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In this article, we will see how to install Kubernetes on ubuntu 20.04. Over the past few years, containerization has provided a lot of flexibility to the developers. One of the most commonly used applications for containerization is Docker. Container provide the developer a virtual environment and isolation for our applications on the host system. However, there were a few problems with it.
Running small applications is not that difficult but what if you want to scale them? When you have hundreds or thousands of servers, scaling isn’t that easy. There should be an automation tool that will take full responsibility for allocating resources to our application on specific machines, and not only this, continuous monitoring and resilience are also required.
One of the main reasons for deploying a service on a container is that they are flexible, lightweight, and easily scalable while deploying on hundreds of machines. But, who is going to manage all these containers? This is where Kubernetes comes into the picture.
What Is Kubernetes?
Kubernetes (also referred to as “K8″) is an open-source project by Google for managing the containerized application on the cluster by providing services such as scaling, deployment, and maintenance. If you want to know more about Kubernetes and its architecture in detail then click here.
Kubernetes is currently the market leader and beats its competitors such as Docker Swarm and Apache Mesos in most scenarios. However, one big disadvantage of Kubernetes is its difficulty in setting up. Some cloud vendors do provide pre-made clusters for you to use but they are paid. What to do when you just want to learn Kubernetes and that too for free?
Let us see how we can run a Kubernetes Cluster on Ubuntu 20.04.
Kubernetes Installation – Using kubeadm
First, have two VM’s setup. One of which we will be using as our master node, and other as worker node.
- Install Docker
$ sudo apt update $ sudo apt install docker.io $ sudo systemctl start docker $ sudo systemctl enable docker
- Install Kubernetes
$ sudo apt install apt-transport-https curl $ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add $ sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main" $ sudo apt install kubeadm kubelet kubectl kubernetes-cni
- Disable Swap Memory
$ sudo swapoff -a $ sudo nano /etc/fstab
Inside this file, comment out the
- Set hostnames
$ sudo hostnamectl set-hostname kubernetes-master $ sudo hostnamectl set-hostname kubernetes-worker
- Initialize Kubernetes master server
Run these on the master node:
kubernetes-master:~$ sudo kubeadm init kubernetes-master:~$ mkdir -p $HOME/.kube kubernetes-master:~$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config kubernetes-master:~$ sudo chown $(id -u):$(id -g) $HOME/.kube/config
- Deploy a pod network
kubernetes-master:~$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml kubernetes-master:~$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/k8s-manifests/kube-flannel-rbac.yml kubernetes-master:~$ kubectl get pods --all-namespaces
- Join the Kubernetes cluster
Run these from the worker node:
kubernetes-worker:~$ sudo kubeadm join 192.168.1.220:6443 --token 1exb8s.2t4k3b5syfc3jfmo --discovery-token-ca-cert-hash sha256:72ad481cee4918cf2314738419356c9a402fb609263adad48c13797d0cba2341 kubernetes-master:~$ kubectl get nodes
Kubernetes Installation – Using minikube (Locally)
For this demo, we are going to use an application called minikube. Open a terminal using Ctrl + Alt + T and enter the following commands:
curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 sudo install minikube-linux-amd64 /usr/local/bin/minikube minikube start
This will start a Kubernetes Cluster locally. To stop the cluster, you can:
To access your local Kubernetes’ dashboard: