Certified Kubernetes Application Developer (CKAD) Practice Test

The command "get cluster-info" is valid and retrieves the essential metadata about the Kubernetes cluster, including the master node's details and the services that are running on the cluster. This command is pivotal for anyone needing a quick overview of cluster state and configuration, facilitating operational awareness and troubleshooting insights in a Kubernetes environment.

In contrast, the other command options provided do not align with Kubernetes' command syntax or do not exist as valid commands in `kubectl`, which is the command-line tool for interacting with Kubernetes clusters. For example, "describe cluster" is not a recognized command in the `kubectl` CLI; the `describe` command is typically used with specific resources like pods, nodes, or services rather than at the cluster level. Similarly, "fetch cluster-info" and "cluster-info" are not valid commands, as there is no `fetch` command available in `kubectl`, and commands must follow the `get` or `describe` formats with appropriate resource types. Therefore, using "get cluster-info" is indeed the correct and valid way to access the cluster metadata.