Certified Kubernetes Application Developer (CKAD) Practice Test

Which Kubernetes component is an agent that runs on a node?

1. API Server

2. Scheduler

3. Kubelet

4. Controller

The correct answer is: Kubelet

The Kubelet is a critical component in the Kubernetes architecture that acts as an agent running on each node in a cluster. Its primary role is to manage the state of the containers that are running on its node, ensuring they are healthy and operating as intended. The Kubelet communicates with the Kubernetes control plane to receive instructions and report on the status of the node and its containers. It listens for API requests from the control plane components and is responsible for the following key functions: 1. **Container Management**: The Kubelet ensures that the specified containers are running and are in the expected state as declared by the desired state maintained in the cluster. 2. **Health Checks**: It performs health checks on the containers to determine their readiness and liveliness. This ensures that only healthy containers are serving traffic. 3. **Pod Lifecycle Management**: The Kubelet works with the container runtime to manage the lifecycle of Pods, which are the basic execution units in Kubernetes. 4. **Node Reporting**: It reports the status of the node and its Pods back to the Kubernetes API Server, enabling the control plane to have an updated view of the cluster's state. In contrast, the other components serve different roles. The API Server manages communication