Terraform is an open source utility, created by a HashiCorp company, the same company that created Vagrant, Packer, Consul, and other popular infrastructure tools. It was initially released in July 2014 and since then has come a long way to become one of the most important tools for infrastructure provisioning and management.
This is how Terraform is described by HashiCorp:
... a tool for safely and efficiently building, combining, and launching infrastructure. From physical servers to containers to SaaS products, Terraform is able to create and compose all the components necessary to run any service or application. (https://www.hashicorp.com/blog/terraform.html)
Terraform easily fits most of the requirements listed here:
- At the time of writing, it supports over 30 different providers, from a huge ones such as AWS to a smaller ones such as multiple SaaS DNS providers.
- Terraform provides a special configuration language to declare your infrastructure in simple text templates.
- Terraform also implements a complex graph logic, which allows you to resolve dependencies intelligibility and reliability.
- When it comes to servers, Terraform has multiple ways of configuring and wiring them up with existing configuration management tools.
- Terraform is not platform agnostic in the sense described earlier, but it allows you to use multiple providers in a single template, and there are ways to make it somehow platform agnostic. We will talk about these ways closer to the end of the book.
- Terraform keeps track of the current state of infrastructure it created and applies delta changes when something needs to be updated, added, or deleted. It also provides a way to import existing resources and target only specific resources.
- Terraform is easily extendable with plugins, which should be written in Go programming language.
Over the next seven chapters, we will learn how to use Terraform and all of its features.