Introduction to Infrastructure as Code
Traditional IT infrastructure management was majorly a manual process that was tedious, expensive with little or no scope for scalability, availability and performance visibility. With cloud computing facilitating swift infra set up, automatic provisioning, management and monitoring of resources through Infrastructure as code (IaC) came into being.
IaC is the process of managing and codifying IT infrastructure using configuration files. It is the means for DevOps teams to develop scripts that can automate IT processes, by using a descriptive language to explain what needs to be deployed while the IaC platform answers the “how to deploy automatically”. It eliminates the need for manual configuration and installations.
Code-based infrastructure deployment is same as deploying software on production. In both cases, templates can be built to conduct multiple rounds of testing, manage code changes using version control and deploy only when the software is ready. IaC can also be leveraged to automate security processes and integrate them with DevOps for better operational efficiencies. For example, IaC tool can read a text file and execute actions like installing and running a database server or creating new accounts and database connections, etc.
How IaC works?
There are two approaches to IaC, imperative and declarative. Imperative or procedural approach involves defining a series of commands to build infrastructure as desired whereas a declarative or functional approach that shows what the final result looks like without outlining the execution steps needed to set up any infrastructure.
Imperative emphasizes on how the infrastructure can be modified to match the desired outcome. Declarative answers questions like “What should be the actual configuration?” or “what is the list of requirements or third-party software needed to set up the infrastructure?”
Top five Infrastructure as Code tools
- Ansible: Red Hat’s Ansible modernizes IT by helping DevOps with faster and reliable deployments. It automates provisioning, configuration and management of application and infrastructure by setting up multiple identical environments with security baselines without the need to fulfil compliance requirements. Ansible brings in innovation while enabling alignment of IT with business needs.
- Terraform: HashiCorp Terraform is an open-source tool for Infrastructure automation that helps configure, provision and manage IaC. Using the declarative approach, Terraform facilitates defining and creation of IaC across numerous infra providers with the same workflow as well as allows conducting pre-execution checks to ensure all configurations meet expectations before actually provisioning the infrastructure.
- AWS CloudFormation: AWS CloudFormation is an in-built IaC tool that enables best practices implementation of DevOps and GitOps. Resources can be automated and scaled by integrating CloudFormation with other AWS resources as well as provisioning of 3rd party application resources along with native AWS resources.
- Azure Resource Manager: Azure Resource Manager (ARM) is an ideal service with an Azure specific IaC tool for deploying, managing and monitoring Azure resources at one go. It provides Role-Based Access Control (RBAC), allowing users to apply specific access controls to all resources being managed within one resource category using declarative templates. The infrastructure deployment solutions can be used multiple times across the application development lifecycle.
- Google Cloud Deployment Manager: Google Cloud Deployment Manager is GCP’s infrastructure deployment service that enables automation of creating, configuring, provisioning and managing GCP resources. With the deployment manager, user can build models, preview changes before deployment and view actual deployments in a console user interface. Its IaC tool uses declarative language to state the desired configuration. Google Cloud Deployment Manager provides back-to-back deployments of multiple resources, helps create and control resources and resource definition dependencies as well.
Infrastructure as Code benefits
- Accelerated development lifecycle: IaC enables faster infra deployments on all environments like development, QA and production environments through running scripts. IaC helps streamline the entire software development lifecycle.
- Improved accuracy and consistency: Manual efforts are often prone to errors leading to large discrepancies. IaC helps rectify and manage such flaws by ensuring the configuration files remain the same through all deployments to maintain consistency.
- Better visibility and accountability: IaC config files can be version controlled just like source code for complete visibility on all changes a configuration has gone through.
- Version control: As infrastructure is treated as code, it is possible to be checked in, reviewed and version controlled using software engineering operations. Infrastructure can be modified with the help of available CI/CD tools.
- Support for DevOps: With IaC adopting the same approach as application code deployment via CI/CD pipelines, Infrastructure can be set up similarly along with version control and automated testing to create trackable and auditable infra. IaC can be used alongside containers to customize, remove or automate applications with software instead of hardware. As the hardware and OS infra are provisioned automatically where applications are enclosed on top of it, they can be deployed across staging, testing and production environments.
IaC best practices
To make the most of IaC strategies, following best practices must be implemented.
- Ensure coding all infra specifications in config files that answers all infrastructure management concerns.
- Version control all configuration files.
- As config files are from a single source point, documenting infra specifications can be kept to a minimum.
- Test and monitor IaC to check for errors and inconsistencies before deployment to production.