CoreOS Vagrant Kubernetes

This repo provides a template Vagrantfile to create a CoreOS virtual machine with a single node Kubernetes cluster using the VirtualBox software hypervisor based off coreos-vagrant and inspired by this coreos blog post about kubelet being added to CoreOS. After setup is complete you will have a single CoreOS virtual machine with Kubernetes running on your local machine. It will also download and install kubectl if it isn't already installed.

Streamlined setup

1. Install dependencies

• VirtualBox 4.3.10 or greater.
• Vagrant 1.6 or greater.

2. Clone this project and get it running!

git clone https://github.com/jtblin/coreos-vagrant-kubernetes.git
cd coreos-vagrant-kubernetes

3. Startup and SSH

There are two "providers" for Vagrant with slightly different instructions. Follow one of the following two options:

VirtualBox Provider

The VirtualBox provider is the default Vagrant provider. Use this if you are unsure.

./configure
vagrant ssh

VMware Provider

The VMware provider is a commercial addon from Hashicorp that offers better stability and speed. If you use this provider follow these instructions.

VMware Fusion:

PROVIDER=vmware_fusion
./configure
vagrant ssh

VMware Workstation:

PROVIDER=vmware_workstation
vagrant ssh

./configure triggers vagrant to download the CoreOS image (if necessary) and (re)launch the instance. It will also download kubectl if needed and setup the kube-ui and kube-dns services.

vagrant ssh connects you to the virtual machine. Configuration is stored in the directory so you can always return to this machine by executing vagrant ssh from the directory where the Vagrantfile was located.

4. Get started using CoreOS

kubernetes cluster

By default, a cluster named core will be configured. You can change the name of the cluster by setting up the CLUSTER_NAME environment variable before you run vagrant up:

CLUSTER_NAME=my-cluster
./configure
vagrant ssh

You can interact with your kubernetes cluster with the kubectl cli:

kubectl --cluster=core get pods

This repo will also setup kube-ui and kube-dns addons.

Access kubernetes ui or cadvisor ui.

Shared Folder Setup

There is optional shared folder setup. You can try it out by adding a section to your Vagrantfile like this.

config.vm.network "private_network", ip: "172.17.8.150"
config.vm.synced_folder ".", "/home/core/share", id: "core", :nfs => true,  :mount_options   => ['nolock,vers=3,udp']

After a 'vagrant reload' you will be prompted for your local machine password.

Provisioning with user-data

The Vagrantfile will provision your CoreOS VM(s) with coreos-cloudinit using the user-data.sample.yaml found in the project directory which setup the kubernetes cluster. coreos-cloudinit simplifies the provisioning process through the use of a script or cloud-config document.

Check out the coreos-cloudinit documentation to learn about the available features.

Configuration

The Vagrantfile will parse the config.rb file containing a set of options used to configure your CoreOS cluster.

New Box Versions

CoreOS is a rolling release distribution and versions that are out of date will automatically update. If you want to start from the most up to date version you will need to make sure that you have the latest box file of CoreOS. Simply remove the old box file and vagrant will download the latest one the next time you vagrant up.

vagrant box remove coreos --provider vmware_fusion
vagrant box remove coreos --provider vmware_workstation
vagrant box remove coreos --provider virtualbox

Docker Forwarding

By setting the $expose_docker_tcp configuration value you can forward a local TCP port to docker on each CoreOS machine that you launch. The first machine will be available on the port that you specify and each additional machine will increment the port by 1.

Follow the Enable Remote API instructions to get the CoreOS VM setup to work with port forwarding.

Then you can then use the docker command from your local shell by setting DOCKER_HOST:

export DOCKER_HOST=tcp://localhost:2375