Clusters

A 4-post collection

Managing Cluster With Ansible Playbooks

While ad hoc commands are indispensable for learning Ansible and executing one time tasks, playbooks are real workhorses. In this introductory post I will explain the essence of a playbook on example.

So what is a playbook?

At the first glance, it's a file written in YAML that contains a list of plays. If we look closer, we'll see that a playbook file is a mixture of configuration and script concepts. On one hand, it specifies the desired configuration of systems. On the other hand, like in a script, it defines in which order tasks must be executed in a

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Playing With Ansible Using Ad-Hoc Commands

In previous posts we created a cluster of VMs and set up Ansible to manage the cluster. So we have a cluster of VMs ready to play with. Today we will explore Ansible with a bunch of ad hoc commands, which is the easiest way to get a flavour of cluster management.

Ansible

Before going any further it's important to understand Ansible philosophy, because it drastically differentiates Ansible from similar tools.

In contrast to Puppet and other tools that automate execution of commands on remote systems, Ansible manages remote systems' state. In Ansible you specify a state that remote systems

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Setting Up Ansible To Manage Cluster Of VMs On Mac OS X

Last time we created a cluster of VMs on Mac OS X. In this post you will learn how to setup Ansible to manage the cluster.

Installing Ansible

If your OS X version is below El Capitan, follow instruction from Ansible.

OS X El Capitan introduced System Integrity Protection, which disallowed modification of system-level components. As result, official instruction from Ansible does not work anymore. Fortunately, Marc Weisel has written a nice post on how to Install Ansible on OS X El Capitan.

When Ansible is installed, let's configure inventory for our cluster.

Inventory

Ansible allows to configure and install

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How To Create Your Own Cluster With VirtualBox

Are you itching to play with a cluster, but not lucky enough to have one at work? No problem. In this post I will show you how to create your own cluster with VirutalBox. For that you will create and configure a prototype node (Virtual Machine) that fits your needs and clone it to create a cluster.

This is a foundation for future posts where I will show how to use Ansible and other technologies operating on a cluster. But first things first - let's create our own cluster of virtual machines.

Installing VirtualBox and creating a prototype VM

First

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