Certified Kubernetes Administrator (CKA) Practice Test

Kubernetes utilizes DNS for service discovery, which is a key component of how it enables communication between different services within a cluster. When a service is created in Kubernetes, the system automatically assigns it a DNS entry that can be resolved to the corresponding IP address of the service. This allows pods and other services to easily discover and interact with each other using human-readable names instead of relying on IP addresses, which can change over time.

By using DNS, Kubernetes ensures that service discovery is dynamic and scalable. For example, if a service is updated or if pods are scaled up or down, the DNS records are automatically updated without the need for manual intervention. Furthermore, DNS can handle multiple instances of a service, allowing load balancing across them.

In contrast, static IP addresses are not practical in dynamic environments like Kubernetes where pods may be created and destroyed frequently. Environment variables can be used for passing configuration data to pods but are not a comprehensive method for service discovery. Filename references do not play a role in service discovery within Kubernetes, as they are typically related to configuration or resource definitions rather than communication between services. Thus, using DNS provides a robust and efficient mechanism for enabling service discovery within Kubernetes.