Setting up the Kubernetes cluster on macOS by minikube

Kubernetes consists of combination of multiple open source components. These are developed by different parties, making it difficult to find and download all the related packages and install, configure, and make them work from scratch.

Fortunately, there are some different solutions and tools that have been developed to set up Kubernetes clusters effortlessly. Therefore, it is highly recommended you use such a tool to set up Kubernetes on your environment.

The following tools are categorized by different types of solution to build your own Kubernetes:

• Self-managed solutions that include:
  • minikube
  • kubeadm
  • kubespray
  • kops
• Enterprise solutions that include:
  • OpenShift (https://www.openshift.com)
  • Tectonic (https://coreos.com/tectonic/)
• Cloud-hosted solutions that include:
  
  • Google Kubernetes engine (https://cloud.google.com/kubernetes-engine/)
  • Amazon elastic container service for Kubernetes (Amazon EKS, https://aws.amazon.com/eks/)
  • Azure Container Service (AKS, https://azure.microsoft.com/en-us/services/container-service/)

A self-managed solution is suitable if we just want to build a development environment or do a proof of concept quickly.

By using minikube (https://github.com/kubernetes/minikube) and kubeadm (https://kubernetes.io/docs/admin/kubeadm/), we can easily build the desired environment on our machine locally; however, it is not practical if we want to build a production environment.

By using kubespray (https://github.com/kubernetes-incubator/kubespray) and kops (https://github.com/kubernetes/kops), we can also build a production-grade environment quickly from scratch.

An enterprise solution or cloud-hosted solution is the easiest starting point if we want to create a production environment. In particular, the Google Kubernetes Engine (GKE), which has been used by Google for many years, comes with comprehensive management, meaning that users don't need to care much about the installation and settings. Also, Amazon EKS is a new service that was introduced at AWS re: Invent 2017, which is managed by the Kubernetes service on AWS.

Kubernetes can also run on different clouds and on-premise VMs by custom solutions. To get started, we will build Kubernetes using minikube on macOS desktop machines in this chapter.

Getting ready

minikube runs Kubernetes on the Linux VM on macOS. It relies on a hypervisor (virtualization technology), such as VirtualBox (https://www.virtualbox.org), VMWare fusion (https://www.vmware.com/products/fusion.html), or hyperkit (https://github.com/moby/hyperkit) In addition, we will need to have the Kubernetes command-line interface (CLI) kubectl, which is used to connect through the hypervisor, to control Kubernetes.

With minikube, you can run the entire suite of the Kubernetes stack on your macOS, including the Kubernetes master, node, and CLI. It is recommended that macOS has enough memory to run Kubernetes. By default, minikube uses VirtualBox as the hypervisor.

In this chapter, however, we will demonstrate how to use hyperkit, which is the most lightweight solution. As Linux VM consumes 2 GB of memory, at least 4 GB of memory is recommended. Note that hyperkit is built on the top of the hypervisor framework (https://developer.apple.com/documentation/hypervisor) on macOS; therefore, macOS 10.10 Yosemite or later is required.

The following diagram shows the relationship between kubectl, the hypervisor, minikube, and macOS:

How to do it...

macOS doesn't have an official package management tool, such as yum and apt-get on Linux. But there are some useful tools available for macOS. Homebrew (https://brew.sh) is the most popular package management tool and manages many open source tools, including minikube.

In order to install Homebrew on macOS, perform the following steps:

1. Open the Terminal and then type the following command:

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

2. Once installation is completed, you can type /usr/local/bin/brew help to see the available command options.

If you just install or upgrade Xcode on your macOS, the Homebrew installation may stop. In that case, open Xcode to accept the license agreement or type sudo xcodebuild -license beforehand.

3. Next, install the hyperkit driver for minikube. At the time of writing (February 2018), HomeBrew does not support hyperkit; therefore type the following command to install it:

$ curl -LO https://storage.googleapis.com/minikube/releases/latest/docker-machine-driver-hyperkit \
&& chmod +x docker-machine-driver-hyperkit \
&& sudo mv docker-machine-driver-hyperkit /usr/local/bin/ \
&& sudo chown root:wheel /usr/local/bin/docker-machine-driver-hyperkit \
&& sudo chmod u+s /usr/local/bin/docker-machine-driver-hyperkit

4. Next, let's install the Kubernetes CLI. Use Homebrew with the following comment to install the kubectl command on your macOS:

//install kubectl command by "kubernetes-cli" package
$ brew install kubernetes-cli

Finally, you can install minikube. It is not managed by Homebrew; however, Homebrew has an extension called homebrew-cask (https://github.com/caskroom/homebrew-cask) that supports minikube.

5. In order to install minikube by homebrew-cask, just simply type the following command:

//add "cask" option
$ brew cask install minikube

6. If you have never installed Docker for Mac on your machine, you need to install it via homebrew-cask as well

//only if you don't have a Docker for Mac
$ brew cask install docker

//start Docker
$ open -a Docker.app

7. Now you are all set! The following command shows whether the required packages have been installed on your macOS or not:

//check installed package by homebrew
$ brew list
kubernetes-cli


//check installed package by homebrew-cask
$ brew cask list
minikube

How it works...

minikube is suitable for setting up Kubernetes on your macOS with the following command, which downloads and starts a Kubernetes VM stet, and then configures the kubectl configuration (~/.kube/config):

//use --vm-driver=hyperkit to specify to use hyperkit
$ /usr/local/bin/minikube start --vm-driver=hyperkit
Starting local Kubernetes v1.10.0 cluster...
Starting VM...
Downloading Minikube ISO
 150.53 MB / 150.53 MB [============================================] 100.00% 0s
Getting VM IP address...
Moving files into cluster...
Downloading kubeadm v1.10.0
Downloading kubelet v1.10.0
Finished Downloading kubelet v1.10.0
Finished Downloading kubeadm v1.10.0
Setting up certs...
Connecting to cluster...
Setting up kubeconfig...
Starting cluster components...
Kubectl is now configured to use the cluster.
Loading cached images from config file.


//check whether .kube/config is configured or not
$ cat ~/.kube/config 
apiVersion: v1
clusters:
- cluster:
    certificate-authority: /Users/saito/.minikube/ca.crt
    server: https://192.168.64.26:8443
  name: minikube
contexts:
- context:
    cluster: minikube
    user: minikube
  name: minikube
current-context: minikube
kind: Config
preferences: {}
users:
- name: minikube
  user:
    as-user-extra: {}
    client-certificate: /Users/saito/.minikube/client.crt
    client-key: /Users/saito/.minikube/client.key

After getting all the necessary packages, perform the following steps:

1. Wait for a few minutes for the Kubernetes cluster setup to complete.
2. Use kubectl version to check the Kubernetes master version and kubectl get cs to see the component status.
3. Also, use the kubectl get nodes command to check whether the Kubernetes node is ready or not:

//it shows kubectl (Client) is 1.10.1, and Kubernetes master (Server) is 1.10.0
$ /usr/local/bin/kubectl version --short
Client Version: v1.10.1
Server Version: v1.10.0


//get cs will shows Component Status
$ kubectl get cs
NAME                 STATUS    MESSAGE              ERROR
controller-manager   Healthy   ok                   
scheduler            Healthy   ok                   
etcd-0               Healthy   {"health": "true"}   


//Kubernetes node (minikube) is ready
$ /usr/local/bin/kubectl get nodes
NAME       STATUS    ROLES     AGE       VERSION
minikube   Ready     master    2m        v1.10.0

4. Now you can start to use Kubernetes on your machine. The following sections describe how to use the kubectl command to manipulate Docker containers.
5. Note that, in some cases, you may need to maintain the Kubernetes cluster, such as starting/stopping the VM or completely deleting it. The following commands maintain the minikube environment:

Command	Purpose
minikube start --vm-driver=hyperkit	Starts the Kubernetes VM using the hyperkit driver
minikube stop	Stops the Kubernetes VM
minikube delete	Deletes a Kubernetes VM image
minikube ssh	ssh to the Kubernetes VM guest
minikube ip	Shows the Kubernetes VM (node) IP address
minikube update-context	Checks and updates ~/.kube/config if the VM IP address is changed
minikube dashboard	Opens the web browser to connect the Kubernetes UI

For example, minikube starts a dashboard (the Kubernetes UI) by the default. If you want to access the dashboard, type minikube dashboard; it then opens your default browser and connects the Kubernetes UI, as illustrated in the following screenshot:

See also

This recipe describes how to set up a Kubernetes cluster on your macOS using minikube. It is the easiest way to start using Kubernetes. We also learned how to use kubectl, the Kubernetes command-line interface tool, which is the entry point to control our Kubernetes cluster!