Kubernetes Cookbook - Second Edition

DNS for StatefulSet

StatefulSet was described in Chapter 3, Playing with Containers. It assigns a pod name with a sequence number—for example, my-nginx-0, my-nginx-1, my-nginx-2. StatefulSet also uses these pod names to assign a DNS entry instead of IP addresses. Because it uses Kubernetes Service, FQDN appear as follows: <StatefulSet name>-<sequence number>.<Service name>.<Namespace name>.svc.cluster.local.

Let's create StatefulSet to examine how DNS works in StatefulSet:

1. Prepare StatefulSet and normal service YAML configurations as follows:

$ cat nginx-sts.yaml apiVersion: v1kind: Servicemetadata:  name: nginx-sts-svc  labels:    app: nginx-stsspec:  ports:  - port: 80  selector:    app: nginx-sts---apiVersion: apps/v1beta1kind: StatefulSetmetadata: ...