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.
Navigate to the Vagrant downloads page and grab the appropriate package for your system. Install the Vagrant software before continuing.
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/v1.2.4/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/v1.2.4/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
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
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
By default, Calico network policy is disabled. To enable it, change the line export USE_CALICO=false
to export USE_CALICO=true
in both the ../generic/controller-install.sh
and the ../generic/worker-install.sh
scripts. With Calico enabled, ensure that the K8S_VER
variable in both of those files refers to a version of the hyperkube image that bundles the CNI binaries, e.g. export K8S_VER=v1.2.4_coreos.cni.1
. This is not the default, and must be manually changed when using Calico.
Ensure the latest CoreOS vagrant image will be used by running vagrant box update
.
Then run vagrant up
and wait for Vagrant to provision and boot the virtual machines.
Choose one of the two following ways to configure kubectl
to connect to the new cluster:
$ export KUBECONFIG="${KUBECONFIG}:$(pwd)/kubeconfig"
$ kubectl config use-context vagrant-multi
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 kubectl
is configured properly by inspecting the cluster:
$ kubectl get nodes
NAME LABELS STATUS
172.17.4.201 kubernetes.io/hostname=172.17.4.201 Ready
NOTE: When the cluster is first launched, it must download all container images for the cluster components (Kubernetes, dns, heapster, etc). Depending on the speed of your connection, it can take a few minutes before the Kubernetes api-server is available. Before the api-server is running, the kubectl command above may show output similar to:
The connection to the server 172.17.4.101:443 was refused - did you specify the right host or port?
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