Book Image

Learning SaltStack - Second Edition

By : Colton Myers
Book Image

Learning SaltStack - Second Edition

By: Colton Myers

Overview of this book

SaltStack is one of the best infrastructure management platforms available. It provides powerful tools for defining and enforcing the state of your infrastructure in a clear, concise way. With this book learn how to use these tools for your own infrastructure by understanding the core pieces of Salt. In this book we will take you from the initial installation of Salt, through running their first commands, and then talk about extending Salt for individual use cases. From there you will explore the state system inside of Salt, learning to define the desired state of our infrastructure in such a way that Salt can enforce that state with a single command. Finally, you will learn about some of the additional tools that salt provides, including salt-cloud, the reactor, and the event system. We?ll finish by exploring how to get involved with salt and what'?s new in the salt community. Finally, by the end of the book, you'll be able to build a reliable, scalable, secure, high-performance infrastructure and fully utilize the power of cloud computing.
Table of Contents (17 chapters)
Learning SaltStack Second Edition
About the Author
About the Reviewer

Managing groups of VMs with map files

So far, our exploration of Salt Cloud has been limited to operations on single VMs or manually compiled lists of VMs. This is very useful but doesn't scale as well because there's no central source of truth for your VMs, especially if you have VMs across multiple cloud providers.

Salt Cloud provides a tool to solve this problem: map files. Basically, we create a map of our infrastructure and all the VMs that are in it. When a map is executed, your infrastructure will be brought to the state defined in the map file. Any VMs that already exist will be unmodified, and any new VMs will be created.

Let's create a map file to create multiple Ubuntu and CentOS minions. The location of the map file is unimportant, as we will pass in an absolute path to the map file anyway. Let's create it at /etc/salt/mymap.sls, as follows:

  - db1
  - db2
  - web1
  - web2
  - load

As you can see, cloud maps are also formatted in YAML. At their most basic, they...