CKA (CNCF) study guide
CKA · Work through your exam, one topic at a time.
The Certified Kubernetes Administrator (CKA) is a hands-on certification created by the Cloud Native Computing Foundation in collaboration with The Linux Foundation. It is aimed at engineers who operate Kubernetes clusters day to day - cluster lifecycle and installation, upgrades, networking, storage, and on-call troubleshooting - rather than at application developers, which is the separate CKAD track. The exam is an online, proctored, performance-based test: you solve a set of problems on a real command line, and you have 2 hours to complete the tasks. Scoring is domain-weighted: Cluster Architecture, Installation & Configuration 25%; Workloads & Scheduling 15%; Services & Networking 20%; Storage 10%; and Troubleshooting 30% - the single largest block, so fast, structured debugging matters most. The CKA study guide has 5 sections and about 1,330 words.
01Cluster Architecture, Installation & Configuration
The control plane is the API server (front door and admission/RBAC enforcement), etcd (the only state store), scheduler (binds Pods to nodes), and controller-manager (reconciliation loops). Every node runs kubelet (Pod lifecycle), kube-proxy or equivalent (Service dataplane), and a CRI runtime.
283 words, about 1 min02Workloads & Scheduling
Deployments manage ReplicaSets and rolling updates; StatefulSets give stable names and per-Pod PVCs; DaemonSets run one Pod per eligible node; Jobs run to completion and CronJobs schedule them. Pods can have init containers (run sequentially before app containers) and sidecars (long-running helpers).
257 words, about 1 min03Services & Networking
ClusterIP is a virtual IP reachable inside the cluster; NodePort exposes a port on every node; LoadBalancer asks a cloud/provider for an external LB; ExternalName returns a DNS CNAME. Services select Pods by labels and produce EndpointSlices.
265 words, about 1 min04Storage
A Pod volume outlives container restarts but not Pod deletion. emptyDir is node-local scratch; hostPath binds a node path and is risky for scheduling.
267 words, about 1 min05Troubleshooting
Start with the symptom scope: one Pod, one Service, one node, or the whole cluster. Use kubectl get pods -o wide, describe, events, and logs.
258 words, about 1 min