Install Kubeadm on Ubuntu 22.04

In this Article we are going to learn How to Create Kubernetes cluster using Kubeadm on Ubuntu 22.04 LTS and Join Worker Node to the Cluster.

Prerequisites:

• 2 Ubuntu 20.04 LTS System with Minimal Installation
• Minimum 2 or more CPU, 3 GB RAM.
• SSH Access with sudo privileges

Step1: Login to ubuntu 20.04 instances using your favourite tool

Update & Upgrade Your System:

Start by ensuring your package manager is up-to-date:

ubuntu@ip-172-31-6-61:~$ sudo apt-get update

Step2: Change the hostname:

Setting the hostname on an Ubuntu server permanently involves a couple of steps. Here’s how you can do it:

Open a terminal session and use the hostnamectl command (available on newer versions of Ubuntu):

Syntax: sudo hostnamectl set-hostname new-hostname 

Replace new-hostname with your desired hostname.

sudo hostnamectl set-hostname kubeadm-master (For master)

sudo hostnamectl set-hostname kubeadm-node1 (For node server)

Execute teh above two commands on master and node servers

ubuntu@ip-172-31-2-122:~$ sudo hostnamectl set-hostname kubeadm-master

ubuntu@ip-172-31-6-61:~$ sudo hostnamectl set-hostname kubeadm-node1

Step2: Edit the /etc/hosts file:

Often, you will also want to update the /etc/hosts file to reflect the new hostname, This ensures that the system can resolve its own hostname correctly. Edit the file using a text editor like nano:

syntax: sudo nano /etc/hosts

You might see a line that looks something like: 127.0.1.1 old-hostname Change old-hostname to your new-hostname.

ubuntu@ip-172-31-2-122:~$ sudo nano /etc/hosts

Open the hosts file and comment local IP and and name it as kubeadm-master as show in below image

Save and Exit from nano editor using these options Ctrl X Shift Y Enter

Step3:Reboot (Optional): Although it’s not always necessary, it’s a good idea to reboot your server to ensure that all services recognize the changed hostname:

ubuntu@ip-172-31-2-122:~$ sudo reboot

After the reboot, your server should recognize and use the new hostname permanently. You can always check the current hostname by typing hostname in the terminal.

Output:

Step3: Install apt-transport-https curl

ubuntu@kubeadm-master:~$ sudo apt-get install -y apt-transport-https curl

Next, add docker repository,

ubuntu@kubeadm-master:~$ sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/docker.gpg

ubuntu@kubeadm-master:~$ sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

After adding repo, install containerd using script https://get.docker.com/

download the script

ubuntu@kubeadm-master:~$ curl -fsSL https://get.docker.com -o install-docker.sh

run the script either as root, or using sudo to perform the installation.

ubuntu@kubeadm-master:~$ sudo sh install-docker.sh

Once docker installed verify with below commands

ubuntu@kubeadm-master:~$ docker –version