Book Image

Mastering SaltStack - Second Edition

By : Joseph Hall
Book Image

Mastering SaltStack - Second Edition

By: Joseph Hall

Overview of this book

SaltStack is a powerful configuration management and automation suite designed to manage servers and tens of thousands of nodes. This book showcases Salt as a very powerful automation framework. We will review the fundamental concepts to get you in the right frame of mind, and then explore Salt in much greater depth. You will explore Salt SSH as a powerful tool and take Salt Cloud to the next level. Next, you’ll master using Salt services with ease in your infrastructure. You will discover methods and strategies to scale your infrastructure properly. You will also learn how to use Salt as a powerful monitoring tool. By the end of this book, you will have learned troubleshooting tips and best practices to make the entire process of using Salt pain-free and easy.
Table of Contents (20 chapters)
Mastering SaltStack Second Edition
About the Author
About the Reviewer

Working with beacons

Beacons are a very new feature in Salt, but they've already gained quite a following. In past versions of Salt, if a third-party process needed to raise an event inside Salt, it would have to explicitly make a call to Salt to do so. Beacons overcome this by allowing events to be triggered by third-party processes without having to perform any work inside that process itself.

As you can imagine, beacons were designed for monitoring and, specifically, alerting purposes. While monitoring states are fairly passive, in which they only run when called explicitly or via the scheduler, beacons are very proactive, in which they are constantly watching for changes.

Monitoring file changes

Beacons are run on a regular basis on the target minion. When they pick up important changes, they will fire an event that describes these changes.

The first beacon that was ever added was for the inotify system. This is built in the Linux kernel, starting with version 2.6.13. The inotify system...