Overview:

Scaling in Kubernetes allows you to adjust the number of replicas of a Pod to handle changes in workload.

Manual Scaling:

1. Scale a Deployment:

   kubectl scale deployment my-app-deployment --replicas=5

2. Verify Scaling:

   kubectl get pods

Autoscaling:

1. Enable the Metrics Server:

   • Install the Metrics Server:

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

2. Create a Horizontal Pod Autoscaler (HPA):

   • Example HPA YAML manifest:

     apiVersion: autoscaling/v1
     kind: HorizontalPodAutoscaler
     metadata:
       name: my-app-hpa
     spec:
       scaleTargetRef:
         apiVersion: apps/v1
         kind: Deployment
         name: my-app-deployment
       minReplicas: 2
       maxReplicas: 10
       targetCPUUtilizationPercentage: 50

   • Apply the HPA:

     kubectl apply -f hpa.yaml

3. Verify Autoscaling:

   kubectl get hpa

Activity:

Create and apply an HPA for your Nginx Deployment. Simulate a load and observe the scaling behavior.