Desplegando PaaS a golpe de "click"

Siguiendo en la línea del posts sobre Infraestructura como Código (IaC) con la herramienta Terraform, os traemos un nuevo tutorial para desplegar la plataforma de PaaS Rancher de forma totalmente automatizada utilizando RKE.

RKE es el acrónimo de Rancher Kubernetes Engine y se trata de un instalador de Kubernetes escrito en Golang. Es fácil de usar y no requiere mucha preparación por parte del usuario para comenzar.

Como en el tutorial anterior utilizaremos el provider de Terraform para OpenNebula, en esta ocasión utilizaremos una versión mejorada del provider desarrollado por el equipo de Blackberry.

Para acabar recordaros que el próximo 12 y 13 de Noviembre se celebra una nueva edición de la OpenNebulaConf en esta ocasión el lugar elegido a sido Amsterdam y algunos de los miembros de Cloudadmins estaremos allí y participaremos con la ponencia: Hybrid Clouds: Dancing with “Automated” Virtual Machines

Tutorial

Install Terraform

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

$ curl -O https://releases.hashicorp.com/terraform/0.11.10/terraform_0.11.10_linux_amd64.zip

After downloading Terraform, unzip the package

$ sudo mkdir /bin/terraform
$ sudo unzip terraform_0.11.10_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

Add Terraform providers for Opennebula and RKE

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/blackberry/terraform-provider-opennebula
$ go install github.com/blackberry/terraform-provider-opennebula

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

For RKE provider, download the binary and copy in the same folder:

$ wget https://github.com/yamamoto-febc/terraform-provider-rke/releases/download/0.5.0/terraform-provider-rke_0.5.0_linux-amd64.zip
$ sudo unzip terraform-provider-rke_0.5.0_linux-amd64.zip -d /usr/local/bin/terraform-provider-rke

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

Install Rancher

This repository provide a TF file to install Rancher in a high-availability configuration. The goal is easily install a Rancher on machines running CentOS 7.
Clone this repo:

$ git clone https://github.com/mangelft/terraform-rke-paas.git

Create infrastructure

First we have to initialize terraform simply with:

$ terraform init

This will read your configuration files and install the plugins for your provider.
We let terraform create a plan, which we can review:

$ terraform plan

The plan command lets you see what Terraform will do before actually doing it.
Now we execute:

$ terraform apply

 
Kubectl is the CLI tool for interacting with the Kubernetes cluster. Please make sure these tools are installed and available.
To make sure it works, run a simple get nodes command.

$ kubectl get nodes

 
 
That’s it you should have a functional Rancher server. Point a browser at the hostname: https://rancher.my.org.