Linux Foundation CKS Exam - Topic 3 Question 68 Discussion

Question

Fix all issues via configuration and restart the affected components to ensure the new setting takes effect.

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

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

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

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

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

a. Ensure the --anonymous-auth argument is set to false.

b. Ensure that the --authorization-mode argument is set to Webhook.

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

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

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

Hint: Take the use of Tool Kube-Bench

Alfred · Accepted Answer

A) Explanation:
Fix all of the following violations that were found against theAPI 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=<ca-string>
scored: true
Fix all of the following violations that were found against theETCD:-
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