What Is Infrastructure as Code (IaC)?

Infrastructure as Code (IaC) is the practice of managing and provisioning IT infrastructure — such as servers, networks and storage — using machine-readable configuration files rather than physical hardware or manual processes. By treating infrastructure as software, IaC enables consistent, automated deployments that improve scalability, reproducibility and efficiency.

Infrastructure as Code is a key component of software-defined and programmable infrastructure, focusing on managing resources through code.

How Does Infrastructure as Code Work?

Unlike traditional scripting, which automates individual tasks, IaC uses machine-readable definition files to provision and manage infrastructure in a consistent, repeatable way.

For example, consider a popular IaC IT management tool, Ansible. This tool uses automation to:

• Install MySQL servers
• Ensure MySQL runs correctly
• Create and destroy databases
• Create and manage user accounts

Ansible uses the markup language YAML to specify the state of provisioning and processes.

Mutable vs. Immutable Infrastructure as Code

IaC can follow either a mutable or immutable infrastructure model. In a mutable setup, resources are updated in place; in an immutable approach, infrastructure is replaced entirely with each change. Immutable infrastructure reduces configuration drift, simplifies rollbacks and improves reliability across deployments.

Why Use Infrastructure as Code?

In the early 2000s, managing an IT infrastructure was a highly manual and complex process for big companies. Experts had to physically install and configure servers and other types of hardware, which was a slow, inconsistent and costly way to manage IT. 

With IaC, there’s no need for this kind of manual configuration. Instead, DevOps teams can automatically manage and provision resources. By using IaC, the provisioning code becomes easy to edit, copy and distribute.

Notice that, like any other software development project, developers must maintain version control, test iterations and limit deployments. So, even though IaC is a great approach for automating complex manual processes, it also includes new tools and overhead for the developers.

Advantages of Infrastructure as Code

Efficiency

IaC is faster than manual processes for database management, networking, user account management and other similar services.

Consistency

While using IaC, developers can easily provision and deploy servers and apps while also following business practices and policies. This is better than relying on system admins in a DevOps setting because the developers get to directly provision systems with which they’re already familiar and on which they’re already working.

Reduced Risk

IaC automation minimizes the risks of human error we often see in manual configuration. Reducing these risks can increase the software’s uptime and reliability.

Visibility

Developers can place any IaC configuration files under version control similar to any other source code. This means developers can track the history of changes made to the configuration files in the same place where the software projects live.

Documentation

IaC acts as complete documentation of how to instantiate the infrastructure. This documentation becomes critical when onboarding new engineers or in cases of employees with institutional knowledge leaving.

Disadvantages of Infrastructure as Code

Additional Tools

IaC requires additional tools, such as configuration management and orchestration systems. Some tools might pose a learning curve, which increases the workload and room for errors as developers get up to speed.

To prevent errors caused by extensive automation and new tools, proper version control, pre-release testing and monitoring need to take place.

Configuration Drift

IaC comes with a risk of configuration drift. This happens if the developers make ad-hoc changes to the server configurations outside the IaC template without using change management tools. To prevent this, it’s important to integrate the IaC into system administration, IT operations and DevOps with clearly documented policies.

Increased Responsibility for Developers

Last but not least, IaC increases the responsibility of software developers. The developers must learn how to write code that smoothly transforms into production environments. Besides, they need to learn IaC languages, such as YAML, JSON, Ruby or SQL.

Infrastructure as Code Tools

Here are some notable IaC tools that companies use to create and sustain a strong Infrastructure as Code.

• Terraform is an open-source IaC tool for creating, changing and improving infrastructure in a safe and predictable manner. It uses HashiCorp Configuration Language (HCL) and supports multi-cloud provisioning.
• Ansible is a robust provisioning system. It automates configuration, application deployment and task execution, typically on already provisioned resources.
• Pulumi is an open-source IaC SDK. With Pulumi, you can use your favorite language to create, deploy and manage infrastructure on any cloud.
• Chef is a configuration management tool that uses Ruby DSL to define infrastructure as code for managing nodes across environments.”
• Puppet is an open source tool for systems management and deployments. Puppet allows for centralizing and automating configuration management to handle the information that describes the enterprise’s hardware and software.
• Vagrant makes building and managing virtual machine environments happen within a single workflow. This lowers the environment setup time and increases production parity. While not a full IaC tool, Vagrant helps manage virtual environments and supports reproducible development setups.

Frequently Asked Questions