Embarking on your Kubernetes cloud cluster journey for practice may seem daunting, but fear not. We're here to walk you through the process, step by step, as you set up a Kubernetes cluster on the Ubuntu OS in the cloud.
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Pre-configuration for cluster nodes (Step-1 to Step-6) on each node instance
Create instances over the cloud
I am taking here AWS instances t2.medium, ubuntu OS, 20 GB storage each, Firewall security Allows ALL traffic, and swap memory disabled. I will go with three nodes cluster (1 Master + 2 Worker Node) with the same above configuration.
| Instance Type | Configuration | Storage |
| T2.medium or higher | 2vC Core + 4 GB RAM or more | 20 GB or more |
Step - 1 (Create a non-root user and allow sudoers privileges)
We are going to create a new user admin (If there is not) and assign sudoers privileges to him. so for this we create a new folder under /etc/sudoers.d/admin, and do the below entry in /etc/sudoers.d/admin. Dont forget to restart sshd service
$ sudo adduser admin
$ sudo echo "admin ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers.d/admin
$ sudo systemctl restart sshd
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NOTE: We'll execute each command using an admin user, not the root user, for enhanced security and best practices
Step - 2 ( Define your machine Hostname )
Change the Hostname of each machine using hostnamectll command.
| Machine (Public_IP) | Machine (Private_IP) | Hostname |
| 52.168.32.71 | 172.25.32.32 | masternode.example.com |
| 52.168.23.28 | 172.35.32.64 | workernode1.example.com |
| 52.168.23.28 | 172.25.64.63 | workernode2.example.com |
$ sudo hostnamectl set-hostname <your-hostname>
$ sudo exec bash
$ hostname
Step - 3 (Host entry with private IP & hostname)
$ sudo vi /etc/hosts
172.25.32.32 masternode.example.com
172.35.32.64 workernode1.example.com
172.25.64.63 workernode2.example.com
Note: Ping all machines to each other
Step - 4 ( Allow some entry in sshd_config file)
In /etc/ssh/sshd_config file uncomment and allow the following lines.
$ sudo vi /etc/ssh/sshd_config
PermitRootLogin yes
PubkeyAuthentication yes
PasswordAuthentication yes
And restart sshd service
$ sudo systemctl restart sshd
$ sudo systemctl enable sshd
Step - 5 (Create SSH key and copy to worker node instances)
Generate an SSH key and distribute it to your worker node instances for secure and efficient communication. This step involves creating an SSH key and seamlessly deploying it across your worker node instances to streamline the communication process.
$ ssh-keygen
$ ssh-copyid workernode1.example.com
$ ssh-copyid workernode2.example.com
Step-6 (Disable swap memory & Add kernel Parameters)
$ sudo swapoff -a
$ sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
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NOTE: All pre-configurations is completed. So let's move to setup Kubernetes setup installation.
Step - 7 ( Run the following commands on each instance node as admin user rights )
$ sudo tee /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF
$ 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
$ sudo sysctl --system
$ sudo apt install -y curl gnupg2 software-properties-common apt-transport-https ca-certificates
$ sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/docker.gpg
$ sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
$ sudo apt update
$ sudo apt install -y containerd.io
$ containerd config default | sudo tee /etc/containerd/config.toml >/dev/null 2>&1
$ sudo sed -i 's/SystemdCgroup \= false/SystemdCgroup \= true/g' /etc/containerd/config.toml
$ sudo systemctl restart containerd
$ sudo systemctl enable containerd
Add Repository for kubernetes
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
Install kubelet, kubectl, kubeadm
$ sudo apt update
$ sudo apt install -y kubelet kubeadm kubectl
$ sudo apt-mark hold kubelet kubeadm kubectl
Step - 8 ( Run "kubeadm init" On Master Node to create clusters master node)
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Initialize Kubernetes cluster with kubeadm (Only on master node).
$ sudo kubeadm init --control-plane-endpoint=<your-master-node-hostname>
NOTE: on master node with the admin user. and check status of master node
$ mkdir -p $HOME/.kube
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config
$ kubectl get nodes -o wide
$ kubectl get pods -n kube-system
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Install CNI plugin CALICO on master node as admin user rights.
$ kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml
Step - 9 (Run "kubeadm join" on worker nodes To join with master node in the cluster)
$ sudo kubeadm join masternode.example.net:6443 --token vt3ua6.scma2y8rl4menfh2 \
--discovery-token-ca-cert-hash sha256:049xaa7fcdced8a8e7b20d37ec0c5dd699ds5f8x616885697q2ff917d4c94962a36
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NOTE: Your setup is being created. Congratulation !
Step - 10 (Test your kubernetes cluster to Deploy an application)
$ kubectl create -f https://raw.githubusercontent.com/kubernetes/website/main/content/en/examples/controllers/nginx-deployment.yaml
$ kubectl expose deployment nginx-deployment --name=my-svc --port=80 --target-port=80 --type=NodePort
$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
my-svc NodePort 10.100.124.129 <none> 80:32567/TCP 2m
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Check your nginx web application publically, for this find your any instances nodes public IP address and then colon 32567. For example go to web broswer like chrome or firefox
<Public-IP-of-any-of-nodes>:32567
Congratulations........It works! Thank you!
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