Book Image

Extending SaltStack

Book Image

Extending SaltStack

Overview of this book

Salt already ships with a very powerful set of tools, but that doesn't mean that they all suit your needs perfectly. By adding your own modules and enhancing existing ones, you can bring the functionality that you need to increase your productivity. Extending SaltStack follows a tutorial-based approach to explain different types of modules, from fundamentals to complete and full-functioning modules. Starting with the Loader system that drives Salt, this book will guide you through the most common types of modules. First you will learn how to write execution modules. Then you will extend the configuration using the grain, pillar, and SDB modules. Next up will be state modules and then the renderers that can be used with them. This will be followed with returner and output modules, which increase your options to manage return data. After that, there will be modules for external file servers, clouds, beacons, and finally external authentication and wheel modules to manage the master. With this guide in hand, you will be prepared to create, troubleshoot, and manage the most common types of Salt modules and take your infrastructure to new heights!
Table of Contents (21 chapters)
Extending SaltStack
Credits
Foreword
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

How Salt uses files


There are two ways that Salt's built-in file server uses files when communicating with Minions. They can be served whole and intact, or they can be processed by a templating engine, using a renderer module as discussed in Chapter 5, Rendering Data.

In either case, these files are stored in one or more sets of directories, as configured with the file_roots directive in the master configuration file. These directories are grouped by environment. When Salt is looking for a file, it will search through the directories in the order in which they are listed. The default environment, base, normally uses /srv/salt/ to store files. Such a configuration would look like:

file_roots:
  base:
    - /srv/salt/

What many users don't realize is that the file_roots directive is actually a configuration option that is specific to a file server module called roots. This module, along with all other file server modules, is configured using the fileserver_backend directive:

fileserver_backend...