UCKS Exam Series #1 Create Cluster & Security Best Practices

Kubernetes CKS Example Exam Question Series

Kim Wuestkamp

Published in

ITNEXT

4 min readDec 7, 2020

CKS Exam Series | CKA Exam Series | CKAD Exam Series

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THIS CHALLENGE WON’T BE UPDATED HERE AND MOVED TO:

https://killercoda.com/killer-shell-cks

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Content

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→ Check out the FULL CKS COURSE on Udemy ←

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Rules!

Be fast, avoid creating yaml manually from scratch
Use only kubernetes.io/docs for help.
Check our solution after you did yours. You probably have a better one!

Todays Task: Create a CKS Cluster for studying and check Security Best Practices

This is the first task of this series, hence it’ll be a bit about preparation rather than solving scenarios yourself. We think the best way to study for the CKS is to have your own cluster on hand.

This can be just a simple cluster, one controlplane (master), one node (worker) and installed using kubeadm. You’ll work with this exact cluster setup in the CKS exam.

Create two Virtual Machines
Install the controlplane using kubeadm
Install the node using kubeadm
Add the node to the cluster
Watch Kubernetes Best Practices and get mentally ready!

Solution

We’ll use Gcloud in this series, because it’s easy, simple and free (free credit). But you can create the necessary two VMs anywhere you like!

Three is also a Vagrant repo by Preston Sheldon that people could use instead: https://github.com/pksheldon4/cks-cluster

1. Create two Virtual Machines

To create the VMs in Gcloud we can run:

Create cks-controlplane:

gcloud compute instances create cks-controlplane --zone=europe-west3-c \
--machine-type=e2-medium \
--image=ubuntu-1804-bionic-v20201014 \
--image-project=ubuntu-os-cloud \
--boot-disk-size=50GB

Create cks-node:

gcloud compute instances create cks-node --zone=europe-west3-c \
--machine-type=e2-medium \
--image=ubuntu-1804-bionic-v20201014 \
--image-project=ubuntu-os-cloud \
--boot-disk-size=50GB

You can also choose a different zone near you: https://cloud.google.com/compute/docs/regions-zones

2. Install Controlplane using Kubeadm

There is a repository for this challenge series.

gcloud compute ssh cks-controlplane
> sudo -i
> bash <(curl -s https://raw.githubusercontent.com/killer-sh/cks-challenge-series/master/cluster-setup/latest/install_controlplane.sh) exit
sudo -i # login again to get nicer bash with autocompletion

3. Install Node using Kubeadm

gcloud compute ssh cks-node
> sudo -i
> bash <(curl -s https://raw.githubusercontent.com/killer-sh/cks-challenge-series/master/cluster-setup/latest/install_node.sh)exit
sudo -i # login again to get nicer bash with autocompletion

4. Add Node to the cluster

Copy the kubeadm join command which the install_controlplane.sh script outputs on the controlplane-VM to the node-VM and execute it there:

We could also create a new join token with: kubeadm token create -—print-join-command —-ttl 0.

Afterwards we should see:

5. Watch Kubernetes Security Best Practices

…and get mentally ready!

ALWAYS STOP YOUR INSTANCES when not in use, and only start again when needed, like:

gloud compute instances stop cks-controlplane cks-node
gloud compute instances start cks-controlplane cks-node

This saves you precious cloud resources!

You have a different solution?

Let us know by writing a comment below!

— — — The END — — —

So much for this first session. You should now already have a good K8s cluster as a base which you can use for studying and learning.

See you at the next one and happy learning!

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