In this tutorial, we will show you how to install Kubernetes on Ubuntu 20.04 LTS. For those of you who didn’t know, Kubernetes is a free and open-source container management system that provides a platform for deployment automation, scaling, and operations of application containers across clusters of host computers. With Kubernetes, you can freely make use of the hybrid,on-premise, and public cloud infrastructure in order to run deployment tasks of your organization.
This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘
sudo‘ to the commands to get root privileges. I will show you through the step-by-step installation of Kubernetes on a Ubuntu 20.04 (Focal Fossa) server.
Install Kubernetes on Ubuntu 20.04 LTS Focal Fossa
Step 1. First, make sure that all your system packages are up-to-date by running the following
apt commands in the terminal.
sudo apt update sudo apt upgrade sudo apt install apt-transport-https curl
Step 2. Installing Docker.
Follow the command to install Docker CE on Ubuntu 20.04:
sudo apt install docker.io
Once the Docker is installed ensure that it is enabled to start after reboot:
sudo systemctl enable docker sudo systemctl start docker
You can verify the Docker installation:
Step 3. Installing Kubernetes on Ubuntu 20.04.
Now we add the Kubernetes signing key:
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
Next, we’ll add the Kubernetes package repository:
sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"
After that, run the following command to install Kubernetes:
sudo apt install kubeadm kubelet kubectl kubernetes-cni
Step 4. Disable swap memory.
Running Kubernetes requires that you disable swap:
sudo swapoff -a
To permanently disable swap, comment out or remove the swap line on
sudo nano /etc/fstab
... # # / was on /dev/sda2 during curtin installation /dev/disk/by-uuid/f3d575c6-e46go-4472-b406-30dmeilana965a / ext4 defaults 0 0 #/swap.img none swap sw 0 0
Step 5. Set hostnames.
Now give hostnames to each node. In our scenario, we’re using the hostnames master-node and master-node to easily differentiate our hosts and identify their roles:
sudo hostnamectl set-hostname master-node sudo hostnamectl set-hostname slave-node
Step 6. Initialize Kubernetes master server.
First, enter the following command on your master node:
sudo kubeadm init
Next, run those three commands on the 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
Step 7. Deploy a pod network.
The next step is to deploy a pod network. Run the following two commands on the master node:
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/k8s-manifests/kube-flannel-rbac.yml
You can use the
kubectl command to confirm that everything is up and ready:
kubectl get pods --all-namespaces
Step 8. Join the Kubernetes cluster.
Now our cluster is ready to have the worker nodes join. Use the
kubeadm join command retrieved earlier from the Kubernetes master node initialization output to join your Kubernetes cluster:
sudo kubeadm join 192.168.77.21:6443 --token 1exb8s.2t4k3bramnoamo --discovery-token-ca-cert-hash sha256:72gama4918cf2cute19356c9a402fb609263adad48c13797d0cba2341
Confirm that master-node is now part of our Kubernetes cluster with this command:
kubectl get nodes
Step 9. Deploying a service on the Kubernetes cluster.
In these steps, we are ready to deploy a service into the Kubernetes cluster. Run the following two commands on your master node:
kubectl run --image=nginx nginx-server --port=80 --env="YOUR-DOMAIN=cluster" kubectl expose deployment nginx-server --port=80 --name=nginx-http
You should now see a new Nginx docker container deployed on your worker node:
sudo docker ps
Finally, you can see a running list of all available services running in your cluster with the following command, issued from the Kubernetes master node:
kubectl get svc
Congratulations! You have successfully installed Kubernetes. Thanks for using this tutorial for installing Kubernetes on Ubuntu 20.04 LTS Focal Fossa systems. For additional help or useful information, we recommend you to check the official Kubernetes website.