Deploying a Kubernetes Cluster to ONE with Ansible and Terraform

Installation information

Installing Terraform

To install Terraform, find the appropriate package for your system and download it

$ curl -O https://releases.hashicorp.com/terraform/0.11.4/terraform_0.11.4_linux_amd64.zip

After downloading Terraform, unzip the package

$ sudo mkdir /bin/terraform
$ sudo unzip terraform_0.11.4_linux_amd64.zip -d /bin/terraform

After installing Terraform, verify the installation worked by opening a new terminal session and checking that terraform is available.

$ export PATH=$PATH:/bin/terraform
$ terraform --version

Installing Terraform provider Opennebula

You need to install go first: https://golang.org/doc/install

Install Prerequisites

$ sudo apt install bzr

Use the wget command and the link from Go to download the tarball:

$ wget https://dl.google.com/go/go1.10.linux-amd64.tar.gz

The installation of Go consists of extracting the tarball into the /usr/local

$ sudo tar -C /usr/local -xvzf  go1.10.linux-amd64.tar.gz 

We will call our workspace directory projects, but you can name it anything you would like. The -p flag for the mkdir command will create the appropriate directory tree

$ mkdir -p ~/projects/{bin,pkg,src}

To execute Go like any other command, we need to append its install location to the $PATH variable.

$ export PATH=$PATH:/usr/local/go/bin

Additionally, define the GOPATH and GOBIN Go environment variables:

$ export GOBIN="$HOME/projects/bin"
$ export GOPATH="$HOME/projects/src"

After go is installed and set up, just type:

$ go get github.com/runtastic/terraform-provider-opennebula
$ go install github.com/runtastic/terraform-provider-opennebula

Optional post-installation Step

Copy your terraform-provider-opennebula binary in a folder, like /usr/local/bin, and write this in ~/.terraformrc:

$ sudo cp ~/projects/bin/terraform-provider-opennebula /usr/local/bin/terraform-provider-opennebula

providers {
  opennebula = "$YOUR_PROVIDER_PATH"
}

Example for /usr/local/bin:

providers {
  opennebula = "/usr/local/bin/terraform-provider-opennebula"
}

Install Ansible

We can add the Ansible PPA by typing the following command:

$ sudo apt-add-repository ppa:ansible/ansible

Next, we need to refresh our system's package index so that it is aware of the packages available in the PPA. Afterwards, we can install the software:

$ sudo apt-get update
$ sudo apt-get install ansible

Deploy a Kubernetes cluster

Terraform code is written in a language called HCL in files with the extension “.tf”. It is a declarative language, so your goal is to describe the infrastructure you want, and Terraform will figure out how to create it.

This repository provide an Ansible playbook to Build a Kubernetes cluster with kubeadm. The goal is easily install a Kubernetes cluster on machines running CentOS 7

$ git clone https://github.com/mangelft/terransible-kubernetes-cluster.git

First, initialize Terraform for your project. This will read your configuration files and install the plugins for your provider:

$ terraform init

In a terminal, go into the folder where you created main.tf, and run the terraform plan command:

The plan command lets you see what Terraform will do before actually doing it.

To actually create the instance, run the terraform apply command:

You can access Dashboard using the kubectl command-line tool by running the following command:

$ kubectl proxy --address $MASTER_IP --accept-hosts='^*$'

The last step is to complete the cluster life cycle by removing your resources, do: terraform destroy

Created by:

Miguel Ángel Flores - ([email protected])