Kubernetes Installation with Vagrant & CoreOS

This guide walks a deployer through launching a multi-node Kubernetes cluster using Vagrant and CoreOS. After completing this guide, a deployer will be able to interact with the Kubernetes API from their workstation using the kubectl CLI tool.

Install Prerequisites

Vagrant

Navigate to the Vagrant downloads page and grab the appropriate package for your system. Install the Vagrant software before continuing.

kubectl

kubectl is the main program for interacting with the Kubernetes API. Download kubectl from the Kubernetes release artifact site with the curl tool.

The linux kubectl binary can be fetched with a command like:

$ curl -O https://storage.googleapis.com/kubernetes-release/release/v1.1.8/bin/linux/amd64/kubectl

On an OS X workstation, replace linux in the URL above with darwin:

$ curl -O https://storage.googleapis.com/kubernetes-release/release/v1.1.8/bin/darwin/amd64/kubectl

After downloading the binary, ensure it is executable and move it into your PATH:

$ chmod +x kubectl
$ mv kubectl /usr/local/bin/kubectl

Clone the Repository

The following commands will clone a repository that contains a "Vagrantfile", which describes the set of virtual machines that will run Kubernetes on top of CoreOS.

$ git clone https://github.com/coreos/coreos-kubernetes.git
$ cd coreos-kubernetes/multi-node/vagrant

Start the Machines

The default cluster configuration is to start a virtual machine for each role — master node, worker node, and etcd server. However, you can modify the default cluster settings by copying config.rb.sample to config.rb and modifying configuration values.

#$update_channel="alpha"

#$controller_count=1
#$controller_vm_memory=512

#$worker_count=1
#$worker_vm_memory=512

#$etcd_count=1
#$etcd_vm_memory=512

Next, simply run vagrant up and wait for the command to succeed. Once Vagrant is finished booting and provisioning your machine, your cluster is good to go.

Configure kubectl

You can choose from one of the two following options.

  1. Use a custom KUBECONFIG path

     $ export KUBECONFIG="${KUBECONFIG}:$(pwd)/kubeconfig"
     $ kubectl config use-context vagrant-multi
    
  2. Update the local-user kubeconfig

    Configure your local Kubernetes client using the following commands:

     $ kubectl config set-cluster vagrant-multi-cluster --server=https://172.17.4.101:443 --certificate-authority=${PWD}/ssl/ca.pem
     $ kubectl config set-credentials vagrant-multi-admin --certificate-authority=${PWD}/ssl/ca.pem --client-key=${PWD}/ssl/admin-key.pem --client-certificate=${PWD}/ssl/admin.pem
     $ kubectl config set-context vagrant-multi --cluster=vagrant-multi-cluster --user=vagrant-multi-admin
     $ kubectl config use-context vagrant-multi
    

Check that your client is configured properly by using kubectl to inspect your cluster:

$ kubectl get nodes
NAME          LABELS                               STATUS
172.17.4.201   kubernetes.io/hostname=172.17.4.201   Ready

Is kubectl working correctly?

Now that you've got a working Kubernetes cluster with a functional CLI tool, you are free to deploy Kubernetes-ready applications. Start with a multi-tier web application from the official Kubernetes documentation to visualize how the various Kubernetes components fit together.

View the Guestbook example app