Follow this documentation to set up a Kubernetes cluster on REDHAT machines.

This documentation guides you in setting up a cluster with one master node and two worker nodes.

1. System Requirements

   Master: t2.medium (2 CPUs and 2GB Memory)
   Worker Nodes: t2.micro

2. Open Below ports in the Security Group.

   Master node:

   6443 32750 10250 4443 443 8080 179

   On Worker node:

   179

   On Both Master and Worker:

3. Perform all the commands as root user unless otherwise specified

   Install, Enable and start docker service. Use the Docker repository to install docker.

   If you use docker from CentOS OS repository, the docker version might be old to work with Kubernetes v1.13.0 and above

   sudo yum install -y yum-utils
   sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
   sudo yum install docker-ce docker-ce-cli containerd.io docker-compose-plugin

4. Start Docker services

   systemctl enable docker
   systemctl start docker

5. Disable SELinux

   setenforce 0
   sed -i --follow-symlinks 's/^SELINUX=enforcing/SELINUX=disabled/' /etc/sysconfig/selinux

6. Disable Firewall

   systemctl disable firewalld
   systemctl stop firewalld

7. Disable swap

   sed -i '/swap/d' /etc/fstab
   swapoff -a

8. Update sysctl settings for Kubernetes networking

   sudo tee /etc/sysctl.d/kubernetes.conf<<EOF
   net.bridge.bridge-nf-call-ip6tables = 1
   net.bridge.bridge-nf-call-iptables = 1
   EOF
   sysctl --system

1. Add yum repository for kubernetes packages

   sudo tee /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

2. Install Kubernetes

   yum install -y kubeadm kubelet kubectl

3. Enable and Start kubelet service

   systemctl enable kubelet
   systemctl start kubelet

1. Initialize Kubernetes Cluster

   kubeadm init --apiserver-advertise-address=<MasterServerIP> --pod-network-cidr=192.168.0.0/16

2. Create a user for kubernetes administration and copy kube config file.
   To be able to use kubectl command to connect and interact with the cluster, the user needs kube config file.
   In this case, we are creating a user called kubeadmin

   useradd kubeadmin 
   mkdir /home/kubeadmin/.kube
   cp /etc/kubernetes/admin.conf /home/kubeadmin/.kube/config
   chown -R kubeadmin:kubeadmin /home/kubeadmin/.kube

3. Deploy Calico network as a kubeadmin user.

   This should be executed as a user (heare as a kubeadmin )

   sudo su - kubeadmin 
   curl https://docs.projectcalico.org/manifests/calico.yaml -o calico.yaml
   kubectl apply -f calico.yaml

4. Cluster join command

   kubeadm token create --print-join-command

1. Add worker nodes to cluster

   Use the output from kubeadm token create command in previous step from the master server and run here.

1. Verifying the cluster To Get Nodes status

   kubectl get nodes

   To Get component status

   kubectl get cs

rm -rf /etc/containerd/config.toml

systemctl restart containerd

kubectl label node ip-172-31-86-115.ec2.internal kubernetes.io/role=worker --overwrite=true