Kubernetes architecture (control plane and nodes) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the role of the Kubernetes control plane?

The control plane manages the Kubernetes cluster. It makes decisions like scheduling pods, responding to cluster events, and maintaining the desired state of the cluster.

beginner

Name the main components of the Kubernetes control plane.

The main components are: API Server, Scheduler, Controller Manager, and etcd (the key-value store).

beginner

What is a Kubernetes node?

A node is a worker machine in Kubernetes. It runs the applications and services inside containers.

intermediate

What components run on a Kubernetes node?

Each node runs kubelet (agent), container runtime (like Docker or containerd), and kube-proxy (networking).

intermediate

How does the control plane communicate with nodes?

The control plane communicates with nodes through the API Server. Nodes run kubelet which talks to the API Server to receive instructions and report status.

Which component stores the cluster state in Kubernetes?

A kube-proxy

B kubelet

C Scheduler

D etcd

etcd is the key-value store that holds the cluster's state data.

What is the main function of the kubelet on a node?

A Schedule pods to nodes

B Manage network traffic

C Run containers and report node status

D Store cluster data

kubelet runs on nodes to manage containers and report status to the control plane.

Which component is responsible for scheduling pods to nodes?

A Scheduler

B API Server

C Controller Manager

D kube-proxy

The Scheduler decides which node a pod should run on.

What does kube-proxy do on a Kubernetes node?

A Runs containers

B Manages network rules for pod communication

C Stores cluster state

D Schedules pods

kube-proxy manages network traffic and rules to enable communication between pods and services.

How does the control plane maintain the desired state of the cluster?

A By using the Controller Manager to monitor and adjust resources

B By running containers directly

C By storing data in kubelet

D By managing network traffic

The Controller Manager watches the cluster state and makes changes to keep it as desired.

Explain the roles of the Kubernetes control plane components and how they work together.

Think of the control plane as the brain of the cluster coordinating everything.

Describe what happens on a Kubernetes node and the role of its components.

Nodes are like workers that run the actual applications.