What is Infrastructure as Code? (IaC)

Infrastructure as Code (IaC) is a modern approach to managing and provisioning computing infrastructure through machine-readable configuration files, rather than through physical hardware configuration or interactive configuration tools. IaC treats infrastructure the same way that application code is treated, allowing for automated and consistent deployment of resources.

By using code, IaC enables the provisioning and configuration of Infrastructure in an automated way. The Code refers to the automation, and the Infrastructure is still the infrastructure you’re used to. Not all infrastructure is purely hardware based. In the cloud and modern on-premises systems, there are many infrastructure services and systems that are software defined and can be automated easily through code.

There are two different approaches to implementing IaC:

• Declarative: Specifies the desired end state of the infrastructure.
• Imperative: Specifies the exact steps required to reach the desired configuration.

Let’s look at each a little further.

Declarative Infrastructure as Code

Declarative Infrastructure as Code (IaC) is a method of defining infrastructure in a way that specifies the desired final state rather than the steps to achieve that state. This approach abstracts the complexity of the underlying infrastructure management, allowing users to declare “what” the infrastructure should look like without detailing “how” to achieve it.

Here are a few key points of Declarative IaC:

• Specification of Desired State: Users describe the target configuration.
• State Management: The IaC tool ensures the current state matches the desired state.
• Simplicity: Reduces complexity by focusing on the end result.
• Consistency: Ensures uniformity across different environments.
• Reduced Errors: Minimizes manual errors by abstracting procedural details.

These are a few examples of Declarative IaC tools:

• HashiCorp Terraform: Uses HashiCorp Configuration Language (HCL) to define infrastructure in any cloud or data center.
• Azure Bicep and ARM Templates: Define infrastructure configuration for Microsoft Azure resources.
• AWS CloudFormation: Define infrastructure configuration for Amazon AWS resources.

Using a Declarative IaC approach simplifies the management of resources by allowing users to define the desired state of their infrastructure, more easily ensuring consistency between environments. It is an essential practice for modern cloud-native and DevOps environments.

Related: If you’re new to Terraform, or are looking for a bit more information, then we recommend you check out our “Get Started with Terraform on Azure” article. This will give you a great jump start to both using Terraform for infrastructure automation, as well as some tips on using it with Microsoft Azure.

Imperative Infrastructure as Code

Imperative Infrastructure as Code (IaC) is an approach where the configuration defines the specific commands or steps needed to modify the infrastructure so it achieves the desired state in the end. Unlike declarative IaC, which focuses on the final state, imperative IaC focuses on the sequential steps and actions necessary to reach the desired state in the end.

Here are a few key points of Imperative IaC:

• Procedural Approach: Describes “how” to achieve the desired state with detailed instructions.
• Step-by-Step Execution: Lists the exact commands or operations to perform.
• Flexibility: Allows for detailed control over the execution process.
• Specificity: Enables fine-grained management of each step in the infrastructure setup.
• Adaptability: Can be easily adjusted to accommodate complex or custom requirements.

These are a few examples of Imperative IaC tools:

• Ansible: Uses YAML files to describe automation tasks in a step-by-step manner.
• Chef: Uses Ruby-based recipes to define the steps for configuring infrastructure.
• Puppet: Uses its own declarative language but allows for procedural scripting for detailed configurations.

Imperative IaC provides detailed control over the infrastructure setup process, allowing for precise and flexible management of infrastructure changes. It is particularly useful in scenarios where specific order and procedural details are important.

What are the Benefits of IaC?

Infrastructure as Code (IaC) has transformed the way organizations manage their IT infrastructure, bringing numerous advantages that streamline operations and enhance productivity. By automating the provisioning and management of infrastructure through code, IaC not only accelerates deployment processes but also ensures consistency, reliability, scalability, and security.

Here are several additional benefits of using Infrastructure as Code to manage resources:

• Increased Deployment Speed: IaC ensures consistency across all environments—development, testing, and production—by using code to define infrastructure configurations. This consistency eliminates configuration drift, where discrepancies between environments can lead to deployment issues and bugs. By maintaining a uniform setup across environments, IaC facilitates smoother transitions between stages of the software development lifecycle and reduces the likelihood of environment-specific issues.
• Consistency across Environments: IaC ensures consistency across all environments—development, testing, and production—by using code to define infrastructure configurations. This consistency eliminates configuration drift, where discrepancies between environments can lead to deployment issues and bugs. By maintaining a uniform setup across environments, IaC facilitates smoother transitions between stages of the software development lifecycle and reduces the likelihood of environment-specific issues.
• More Cost Efficient Deployments: Deploying infrastructure using IaC leads to cost efficiency by reducing the need for manual intervention and minimizing the risk of human error. Automated provisioning and configuration allow for optimal use of resources, preventing over-provisioning and underutilization. Additionally, IaC enables precise tracking and management of infrastructure components, which helps in identifying and eliminating unnecessary expenditures, ultimately optimizing operational costs.
• Collaboration and Transparency through Version Control: IaC promotes collaboration and transparency by integrating infrastructure configurations into version control systems like Git. This practice allows multiple teams—development, operations, and security—to work together seamlessly, with a shared and accessible codebase. Version control facilitates tracking changes, reviewing updates, and rolling back configurations when necessary, ensuring that all stakeholders have visibility into infrastructure changes and can contribute to maintaining robust and secure deployments.

Infrastructure as Code (IaC) offers a transformative approach to managing IT infrastructure, providing numerous benefits that enhance efficiency, consistency, cost-effectiveness, and collaboration. By automating deployments, ensuring uniformity across environments, and leveraging version control, IaC streamlines operations and supports agile development practices. Embracing IaC allows organizations to achieve faster deployments, reduce operational costs, and foster a collaborative and transparent infrastructure management culture. These advantages make IaC an essential component of modern DevOps and cloud-native strategies, driving innovation and operational excellence.

Code-First Infrastructure Deployments

Code-First Infrastructure is an approach to Infrastructure as Code (IaC) that emphasizes using programming-like configuration files to define and deploy cloud resources. By treating infrastructure setup as code, it enables version control, automation, and repeatability, allowing teams to maintain consistent environments and streamline changes across cloud providers. Tools like HashiCorp Terraform and Azure Bicep make this approach effective by providing declarative syntaxes, meaning users specify what they want, and the tools handle how it’s deployed, improving collaboration and reducing errors in deployment.

Here are the main benefits of a code-first infrastructure approach:

• Automation: Simplifies deployment and scaling with automated configurations.
• Consistency: Ensures identical environments across development, testing, and production.
• Version Control: Allows tracking, rollback, and auditing of infrastructure changes.
• Scalability: Facilitates management of complex, multi-cloud setups.
• Collaboration: Enhances team efficiency through code sharing and review.

These benefits make code-first infrastructure a powerful method for managing modern cloud environments.

Summary

Infrastructure as Code (IaC) has revolutionized IT infrastructure management by automating deployments, ensuring consistency, and optimizing costs. It fosters collaboration and transparency, making it an essential practice for modern DevOps and cloud-native strategies. Embracing IaC drives operational excellence and supports agile development, ultimately enhancing innovation and productivity.

Original Article Source: What is Infrastructure as Code? (IaC) written by Chris Pietschmann (If you're reading this somewhere other than Build5Nines.com, it was republished without permission.)