Certified Kubernetes Application Developer (CKAD) Practice Test

Which of the following is NOT a requirement for associating a pod with a stateful set?

1. Setting the serviceName property

2. Specifying a headless service name

3. Using a VolumeClaimTemplate

4. Defining network policies

The correct answer is: Defining network policies

When working with StatefulSets in Kubernetes, the first three choices represent essential components that enable the proper creation and management of stateful applications. Setting the serviceName property is crucial because it allows the Kubernetes system to know which service will govern the network identities of the StatefulSet pods. It essentially defines the way that pods communicate with each other and external clients. Specifying a headless service name is also a requirement of StatefulSets. A headless service allows for direct access to the individual pods rather than load balancing them through a cluster IP. This is essential for stateful applications that rely on stable network identities. Using a VolumeClaimTemplate is significant as it's how StatefulSets manage persistent storage. Each pod in a StatefulSet usually needs its own persistent volume, and the VolumeClaimTemplate defines how these volumes are created. Defining network policies, while useful for controlling traffic within a Kubernetes cluster, is not a requirement for associating a pod with a StatefulSet. Network policies are optional and do not affect the fundamental construction or essential characteristics of StatefulSets. Therefore, they are not a necessary part of associating a pod with a StatefulSet.