infrastructure as code

A few years back, IT infrastructure means a big room occupied with several machines and wires and a dedicated team to manage those to provide server availability for business hours. But now the scenario has been changed, and thanks to DevOps and Cloud to make it possible. While cloud technology transformed the way the infrastructure is managed, DevOps changed the approach of development and deployment. DevOps has eliminated the need for full-time management of infrastructure or the need to configuring them for long hours. There comes the concept of Infrastructure as Code ( IAC) concept. 

Related post – DevOps and Cloud: A symbiotic relationship

What is Infrastructure as Code?

According to the definition by Microsoft, “Infrastructure as Code is the management of infrastructure (networks, virtual machines, load balancers, and connection topology) in a descriptive model, using the same versioning as the DevOps team uses for source code.”

In the concept of infrastructure as code, you can manage your operations environment in the same way you do applications or other code for general release. Here you don’t need to make any configuration change manually. Instead of using one-off scripts, you can make adjust operational infrastructure. Additionally, you can implement the same rules and strictures that govern code development—particularly when new server instances are spun up. Here, DevOps’ core best practices mean version control, continuous monitoring, and virtualized tests are applied to the underlying code. On the other hand, this code governs and manages your infrastructure. Hence, infrastructure and code are treated in the same way.

There is no need to log in to a new machine and configure them using documentation. Instead, code is used for this purpose.

The core benefit of IAC

  • The infrastructure as code helps to automate the process of setting up and configuring a machine using a code.
  • It offers a fast and repetitive process.
  • You can replicate the entire process through the script.
  • Though many times just compared with the scripts in IT automation, IAC is not merely a static script. Instead, it gives flexibility for complex actions.
  • IAC is beyond the static script. It applies DevOps practices to automation scripts for ensuring free of error, the capability to redeploy on multiple servers and roll back features in case of problems.
  • You manage infrastructure through source code, so it gives a detailed audit trail for any changes.
  • You can apply testing to infrastructure in all forms, i.e., unit testing, functional testing, and integration testing.
  • There is no need for written documentation since the code itself will document the state of the machine. 
  • It enables collaboration around infrastructure configuration and provisioning, most notably between dev and ops.
  • IAC automation shortens cycle time, making it easy to produce stable and tested platforms for hosting applications.
  • IAC makes the development environment transparent, which makes better version control.
  • It stores all build-up commands in a repository which makes redeployment or roll back faster.

How does IAC improve performance – a use case

Let say you want to migrate a back-end system from Amazon Web Services Elastic Load Balancing to NGINX. This is not necessarily a straightforward transition. There might be three or four different steps, dependencies between the steps, and an ordering of those steps, which results in a clean cutover. CM tools are not built to compute that ordering. In addition, CM tools don’t carry a model of the current state of your deployment, meaning that they must query all conditions multiple times per run. The obvious result is a performance hit.

In contrast, IaC tools model the state of the infrastructure internally and typically only need to touch things that change.

Best practices for Infrastructure as code

As we have discussed fundamentals of Infrastructure as code, let’s discuss some of the best practices – 

IAC tools must be applied with caution

With IAC, you can deploy and reconfigure server environments effortlessly, but that acts as a double sword. As the developers get access to change maximum server instances in one shot, they are vulnerable to create maximum damage within a short time. Hence, go slow when rolling out IAC to the DevOps rank and file, and ensure that users have supervision and guidance, particularly when trying something new.

Make stricter guidelines

The more strictly you define everything in your environment, there is a fewer chance of encountering problems. Be as specific as possible about the infrastructure requirements, including network bandwidth and storage I/O operations per second, if possible. The application developer knows the factors that affect application behavior and performance the best. So, involve the developers in writing the IAC specifications for the infrastructure elements and runtime environments. Use monitoring and feedback information to tweak your configuration management scripts for continuous improvement.

Look for the evolving rate of IAC tools

Platforms like AWS and Windows Azure are evolving very quickly with new features and services. Third parties very scarcely keep up with the velocity of changes. So, it is not unnatural that a third-party tool may often find itself incompatible or behind the times when popular IAC platforms are updated. So, it is always better to accept vendor lock-in or use open-source libraries and contribute your support for new features back to the community.

Azure Resource Manager (ARM)

This tool helps users to provision infrastructure and manage dependencies in one cycle through ARM templates. The resources the template comprehend are described declaratively within JSON. You can declare several Azure resources in a single ARM template to set up the entire project environment. The fact that ARM templates are idempotent, the same template can be reused for an infinite number of times producing the same result every time. Moreover, all the builds of your template can be monitored visually using a VSTS dashboard.

AWS Cloudformation

The tool enables users to define templates that represent software stacks and deploy them automatically to cloud environments. For this, the templates use a human-readable format, which is easy to understand and can be used to check into version control. With this tool, users can spin up automatically anything from one EC2 machine to a complex application using several AWS services.

Puppet

This tool allows users to deploy huge cloud workloads that might contain over 20,000 Puppet nodes. The tool is ideal for multiple public clouds, private cloud systems, and hybrid cloud environments. It enables infrastructure automation with the use of a GUI and Domain Specific Language (DSL)

Terraform

This tool can be used in combination with other tools like Chef or Puppet. Terraform takes its configuration files to create a deployment plan, explaining how to adapt the current infrastructure to reach the desired state. This tool’s prime responsibility is to manage the entire environment, including storage, machines, and networking, DNS configurations, and fine-grained application features.

Final verdict

IAC is a framework that implements proven coding techniques and extends them to an infrastructure directly. This effectively blurs the line between what is an application and what is the environment. In other words, this is the same thing DevOps is doing by melding developers and operations staff into a single entity.

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