CKS Exam Dumps : Certified Kubernetes Security Specialist (CKS)

1) Connect to the correct host

ssh cks000035

sudo -i

export KUBECONFIG=/etc/kubernetes/admin.conf

2) List the 3 container names + images in the Deployment

kubectl -n alpine get deploy alpine -o jsonpath='{range .spec.template.spec.containers[*]}{.name}{"\t"}{.image}{"\n"}{end}'

You’ll get 3 lines like:

c1 alpine:3.xx

c2 alpine:3.yy

c3 alpine:3.zz

3) Identify which alpine image has libcrypto3 at 3.1.4-r5

Fastest reliable method (since it’s Alpine, just query apk inside each image):

Run these one-by-one for each image you saw in step 2:

docker run --rm sh -c 'apk info -v libcrypto3 2>/dev/null | head -n1'

docker run --rm sh -c 'apk info -v libcrypto3 2>/dev/null | head -n1'

docker run --rm sh -c 'apk info -v libcrypto3 2>/dev/null | head -n1'

✅ The correct image is the one that prints exactly:

libcrypto3-3.1.4-r5

Note that full image tag, e.g.:

IMG=alpine:3.xx

4) Create SPDX document with bom for that identified image

(Use the identified image from step 3.)

bom generate --image $IMG --format spdx --output /home/candidate/alpine.spdx

Verify file exists:

ls -l /home/candidate/alpine.spdx

5) Remove ONLY the container that uses that image version

The manifest to edit is:

vi /home/candidate/alpine-deployment.yaml

In the spec.template.spec.containers: list, find the container entry whose image: equals the identified $IMG, and delete that one container block only (name/image/ports/etc for that container).

Save:

wq

6) Apply the updated Deployment (do not change other containers)

kubectl apply -f /home/candidate/alpine-deployment.yaml

Wait rollout:

kubectl -n alpine rollout status deployment/alpine

7) Verify only 2 containers remain

kubectl -n alpine get deploy alpine -o jsonpath='{range .spec.template.spec.containers[*]}{.name}{"\t"}{.image}{"\n"}{end}'

You should now see 2 lines, and the $IMG line should be gone.

If bom generate ... errors (quick fix)

Check exact syntax on that system:

bom --help

bom generate --help

Then rerun with the flags it expects, keeping:

image = $IMG

output = /home/candidate/alpine.spdx

format = spdx

FROM debian:latest

MAINTAINER k@bogotobogo.com

# 1 - RUN

RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -yq apt-utils

RUN DEBIAN_FRONTEND=noninteractive apt-get install -yq htop

RUN apt-get clean

# 2 - CMD

#CMD ["htop"]

#CMD ["ls", "-l"]

# 3 - WORKDIR and ENV

WORKDIR /root

ENV DZ version1

$ docker image build -t bogodevops/demo .

Sending build context to Docker daemon 3.072kB

Step 1/7 : FROM debian:latest

---> be2868bebaba

Step 2/7 : MAINTAINER k@bogotobogo.com

---> Using cache

---> e2eef476b3fd

Step 3/7 : RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -yq apt-utils

---> Using cache

---> 32fd044c1356

Step 4/7 : RUN DEBIAN_FRONTEND=noninteractive apt-get install -yq htop

---> Using cache

---> 0a5b514a209e

Step 5/7 : RUN apt-get clean

---> Using cache

---> 5d1578a47c17

Step 6/7 : WORKDIR /root

---> Using cache

---> 6b1c70e87675

Step 7/7 : ENV DZ version1

---> Using cache

---> cd195168c5c7

Successfully built cd195168c5c7

Successfully tagged bogodevops/demo:latest

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 master

node 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 master

node and either remove the --peer-auto-tls parameter or set it to false.

--peer-auto-tls=false