CKA cheat sheet

Exam at a glance

Domain weightings

How much of the exam each domain covers. Spend your study time in proportion — the heavier the domain, the more questions you'll see.

Key terms

Pod

A Pod is the smallest deployable unit in Kubernetes, wrapping one or more containers that share network and storage. CKA troubleshooting starts with Pod status such as Pending, CrashLoopBackOff, or ImagePullBackOff.

kubectl

kubectl is the command-line client used to inspect and control a Kubernetes cluster through the API server. The CKA is performance-based, so fluent kubectl usage — get, describe, logs, apply — is essential.

kubeadm

kubeadm is the official tool for bootstrapping a Kubernetes cluster and performing control-plane version upgrades. CKA Domain 2 expects you to install a cluster and run kubeadm upgrade.

etcd

etcd is the distributed key-value store that holds all Kubernetes cluster state. CKA requires knowing how to back up and restore etcd, since losing it loses the cluster.

Control Plane

The control plane is the set of components — API server, scheduler, controller manager, and etcd — that manage the cluster's desired state. CKA troubleshooting often means reading control-plane component logs.

kubelet

The kubelet is the node agent that starts and monitors the Pods assigned to its node. A node showing NotReady usually points to a kubelet or container-runtime problem, a common CKA troubleshooting scenario.

Deployment

A Deployment manages a replicated, self-healing set of Pods and supports rolling updates and rollbacks. CKA Domain 4 covers scaling Deployments and reverting a bad rollout.

Service

A Service gives a stable virtual IP and DNS name to a changing set of Pods, with types ClusterIP, NodePort, and LoadBalancer. CKA networking tasks include exposing workloads and debugging endpoints.

Ingress

An Ingress routes external HTTP and HTTPS traffic to Services based on host and path rules, and requires a running Ingress controller. CKA Domain 3 covers configuring Ingress resources and controllers.

NetworkPolicy

A NetworkPolicy specifies which connections are allowed to and from Pods, defaulting to deny once a Pod is selected. CKA expects you to write policies that restrict traffic between workloads.

CoreDNS

CoreDNS is the default in-cluster DNS server that resolves Service and Pod names to addresses. CKA troubleshooting frequently traces failed connectivity to CoreDNS or kube-proxy problems.

PersistentVolumeClaim

A PersistentVolumeClaim (PVC) is a Pod's request for storage that binds to a PersistentVolume, often provisioned dynamically through a StorageClass. CKA Domain 5 covers configuring persistent storage for applications.

StorageClass

A StorageClass defines a class of storage and enables dynamic provisioning of PersistentVolumes on demand. CKA storage tasks include selecting access modes and reclaim policies.

Taints and Tolerations

Taints and Tolerations are a scheduling pair: a taint repels Pods from a node unless the Pod carries a matching toleration, giving fine control over placement. CKA Domain 4 uses them with node affinity to place or isolate workloads.

RBAC

Role-Based Access Control (RBAC) grants permissions through Roles and ClusterRoles bound to users or ServiceAccounts. CKA Domain 2 requires creating and binding roles to enforce least privilege in the cluster.