Running Kubernetes on CENT OS 8:-

Kubernetes is the widely used container management tool. There are multiple ways to setup the kubernetes Software.

Here is will provide sequence of steps and command to setup kubernetes on Virtual Box running Cent OS 8.

Prerequisite to setup the Kubernetes cluster:-

• Virtual Box.
• Install Cent OS : 1 master and 1 node.
• Docker Installation.
• Kubernetes Service.
• POD Network driver, here we will use Flannel.
• Disable SElinux & Firewall

PORTS INFORMATION & USAGE:-

#Disable Firewall and SELinux.
firewall-cmd --permanent --add-port=6443/tcp
firewall-cmd --permanent --add-port=2379-2380/tcp
firewall-cmd --permanent --add-port=10250/tcp
firewall-cmd --permanent --add-port=10251/tcp
firewall-cmd --permanent --add-port=10252/tcp
firewall-cmd --permanent --add-port=10255/tcp
firewall-cmd --reload
modprobe br_netfilter
echo '1' > /proc/sys/net/bridge/bridge-nf-call-iptables
#Enable transparent masquerading and facilitate Virtual Extensible LAN (VxLAN) traffic for communication between Kubernetes pods across the cluster.
$modprobe br_netfilter
# Disable SELinux
setenforce 0
sed -i --follow-symlinks 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/sysconfig/selinux
# Disble swap for kubelet to work properly
sudo sed -i '/swap/d' /etc/fstab
sudo swapoff -a
# Create Docker Repository.
vi /etc/yum.repos.d/docker.repo
[docker]
name=softwares from docker
baseurl=https://download.docker.com/linux/centos/7/x86_64/stable/
gpgcheck=0
#Install Docker.
yum install docker --nobest -y
# Start and enable Docker service
systemctl restart docker && systemctl enable docker
#Create Kubernetes Repository.
vi /etc/yum.repos.d/kubernetes.repo
[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
#Install Kubernetes components.can use dnf or yum installer.
dnf install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
# Start and enable Kubelet service.
systemctl  restart kubelet && systemctl enable kubelet
#Setup POD Network driver. A Pod Network allows nodes within the cluster to communicate. Here, we will use Flannel.
sudo kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
# Join Worker Node to Cluster. The detail command will be provided from master node after 
kubeadm join 192.168.1.8:6443 --token kym3lf.qmdg4q6ok6wa4z8r     --discovery-token-ca-cert-hash sha256:2e0ff2dae56f722fb25a314375119abdc50eb76f80f6fe742380b374149223eb