RKE is a fast, versatile Kubernetes installer that you can use to install Kubernetes on your Linux hosts. You can get started in a couple of quick and easy steps:

  1. Download the RKE Binary
    1. Alternative RKE MacOS X Install - Homebrew
  2. Prepare the Nodes for the Kubernetes Cluster
  3. Creating the Cluster Configuration File
  4. Deploying Kubernetes with RKE
  5. Save your Files
  6. Interacting with your Kubernetes Cluster

Download the RKE binary

  1. From your workstation, open a web browser and navigate to our RKE Releases page. Download the latest RKE installer applicable to your Operating System and Architecture:

    • MacOS: rke_darwin-amd64
    • Linux (Intel/AMD): rke_linux-amd64
    • Linux (ARM 32-bit): rke_linux-arm
    • Linux (ARM 64-bit): rke_linux-arm64
    • Windows (32-bit): rke_windows-386.exe
    • Windows (64-bit): rke_windows-amd64.exe
  2. Copy the RKE binary to a folder in your $PATH and rename it rke (or rke.exe for Windows)

    # MacOS
    $ mv rke_darwin-amd64 rke
    # Linux
    $ mv rke_linux-amd64 rke
    # Windows PowerShell
    > mv rke_windows-amd64.exe rke.exe
    
  3. Make the RKE binary that you just downloaded executable. Open Terminal, change directory to the location of the RKE binary, and then run one of the commands below.

    Using Windows? The file is already an executable. Skip to Prepare the Nodes for the Kubernetes Cluster.

    $ chmod +x rke
    
  4. Confirm that RKE is now executable by running the following command:

    $ rke --version
    

Alternative RKE MacOS X Install - Homebrew

RKE can also be installed and updated using Homebrew, a package manager for MacOS X.

  1. Install Homebrew. See https://brew.sh/ for instructions.

  2. Using brew, install RKE by running the following command in a Terminal window:

    $ brew install rke
    

If you have already installed RKE using brew, you can upgrade RKE by running:

$ brew upgrade rke

Prepare the Nodes for the Kubernetes cluster

The Kubernetes cluster components are launched using Docker on a Linux distro. You can use any Linux you want, as long as you can install Docker on it.

Review the OS requirements and configure each node appropriately.

Creating the Cluster Configuration File

RKE uses a cluster configuration file, referred to as cluster.yml to determine what nodes will be in the cluster and how to deploy Kubernetes. There are many configuration options that can be set in the cluster.yml. In our example, we will be assuming the minimum of one node for your Kubernetes cluster.

There are two easy ways to create a cluster.yml:

  • Using our minimal cluster.yml and updating it based on the node that you will be using.
  • Using rke config to query for all the information needed.

Using rke config

Run rke config to create a new cluster.yml in the current directory. This command will prompt you for all the information needed to build a cluster. See cluster configuration options for details on the various options.

rke config --name cluster.yml

Creating an Empty cluster.yml

You can create an empty template cluster.yml file by specifying the --empty flag.

rke config --empty --name cluster.yml

Printing the cluster.yml

Instead of creating a file, you can print the generated configuration to stdout using the --print flag.

rke config --print

High Availability

RKE is HA ready, you can specify more than one controlplane node in the cluster.yml file. RKE will deploy master components on all of these nodes and the kubelets are configured to connect to 127.0.0.1:6443 by default which is the address of nginx-proxy service that proxy requests to all master nodes.

To create an HA cluster, specify more than one host with role controlplane.

Certificates

Available as of v0.2.0

By default, Kubernetes clusters require certificates and RKE auto-generates the certificates for all cluster components. You can also use custom certificates. After the Kubernetes cluster is deployed, you can manage these auto-generated certificates.

Deploying Kubernetes with RKE

After you’ve created your cluster.yml, you can deploy your cluster with a simple command. This command assumes the cluster.yml file is in the same directory as where you are running the command.

rke up

INFO[0000] Building Kubernetes cluster
INFO[0000] [dialer] Setup tunnel for host [10.0.0.1]
INFO[0000] [network] Deploying port listener containers
INFO[0000] [network] Pulling image [alpine:latest] on host [10.0.0.1]
...
INFO[0101] Finished building Kubernetes cluster successfully

The last line should read Finished building Kubernetes cluster successfully to indicate that your cluster is ready to use. As part of the Kubernetes creation process, a kubeconfig file has been created and written at kube_config_cluster.yml, which can be used to start interacting with your Kubernetes cluster.

Note: If you have used a different file name from cluster.yml, then the kube config file will be named kube_config_<FILE_NAME>.yml.

Save Your Files

Important The files mentioned below are needed to maintain, troubleshoot and upgrade your cluster.

Save a copy of the following files in a secure location:

  • cluster.yml: The RKE cluster configuration file.
  • kube_config_cluster.yml: The Kubeconfig file for the cluster, this file contains credentials for full access to the cluster.
  • cluster.rkestate: The Kubernetes Cluster State file, this file contains credentials for full access to the cluster.

    The Kubernetes Cluster State file is only created when using RKE v0.2.0 or higher.

Kubernetes Cluster State

The Kubernetes cluster state, which consists of the cluster configuration file cluster.yml and components certificates in Kubernetes cluster, is saved by RKE, but depending on your RKE version, the cluster state is saved differently.

As of v0.2.0, RKE creates a .rkestate file in the same directory that has the cluster configuration file cluster.yml. The .rkestate file contains the current state of the cluster including the RKE configuration and the certificates. It is required to keep this file in order to update the cluster or perform any operation on it through RKE.

Prior to v0.2.0, RKE saved the Kubernetes cluster state as a secret. When updating the state, RKE pulls the secret, updates/changes the state and saves a new secret.

Interacting with your Kubernetes cluster

After your cluster is up and running, you can start using the generated kubeconfig file to start interacting with your Kubernetes cluster using kubectl.

After installation, there are several maintenance items that might arise: