Several certifications available

The CNCF delivers several Kubernetes certifications, which are listed in the following table.

Certification	Type
Kubernetes and Cloud Native Associate (KCNA)	MCQ
Kubernetes and Cloud Native Security Associate (KCSA)	MCQ
Certified Kubernetes Application Developer (CKAD)	Practice
Certified Kubernetes Administrator (CKA)	Practice
Certified Kubernetes Security Specialist (CKS) *passing the CKA is a requirement before passing the CKS	Practice

If you pass all those certifications, you become a https://www.cncf.io/training/kubestronaut/.

Expectation for the CKA

The following table summarizes the distribution of the CKA questions across 5 main subjects.

CKA Environment

The CKA is a 2h exam. It contains 15/20 questions and requires at least 66% correct answers. This exam is remotely proctored, so you can take it from home (or any other quiet location) at a time that best suits your schedule.

Before launching the exam, which you do via your Linux Foundation Training Portal, you need to perform a couple of prerequisites including making sure the PSI Browser works correctly on your environment. This browser gives you access to the remote Desktop you’ll use during the exam.

Tips & tricks

Tools

Make sure you have a basic knowledge of

• vi/vim

As this editor is available on almost all Linux distributions, knowing the basic commands is important to be able to create/edit a file quickly.

• openssl

The following command can be useful to verify the content of a certificate.

openssl x509 -in cert.crt -noout -text

• systemd / systemctl / journalctl

systemd related commands are useful to start/restart/stop and get the logs of processes.

# Restart kubelet
systemctl restart kubelet

# Check kubelet logs
journalctl -u kubelet

• sysctl

You may need this tool to change ipv4 forwarding or other networking things

# Check is ipv4 forwarding is enabled
sysctl net.ipv4.ip_forward

# Enable ipv4 forwarding
sysctl -w net.ipv4.ip_forward=1

# Disable ipv4 forwarding
sysctl -w net.ipv4.ip_forward=0

• dpkg

During the exam you may be requested to install a package from its .deb file

sudo dpkg -i my-package.deb

• crictl

crictl is a command-line interface for CRI-compatible container runtimes. It can be used to inspect and debug container runtimes and applications (pods / containers) on a Kubernetes node. During the exam, you may be asked to install crictl.

wget https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.33.0/crictl-v1.33.0-linux-amd64.tar.gz
tar xvf crictl-v1.33.0-linux-amd64.tar.gz 
sudo mv crictl /usr/local/bin/

Aliases

Definiing a couple of aliases at the very beginning of the examination could save time.

alias k=kubectl
export dr=”--dry-run=client -o yaml”
export fd=”--grace-period=0 --force”

Imperative commands

Don’t create specifications manually, instead use --dry-run=client -o yaml as in these examples.

k run nginx --image=nginx:1.20 --dry-run=client -o yaml > pod.yaml
k create deploy www --image=nginx:1.20 --replicas=3 --dry-run=client -o yaml > deploy.yaml
k create role create-pod --verb=create --resource=pods --dry-run=client -o yaml > role.yaml

Quickly change the current Namespace.

k config set-context --current --namespace=dev

Don’t wait for the grace period to get rid of a Pod.

k delete po nginx --force --grace-period=0

Reference guide

The Kubectl quick reference guide is a must-read.

Access to am exam simulator

Registering for the CKA gives you access to two sessions of the official Exam simulator. I hightly recommend using these sessions once you’re almost ready.