Kubernetes - ReplicaSet

In this article let us understand how ReplicaSet in Kubernetes work with an example.

Step 1 : Check the nodes present in the cluster

kubectl get nodes        

Step 2: Create a file rs-nginx.yml

Step 3: Create the replicas and check that 5 pods are running.

kubectl apply -f rs-nginx.yml        

Delete any pod and see the results:

• Let us delete the pod rs-nginx-8wplz

kubectl delete pod rs-nginx-8wplz        

• The pod gets deleted but immediately another pod will be created automatically as we have already mentioned at any given point of time 5 pods should be running.
• rs-nginx-sbhg6 is the new one created 5 seconds ago

If we create another pod with the same label and see whether more than 5 pods will be created or not.

• In one terminal create the pod

kubectl apply -f pod.yml        

• In another terminal run the below command and watch the pods

kubectl get pods -w        

• You can see that even the new pod is deleted immediately. At any given point of time only 5 pods will be kept running!

Hope this gives the clear understanding of ReplicaSet.