1. Metrics Server 설치

kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.5.0/components.yaml

args 에 kubelet-insecure-tls 추가

kubectl edit deployment metrics-server -n kube-system

#spec:
containers:
- args:
- --cert-dir=/tmp
- --secure-port=443
- --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
- --kubelet-use-node-status-port
- --metric-resolution=15s
- --kubelet-insecure-tls <-- 추가

설치 확인 (True값 확인)

kubectl get apiservices |egrep metrics

v1beta1.metrics.k8s.io kube-system/metrics-server True 28m

메트릭 값 확인 (1~2분 후)

kubectl top node

NAME CPU(cores) CPU% MEMORY(bytes) MEMORY%
k8s-master 485m 9% 4852Mi 32%
k8s-node1 413m 8% 4929Mi 33%
k8s-node2 554m 11% 4672Mi 31%

2. HPA (Horizontal Pod Autoscaler)

2-1) Target Deployment (CPU) / Service

apiVersion: apps/v1
kind: Deployment
metadata:
 name: stateless-cpu1
spec:
 selector:
   matchLabels:
      resource: cpu
 replicas: 2
 template:
   metadata:
     labels:
       resource: cpu
   spec:
     containers:
     - name: container
       image: kubetm/app:v1
       resources:
         requests:
           cpu: 10m
         limits:
           cpu: 20m

  apiVersion: v1
  kind: Service
  metadata:
   name: stateless-svc1
  spec:
   selector:
      resource: cpu
   ports:
     - port: 8080
       targetPort: 8080
       nodePort: 30001
   type: NodePort

2-2) HPA - Resource (Utilization)

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: hpa-resource-cpu
spec:
  maxReplicas: 10
  minReplicas: 2
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: stateless-cpu1
  metrics:
  - type: Resource 
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50
    
    

2-3) Target Deployment (Memory) / Service

 apiVersion: apps/v1
kind: Deployment
metadata:
 name: stateless-memory1
spec:
 selector:
   matchLabels:
      resource: memory
 replicas: 2
 template:
   metadata:
     labels:
       resource: memory
   spec:
     containers:
     - name: container
       image: kubetm/app:v1
       resources:
         requests:
           memory: 10Mi
         limits:
           memory: 20Mi

apiVersion: v1
kind: Service
metadata:
 name: stateless-svc2
spec:
 selector:
    resource: memory
 ports:
   - port: 8080
     targetPort: 8080
     nodePort: 30002
 type: NodePort

    

2-4) HPA - Resource (AverageValue)

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: hpa-resource-memory
spec:
  maxReplicas: 10
  minReplicas: 2
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: stateless-memory1
  metrics:
  - type: Resource 
    resource:
      name: memory
      target:
        type: AverageValue
        averageValue: 5Mi

Sample yaml

HPA for - Pods

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: hpa-pods
spec:
  maxReplicas: 10
  minReplicas: 2
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: stateless-app1
  metrics:
  - type: Pods
    pods:
      metric:
        name: packets-per-second
      target:
        type: AverageValue
        averageValue: 10
    
    

HPA - Object

apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
  name: hpa-object
spec:
  maxReplicas: 10
  minReplicas: 2
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: stateless-app1
  metrics:
  - type: Object
    object:
      metric:
        name: requests-per-second
      target:
        type: Value
        value: 10
      describedObject:
        apiVersion: networking.k8s.io/v1beta1
        kind: Ingress
        name: ingress-hpa