Kubernetes : Horizontal Pod Autoscaler

Configure Horizontal Pod Autoscaler to set auto scaling to Pods. This example is based on the environment like follows. +----------------------+ +----------------------+ | [ ctrl.srv.world ] | | [ dlp.srv.world ] | | Manager Node | | Control Plane | +-----------+----------+ +-----------+----------+ eth0|10.0.0.25 eth0|10.0.0.30 | | ------------+--------------------------+----------- | | eth0|10.0.0.51 eth0|10.0.0.52 +-----------+----------+ +-----------+----------+ | [ node01.srv.world ] | | [ node02.srv.world ] | | Worker Node#1 | | Worker Node#2 | +----------------------+ +----------------------+

[1]	Deploy Metrics Server, refer to here.
[2]	This is an example of Deployment to set Horizontal Pod Autoscaler.

debian@ctrl:~$  vi my-nginx.yml apiVersion: apps/v1 kind: Deployment metadata: labels: run: my-nginx name: my-nginx spec: replicas: 1 selector: matchLabels: run: my-nginx template: metadata: labels: run: my-nginx spec: containers: - image: nginx name: my-nginx resources: # requests : set minimum required resources when creating pods requests: # 250m : 0.25 CPU cpu: 250m memory: 64Mi # set maximum resorces limits: cpu: 500m memory: 128Mi debian@ctrl:~$  vi hpa.yml apiVersion: autoscaling/v2 kind: HorizontalPodAutoscaler metadata: name: my-nginx-hpa namespace: default spec: scaleTargetRef: apiVersion: apps/v1 kind: Deployment # target Deployment name name: my-nginx minReplicas: 1 # maximum number of replicas maxReplicas: 4 metrics: - type: Resource resource: # scale if target CPU utilization is over 20% name: cpu target: type: Utilization averageUtilization: 20 debian@ctrl:~$  kubectl apply -f my-nginx.yml -f hpa.yml deployment.apps/my-nginx created horizontalpodautoscaler.autoscaling/my-nginx-hpa created debian@ctrl:~$  kubectl get pods NAME READY STATUS RESTARTS AGE my-nginx-7c748dfbd6-gspm2 1/1 Running 0 8s debian@ctrl:~$  kubectl top pod NAME CPU(cores) MEMORY(bytes) my-nginx-7c748dfbd6-gspm2 0m 7Mi debian@ctrl:~$  kubectl get hpa NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE my-nginx-hpa Deployment/my-nginx cpu: 0%/20% 1 4 1 47s # run some processes to put stress in a pod manually and see current state of pods again debian@ctrl:~$  kubectl get hpa NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE my-nginx-hpa Deployment/my-nginx cpu: 66%/20% 1 4 3 2m38s # pods have been scaled for settings debian@ctrl:~$  kubectl get pods NAME READY STATUS RESTARTS AGE my-nginx-7c748dfbd6-7x2qj 1/1 Running 0 46s my-nginx-7c748dfbd6-gspm2 1/1 Running 0 2m46s my-nginx-7c748dfbd6-rdlqk 1/1 Running 0 46s my-nginx-7c748dfbd6-zr2qs 1/1 Running 0 16s debian@ctrl:~$  kubectl top pod NAME CPU(cores) MEMORY(bytes) my-nginx-7c748dfbd6-7x2qj 0m 7Mi my-nginx-7c748dfbd6-gspm2 0m 8Mi my-nginx-7c748dfbd6-rdlqk 0m 7Mi my-nginx-7c748dfbd6-zr2qs 0m 7Mi