Kubernetes Cookbook - Second Edition

Headless service when pods scale out

The preceding example shows only one IP address, because we have been setup only one Pod. What happens if you increase an instance using the kubectl scale command?

Let's increase the Apache instances on chap8-domain1 from 1 to 3, then see how the headless service DNS works:

//specify --replicas=3 $ kubectl scale deploy my-apache --namespace=chap8-domain1 --replicas=3deployment "my-apache" scaled//Now there are 3 Apache Pods$ kubectl get pods --namespace=chap8-domain1 -o wideNAME                         READY     STATUS    RESTARTS   AGE       IP           NODEmy-apache-55fb679f49-c8wg7   1/1       Running   0          1m        172.17.0.7   minikubemy-apache-55fb679f49-cgnj8   1/1       Running   0          1m        172.17.0.8   minikubemy-apache-55fb679f49-qw58f   1/1       Running   0          8h       172.17.0.4   minikube//launch ...