Infrastructure as Code: What and Why?



Infrastructure as Code (IaC) grew as a response to the difficulty posed by utility computing and second-generation web frameworks. When you use a high-level descriptive coding language to automate the IT infrastructure, it eliminates the need for engineers to manually provision and manage servers, operating systems, database connections, storage, and other infrastructure elements when they want to develop, test, or deploy a software application.

For decades, managing the server infrastructure was a full-time job where system administrators carefully curated their critical systems to ensure the business ran smoothly. Now, however, these datacenters have been moved from being managed or co-located to the cloud, often operated by cloud providers like Google or Amazon, who manage critical business infrastructure for thousands of customers in massive data warehouses. This benefits the software developers and the IT infrastructure administrators as the ability to treat infrastructure as code and utilize the same tools as any other software project would allow them to deploy applications rapidly.

Enterprises these days deploy hundreds of applications into development, UAT, and production every day, which is subject to being modified, enhanced, and scaled up and down in response to the developer and user demands. Therefore, an organization needs to automate infrastructure to control costs, reduce risks, and respond with speed to new business opportunities and competitive threats. IaC makes this is possible.

Apart from the added value and advantages of cost reduction, faster execution, and risk reduction, IaC is also an essential DevOps practice, indispensable to a competitively paced software delivery lifecycle. It enables DevOps teams to rapidly create and change infrastructure in the same way they edit source code and track these version changes to avoid inconsistency among IT environments leading to serious concerns during deployment.

What Is Infrastructure as Code?

Infrastructure as code is a means by which engineers define the computer systems and managing the operations environment in the same way one does applications or other code for general release.

With IaC, the operations infrastructure is managed by applying the same rules and strictures that govern code development instead of making manual configuration changes or using one-off scripts to make adjustments in the infrastructure. Most commonly, the engineers utilize a framework like Chef or Ansible, or Puppet to define their infrastructure. The type of tool is not important in this case as they all have similar facets, each allowing the engineer to define a computer system or network of computer systems necessary to run and support their code. Below is an illustration to depict IaC in action:

Most often, IaC libraries are used in managing web applications, but the potential uses of IaC are endless. Modern applications are complicated and require web servers, load balancers, database servers, and queue processing systems, necessitating hours in provisioning, and managing these interlocking systems. This is a problem that IaC is designed to solve by enabling developers or administrators to create new environments to test code in minutes.

This means improved and more frequent testing, and with frequent testing, the advantage is that the tiny tweaks that would emerge at a later stage are now identified. System administrators can document these tweaks and check them into source code. In the same way, configuration issues are easily identified when administrators need to change systems manually.

The right approach

There are two major approaches to IaC as far as the specifics of how they work, but we can generally divide them into two main types: the imperative approach and the declarative approach based on programming language paradigms.
The imperative approach, or procedural approach, defines a sequence of commands or instructions so the infrastructure can reach the final result. The administrator can write a script to install some bit of software on a server instead of logging in and doing it themselves. Over time, engineers combine these scripts to create a full system configuration script. The main advantage of going with the imperative approach to IaC is that it is very simple to set up and easier for management to understand. However, it often requires more manual work from your administrators to keep those scripts up to date and can be more prone to unexpected breakage.

Whereas, with the declarative approach or functional approach, rather than explicitly outlining the sequence of steps the infrastructure needs to reach the final result like the imperative approach, the declarative approach shows what the final result looks like. When choosing a declarative option, administrators do not delineate the steps to set up a server. Instead, a list of requirements is provided, and third-party software does the work of installing the necessary software. This approach to IaC tends to be more robust than imperative IaC as it requires less manual modification of scripts because external software manages the installation process. Automated programs like Chef or Puppet manage the process of resolving system dependencies.

Best practices to follow

  • Manage infrastructure via source control by providing a detailed audit trail for changes. Your configuration files should be the single source for all your infrastructure management concerns.
  • Written documentation since the code itself will document the state of the machine. This is particularly powerful because it means that infrastructure documentation is always up to date.
  • Make sure that your Dev and Ops teams are involved in infrastructure configuration and provisioning.
  • And finally, test and monitor your configurations to check for errors and inconsistencies in your servers before you deploy them to production. This could be in the form of unit testing, functional testing, and integration testing.

IaC is in some ways still an emerging and evolving concept, and many organizations are still figuring out how best to implement the practices listed above in their existing DevOps framework. Get in touch with us to learn how we can help you enhance your existing IT infrastructure. We also encourage you to check out our DevOps and ITOps services to get a glimpse of how we accelerate business transformation and streamline processes by the seamless integration of development, IT and operations.

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