Salt Essentials

Chapter 1. Introduction

What Is Salt?

Salt is a remote execution framework and configuration management system. It is similar to Chef, Puppet, Ansible, and cfengine. These systems are all written to solve the same basic problem: how do you maintain consistency across many machines, whether it is 2 machines or 20,000? What makes Salt different is that it accomplishes this high-level goal via a very fast and secure communication system. Its high-speed data bus allows Salt to manage just a few hosts or even a very large environment containing thousands of hosts. This is the very backbone of Salt. Once this encrypted communication channel is established, many more options open up. On top of this authenticated event bus is the remote execution engine. Then, continuing to build on existing layers, comes the state system. The state system uses the remote execution system, which, in turn, is layered on top of the secure event bus. This layering of functionality is what makes Salt so powerful.

But this is just the core of what Salt provides. Salt is written in Python, and its execution framework is just more Python. The default configuration uses a standard data format, YAML. Salt comes with a couple of other options if you don’t want to use YAML. The power of Salt is in its extensibility. Most of Salt can easily be customized—everything from the format of the data files to the code that runs on each host to how data is exchanged. Salt provides powerful application programming interfaces ...