What is Minikube?

Minikube was developed to allow users to run Kubernetes locally. When you install and run Minikube on your computer, it runs a single-node Kubernetes cluster inside a virtual machine.

Why Minikube?

Minikube is intended for both new users and regular developers. Installing Kubernetes is time-consuming and resource-intensive. With Minikube, you get a smaller working version of a single-node Kubernetes cluster on your personal computer.

If you’re a learner, it gives you the ability to play around and understand the basic concepts. Once you become regular practitioner you can still use Minikube to test out your ideas locally before you deploy it in your data center or server. It can work as your test environment.

What Can You Do With Minikube?

Minikube is great for learning Kubernetes and testing your concepts and ideas during development.

Prerequisite

Even though it’s not necessary for this tutorial, a basic knowledge of containers like Docker is helpful to understand Minikube/Kubernetes.

Basic Definitions of Minikube/Kubernetes Concepts

To use Minikube, you need to understand the basic ideas discussed below. The definitions are not trying to explain the technology in depth. It’s only giving you an understanding of the basic concepts of Kubernetes. In this discussion, Kubernetes and Minikube mean the same thing

• Container – In Minikube, containers are used as the building blocks of creating applications.
• Pod – Pod is a collection of one or more containers that share storage and network resources. Pods contain the definition of how the containers should be run in Minikube. Minikube uses these definitions to maintain the necessary resources. For example, you can define you need two pods. During execution, if a pod goes down, Minikube will automatically fire up a new pod.
• Service – Because pods are replaceable, Minikube needs an abstraction layer to keep the interaction between the different pods seamless. For example, if a pod dies and a new pod is created, the application users shouldn’t get bogged down in the details of network addresses and related issues. Services are wrappers around the pods to create levels of abstraction.
• Master – Master coordinates the cluster. It’s like the brains of the operation.
• Node – Workers who run the pods.
• kubectl – It’s the command line interface for running commands on Kubernetes cluster.

To better understand how these concepts fit together in Kubernetes, watch this short video:

How to Install Minikube

Your hardware needs have virtualization enabled in your computer’s BIOS. The good news is most modern machine already has this turned on.

Here are the steps to install Minkube on your machine:

• Install VirtualBox
• Install kubectl
• Install Minikube

Simple Example of Deploying on Minikube

Once you have everything installed, you can start Minikube with the following command:

On your first run, it will take time to fire up Minikube as it will build the VM for you. You can check you VirtualBox to see the virtual machine Minikube spins up:

Later when you restart Minikube it will be faster.

You can use the following command to check your Minikube status:

A great feature of Minikube is the dashboard. From the dashboard, you can see everything that is going on in Minikube. You can also control resources in your cluster from the dashboard. Use the following command to start up the dashboard in your default browser:

Here is how the dashboard should look:

Let’s deploy an NGINX application on Minikube. Here are the steps:

1. Create a pod:

2. Create a service:

3. Check your pod and service status:

You can see that the pod and the service running for mynginxapp.

4. Let’s find at what address and port Minikube is running mynginxapp:

If you go to the returned URL (in this case it is http://192.168.99.100:30964) on your browser, you should see the NGINX service running.

5. Check the dashboard again:

6. Delete the service and the pod and stop Minikube

Summary of the Example

In this example, you first deployed an NGINX pod called mynginxapp. The NGINX image was downloaded from Docker Hub. Then you created a service to support the pod. You were able to see the service from the browser. At last, you deleted the pod and the service and then stopped Minikube.

More Detailed Minikube Example

Check out our Kubernetes: Getting Started article that has a more detailed Minikube example.

Quiz – Test Your Knowledge

1. Can you explain the concept of containers, pods, and services?
2. How do containers, pods, and services interact with each other?
3. What is kubectl?
4. How many Kubernetes clusters can you start on Minikube?

Further Study

• https://kubernetes.io/docs/tutorials/hello-Minikube
• https://kubernetes.io/docs/home
• https://www.digitalocean.com/community/tutorials/an-introduction-to-kubernetes