CKA Learning Series: Build K8s Cluster using Kubeadm in minutes !

Arun Kumar Singh
5 min readNov 7, 2020

CKA 2020 Exam Updates(Sep onwards)

Proctored exam, 15-20 hands on questions, 2 hours, 6 k8s clusters, K8s 1.19 and no multiple choice drama !

CKA exam, tests your skills in specific domains of k8s platform. Creating/managing k8s cluster using kubeadm is one of primary requirement. I have recently passed this exam and In my opinion practising on kubeadm based cluster can help you to cover a big part of exam syllabus. I suggest create your own cluster using kubeadm and practise as much as possible to get through in first attempt. This blogpost is part of series which I will be publishing in coming days to help you pass the exam.

In this post we will cover the part in which we are building a k8s cluster using kubeadm.

What you need to start -

Free cloud account or Virtual Box
3 VMs

I am using 3 VMs named —

  • node-1 [Ubuntu 18.x machine / master or controlplane]
  • node-2 [Ubuntu 18.x machine / worker]
  • node-3 [Ubuntu 18.x machine / worker]

What are the steps -

Perform these steps on all 3 VMs. These steps deploy required component for building k8s cluster using kubeadm.

Step 1: Configure iptables to receive bridged network traffic

# add following lines in /etc/ufw/sysctl.conf filenet/bridge/bridge-nf-call-ip6tables = 1
net/bridge/bridge-nf-call-iptables = 1
net/bridge/bridge-nf-call-arptables = 1

Step 2: Make sure you have installed ebtables and ethtool. If not please install

apt-get install ebtables ethtool

Step 3: Install HTTPS-TRANSPORT component

apt-get updateapt-get install -y apt-transport-https

Step 4: Install docker

apt-get install -y
Arun Kumar Singh

In quest of understanding How Systems Work !