CKA Cluster Architecture, Installation and Configuration Practice Test 7 — 15 Questions

Question 1

What is the purpose of 'kubeadm reset'?

Accepted Answer

To remove the node from the cluster and clean up.. `kubeadm reset` is designed to revert any changes made by `kubeadm init` or `kubeadm join` on a node, effectively cleaning up the node's local state (e.g., removing CNI configurations, etcd member data, and kubelet certificates) so it can be safely removed from the cluster or reinitialized. Option C correctly identifies this as removing the node from the cluster and cleaning up, which is the primary purpose of the command.

Answer

To restart the Kubernetes services on a node.

Answer

To reinitialize the cluster with new configuration.

Answer

To rollback the last upgrade.

Question 2

Which TWO of the following are valid resources for granting permissions in RBAC?

Accepted Answer

ClusterRoleBinding. C is correct because a ClusterRoleBinding grants the permissions defined in a ClusterRole to a subject. E is correct because a RoleBinding grants the permissions defined in a Role to a subject within a namespace. These are the resources that actually assign permissions to users, groups, or service accounts.

Answer

Role

Answer

ServiceAccount

Answer

ClusterRole

Question 3

Which THREE of the following are valid options for the 'kubectl drain' command to safely evict pods from a node?

Accepted Answer

--force. To make the question technically accurate and unambiguous, the stem should be rephrased to specifically ask for the three flags required to bypass the common blocking conditions of a drain operation (unmanaged pods, local emptyDir data, and DaemonSets). This makes C, D, and E the only correct answers, while A and B become incorrect distractors in this context.

Answer

--grace-period=0

Answer

--timeout=30s

Question 4

Which TWO of the following are control plane components?

Accepted Answer

cloud-controller-manager. The cloud-controller-manager is a control plane component that integrates with cloud provider APIs to manage cloud-specific resources such as load balancers, storage volumes, and nodes. It runs as a daemon on the control plane and interacts with the Kubernetes API server to reconcile cloud resources with cluster state.

Answer

kubelet

Answer

container runtime

Answer

kube-proxy

Question 5

You are using kubeadm to initialize a Kubernetes cluster. After running 'kubeadm init', the control-plane node is not ready. You run 'kubectl get nodes' and see the node status as 'NotReady'. Which component is most likely not functioning correctly?

Answer

kube-scheduler

Answer

etcd

Answer

kube-apiserver

Answer

kubelet

Question 6

Which command is used to take a snapshot of etcd data for backup?

Accepted Answer

etcdctl snapshot save. The correct command to take a snapshot of etcd data for backup is `etcdctl snapshot save`. This command creates a point-in-time snapshot of the etcd key-value store, which can be used to restore the cluster state. The `snapshot save` subcommand is the official method for backing up etcd data in Kubernetes environments.

Answer

etcdctl export

Answer

etcdctl backup

Answer

etcdctl dump

Question 7

What is the purpose of the kube-proxy component in a Kubernetes cluster?

Accepted Answer

It provides network proxy and load balancing for services. Kube-proxy is the component responsible for implementing the Kubernetes Service concept by maintaining network rules on each node. It performs connection forwarding and load balancing for Service endpoints using either iptables, IPVS, or userspace mode, ensuring that traffic destined for a Service's ClusterIP is correctly routed to healthy Pods.

Answer

It schedules pods to nodes

Answer

It manages the lifecycle of pods

Answer

It stores cluster configuration data

Question 8

You are troubleshooting a pod that is in 'Pending' state. Running 'kubectl describe pod' shows the event: '0/3 nodes are available: 3 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate.' What is the most likely cause?

Accepted Answer

The pod is trying to schedule on the master node which has a taint that is not tolerated. The pod is in 'Pending' state because none of the three nodes are schedulable for it. The 'kubectl describe pod' event explicitly states that all three nodes have the taint 'node-role.kubernetes.io/master: ' and the pod does not have a corresponding toleration. Master nodes are typically tainted to prevent general workloads from scheduling on them, so a pod without a toleration for that taint cannot be placed on any master node, leaving zero available nodes.

Answer

The pod requires more CPU than any node can provide

Answer

The pod is using a hostPort that conflicts with another pod

Answer

The pod has a node selector that doesn't match any node

Question 9

Which TWO of the following are valid methods to restore an etcd cluster from a snapshot? (Choose TWO.)

Accepted Answer

Stopping all etcd members, copying the snapshot to the data directory, and starting etcd. To restore an etcd cluster from a snapshot, the `etcdctl snapshot restore` (or `etcdutl snapshot restore` in newer etcd versions) command must be used. This command extracts the snapshot database and reconstructs the necessary directory structure (including the WAL and member data) so that etcd can successfully start and recover its state.

Answer

etcdctl restore

Answer

kubectl apply -f etcd-backup.yaml

Answer

etcdctl snapshot restore

Answer

kubeadm reset

Question 10

Which THREE of the following are components of the Kubernetes control plane? (Choose THREE.)

Accepted Answer

kube-apiserver. The kube-apiserver is the front-end of the Kubernetes control plane, exposing the Kubernetes API. All administrative tasks and component interactions (e.g., from kubectl, the scheduler, the controller manager) go through the API server, which validates and processes RESTful requests before persisting state to etcd.

Answer

kubelet

Answer

kube-proxy

Question 11

Which command correctly backs up etcd data using etcdctl with API version 3?

Accepted Answer

ETCDCTL_API=3 etcdctl snapshot save /backup/snapshot.db. Etcdctl requires the environment variable `ETCDCTL_API=3` to use the v3 API, which supports the `snapshot save` command for creating a consistent point-in-time backup of etcd data. The command `ETCDCTL_API=3 etcdctl snapshot save /backup/snapshot.db` correctly specifies the API version and the subcommand to save a snapshot to the given file path.

Answer

etcdctl backup /backup/snapshot.db

Answer

etcdctl snapshot-backup /backup/snapshot.db

Answer

ETCDCTL_API=3 etcdctl --snapshot /backup/snapshot.db

Question 12

A cluster was upgraded from version 1.28 to 1.29. After the upgrade, you notice that a custom controller using the 'batch/v2alpha1' API for CronJobs no longer works. What is the most likely reason?

Accepted Answer

The batch/v2alpha1 API version is deprecated and removed in 1.29. The batch/v2alpha1 API version for CronJobs was deprecated in Kubernetes 1.21 and removed entirely in 1.29. Since the cluster was upgraded from 1.28 to 1.29, the custom controller can no longer use this API version because the API server no longer serves it. Controllers must migrate to the stable batch/v1 API version to function correctly.

Answer

The API server was not restarted after the upgrade

Answer

The CronJob resource has been renamed to ScheduledJob

Answer

The custom controller uses an incorrect kubeconfig

Question 13

Which component is responsible for maintaining network rules on each worker node to enable service discovery and load balancing?

Accepted Answer

kube-proxy. kube-proxy is the component responsible for maintaining network rules on each worker node. It implements the Kubernetes Service concept by managing IP tables or IPVS rules to route traffic to the correct Pods, enabling service discovery and load balancing across Pod endpoints.

Answer

kube-controller-manager

Answer

CoreDNS

Answer

kubelet

Question 14

You need to restore an etcd snapshot taken with 'etcdctl snapshot save'. You have a single control plane node. Which sequence of commands is correct?

Accepted Answer

Stop the API server, run 'etcdctl snapshot restore /backup/snapshot.db --data-dir /var/lib/etcd-restored', then start etcd with the restored data. Restoring an etcd snapshot requires stopping the API server first to prevent data corruption, then using 'etcdctl snapshot restore' to create a new data directory, and finally starting etcd with the restored data. The API server depends on etcd, so it must be stopped before the restore, and the restored data directory must be specified to avoid overwriting the existing etcd data.

Answer

Run 'etcdctl import /backup/snapshot.db' and restart the API server

Answer

Stop the API server, run 'etcdctl restore /backup/snapshot.db', then restart etcd

Answer

Run 'etcdctl snapshot restore /backup/snapshot.db' while etcd is running, then restart etcd

Question 15

A pod is stuck in 'Pending' state. 'kubectl describe pod' shows '0/1 nodes are available: 1 node(s) had taint {node.kubernetes.io/unreachable: }, that the pod didn't tolerate'. What does this indicate?

Accepted Answer

The node is not reachable by the control plane. The error message indicates that the node has a taint of `node.kubernetes.io/unreachable`, which is automatically added by the node controller when the control plane cannot communicate with the node (e.g., due to network failure or kubelet being down). The pod remains in 'Pending' because no node is available that tolerates this taint, meaning the node is unreachable from the control plane. This matches option C.

Answer

The pod has been successfully scheduled to the node

Answer

The node has insufficient resources and is tainted

Answer

The node does not exist