Infrastructure as code

Definition

Infrastructure as Code (IaC) is the process of managing, provisioning, and configuring IT infrastructure through code rather than manual setups. Instead of using graphical interfaces or command-line inputs for each server or network, administrators define infrastructure requirements in machine-readable files. These definitions can then be version controlled, tested, and reused like application code.

IaC allows businesses to automate the creation and management of servers, networks, databases, and storage. By treating infrastructure as code, organizations reduce human error, achieve consistent environments, and accelerate deployments across development, testing, and production. Popular IaC tools include Terraform, Ansible, Puppet, and AWS CloudFormation.

Advanced

IaC can be applied in two models. Declarative defines the desired state of infrastructure, as seen in Terraform or CloudFormation. Imperative gives step by step instructions, as in Ansible or Chef. Declarative approaches align with GitOps, where infrastructure definitions live in repositories and updates are applied through pull requests.

IaC also integrates with CI and CD pipelines to automatically provision environments. It supports immutability, where resources are replaced instead of modified, helping avoid configuration drift. Advanced practices extend into policy as code for governance, compliance automation, and multi cloud orchestration.

Why it matters

• Automates infrastructure provisioning and reduces manual effort.
• Ensures consistency across environments and teams.
• Enhances agility with faster deployments and scaling.
• Strengthens governance with version control and auditing.
• Supports cloud native and DevOps workflows.

Use cases

• Provisioning cloud infrastructure on AWS, Azure, or GCP.
• Automating test environments for software development.
• Managing multi cloud or hybrid deployments at scale.
• Enforcing compliance policies as code.

Metrics

• Deployment time for infrastructure resources.
• Rate of configuration drift across environments.
• Number of successful automated builds vs manual changes.
• Compliance audit pass rates for infrastructure code.
• Error rate during provisioning or updates.

Issues

• Misconfigured code can cause large scale outages.
• Learning curve for teams new to IaC tools.
• Versioning conflicts if code is not properly managed.
• Security risks if secrets are hardcoded.

Example

A financial services company uses Terraform to define infrastructure as code. Developers submit pull requests to update environments, and changes are automatically applied through CI and CD pipelines. This reduces manual effort, improves compliance visibility, and accelerates delivery of new services.