Learning SaltStack

Table of Contents

Learning SaltStack

Credits

About the Author

About the Reviewers

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Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

1. Diving In – Our First Salt Commands

Introducing Salt

Installing Salt

Installation with system packages (Ubuntu)

Installing with Salt-Bootstrap

Configuring Salt

Firewall configuration

Salt minion configuration

Starting the Salt master and Salt minion

Accepting the minion key on the master

A game of ping pong

Masterless Salt

Summary

2. Controlling Your Minions with Remote Execution

The structure of a remote execution command

Command-line options

Targeting strings

Glob matching

Perl-compatible regular expression matching

List matching

Grain and pillar matching

Grains

Pillars

Compound matching

Remote execution modules and functions

Adding users

Installing packages

Managing services

Monitoring minion states

Running arbitrary commands

Summary

3. Execution Modules – Write Your Own Solution

Exploring the source

Cross-calling execution modules

Grains and the __virtual__ function

The__opts__ and __pillar__ functions

Reformatting return data

An advanced example

Summary

4. Defining the State of Your Infrastructure

Our first state

The pieces of a state declaration

Expanding to encompass multiple pieces of state

Dependencies using requisites

The require requisite

The watch requisite

Other requisites

The _in requisites

Summary

5. Expanding Our States with Jinja2 and Pillar

Adding a new minion

Jinja2

apache2 or httpd?

Defining secure minion-specific data in pillar

Using pillar data in states

Summary

6. The Highstate and Environments

The highstate

Environments

Environments in pillar

Expanding our base environment

Storing our states in Git with GitFS

Summary

7. Using Salt Cloud to Manage Virtual Minions

Setting up Salt Cloud

Setting up Linode

Creating an API key

Creating a cloud provider configuration

Creating cloud VM profiles

Create and destroy machines

Managing groups of VMs with map files

Creating new masters with map files

Summary

8. The Reactor and the Event System

The Salt event system

Listening for events

Event structure

Firing events from Salt

Firing events from custom code

Reacting to events

Summary

Index

Learning SaltStack

Learning SaltStack

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: January 2015

Production reference: 1210115

Published by Packt Publishing Ltd.

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ISBN 978-1-78439-460-8

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Credits

Author

Colton Myers

Reviewers

Darrel Clute

Cameron R. Lane

Hoàng Đình Quân

Commissioning Editor

Pramila Balan

Acquisition Editor

Kevin Colaco

Content Development Editor

Parita Khedekar

Technical Editor

Vijin Boricha

Copy Editors

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Relin Hedly

Project Coordinator

Neha Thakur

Proofreaders

Simran Bhogal

Stephen Copestake

Maria Gould

Ameesha Green

Paul Hindle

Indexer

Tejal Soni

Production Coordinator

Alwin Roy

Cover Work

Alwin Roy

About the Author

Colton Myers is a software engineer living in Salt Lake City, Utah. Since graduating with a BS in computer science from the University of Utah, he has worked professionally writing software in Python. Colton loves working on open source software, and he has represented the US PyCon conference as a speaker multiple times.

He is a SaltStack Certified Trainer and has worked on the Salt open source software for years. At the time of writing this book, Colton was working as a platform engineer for SaltStack.

You can find him on Twitter and GitHub at @basepi.

I would like to thank my friends and family for the support they've given me while writing this book. I especially want to thank my parents, Mark and Annette, as I would not be who or where I am without their support. Finally, I'd like to thank Thomas Hatch, the creator of SaltStack, who gave me the opportunity to help develop such a great piece of software.

About the Reviewers

Darrel Clute is an IT Infrastructure Architect. Throughout his career, he has been predominately focused on network engineering, but has spent equal amounts of time on systems engineering, primarily with UNIX-based systems. Besides his employment, he is also an advocate for open source software used in the enterprise as well as for individuals, but will never advocate the use of open source purely for the sake of it.

Outside his core competencies, Darrel also has extensive experience with proprietary and open source virtualization platforms. His knowledge and experience in IaaS solutions such as OpenStack are constantly increasing as well. Additionally, through his systems engineering experience, he has been exposed to and supported various web and enterprise applications. The most recent exposure has been to PaaS solutions, and this has led to advocation that either a public or private cloud offering is not complete without a coupling of both Iaas and PaaS solutions designed and deployed in lockstep.

Besides core infrastructure, he has, at various times, and especially more so recently, been developing programming skills to augment his daily activities. Throughout his career, Darrel has utilized various languages and utilities to automate infrastructure. Some of his programming has been with the use of Bash, Net-SNMP, Sed, and Awk, and holistically with Python.

Cameron R. Lane is a full-stack engineer with an interest in a broad range of languages and technologies. He is currently a senior software developer at Synapp.io in Atlanta, GA, where he designs and builds scalable APIs for the Web using MongoDB and Python.

I would like to thank my wife, Stephanie, for her understanding and patience through all of life's changes, big and small. It is her support that gives me the motivation and confidence to take on big challenges. I would also like to thank my colleagues at Synapp.io, who teach me something new about technology every day.

Hoàng Đình Quân is a Vietnamese System Administrator with experience in operating Network Infrastructure and OpenStack cloud platform automation tools (such as Ansible and SaltStack).

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Preface

SaltStack (or Salt, for short) is an open source project that was started by Thomas Hatch in 2011. It was originally intended to be a lightning-fast remote-execution system. Later, the various pieces that make up the Salt that we know today were added on top of this flexible layer. Salt is now one of the most popular open source projects in the world and one of the most popular infrastructure management platforms.

The project is managed by SaltStack, a company dedicated to preserving the open source nature of the software. SaltStack provides service, long-term support, and custom code in its enterprise product. The company also supports the open source Salt project with a team of dedicated engineers.

Why do you care? What can Salt do for you?

Salt is the easiest, most powerful way to manage your servers. Whether you have a few, hundreds, or even tens of thousands of servers, you can use Salt to manage them from a single, central point. You can use it to flexibly target any subset of your servers to run commands or accomplish tasks. You can use the state system to define the state of your infrastructure in a data-driven way and then enforce that state in seconds, with a single command. You can even create a reactive, self-healing infrastructure using the event system. Salt is written in Python and designed to be easy to extend for your own specific use cases or purposes.

We're going to learn how to do all this and more in these pages. By the end of this book, you will have the knowledge you need to begin making the management of your infrastructure easier with Salt.

Let's get to it!

What this book covers

Chapter 1, Diving In – Our First Salt Commands, teaches you how to install Salt and execute basic commands.

Chapter 2, Controlling Your Minions with Remote Execution, covers how to use Salt to accomplish tasks on your minions through remote execution.

Chapter 3, Execution Modules – Write Your Own Solution, teaches you how to write your own custom remote-execution modules to extend Salt for your own purposes.

Chapter 4, Defining the State of Your Infrastructure, covers how to use Salt states to define and enforce the state of your infrastructure.

Chapter 5, Expanding Our States with Jinja2 and Pillar, shows how to make your states more flexible and powerful using Jinja2 and pillar data.

Chapter 6, The Highstate and Environments, teaches you how to structure your states into environments and enforce the state of your entire infrastructure using a single command.

Chapter 7, Using Salt Cloud to Manage Virtual Minions, covers how to manage your cloud virtual machines using