Install Kubernetes Cluster using kubeadm script

setup Kubernetes Version 1.21.0 cluster on CentOS 7.

Cluster

1 master node (IP = 192.168.100.208)

1 worker node (IP = 192.168.100.209)

On both master and worker (master node and worker node)

sudo su
yum -y update
yum -y install git

Edit hostname on master node and change the name to master (master node)

sudo su
vi /etc/hostname

Edit hostname on worker node and change the name to worker (worker node)

sudo su
vi /etc/hostname

Add known host on master node and worker node (Use your IP)

vi /etc/hosts

Add this to /etc/hosts of master node and worker node (master node and worker node)

192.168.100.208 master
192.168.100.209 worker

Make the system to sudo without password so when script is running, the script is not asking for the password (master node)

sudo su
sudo visudo

Scroll down to the end of the file and add the following line that will allow the user “centos” to run any command with sudo without being asked for a password (master node):

centos  ALL=(ALL) NOPASSWD:ALL

Clone the repository on master node and worker node (master node and worker node)

sudo su
git clone https://github.com/daus2936/kubeadm-script.git

Give execute permission to the script file on master node and worker node (master node and worker node)

cd kubeadm-script
chmod +x ccluster.sh kubernetes.sh variable.sh docker.sh

Edit the variable,change the the variable of MASTER_IP to your master node IP address,and make sure to change the other variable (master node and worker node)

sudo su
vi variable.sh

Install docker with docker.sh (Run it as root) (master node and worker node)

sudo su
./docker.sh

After the script of docker.sh is finish,login to docker hub (master node and worker node)

docker login

After login to dockerhub,run kubernetes.sh script (Run it as root) (master node and worker node)

sudo su
./kubernetes.sh

After the script of kubernetes.sh is finish,create kubernetes cluster,run ccluster.sh on master node (Run it as root) (master node)

sudo su
./ccluster.sh

To test if the cluster is installed (master node) :

kubectl get nodes

Use this command so the worker node can join the cluster,the token will be different in your cluster (use your token),type this on worker node:

kubeadm join 192.168.100.208:6443 --token 4niztf.rc6y0xfbnih81jxv \
        --discovery-token-ca-cert-hash sha256:b44d3ac51430f7e7dad4639e4a8eeb5f3f03769ed8319c26e437ff49915659d7

If you want to make a new token,type this (master node)

kubeadm token create --print-join-command