CKS Linux Foundation Certified Kubernetes Security Specialist (CKS) Free Practice Exam Questions (2025 Updated)

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

$ kubectl get ing -n

NAME HOSTS ADDRESS PORTS AGE

cafe-ingress cafe.com 10.0.2.15 80 25s

$ kubectl describe ing -n

Name: cafe-ingress

Namespace: default

Address: 10.0.2.15

Default backend: default-http-backend:80 (172.17.0.5:8080)

Rules:

Host Path Backends

---- ---- --------

cafe.com

/tea tea-svc:80 ()

/coffee coffee-svc:80 ()

Annotations:

kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"networking.k8s.io/v1","kind":"Ingress","metadata":{"annotations":{},"name":"cafe-ingress","namespace":"default","selfLink":"/apis/networking/v1/namespaces/default/ingresses/cafe-ingress"},"spec":{"rules":[{"host":"cafe.com","http":{"paths":[{"backend":{"serviceName":"tea-svc","servicePort":80},"path":"/tea"},{"backend":{"serviceName":"coffee-svc","servicePort":80},"path":"/coffee"}]}}]},"status":{"loadBalancer":{"ingress":[{"ip":"169.48.142.110"}]}}}

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal CREATE 1m ingress-nginx-controller Ingress default/cafe-ingress

Normal UPDATE 58s ingress-nginx-controller Ingress default/cafe-ingress

$ kubectl get pods -n

NAME READY STATUS RESTARTS AGE

ingress-nginx-controller-67956bf89d-fv58j 1/1 Running 0 1m

$ kubectl logs -n ingress-nginx-controller-67956bf89d-fv58j

-------------------------------------------------------------------------------

NGINX Ingress controller

Release: 0.14.0

Build: git-734361d

Repository: https://github.com/kubernetes/ingress-nginx

-------------------------------------------------------------------------------

[desk@cli] $ k create sa backend-qa -n qasa/backend-qa created[desk@cli] $ k get role,rolebinding -n qaNo resources found in qa namespace.[desk@cli] $ k create role backend -n qa --resource pods,namespaces,configmaps --verb list# No access to secret[desk@cli] $ k create rolebinding backend -n qa --role backend --serviceaccount qa:backend-qa[desk@cli] $ vim /home/cert_masters/frontend-pod.yaml

apiVersion: v1

kind: Pod

metadata:

 name: frontend

spec:

 serviceAccountName: backend-qa # Add this

  image: nginx

  name: frontend

[desk@cli] $ k apply -f /home/cert_masters/frontend-pod.yamlpod created

[desk@cli] $ k create sa backend-qa -n qaserviceaccount/backend-qa created[desk@cli] $ k get role,rolebinding -n qaNo resources found in qa namespace.[desk@cli] $ k create role backend -n qa --resource pods,namespaces,configmaps --verb listrole.rbac.authorization.k8s.io/backend created[desk@cli] $ k create rolebinding backend -n qa --role backend --serviceaccount qa:backend-qarolebinding.rbac.authorization.k8s.io/backend created[desk@cli] $ vim /home/cert_masters/frontend-pod.yaml

apiVersion: v1

kind: Pod

metadata:

 name: frontend

spec:

 serviceAccountName: backend-qa # Add this

  image: nginx

  name: frontend

[desk@cli] $ k apply -f /home/cert_masters/frontend-pod.yamlpod/frontend createdhttps://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/

A service account provides an identity for processes that run in a Pod.

When you (a human) access the cluster (for example, using kubectl), you are authenticated by the apiserver as a particular User Account (currently this is usually admin, unless your cluster administrator has customized your cluster). Processes in containers inside pods can also contact the apiserver. When they do, they are authenticated as a particular Service Account (for example, default).

When you create a pod, if you do not specify a service account, it is automatically assigned the default service account in the same namespace. If you get the raw json or yaml for a pod you have created (for example, kubectl get pods/ -o yaml), you can see the spec.serviceAccountName field has been automatically set.

You can access the API from inside a pod using automatically mounted service account credentials, as described in Accessing the Cluster. The API permissions of the service account depend on the authorization plugin and policy in use.

In version 1.6+, you can opt out of automounting API credentials for a service account by setting automountServiceAccountToken: false on the service account:

apiVersion: v1

kind: ServiceAccount

metadata:

name: build-robot

automountServiceAccountToken: false

In version 1.6+, you can also opt out of automounting API credentials for a particular pod:

apiVersion: v1

kind: Pod

metadata:

name: my-pod

spec:

serviceAccountName: build-robot

automountServiceAccountToken: false

The pod spec takes precedence over the service account if both specify a automountServiceAccountToken value.

master1 $ k get pods -n test --show-labels

NAME READY STATUS RESTARTS AGE LABELS

test-pod 1/1 Running 0 34s role=test,run=test-pod

testing 1/1 Running 0 17d run=testing

$ vim netpol.yaml

apiVersion: networking.k8s.io/v1

kind: NetworkPolicy

metadata:

name: deny-network

namespace: test

spec:

podSelector: {}

policyTypes:

- Ingress

- Egress

master1 $ k apply -f netpol.yaml

Explanationcontrolplane $ k get pods -n test --show-labels

NAME READY STATUS RESTARTS AGE LABELS

test-pod 1/1 Running 0 34s role=test,run=test-pod

testing 1/1 Running 0 17d run=testing

master1 $ vim netpol1.yaml

apiVersion: networking.k8s.io/v1

kind: NetworkPolicy

metadata:

name: deny-network

namespace: test

spec:

podSelector: {}

policyTypes:

- Ingress

- Egress

Fix all of the following violations that were found against the API server:-

 a. Ensure that the RotateKubeletServerCertificate argument is set to true.

apiVersion: v1

kind: Pod

metadata:

creationTimestamp: null

labels:

component: kubelet

tier: control-plane

name: kubelet

namespace: kube-system

spec:

containers:

- command:

- kube-controller-manager

+ - --feature-gates=RotateKubeletServerCertificate=true

image: gcr.io/google_containers/kubelet-amd64:v1.6.0

livenessProbe:

failureThreshold: 8

httpGet:

host: 127.0.0.1

path: /healthz

port: 6443

scheme: HTTPS

initialDelaySeconds: 15

timeoutSeconds: 15

name: kubelet

resources:

requests:

cpu: 250m

volumeMounts:

- mountPath: /etc/kubernetes/

name: k8s

readOnly: true

- mountPath: /etc/ssl/certs

name: certs

- mountPath: /etc/pki

name: pki

hostNetwork: true

volumes:

- hostPath:

path: /etc/kubernetes

name: k8s

- hostPath:

path: /etc/ssl/certs

name: certs

- hostPath:

path: /etc/pki

name: pki

  b. Ensure that the admission control plugin PodSecurityPolicy is set.

audit: "/bin/ps -ef | grep $apiserverbin | grep -v grep"

tests:

test_items:

- flag: "--enable-admission-plugins"

compare:

op: has

value: "PodSecurityPolicy"

set: true

remediation: |

Follow the documentation and create Pod Security Policy objects as per your environment.

Then, edit the API server pod specification file $apiserverconf

on the master node and set the --enable-admission-plugins parameter to a

value that includes PodSecurityPolicy :

--enable-admission-plugins=...,PodSecurityPolicy,...

Then restart the API Server.

scored: true

c. Ensure that the --kubelet-certificate-authority argument is set as appropriate.

audit: "/bin/ps -ef | grep $apiserverbin | grep -v grep"

tests:

test_items:

- flag: "--kubelet-certificate-authority"

set: true

remediation: |

Follow the Kubernetes documentation and setup the TLS connection between the

apiserver and kubelets. Then, edit the API server pod specification file

$apiserverconf on the master node and set the --kubelet-certificate-authority

parameter to the path to the cert file for the certificate authority.

--kubelet-certificate-authority=

scored: true

Fix all of the following violations that were found against the ETCD:-

a. Ensure that the --auto-tls argument is not set to true

Edit the etcd pod specification file $etcdconf on the masternode and either remove the --auto-tls parameter or set it to false.--auto-tls=false

b. Ensure that the --peer-auto-tls argument is not set to true

Edit the etcd pod specification file $etcdconf on the masternode and either remove the --peer-auto-tls parameter or set it to false.--peer-auto-tls=false

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

se kubectl to create a CSR and approve it.

Get the list of CSRs:

kubectl get csr

Approve the CSR:

kubectl certificate approve myuser

Get the certificateRetrieve the certificate from the CSR:

kubectl get csr/myuser -o yaml

here are the role and role-binding to give john permission to create NEW_CRD resource:

kubectl apply -f roleBindingJohn.yaml --as=john

rolebinding.rbac.authorization.k8s.io/john_external-rosource-rb created

kind: RoleBinding

apiVersion: rbac.authorization.k8s.io/v1

metadata:

name: john_crd

namespace: development-john

subjects:

- kind: User

name: john

apiGroup: rbac.authorization.k8s.io

roleRef:

kind: ClusterRole

name: crd-creation

kind: ClusterRole

apiVersion: rbac.authorization.k8s.io/v1

metadata:

name: crd-creation

rules:

- apiGroups: ["kubernetes-client.io/v1"]

resources: ["NEW_CRD"]

verbs: ["create, list, get"]

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated

Text Description automatically generated