For most up-to-date instructions on prerequisites, software and hardware requirements, as well as setup instructions, refer to the following GitHub repository:

https://github.com/schoolofdevops/ansible-playbook-essentials.

For the purpose of setting up the learning environment, we recommend using the following software:

The following table lists the version OS the software used to develop the code provided with the book, with download links:

Learners are advised to download, install, and refer to the respective documentation pages to get familiar with these tools before proceeding.

Once you have installed the base software, you can use vagrant to bring up the virtual machines required. Vagrant uses a specification file by the name Vagrantfile, a sample of which is as follows:

# -*- mode: ruby -*-
# vi: set ft=ruby :
# Sample Vagranfile to setup Learning Environment
# for Ansible Playbook Essentials

VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  config.vm.box = "ansible-ubuntu-1204-i386"
  config.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-i386-vagrant-disk1.box"
  config.vm.define "control" do |control|
    control.vm.network :private_network, ip: "192.168.61.10"
  end
  config.vm.define "db" do |db|
    db.vm.network :private_network, ip: "192.168.61.11"
  end
  config.vm.define "dbel" do |db|
    db.vm.network :private_network, ip: "192.168.61.14"
    db.vm.box = "opscode_centos-6.5-i386"
    db.vm.box = "http://opscode-vm-bento.s3.amazonaws.com/vagrant/virtualbox/opscode_centos-6.5_chef-provisionerless.box"
  end
  config.vm.define "www" do |www|
    www.vm.network :private_network, ip: "192.168.61.12"
  end
  config.vm.define "lb" do |lb|
    lb.vm.network :private_network, ip: "192.168.61.13"
  end
end

The preceding Vagrant file contains specifications to set up five virtual machines, as described in the beginning of this chapter, which are, control, db, dbel, www, and lb.

Learners are advised to use following instructions to create and start the virtual machines required to set up the learning environment:

Once the virtual machines are created and brought up, Ansible needs to be installed on the controller. Since Ansible is agentless and manages nodes using SSH transport, no additional setup is needed on the nodes except for ensuring that the SSH service is running. To install Ansible on the controller, refer to the following steps. These instructions are specific to the Ubuntu distribution of Linux, as that's what we use on our controller. For generic installation instructions, please refer to the following page:

http://docs.ansible.com/intro_installation.html.

The steps are as follows:

The sample code provided with this book is divided as per the chapter numbers. A directory named after the chapter number contains the snapshot of the state of the code at the end of the respective chapter. Learners are advised to independently create their own code and use the sample code as a reference. Moreover, if the readers skip one or more chapters, they can use the sample code from the previous chapter as a base.

For example, while using Chapter 6, Iterative Control Structures – Loops, you can use the sample code from Chapter 5, Controlling Execution Flow – Conditionals, as a base.