In Chapter 5, Connecting with Other Tools, you learned how to connect Terraform with various existing infrastructure tools. We've spent a lot of time on configuration management systems in particular. It is a popular thing to say these days that configuration management tools are not required any longer and immutable infrastructure, containers, or whatever is the best and only practice. Some people on the Internet can even argue that you can replace Chef and Puppet with only Terraform. Certainly, that's not the case. Even though you could replace Terraform with Chef or Puppet indeed.

Terraform covers only one level of infrastructure (as discussed in Chapter 1, Infrastructure Automation), and it does it reasonably well. For everything that goes inside a particular piece of hardware (or virtual hardware), you need a proper configuration management tool, regardless whether you need to configure EC2 instance, big bare metal server, or a networking hardware. If you have thousands of machines, the benefits of Chef or Puppet become even more clear. So, do yourself a favor and learn at least one of them and then combine it with Terraform to achieve infrastructure excellence at every layer of your environments.