Infrastructure as Code 101: What Is it, and Why Does It Matter?

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Omry Hay

CTO & Co-founder

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Infrastructure as Code (IaC) is a method of managing and provisioning infrastructure with code. Instead of manually clicking buttons on a web console, IaC enables organizations to describe their system architecture using code, allowing them to store, version, and track changes to their systems and application infrastructure. The goal is to automate the process of setting up, configuring, deploying, and managing applications.

IaC is an emerging and evolving concept, a powerful technology that allows you to provision and manage any cloud resource in an automated, declarative way. In this guide we will explore:

  • What infrastructure management looked like before IaC
  • The benefits of IaC
  • The primary users of IaC
  • When to adopt IaC
  • The main IaC tools
  • Potential pitfalls to avoid

Before IaC

IaC has transformed the way IT infrastructure is set up and managed, by provisioning and managing IT infrastructure and application resources through machine-readable definition files rather than through physical hardware configuration or interactive configuration tools. What does this mean? You can create a consistent, repeatable workflow, enabling wider-scale deployments across a range of resources, environments, and locations.

Before, managing infrastructure was a costly, manual process that hindered scale and availability.

Human error → environment drift

System administrators (sysadmins) used to have to provision new hardware and resources manually, by connecting to remote cloud providers via APIs or web dashboards. If they made changes to one environment, they’d have to remember to go and make those updates to all other environments to ensure consistency. When an application’s deployment environments aren’t consistent, this is known as “environment drift.”

Environment drift: When infrastructure for an application’s development, staging, and production environments falls out of sync. Environment drift, or configuration drift, causes inefficiencies and can be expensive in direct cost and potential user experience impacts. If your app’s development environment varies from the production environment, this can lead to failure in production or bugs, and even prevent recovery in the event of disaster.

Benefits of IaC

Now, IaC has made IT more efficient than ever before, solving numerous IT challenges and enabling new capabilities such as:

Recreating environments

It used to be challenging to recreate an identical environment after a deployment because the systems it interacted with also had to be updated.

With IaC, users can recreate infrastructure from scratch, and on demand, simply by replaying code. The pipeline uses a prescribed set of parameters for deployment and creates a new environment that is identical in terms of the number of hosts, networks, data centers, clusters, and data stores, etc., each and every time it’s run. The infrastructure code can even be versioned with the product, making it easy for engineers to recreate the infrastructure as it was when a previous version of the product was released.

Minimizing errors

IaC minimizes the need for manual management, reducing the risk of human error. Rather than depending on engineers to remember past configurations or respond to failures, everything is in the code, under version control.

When changes go to production, the infrastructure code is checked in a code review or in a review by a gatekeeper.

Supporting teamwork and collaboration

Using IaC, engineers don’t have to deal with problems caused by conflicting changes in a shared environment. IaC makes it easier to work as a team and to share code with colleagues and other teams, so they can utilize it to set up their own environments. Using a version control system, different teams can each work on a separate piece of the infrastructure, rolling out their changes in a controlled manner.

Reducing cloud expenditure

The shift from bare metal infrastructure investments to the cloud reduced CapEx, and IaC has reduced them even further by enabling auto scaling capabilities. With IaC, a developer writes code and configuration management instructions that trigger actions according to actual need and accurately reflect the structure of the real operating environment. IaC lets you manage your environments easily, and automatically deactivates environments you no longer need.

DevOps and IaC: DevOps puts an emphasis on automating away manual tasks that typically take up a lot of developer and IT operator time. IaC is one of the key technical practices that enable DevOps within an organization, by automating the provisioning and management of IT infrastructure. With IaC, developers are able to self-serve the provisioning of environments, saving time for them and the operations team.

Who benefits from IaC?

  • Developers: IaC helps developers quickly and easily spin up new environments with the exact specifications they need, allowing them to focus on writing code rather than worrying about the underlying infrastructure. See why IaC is a creative job for developers.
  • System administrators: IaC allows sysadmins to automate mundane tasks (like spinning up new environments for developers), freeing up their time to focus on more important and complex work. 
  • Cloud architects: IaC helps cloud architects standardize cloud deployments, collaborate with members of their team, and significantly reduce the time required to create new environments.
  • IT managers: IaC helps IT managers quickly and easily scale their systems up and down as needed, reducing costs and increasing efficiency. 
  • FinOps: IaC allows FinOps to control the budget and have one place to enforce tag management to structure and get a better visibility on cloud cost.
  • CISO / DevSecOps: IaC allows CISOs and DevSecOps to make sure cloud infrastructure is managed in a secure way across the entire organization by integrating with security tools on top of IaC.

When to use IaC

Some technologies and practices are only really advantageous at scale. However, organizations of any size and complexity can benefit from managing their infrastructure in a consistent, repeatable way. Setting up IaC from the outset can make it easier to scale later. 

Primary Infrastructure as Code Frameworks

Framework Languages Maintained by Approach
Terraform HCL / JSON HashiCorp Declarative
AWS CloudFormation YAML / JSON AWS Declarative
AWS CDK TypeScript, JavaScript, Python, Java, and C# AWS Imperative
ARM Templates JSON, Bicep (HCL) Azure Declarative
Google Cloud Deployment Manager YAML Google Declarative
Terragrunt HCL / JSON Gruntwork Declarative
Pulumi Node.js, Python, .NET Core, and Go Pulumi Imperative
Serverless Framework YAML / JSON Serverless Declarative
Crossplane YAML Upbound Declarative

Imperative vs declarative IaC: These are the two main approaches to writing infrastructure code. In the imperative approach, users specify exactly what commands are needed (and in what order) to implement the desired configuration. In the declarative approach, users specify the desired state of the system and resources, delegating the rest to an IaC tool to configure. You can see from the table above that the declarative approach is preferred by most IaC tools due the flexibility it enables.

Watch out for these IaC pitfalls

While IaC has clear advantages, it also presents unique challenges which usually emerge as you scale.

Integration with management tools

In order to harness the full benefits of IaC, it must be integrated into all processes, including CI/CD workflows, notification tools like Slack, security tools, system administration, IT operations, and DevOps, with well documented policies and procedures. Without full integration, errors can quickly spread across the system.

Longer turnaround

When using IaC, every change has to be coded, tested and reviewed before it is applied. Changes are more complex and must be planned carefully to avoid significant downtime.

Learn more: Video: Top IaC Challenges

Lack of cloud expense oversight

Since IaC deploys infrastructure automatically, it can be hard to keep track of expenses. Development teams are often unaware of the financial ramifications of their code, and expenses can build up quickly without monitoring tools that are designed for IaC.

IaC toolchain sprawl

One of the primary benefits of adopting Infrastructure as Code is consistency, which is hard to achieve if teams across your organization are using different IaC tools and approaches. In many cases, implementing IaC requires a cultural shift in addition to the technical one to ensure success. 

The advantages far outweigh any overhead associated with implementing and managing IaC. In our next guide, we’ll cover how to get started with IaC, and what tools and practices you can put in place to address any challenges you encounter along the way.

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Omry Hay


The best way to manage your Terraform

Custom workflows let you model any process you have.

Improve collaboration so your teams are always on the same page with your Infrastructure as Code

Visualize the effect of IaC changes before and after deployment.

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