What is Infrastructure-as-Code (IaC)?


Infrastructure-as-code (IaC) is a concept that has revolutionized the way IT infrastructure is managed and deployed. By using IaC, infrastructure is treated like a software application where its attributes are written through code.
In this article, we will be talking about Infrastructure-as-code, what it is, and how it can help us better manage our infrastructure.

What is Infrastructure As Code?

Infrastructure-as-code (IaC) is a concept where we manage and deploy the infrastructure through code instead of manual configurations.

Traditionally, when you need to set up a server, the admin will manually go through the steps of configuring the resources like CPU, Memory, Storage, and Network, then install the operating system and all the necessary software for it to run.

Sure, this is a doable approach when you have a few servers. But when there is a need to provision hundreds or more servers, this approach becomes extremely tedious.

Additionally, if you manage to provision hundreds of servers with the manual approach but suddenly want to make changes, you'd have to go through each server making the changes manually.

That can cause a configuration drift. A situation where servers that are supposed to be similar end up having different configurations. This can result in an application running perfectly on some of your servers and crashing on others.

The scenario above elaborates why the manual way is no longer feasible. This is where IaC comes into play. With IaC, we treat the infrastructure as if it's an application by defining it as code.

Let’s briefly discuss how to approach IaC.

Approaches to IaC

There are two ways of approaching IaC:

  • Declarative approach: Where we write code that describes how we want our infrastructure to be, and when we deploy it, the infrastructure will reflect how the code was written.
  • Procedural approach: Where we instruct how the infrastructure will be configured in a step-by-step format.

Advantages of Infrastructure-As-Code

Now let's look at some more advantages of IaC.

  • It brings efficiency and speed. Since the infrastructure is treated as code, we can introduce automation mechanisms to make changes to the infrastructure efficiently. If we need to apply a change, we only need to change the code that describes the infrastructure, and that saves us time.
  • It makes infrastructure replication possible. Let's say we have a task to make another environment similar to production. With IaC, this will be much easier since we only need to make a few changes to the code that describes our infrastructure and deploy it as opposed to setting everything up from scratch.
  • It makes scalability easy. Let's say our infrastructure runs on one server. If we were to scale it up with IaC, we just need to declare the number of servers or replicas we need in the code and apply it to our infrastructure.
  • It enhances reliability. IaC makes our infrastructure easier to debug since we can easily look at the "source code" and troubleshoot.
  • It makes version control possible. Since our infrastructure is defined through files that contain code, we can then implement a Git versioning control on it for better manageability.
  • It increases infrastructure security. That’s because only changes that have been reviewed can be implemented. In the event that there is an issue because of a recent code change, we can easily roll back to a previous version.

IaC makes the infrastructure more flexible and agile. That’s because when we want to make changes to it, we simply update the code, and the infrastructure will update itself. And what's more amazing about IaC is that servers that are created from the same code will certainly be configured the same way and behave the same way.

Disadvantages of Infrastructure-As-Code

IaC has some drawbacks as well. Let’s look at some of them:

  • It can get complex. As with software development, the more complex an application becomes, the bigger the codebase that needs to be managed. As your infrastructure gets bigger, its code grows along with it. So when implementing IaC, make sure to pair it with detailed documentation so that anyone who will be managing your infrastructure won't have a hard time managing it.
  • It carries some security risks. Since the infrastructure is declared through code, there may be instances where sensitive data may make its way into the code that an unauthorized person can see.

Be sure to implement security best practices by storing all sensitive data in a separate location to protect your infrastructure from being breached by hackers and causing damage.

  • It is resource intensive. Implementing IaC requires a considerable amount of knowledge of specialized tools. Hiring engineers who understand these tools can be expensive.
  • It takes a long time to implement. Implementing IaC requires careful planning and execution. This is especially true if you are planning to transition your infrastructure from the traditional setup to one powered by IaC.

There are many available IaC tools out there, but we will be listing only the most widely used.

Alright, let’s look at IaC tools.


Terraform is an open-source IaC tool from Hashicorp that uses a Declarative approach in its implementation. It lets you provision the entire infrastructure and services through code. It gives you access to hundreds of ready-to-use systems that get your infrastructure running in record time.

If you want to learn more about Terraform, check out KodeKloud’s Terraform Basics Training course.


Ansible is an open-source tool that uses a Procedural approach from RedHat to implement IaC. It allows users to configure and manage applications through automated deployment. The commands are simple and easy to understand.

If you want to learn more about Ansible, check out KodeKloud’s Ansible Basics course.


Puppet is another popular IaC tool that you can use to automate your infrastructure. It uses a Declarative style to configure your infrastructure. It features idempotency, which means that even if you apply the code repeatedly, you will get the same result.

If you want to learn Puppet, check out KodeKloud’s Puppet for the Absolute Beginners course.


Chef or Progress Chef is another Procedural IaC tool written in Ruby and Erlang. It allows you to configure and manage your infrastructure by writing recipes that describe in human-readable code each system’s desired state. These recipes are then grouped together and called "cookbooks"

If you want to learn more about Chef, check out KodeKloud’s Chef for the Absolute Beginners course.

And those are the popular IaC tools you can use today. Most of these tools are similar in functionality but differ in implementation.


IaC allows us to create consistent infrastructure easily. It eliminates manual configuration shortcomings such as configuration drifts and allows you to save time and money. Currently, the most popular IaC tools include Ansible, Terraform, Puppet, and Chef.

If you want to learn how to use any of these tools, KodeKloud has beginner and advanced courses for all four tools.

For a more in-depth look at all the concepts and ideas behind IaC, check out these KodeKloud’s Infrastructure as Code courses.