ITGSS Certified DevOps Engineer Practice Test

How is the set of Pods targeted by a Service in Kubernetes usually determined?

1. By the Configuration file

2. Through a LabelSelector

3. By Resource allocation

4. By YAML specification

The correct answer is: Through a LabelSelector

The correct answer is determined by the use of a LabelSelector. In Kubernetes, Services are designed to route traffic to a specific set of Pods that fulfill certain criteria, and this is primarily achieved through Labels and LabelSelectors. Labels are key-value pairs associated with Kubernetes objects, such as Pods, which can be used to identify and categorize them. The LabelSelector enables a Service to define which Pods to target based on the specified labels. When a Service is created, the LabelSelector tells the Service which Pods should receive network traffic directed to that Service, allowing flexible and dynamic management of traffic to Pods that fulfill certain roles or stages in their lifecycle. Other options, while they are relevant to Kubernetes, do not directly address how Pods are selected by a Service. The configuration file refers to the overall configuration of the application in Kubernetes, but it is the LabelSelector within that configuration that specifically determines which Pods to target. Resource allocation pertains to the distribution of CPU and memory resources among Pods rather than which Pods a Service should route traffic to. YAML specification describes how Kubernetes objects need to be structured in a YAML file but does not specifically encapsulate the mechanism of Pod selection for Services.