Infrastructure as Code, 3rd Edition

Chapter 2. Principles of Cloud Infrastructure

A Note for Early Release Readers

With Early Release ebooks, you get books in their earliest form—the author’s raw and unedited content as they write—so you can take advantage of these technologies long before the official release of these titles. This will be the 2nd chapter of the final book. Please note that the GitHub repo will be made active later on. If you have comments about how we might improve the content and/or examples in this book, or if you notice missing material within this chapter, please reach out to the editor at [e-mail].

The last chapter gave context for the use of Infrastructure as Code, including how it can support organizational strategy, and the importance of creating systems that are easy to improve and evolve. This chapter discusses how to do these things, outlining high-level principals for using cloud Infrastructure as Code effectively.

Computing resources in the Iron Age of IT were tightly coupled to physical hardware. We assembled CPUs, memory, and hard drives in a server, mounted the server into a rack, and cabled it to switches and routers. We installed and configured an operating system and application software. We could describe where an application server was in the data center: which floor, which row, which rack, which slot.

Cloud decouples computing resources from the physical hardware they run on. The hardware still exists, of course. But servers, hard drives, and routers have transformed ...