KCNA Kubernetes Fundamentals Practice Question
Which two components are part of the Kubernetes worker node? (Select TWO)
⚠ Common exam trap
The CNCF exam often tests the distinction between control plane and worker node components; the trap here is that candidates confuse the kubelet (worker node agent) with the kube-controller-manager or kube-scheduler, which are control-plane-only services, or mistakenly think etcd runs on every node.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
kubelet
The kubelet (A) is correct because it is the primary node agent that runs on every worker node, registering the node with the API server and ensuring containers described in PodSpecs are running and healthy. The container runtime (E) is correct because the worker node needs a CRI-compliant runtime such as containerd or CRI-O to actually pull images and run containers. The kube-controller-manager (B), etcd (C), and kube-scheduler (D) are all control plane components that typically run on master nodes, not on worker nodes, so they are not part of the worker node.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
kubelet
Why this is correct
kubelet is the node agent that registers the node with the control plane, watches for assigned PodSpecs, and ensures containers run and report health. It is a core worker node component, distinct from control plane services like the scheduler.
- ✗
kube-controller-manager
Why it's wrong here
kube-controller-manager runs on control plane nodes, reconciling cluster state via controllers; it never runs on worker nodes. It is tempting because controllers influence workloads scheduled onto workers, but the worker node hosts kubelet and kube-proxy instead.
- ✗
etcd
Why it's wrong here
etcd is the control plane's distributed key-value store holding cluster state; it does not reside on worker nodes. It appears plausible since workers interact with cluster state, but the worker node's components are kubelet and kube-proxy.
- ✗
kube-scheduler
Why it's wrong here
kube-scheduler is a control plane component that assigns pods to nodes; it does not execute on worker nodes. It seems relevant because it decides which worker receives each pod, yet the worker itself runs kubelet and kube-proxy, not the scheduler.
- ✓
container runtime
Why this is correct
The container runtime runs on every worker node, pulling images and starting containers for pods scheduled there. It satisfies the stem's worker-node constraint because the control plane never executes workloads; kubelet delegates container lifecycle operations to this runtime via the Container Runtime Interface (CRI), making it an essential node component.
Go deeper
Related to this question
About these practice questions
Courseiva writes every KCNA question from scratch — 930 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This KCNA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCNA exam.