Install, start and enable docker service

yum install -y -q yum-utils device-mapper-persistent-data lvm2 > /dev/null 2>&1

yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo > /dev/null 2>&1

yum install -y -q docker-ce >/dev/null 2>&1

systemctl start docker

systemctl enable docker

======================================================================

Update sysctl settings for Kubernetes networking

cat >>/etc/sysctl.d/kubernetes.conf<<EOF

net.bridge.bridge-nf-call-ip6tables = 1

net.bridge.bridge-nf-call-iptables = 1

EOF

sysctl --system

============================================================================================

Add Kubernetes to yum repository

cat >>/etc/yum.repos.d/kubernetes.repo<<EOF

[kubernetes]

name=Kubernetes

baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64

enabled=1

gpgcheck=1

repo_gpgcheck=1

gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg

https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg

EOF

======================================================================================

Install Kubernetes

yum install -y kubeadm kubelet kubectl

==================================================================================

Enable and start Kubernetes service

systemctl start kubelet

systemctl enable kubelet

=====================================================================================

Repeat the above steps on Master and slaves

=======================================================================================

On Master=============

===========

Initilise the Kubernetes cluster

-----------------------------------------

kubeadm init --apiserver-advertise-address=ip_of_master --pod-network-cidr=192.168.0.0/16

=========================================================================================

To be able to use kubectl command to connect and interact with the cluster,

the user needs kube config file.

mkdir /home/centos/.kube

cp /etc/kubernetes/admin.conf /home/centos/.kube/config

chown -R centos:centos /home/centos/.kube

========================================================================================

Deploy calico network

kubectl create -f https://docs.projectcalico.org/v3.9/manifests/calico.yaml

========================================================================================

For slaves to join the cluster

kubeadm token create --print-join-command

======================================================================================

Check the pods of kube-system are running

kubectl get pods -n kube-system