Infrastructure as Code (IaC)

7 minutes read

Applications fuel the growth and efficiency of modern businesses. They depend on infrastructure—such as compute, storage, and networking—to run effectively. Traditionally, system administrators and IT professionals managed this infrastructure manually, physically setting up servers, network devices, and other hardware components needed for business applications.

In the early days, every business application required dedicated physical hardware. This meant deploying and configuring individual servers for each application—a time-intensive and resource-heavy process. Virtualization revolutionized this approach by allowing multiple virtual machines (VMs) to run on a single physical server using hypervisors, making better use of underutilized hardware. Despite this innovation, infrastructure provisioning and configuration were still mostly done manually, which brought its own set of challenges.

  • Human Error: Each step must be carefully executed, and even small errors can result in system failures or inconsistent environments. Manual processes are prone to mistakes, such as typos or misconfigurations, which can lead to system failures or security vulnerabilities.

  • Inconsistency: Without standardized processes and procedures, different administrators might configure systems differently, leading to difficult-to-troubleshoot inconsistencies. Manual setups make reproducing identical testing, staging, and production environments extremely difficult. Differences in configurations can lead to bugs that only appear in specific environments.

  • Scalability Issues: Manually scaling infrastructure is impractical in today’s fast-paced world of modern applications. Cloud environments and microservices architectures require rapid and often automated scaling, which manual processes struggle to support.

  • Time Consumption: Manually setting up and configuring servers, storage, and networks takes significant time and effort. For example, routine tasks like provisioning a server could take hours or days, slowing down the deployment of applications and features.

  • Limited Agility: Manual provisioning relies heavily on the expertise of individual administrators. Poor documentation or a lack of standardized processes can make collaboration and troubleshooting difficult. As such, responding to business needs or technological changes requires a lot of work, which affects competitiveness and innovation.

Manual provisioning provides hands-on control over every step, making it possible to handle unique or non-standard configurations that might not fit automation scripts. For beginners, manually setting up infrastructure can provide valuable insights into the underlying components and how they work together, building a good foundation for understanding automated tools.

While manual provisioning worked well in legacy systems and simpler IT setups, it has significant drawbacks in modern application development and deployment. Infrastructure as Code offers a solution that automates infrastructure management, ensuring speed, consistency, and scalability in a way manual processes cannot match.

To overcome the shortcomings of the manual provisioning approach, Infrastructure as Code (IaC) is a practice in which you manage and provision your infrastructure components—such as servers, networks, and storage—using code and software development techniques rather than manually configuring hardware and systems.

Simply, it means you write scripts or configuration files describing how your servers, networks, and other resources should be set up. This approach allows you to automate the deployment and management of your infrastructure, making it more efficient, consistent, and scalable. By treating infrastructure like software code, you can version control, share, and replicate it easily across different environments, reducing errors and saving time.

By treating infrastructure as software-defined, IaC empowers teams to deploy and maintain complex environments in a reliable way and with minimal effort.

  • Consistency and Reliability: IaC ensures consistency across environments. You can use code to define infrastructure components. This minimizes the chance for human error, and environments such as development, staging, and production can be set up identically. This reduces the risk of bugs and unexpected issues caused by mismatched configurations.

  • Automation and Efficiency: IaC enables you to automate infrastructure provisioning and updating, significantly reducing the time needed to deploy and configure resources. This ensures you can apply the same configuration across multiple environments, reducing discrepancies. Tasks that traditionally took hours or days can now be completed in minutes with IaC scripts.

  • Version Control and Traceability: Like application code, infrastructure configuration code can be stored in version control systems like Git. This allows you to track changes over time, collaborate with team members, and easily roll back to previous versions should any issues arise.

  • Scalability: With IaC, scaling infrastructure is seamless. You can use scripts to define resources for multiple environments or scale your infrastructure up or down as needed without manual intervention, making it ideal for handling dynamic workloads in modern cloud environments.

  • Faster Recovery and Deployment: In the event of a failure, you can quickly recreate infrastructure using pre-existing configuration files, ensuring faster recovery from outages or failures. IaC also allows infrastructure to be tested just like application code. You can use tools to validate configurations before they are applied, reducing the likelihood of errors in production environments. This reduces downtime and accelerates the deployment of new features for testing or production.

  • Cost Efficiency: Automation reduces the need for manual labor, lowering operational costs. Additionally, efficient resource management helps optimize expenses, especially in cloud environments where you pay for what you use.

  • Flexibility: IaC is platform-agnostic and works across various cloud providers, such as AWS, Azure, or GCP, and on-premises systems. It gives you the flexibility to deploy infrastructure in diverse environments using the same tools and practices.

By leveraging these benefits, organizations can achieve more reliable, efficient, and scalable infrastructure management, aligning IT operations closely with business objectives.

There are generally two approaches to IaC: declarative (functional) and imperative (procedural). The difference between the declarative and imperative approaches is essentially ‘what’ versus ‘how’.

The declarative approach describes the desired end state of the infrastructure. You define what you want the infrastructure to look like, and the IaC tool determines how to make it happen. For example, if you declare that you need two virtual machines, the tool will create them if they don’t exist or adjust their number to meet the desired state.

Teams prefer the declarative approach because it’s simple and easy to use. Instead of focusing on the steps to get there, it focuses on the end result, making it easier to manage, even for complex setups. It also helps keep environments consistent since the tool handles the details automatically. However, the downside is that it can be harder to troubleshoot because you don’t see the exact steps the tool is taking.

The imperative approach defines the exact steps or commands to reach the desired state. Instead of stating, “I need two virtual machines”, you would write specific instructions to create them step by step. This approach is like writing a recipe, where each step must be followed in the exact order. While less common in modern IaC tools, it can still be helpful in specific scenarios, such as when a process requires precise control over the execution steps.

The imperative approach gives more control over how tasks are done, making it useful when order and precision are essential. It’s also easier to debug because the steps are clearly laid out. However, it can be more complicated and prone to mistakes. Writing and managing imperative code for large systems can take time and effort, especially when scaling or making changes.

Which approach to use depends on the situation. Declarative IaC works best for large, dynamic setups where automation and simplicity are priorities, while imperative IaC is better for smaller projects or tasks that need detailed control.

Infrastructure as Code (IaC) tools simplify managing and automating infrastructure by using code to define, provision, and configure resources. These tools help ensure consistency, scalability, and efficiency, making them essential for modern IT operations. Popular IaC tools include Meshery, OpenTofu, Terraform, Pulumi, Ansible, Chef, and more. Each tool has its strengths and is suited for different use cases. For example, OpenTofu provides the flexibility and transparency needed for organizations to customize and optimize their infrastructure processes without vendor lock-in; Ansible excels in configuration management and automation tasks, while Chef and SaltStack cater to specific needs such as server configuration and orchestration.