CentOS Stream 10: Horizontal Pod Autoscaler
Configure Horizontal Pod Autoscaler (HPA) to automatically scale applications based on metrics on CentOS Stream 10.
May 24, 2026 • 8 min read
centoscentos-stream-10kubernetesk8scluster
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 |
+----------------------+ +----------------------+
Step 1
Deploy Metrics Server.
Step 2
This is an example of Deployment to set Horizontal Pod Autoscaler.
[cent@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:
<span class="color2"># requests : set minimum required resources when creating pods</span>
requests:
<span class="color2"># 250m : 0.25 CPU</span>
cpu: 250m
memory: 64Mi
<span class="color2"># set maximum resorces</span>
limits:
cpu: 500m
memory: 128Mi
[cent@ctrl ~]$ vi hpa.yml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
name: my-nginx-hpa
namespace: default
spec:
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
<span class="color2"># target Deployment name</span>
name: my-nginx
minReplicas: 1
<span class="color2"># maximum number of replicas</span>
maxReplicas: 4
metrics:
- type: Resource
resource:
<span class="color2"># scale if target CPU utilization is over 20%</span>
name: cpu
target:
type: Utilization
averageUtilization: 20
[cent@ctrl ~]$ kubectl apply -f my-nginx.yml -f hpa.yml
deployment.apps/my-nginx created
horizontalpodautoscaler.autoscaling/my-nginx-hpa created
[cent@ctrl ~]$ kubectl get pods
NAME READY STATUS RESTARTS AGE
my-nginx-5496ddfbbb-z2zbl 1/1 Running 0 8s
[cent@ctrl ~]$ kubectl top pod
NAME CPU(cores) MEMORY(bytes)
my-nginx-5496ddfbbb-z2zbl 0m 7Mi
[cent@ctrl ~]$ kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
my-nginx-hpa Deployment/my-nginx cpu: 0%/20% 1 4 1 70s
run some processes to put stress in a pod manually and see current state of pods again
[cent@ctrl ~]$ kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
my-nginx-hpa Deployment/my-nginx cpu: 200%/20% 1 4 4 2m32s
pods have been scaled for settings
[cent@ctrl ~]$ kubectl get pods
NAME READY STATUS RESTARTS AGE
my-nginx-5496ddfbbb-886zt 1/1 Running 0 31s
my-nginx-5496ddfbbb-gt489 1/1 Running 0 31s
my-nginx-5496ddfbbb-p7zcn 1/1 Running 0 31s
my-nginx-5496ddfbbb-z2zbl 1/1 Running 0 2m46s
[cent@ctrl ~]$ kubectl top pod
NAME CPU(cores) MEMORY(bytes)
my-nginx-5496ddfbbb-886zt 0m 7Mi
my-nginx-5496ddfbbb-gt489 0m 7Mi
my-nginx-5496ddfbbb-p7zcn 0m 7Mi
my-nginx-5496ddfbbb-z2zbl 0m 8Mi