IT teams use HashiCorp's Terraform to streamline deployments on premises and in the cloud, but there are many elements of this infrastructure-as-code tool to understand.
With Terraform, IT engineers configure the tool to fit their needs, such as support for multi-cloud environments; however, they must first grasp certain Terraform best practices -- including those related to functions, modules and variables. Get a glimpse of these components and see them applied in the tutorials below from TechTarget contributors Prateek Singh and Zachary Flower.
Become familiar with Terraform functions
Terraform functions are a built-in capability of the IaC tool that enables IT teams to manipulate values and strings within a configuration, perform computations and execute other tasks. These functions are categorized into nine general types, based on the specific operations they carry out.
Admins can use one type of function -- string functions -- to quickly enforce changes to a string, which is a type of value in Terraform. For instance, the lower() function converts all uppercase characters to lowercase, while the upper() function does the opposite. Another function type -- Date and Time -- captures the current date and time related to a Terraform configuration and converts existing timestamps into new formats.
While there are a range of built-in functions, admins are limited to what's available; Terraform does not allow custom function creation.
Create an Amazon VPC with Terraform
IT teams can use Terraform to apply IaC across multiple environments -- including cloud platforms like AWS. It's possible, for example, to use Terraform to configure and deploy an Amazon Virtual Private Cloud (VPC). To start, be sure to have an AWS account and Terraform installed.
A Terraform script defines the VPC deployment. First, create a folder in which to store all Terraform files with a .tf extension, and then build a variables.tf file that defines variables -- such as the access key, secret key and AWS region -- for the VPC configuration. These files, along with a few other required documents, shape the primary Terraform script for the Amazon VPC.
Follow the link above to walk through next steps on configuring and deploying a VPC, such as initializing and applying the Terraform configuration.
Support reusable code with Terraform modules
With Terraform modules, IT teams package code into reusable templates for repeated use in IaC deployments. A module consists of a set of configuration files contained within a folder.
To benefit from Terraform modules, get familiar with core concepts and components, including root modules -- which act as the top-level directory that contains the configuration files -- and input and output variables.
Learn best practices to build and use Terraform modules in this tutorial, which also features AWS infrastructure. In addition, prepare for the potential limitations of modules, including those related to security. For example, don't store passwords or other sensitive information in shareable configuration files.
Deploy IT resources with Terraform variables
With Terraform, IT engineers write infrastructure configurations as code to expedite IT resource deployments. Organizations that wish to promote IaC use across multiple application hosting choices can look to Terraform variables.
Variables are split into two groups -- input and output -- based on how a resource plan will use them. Terraform variables enable IT admins to define and save values in a centralized and flexible way. Variables can be used in any Terraform resource, and are independent of any specific Terraform execution plan.
In a Terraform module, variables create a template that admins can adjust based on the variables' assigned input.
Manage multi-cloud architectures with Terraform
With a multi-cloud strategy, enterprises must prepare to overcome complexities across cloud providers -- especially when they look to deploy services. When IT teams follow Terraform best practices, the IaC tool creates a single workflow that enables admins to make changes that are predictable and reproducible across cloud providers.
Terraform provisions application infrastructure with well-defined configuration files. For example, it can provision both an Amazon EC2 instance and a Google App Engine application. Due to Terraform's adaptability, admins can apply changes to the configuration file with minimal effort.
While the Terraform platform brings many benefits to an enterprise, there are still challenges to overcome with implementation, so users must be wary of how they use the tool.