Deploy Kubernetes Cluster on Ubuntu VPS

This article provides a guide for how to deploy a Kubernetes cluster on Ubuntu VPS.

How to deploy a Kubernetes Cluster on Ubuntu VPS

Deploying a Kubernetes cluster on a fresh Ubuntu VPS involves a series of steps, from setting up the prerequisites to initializing the cluster and adding nodes. This guide will walk you through deploying a single-node Kubernetes cluster using kubeadm, which is a popular tool that simplifies the process.

Prerequisites

1. Ubuntu VPS Setup: You should start with a fresh install of Ubuntu 20.04 LTS on your VPS. This guide assumes you have root access to your VPS.
2. Hardware Requirements:
   • CPU: 2 cores or more
   • Memory: 2GB RAM or more
   • Storage: 20GB or more of free disk space
   • Network: Full network connectivity between all machines in the cluster
3. Install Required Packages:
   • Curl
   • apt-transport-https
   • Software Properties (optional, for adding repositories if needed)

Step 1: Update and Upgrade Ubuntu Packages

Ensure your system is up-to-date with the latest packages and security patches.

sudo apt update && sudo apt upgrade -y
sudo apt install -y curl apt-transport-https software-properties-common

Step 2: Install Docker

Kubernetes requires a container runtime, and Docker is a popular choice.

1. Install Docker:

   sudo apt install docker.io -y
   

2. Start and Enable Docker:

   sudo systemctl start docker
   sudo systemctl enable docker
   

3. Add your user to the Docker group (optional):

   sudo usermod -aG docker $USER
   newgrp docker
   

Step 3: Install Kubernetes Components

You need to install kubeadm, kubelet, and kubectl.

1. Add the Kubernetes Signing Key:

   curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
   

2. Add Kubernetes to the Repository List:

   echo "deb https://apt.kubernetes.io/ kubernetes-focal main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
   

3. Update and Install Kubernetes Components:

   sudo apt update
   sudo apt install kubeadm kubelet kubectl -y
   sudo apt-mark hold kubeadm kubelet kubectl
   

Step 4: Initialize the Kubernetes Cluster

Use kubeadm to initialize the cluster:

1. Initialize Cluster:

   sudo kubeadm init --pod-network-cidr=10.244.0.0/16
   

   Note: The CIDR block may vary depending on the network plugin you choose.

2. Set Up Local kubeconfig:

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

Step 5: Deploy a Pod Network

A network plugin is necessary for Pods to communicate with each other.

1. Install Flannel (as an example of a network plugin):

   kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
   

Step 6: Verify Installation

Check the status of the node and ensure that everything is running correctly.

kubectl get nodes

Additional Configuration (Optional)

1. Allow workloads on the master node (since this is a single-node cluster):

   kubectl taint nodes --all node-role.kubernetes.io/master-
   

2. Install Helm (a Kubernetes package manager):

   curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash
   

Conclusion

You now have a basic Kubernetes cluster running on a single Ubuntu VPS. From here, you can deploy applications, scale your cluster, or add additional nodes if needed. This setup is ideal for development, testing, or small production environments.