
- instanceType: m5.large
  amiFamily: AmazonLinux2023
  name: ${CLUSTER_NAME}-ng
  desiredCapacity: 2
  minSize: 1
  maxSize: 10
  iam:
    withAddonPolicies:
      externalDNS: true

addons:
- name: eks-pod-identity-agent
EOF


# eks 배포 확인
eksctl get cluster
eksctl get nodegroup --cluster $CLUSTER_NAME
eksctl get iamidentitymapping --cluster $CLUSTER_NAME
eksctl get iamserviceaccount --cluster $CLUSTER_NAME
eksctl get addon --cluster $CLUSTER_NAME

# 
kubectl ctx
kubectl config rename-context "<각자 자신의 IAM User>@<자신의 Nickname>-karpenter-demo.ap-northeast-2.eksctl.io" "karpenter-demo"
kubectl config rename-context "admin@gasida-karpenter-demo.ap-northeast-2.eksctl.io" "karpenter-demo"

# k8s 확인
kubectl ns default
kubectl cluster-info
kubectl get node --label-columns=node.kubernetes.io/instance-type,eks.amazonaws.com/capacityType,topology.kubernetes.io/zone
kubectl get pod -n kube-system -owide
kubectl get pdb -A
kubectl describe cm -n kube-system aws-auth

 

  • Install Karpenter
# Logout of helm registry to perform an unauthenticated pull against the public ECR
helm registry logout public.ecr.aws

# Karpenter 설치를 위한 변수 설정 및 확인
export CLUSTER_ENDPOINT="$(aws eks describe-cluster --name "${CLUSTER_NAME}" --query "cluster.endpoint" --output text)"
export KARPENTER_IAM_ROLE_ARN="arn:${AWS_PARTITION}:iam::${AWS_ACCOUNT_ID}:role/${CLUSTER_NAME}-karpenter"
echo "${CLUSTER_ENDPOINT} ${KARPENTER_IAM_ROLE_ARN}"

# karpenter 설치
helm upgrade --install karpenter oci://public.ecr.aws/karpenter/karpenter --version "${KARPENTER_VERSION}" --namespace "${KARPENTER_NAMESPACE}" --create-namespace \
  --set "settings.clusterName=${CLUSTER_NAME}" \
  --set "settings.interruptionQueue=${CLUSTER_NAME}" \
  --set controller.resources.requests.cpu=1 \
  --set controller.resources.requests.memory=1Gi \
  --set controller.resources.limits.cpu=1 \
  --set controller.resources.limits.memory=1Gi \
  --wait

# 확인
helm list -n kube-system
kubectl get-all -n $KARPENTER_NAMESPACE
kubectl get all -n $KARPENTER_NAMESPACE
kubectl get crd | grep karpenter
  • Add optional monitoring with Grafana
#
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

# 프로메테우스 설치
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
extraScrapeConfigs: |
    - job_name: karpenter
      kubernetes_sd_configs:
      - role: endpoints
        namespaces:
          names:
          - kube-system
      relabel_configs:
      - source_labels:
        - __meta_kubernetes_endpoints_name
        - __meta_kubernetes_endpoint_port_name
        action: keep
        regex: karpenter;http-metrics

# 프로메테우스 얼럿매니저 미사용으로 삭제
kubectl delete sts -n monitoring prometheus-alertmanager

# 프로메테우스 접속 설정
export POD_NAME=$(kubectl get pods --namespace monitoring -l "app.kubernetes.io/name=prometheus,app.kubernetes.io/instance=prometheus" -o jsonpath="{.items[0].metadata.name}")
kubectl --namespace monitoring port-forward $POD_NAME 9090 &
open http://127.0.0.1:9090

# 그라파나 설치
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
datasources:
  datasources.yaml:
    apiVersion: 1
    datasources:
    - name: Prometheus
      type: prometheus
      version: 1
      url: http://prometheus-server:80
      access: proxy
dashboardProviders:
  dashboardproviders.yaml:
    apiVersion: 1
    providers:
    - name: 'default'
      orgId: 1
      folder: ''
      type: file
      disableDeletion: false
      editable: true
      options:
        path: /var/lib/grafana/dashboards/default
dashboards:
  default:
    capacity-dashboard:
      url: https://karpenter.sh/preview/getting-started/getting-started-with-karpenter/karpenter-capacity-dashboard.json
    performance-dashboard:
      url: https://karpenter.sh/preview/getting-started/getting-started-with-karpenter/karpenter-performance-dashboard.json

# admin 암호
kubectl get secret --namespace monitoring grafana -o jsonpath="{.data.admin-password}" | base64 --decode ; echo
17JUGSjgxK20m4NEnAaG7GzyBjqAMHMFxRnXItLj

# 그라파나 접속
kubectl port-forward --namespace monitoring svc/grafana 3000:80 &
open http://127.0.0.1:3000
  • First Use
# pause 파드 1개에 CPU 1개 최소 보장 할당
$ 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
      containers:
        - name: inflate
          image: public.ecr.aws/eks-distro/kubernetes/pause:3.7
          resources:
            requests:
              cpu: 1
EOF

# [신규 터미널] 모니터링
eks-node-viewer --resources cpu,memory
eks-node-viewer --resources cpu,memory --node-selector "karpenter.sh/registered=true" --extra-labels eks-node-viewer/node-age

# Scale up
$ kubectl scale deployment inflate --replicas 5
$ kubectl logs -f -n karpenter -l app.kubernetes.io/name=karpenter -c controller
...

# 확인
kubectl get nodeclaims
NAME            TYPE          CAPACITY    ZONE              NODE                                                 READY   AGE
default-8f5vd   c5a.2xlarge   on-demand   ap-northeast-2c   ip-192-168-176-171.ap-northeast-2.compute.internal   True    79s

kubectl describe nodeclaims
...
Spec:
  Expire After:  720h
  Node Class Ref:
    Group:  karpenter.k8s.aws
    Kind:   EC2NodeClass
    Name:   default
  Requirements:
    Key:       karpenter.k8s.aws/instance-category
    Operator:  In
    Values:
      c
      m
      r
    Key:       node.kubernetes.io/instance-type
    Operator:  In
    Values:
      c4.2xlarge
      c4.4xlarge
      c5.2xlarge
      c5.4xlarge
      c5a.2xlarge
      c5a.4xlarge
      c5a.8xlarge
      c5d.2xlarge
      c5d.4xlarge
      ...
    ...
    Key:       karpenter.sh/capacity-type
    Operator:  In
    Values:
      on-demand
  Resources:
    Requests:
      Cpu:   4150m
      Pods:  8
Status:
  Allocatable:
    Cpu:                        7910m
    Ephemeral - Storage:        17Gi
    Memory:                     14162Mi
    Pods:                       58
    vpc.amazonaws.com/pod-eni:  38
  Capacity:
    Cpu:                        8
    Ephemeral - Storage:        20Gi
    Memory:                     15155Mi
    Pods:                       58
    vpc.amazonaws.com/pod-eni:  38
...

#
kubectl get node -l karpenter.sh/registered=true -o jsonpath="{.items[0].metadata.labels}" | jq '.'
...
  "karpenter.sh/initialized": "true",
  "karpenter.sh/nodepool": "default",
  "karpenter.sh/registered": "true",
...
  • Scale down deployment : 30초 후(ttlSecondsAfterEmpty) Karpenter는 현재 비어 있는 노드를 종료함
# Now, delete the deployment. After 30 seconds (ttlSecondsAfterEmpty), Karpenter should terminate the now empty nodes.
kubectl delete deployment inflate && date

# 출력 로그 분석
kubectl logs -f -n "${KARPENTER_NAMESPACE}" -l app.kubernetes.io/name=karpenter -c controller | jq '.'
...
  • Disruption : 활용도가 낮은 컴퓨팅 인스턴스에서 실행되는 워크로드가 더 적은 수의 인스턴스로 압축되도록 지속적으로 최적화 함
# 기존 nodepool 삭제
kubectl delete nodepool,ec2nodeclass default

# 모니터링
kubectl logs -f -n "${KARPENTER_NAMESPACE}" -l app.kubernetes.io/name=karpenter -c controller | jq '.'
eks-node-viewer --resources cpu,memory --node-selector "karpenter.sh/registered=true" --extra-labels eks-node-viewer/node-age
watch -d "kubectl get nodes -L karpenter.sh/nodepool -L node.kubernetes.io/instance-type -L karpenter.sh/capacity-type"

# Create a Karpenter NodePool and EC2NodeClass
cat <<EOF | envsubst | kubectl apply -f -
apiVersion: karpenter.sh/v1
kind: NodePool
metadata:
  name: default
spec:
  template:
    spec:
      nodeClassRef:
        group: karpenter.k8s.aws
        kind: EC2NodeClass
        name: default
      requirements:
        - 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-size
          operator: NotIn
          values: ["nano","micro","small","medium"]
        - key: karpenter.k8s.aws/instance-hypervisor
          operator: In
          values: ["nitro"]
      expireAfter: 1h # nodes are terminated automatically after 1 hour
  limits:
    cpu: "1000"
    memory: 1000Gi
  disruption:
    consolidationPolicy: WhenEmptyOrUnderutilized # policy enables Karpenter to replace nodes when they are either empty or underutilized
    consolidateAfter: 1m
---
apiVersion: karpenter.k8s.aws/v1
kind: EC2NodeClass
metadata:
  name: default
spec:
  role: "KarpenterNodeRole-${CLUSTER_NAME}" # replace with your cluster name
  amiSelectorTerms:
    - alias: "al2023@latest"
  subnetSelectorTerms:
    - tags:
        karpenter.sh/discovery: "${CLUSTER_NAME}" # replace with your cluster name
  securityGroupSelectorTerms:
    - tags:
        karpenter.sh/discovery: "${CLUSTER_NAME}" # replace with your cluster name
EOF

# 확인 
kubectl get nodepool,ec2nodeclass

# Deploy a sample workload
cat <<EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: inflate
spec:
  replicas: 5
  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
            memory: 1.5Gi
        securityContext:
          allowPrivilegeEscalation: false
EOF

#
kubectl get nodes -L karpenter.sh/nodepool -L node.kubernetes.io/instance-type -L karpenter.sh/capacity-type
kubectl get nodeclaims
kubectl describe nodeclaims
kubectl logs -f -n "${KARPENTER_NAMESPACE}" -l app.kubernetes.io/name=karpenter -c controller | jq '.'
kubectl logs -n "${KARPENTER_NAMESPACE}" -l app.kubernetes.io/name=karpenter -c controller | grep 'launched nodeclaim' | jq '.'



$ kubectl scale deployment inflate --replicas 12
$ kubectl logs -f -n karpenter -l app.kubernetes.io/name=karpenter -c controller


# 인스턴스 확인
# This changes the total memory request for this deployment to around 12Gi, 
# which when adjusted to account for the roughly 600Mi reserved for the kubelet on each node means that this will fit on 2 instances of type m5.large:
$ kubectl get node -l type=karpenter
NAME                                                 STATUS     ROLES    AGE   VERSION
ip-192-168-13-243.ap-northeast-2.compute.internal    NotReady   <none>   28s   v1.24.13-eks-0a21954
ip-192-168-160-30.ap-northeast-2.compute.internal    NotReady   <none>   28s   v1.24.13-eks-0a21954
ip-192-168-164-160.ap-northeast-2.compute.internal   NotReady   <none>   28s   v1.24.13-eks-0a21954
ip-192-168-9-235.ap-northeast-2.compute.internal     NotReady   <none>   28s   v1.24.13-eks-0a21954

$ kubectl get node --label-columns=eks.amazonaws.com/capacityType,karpenter.sh/capacity-type
NAME                                                 STATUS   ROLES    AGE   VERSION                CAPACITYTYPE   CAPACITY-TYPE
ip-192-168-13-243.ap-northeast-2.compute.internal    Ready    <none>   64s   v1.24.13-eks-0a21954                  on-demand
ip-192-168-160-30.ap-northeast-2.compute.internal    Ready    <none>   64s   v1.24.13-eks-0a21954                  on-demand
ip-192-168-164-160.ap-northeast-2.compute.internal   Ready    <none>   64s   v1.24.13-eks-0a21954                  on-demand
ip-192-168-33-157.ap-northeast-2.compute.internal    Ready    <none>   24m   v1.24.13-eks-0a21954   ON_DEMAND      
ip-192-168-7-78.ap-northeast-2.compute.internal      Ready    <none>   24m   v1.24.13-eks-0a21954   ON_DEMAND      
ip-192-168-9-235.ap-northeast-2.compute.internal     Ready    <none>   64s   v1.24.13-eks-0a21954                  on-demand

$ kubectl get node --label-columns=node.kubernetes.io/instance-type,topology.kubernetes.io/zone
NAME                                                 STATUS   ROLES    AGE   VERSION                INSTANCE-TYPE   ZONE
ip-192-168-13-243.ap-northeast-2.compute.internal    Ready    <none>   44s   v1.24.13-eks-0a21954   m5.xlarge       ap-northeast-2a
ip-192-168-160-30.ap-northeast-2.compute.internal    Ready    <none>   44s   v1.24.13-eks-0a21954   m5.xlarge       ap-northeast-2d
ip-192-168-164-160.ap-northeast-2.compute.internal   Ready    <none>   44s   v1.24.13-eks-0a21954   m5.xlarge       ap-northeast-2d
ip-192-168-33-157.ap-northeast-2.compute.internal    Ready    <none>   24m   v1.24.13-eks-0a21954   m5.large        ap-northeast-2c
ip-192-168-7-78.ap-northeast-2.compute.internal      Ready    <none>   24m   v1.24.13-eks-0a21954   m5.large        ap-northeast-2a
ip-192-168-9-235.ap-northeast-2.compute.internal     Ready    <none>   44s   v1.24.13-eks-0a21954   m5.xlarge       ap-northeast-2a

# Next, scale the number of replicas back down to 5:
$ kubectl scale deployment inflate --replicas 5
deployment.apps/inflate scaled

# The output will show Karpenter identifying specific nodes to cordon, drain and then terminate:
$ kubectl logs -f -n karpenter -l app.kubernetes.io/name=karpenter -c controller

# Next, scale the number of replicas back down to 1
$ kubectl scale deployment inflate --replicas 1
$ kubectl logs -f -n karpenter -l app.kubernetes.io/name=karpenter -c controller

kubectl get nodeclaims
NAME            TYPE          CAPACITY    ZONE              NODE                                                 READY   AGE
default-ff7xn   c6g.large     on-demand   ap-northeast-2b   ip-192-168-109-5.ap-northeast-2.compute.internal     True    78s
default-ffnzp   c6g.2xlarge   on-demand   ap-northeast-2c   ip-192-168-185-240.ap-northeast-2.compute.internal   True    16m

kubectl get nodeclaims                                                                                
NAME            TYPE        CAPACITY    ZONE              NODE                                               READY   AGE
default-ff7xn   c6g.large   on-demand   ap-northeast-2b   ip-192-168-109-5.ap-northeast-2.compute.internal   True    3m3s


# 삭제
kubectl delete deployment inflate
kubectl delete nodepool,ec2nodeclass default
  • 삭제
# Karpenter helm 삭제 
helm uninstall karpenter --namespace "${KARPENTER_NAMESPACE}"

# Karpenter IAM Role 등 생성한 CloudFormation 삭제
aws cloudformation delete-stack --stack-name "Karpenter-${CLUSTER_NAME}"

# EC2 Launch Template 삭제
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 {}

# 클러스터 삭제
eksctl delete cluster --name "${CLUSTER_NAME}"

 

 

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