Step 1 — Run this on all the machines

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
echo “deb https://apt.kubernetes.io/ kubernetes-xenial main” | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt update -y
sudo apt -y install vim git curl wget kubelet=1.26.0–00 kubeadm=1.26.0–00 kubectl=1.26.0–00
sudo apt-mark hold kubelet kubeadm kubectl

Load the br_netfilter module and let iptables see bridged traffic

sudo modprobe overlay
sudo modprobe br_netfilter
sudo tee /etc/sysctl.d/kubernetes.conf<<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
sysctl — system

Setup Containerd

cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

# Setup required sysctl params, these persist across reboots.
cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

# Apply sysctl params without reboot
sudo sysctl — system

#Install and configure containerd
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository “deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable”
sudo apt update -y
sudo apt install -y containerd.io
sudo mkdir -p /etc/containerd
containerd config default | sudo tee /etc/containerd/config.toml

#Start containerd
sudo systemctl restart containerd
sudo systemctl enable containerd

sudo kubeadm config images pull — image-repository=registry.k8s.io — cri-socket unix:///run/containerd/containerd.sock — kubernetes-version v1.26.0

Step2 — Run the kubeadm init command on the control plane node

sudo kubeadm init — pod-network-cidr=10.244.0.0/16 — upload-certs — kubernetes-version=v1.26.0 — control-plane-endpoint=74.220.27.73 — cri-socket unix:///run/containerd/containerd.sock

Output for the above command

[init] Using Kubernetes version: v1.26.0
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using ‘kubeadm config images pull’
[certs] Using certificateDir folder “/etc/kubernetes/pki”
[certs] Generating “ca” certificate and key
[certs] Generating “apiserver” certificate and key
[certs] apiserver serving cert is signed for DNS names [kube-1–1–1–26–1–5b02–7bcf18 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.1.21 74.220.27.73]
[certs] Generating “apiserver-kubelet-client” certificate and key
[certs] Generating “front-proxy-ca” certificate and key
[certs] Generating “front-proxy-client” certificate and key
[certs] Generating “etcd/ca” certificate and key
[certs] Generating “etcd/server” certificate and key
[certs] etcd/server serving cert is signed for DNS names [kube-1–1–1–26–1–5b02–7bcf18 localhost] and IPs [192.168.1.21 127.0.0.1 ::1]
[certs] Generating “etcd/peer” certificate and key
[certs] etcd/peer serving cert is signed for DNS names [kube-1–1–1–26–1–5b02–7bcf18 localhost] and IPs [192.168.1.21 127.0.0.1 ::1]
[certs] Generating “etcd/healthcheck-client” certificate and key
[certs] Generating “apiserver-etcd-client” certificate and key
[certs] Generating “sa” key and public key
[kubeconfig] Using kubeconfig folder “/etc/kubernetes”
[kubeconfig] Writing “admin.conf” kubeconfig file
[kubeconfig] Writing “kubelet.conf” kubeconfig file
[kubeconfig] Writing “controller-manager.conf” kubeconfig file
[kubeconfig] Writing “scheduler.conf” kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file “/var/lib/kubelet/kubeadm-flags.env”
[kubelet-start] Writing kubelet configuration to file “/var/lib/kubelet/config.yaml”
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder “/etc/kubernetes/manifests”
[control-plane] Creating static Pod manifest for “kube-apiserver”
[control-plane] Creating static Pod manifest for “kube-controller-manager”
[control-plane] Creating static Pod manifest for “kube-scheduler”
[etcd] Creating static Pod manifest for local etcd in “/etc/kubernetes/manifests”
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory “/etc/kubernetes/manifests”. This can take up to 4m0s
[apiclient] All control plane components are healthy after 7.507032 seconds
[upload-config] Storing the configuration used in ConfigMap “kubeadm-config” in the “kube-system” Namespace
[kubelet] Creating a ConfigMap “kubelet-config” in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Storing the certificates in Secret “kubeadm-certs” in the “kube-system” Namespace
[upload-certs] Using certificate key:
74bfd9237ded9661ca3ee337057caba0be417c19b6493034ec0da3dbcffc8fff
[mark-control-plane] Marking the node kube-1–1–1–26–1–5b02–7bcf18 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
[mark-control-plane] Marking the node kube-1–1–1–26–1–5b02–7bcf18 as control-plane by adding the taints [node-role.kubernetes.io/control-plane:NoSchedule]
[bootstrap-token] Using token: 3y24ca.kq73lohh99nzmcl5
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the “cluster-info” ConfigMap in the “kube-public” namespace
[kubelet-finalize] Updating “/etc/kubernetes/kubelet.conf” to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run “kubectl apply -f [podnetwork].yaml” with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of the control-plane node, running the following command on each as root:

kubeadm join 74.220.27.73:6443 — token 3y24ca.kq73lohh99nzmcl5 \
— discovery-token-ca-cert-hash sha256:f22dadb9c02bd9ac69b1819cbeaa11330ee70bb5fb6343f8b8a288b9ea83b00f \
— control-plane — certificate-key 74bfd9237ded9661ca3ee337057caba0be417c19b6493034ec0da3dbcffc8fff

Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
“kubeadm init phase upload-certs — upload-certs” to reload certs afterward.

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 74.220.27.73:6443 — token 3y24ca.kq73lohh99nzmcl5 \
— discovery-token-ca-cert-hash sha256:f22dadb9c02bd9ac69b1819cbeaa11330ee70bb5fb6343f8b8a288b9ea83b00f

Export KUBECONFIG and install CNI Flannel

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl apply -f https://github.com/coreos/flannel/raw/master/Documentation/kube-flannel.yml

Step 3 — Run the join command on all the worker nodes

kubeadm join 74.220.27.73:6443 — token 3y24ca.kq73lohh99nzmcl5 \
> — discovery-token-ca-cert-hash sha256:f22dadb9c02bd9ac69b1819cbeaa11330ee70bb5fb6343f8b8a288b9ea83b00f
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster…
[preflight] FYI: You can look at this config file with ‘kubectl -n kube-system get cm kubeadm-config -o yaml’
[kubelet-start] Writing kubelet configuration to file “/var/lib/kubelet/config.yaml”
[kubelet-start] Writing kubelet environment file with flags to file “/var/lib/kubelet/kubeadm-flags.env”
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap…

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run ‘kubectl get nodes’ on the control-plane to see this node join the cluster.

Step 4 — Nginx Test

kubectl run nginx — image=nginx
pod/nginx created

kubectl expose pod nginx — type=NodePort — port 80
service/nginx exposed

kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx 1/1 Running 0 10s

kubectl get svc nginx
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx NodePort 10.109.33.40 <none> 80:32573/TCP 10s

Access the service using Node public IP:32573 (make sure your firewall rules are properly set to allow traffic to required ports)