Infrastructure as Code

Chapter 4. Server Configuration Tools

Using scripts and automation to create, provision, and update servers is not especially new, but a new generation of tools has emerged over the past decade or so. CFEngine, Puppet, Chef, Ansible, and others define this category of tooling. Virtualization and cloud has driven the popularity of these tools by making it easy to create large numbers of new server instances which then need to be configured and updated.

Containerization tools such as Docker have emerged even more recently as a method for packaging, distributing, and running applications and processes. Containers bundle elements of the operating system with the application, which has implications for the way that servers are provisioned and updated.

As mentioned in the previous chapter, not all tools are designed to treat infrastructure as code. The guidelines from that chapter for selecting tools apply equally well to server configuration tools; they should be scriptable, run unattended, and use externalized configuration.

This chapter describes how server automation tools designed for infrastructure as code work. This includes different approaches that tools can take and different approaches that teams can use to implement these tools for their own infrastructure.

Patterns for Managing Servers

Several of the chapters in Part II build on the material covered in this chapter. Chapter 6 discusses general patterns and approaches for provisioning servers, Chapter 7 explores ways of ...