Topology as code

When we discuss topology as code, an engineer might jump up and declare: “The network is too complex. It is impossible to summarize it into code!” From personal experience, this has happened in some of the meetings I have been in. In the meeting, we would have a group of software engineers who want to treat infrastructure as code, but the traditional network engineers in the room would declare that it was impossible. Before you do the same and yell at me across the pages of this book, let’s keep an open mind. Would it help if I told you we have been using code to describe our topology in this book already?

If you take a look at any of the lab topology files that we have been using in this book, they are simply YAML files that include a description of the relationship between nodes. For example, in this chapter, we will use same topology we have been using for the last few chapters:

Figure 16.1: Lab Topology

If we open up the topology...