What is Infrastructure as Code and why is it needed?

The amount of servers used by almost any project is growing rapidly mostly due to increasing adoption of cloud technologies. As a result, traditional ways of managing IT infrastructure become less and less relevant.

The manual approach fits well for a farm of a dozen, perhaps even a couple of dozen of servers. But when we're talking about hundreds of them, doing anything by hand is definitely not going to play out well.

It's not only about servers, of course. Every cloud provider gives extra services on top, be it a virtual networking service, object storage, or a monitoring solution, which you don't need to maintain yourself. These services function that a Software as a Service (SaaS). And actually, we should treat various SaaS products as part of our infrastructure as well. If you use New Relic for monitoring purposes, then it is your infrastructure too, with the difference that you don't need to manage servers for it yourself. But how you use it and whether you use it correctly is up to you.

No surprises, companies of any size, from small start-ups to huge enterprises, are adopting new techniques and tools to manage and automate their infrastructures. These techniques eventually got a new name: Infrastructure as Code (IaC).

Dated something 2009, the Infrastructure as Code term is all about approaching your IT-infrastructure tasks the same way you develop software. This includes the things similar to the following:

• Heavy use of source control to store all infrastructure-related code
• Collaboration on this code in the same fashion as applications are developed
• Using unit and integration testing and even applying Test-driven development to infrastructure code
• Introducing continuous integration and continuous delivery to test and release infrastructure code

Infrastructure as Code is a foundation for DevOps culture because both operations and developers approach their work in the same way, and by following the principles laid out before, they already have some common ground.

This is not to say that if your infrastructure is treated as code, then the border between development and operations becomes so blurry that the whole existence of this separation can become eventually quite questionable.

Of course, the introduction of Infrastructure as Code requires new kinds of tools.