one-kubespray

PoC for deploying a Kubernetes cluster with Docker, Terraform and Ansible on OpenNebula

Intro

This is a "proof of concept" for deploying a (production grade) Kubernetes Cluster on OpenNebula. This PoC is based on

• Docker
• Terraform
• Runtastic Terraform Provider for OpenNebula
• Ansible
• Kubespray

Warning: This is no "production" code - it`s an PoC.

The whole ecosystem is contained in a Docker Container.

Building the Docker Container

First clone the repository to your Docker host:

$ git clone https://github.com/smangelkramer/one-kubespray.git

Now build the Docker Image:

$ docker build -t mykubernetescluster .

This builds the a Docker image with all needed tools. This process creates the following steps for you:

• Docker Image from a clean Alpine 3.8 Linux
• Installs Terraform
• Installs the Runtastic Terraform Provider for OpenNebula
• Clones the current "kubespray" Git-Repository inside the Image
• Creates an SSH Keypair for the deployment of the Kubernetes Nodes (SSH / Ansible)
• Offers you a shell for deploying your Cluster

Requirement on your OpenNebula Cloud

• Ubuntu 16.04 Image matching your hypervisor with Contextualization (e.g. from https://marketplace.opennebula.systems, such as Ubuntu 16.04 - KVM by OpenNebula Systems)
• IP-Network which has to be accessible from your Docker Host
• Connectivity to ONE XMLRPC (https://your.cloud.com:2633/RPC2)

The rest is done by Terraform (VM-Template, VMs)

Deployment of a Kubernetes Cluster

OpenNebula Credentials

Set your OpenNebula crdentials in code/terraform/variables.tf:

variable "endpoint_url" { default = "https://your.cloud.com:2633/RPC2" }
variable "one_username" { default = "username" }
variable "one_password" { default = "password" }

OpenNebula VM Template for Terraform

Check the OpenNebula template in code/terraform/opennebula_kubernetes_template.tmpl and set / point to your OpenNebula ressources:

• IMAGE_ID= ID of your Ubuntu 16.04 Image with Contextualization

• NETWORK= Name of your network in OpenNebula

• NETWORK_UNAME= Username for your network

    CONTEXT = [
      NETWORK = "YES",
      SSH_PUBLIC_KEY = "${file("/code/id_rsa_kubespray.pub")}",
      SET_HOSTNAME="$$NAME",
      USERNAME = "root",
      START_SCRIPT_BASE64 = "c3dhcG9mZiAtYQ=="
    ]
    CPU = "0.25"
    VCPU = "6"
    DISK = [
      IMAGE_ID = "71" ]
    GRAPHICS = [
      LISTEN = "0.0.0.0",
      TYPE = "VNC" ]
    INPUTS_ORDER = ""
    MEMORY = "5000"
    MEMORY_UNIT_COST = "MB"
    NIC = [
      NETWORK = "NET-NAME",
      NETWORK_UNAME = "user" ]
    OS = [
      ARCH = "x86_64",
      BOOT = "" ]
  

Start the Image and provision your Kubernets Cluster

$ docker run -it -v /path/to/one-kubespray/Docker/code/terraform:/code/terraform mykubernetescluster /bin/bash

$ cd terraform

$ terraform init
$ terraform apply

This builds 3 VMs in your OpenNebula Cloud and provsions a Kubernetes Cluster with Kubespray on them. You are completely free to customize this provisioning for your infrastructrure. For me it`s just a small PoC :-)