Infrastructure as code (IaC) is an approach to managing infrastructure from virtual machines to storage to networks through code. With IaC, resources are defined and managed using configuration files written in high-level languages, such as YAML, JSON, or HCL.
IaC is a response to the challenges associated with traditional infrastructure management methods that are difficult to manage at scale. Where once changes to infrastructure were difficult to track and troubleshoot, IaC provides a consistent, version-controlled, and automated way to manage infrastructure. IaC is becoming the standard as DevOps continues to dominate software development, delivery, and management. Why?
In short, IaC provides:
- Consistency: Infrastructure resources are defined and managed in a consistent and repeatable manner, reducing configuration drift and other issues.
- Version control: Infrastructure configurations can be version-controlled with tools like Git, making it easier to keep track of changes.
- Automation: IaC enables automation of infrastructure provisioning, configuration, and management, allowing teams to deploy changes quickly and reliably.
- Scalability: IaC can manage infrastructure resources across environments and cloud providers, enabling teams to scale their infrastructure as needed.
Among the infrastructure as code options Terraform has quickly become one of the top solutions offering a wide range of benefits including multicloud support, modularity, a strong community, and continuous improvement.
What is Terraform?
Terraform is an open source infrastructure as code tool developed by HashiCorp. It allows developers and operations teams to define and manage infrastructure resources in a declarative language called HCL or HashiCorp Configuration Language. It makes it easy for DevOps teams to programmatically provision infrastructure resources by describing the desired end state infrastructure for running a given application — ultimately generating and executing the plan.
Additionally, Terraform works across cloud providers, including Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), and on-premises data centers making it a versatile option.
There are two key aspects to Tarraform, Terraform Core and Terraform Plugins. Core takes care of reading and parsing of resource plan executions, graphs, state features, and configuration files. Compiled binaries written in Go comprise it. Plugins define resources for specific services, including authentication of infrastructure providers and running libraries used to make API calls. Terraform Plugins are also written in Go as executable binaries that can be used for specific resources or as a provisioner.
How does Terraform work?
Terraform uses a declarative configuration language known as HCL, or (optionally) JSON, to define the desired state of the infrastructure making it easier to to keep resource management consistent — from how it’s defined to how it’s provisioned. With code at its root, it’s also easier to keep to infrastructure configurations version controlled, shared, and collaborated on using management tools like Git. Terraform also provides the ability to create, update, and destroy resources in a safe and predictable manner, making it suitable for production environments. In practice, when a command is given to deploy and run a server, database, or other infrastructure resource, Terraform goes through code and translates it into an API call to the resource provider.
What are Terraform modules?
Terraform modules are infrastructure resources that can be reused across different environments and use cases. They make it easy to abstract away complex infrastructure configurations into reusable components in order to better manage and maintain infrastructure as code. A module is composed of one or more Terraform configuration files that define the resources that make up the module. These configuration files can include variables that allow for customization depending on the environment or use case. Terraform modules can be shared and reused by others in the Terraform community and can be publicly available to get started with a project quickly.
Terraform vs. Kubernetes
Sometimes folks may conflate what both platforms can do, thinking they are competitive when they are not. In fact, they are quite complementary. Kubernetes is an open source container orchestration system for scheduling deployments and managing containerized workloads. Terraform is an IaC that works more broadly, enabling developers to automate their environments across public and private clouds. In essence, you can use Terraform to automate Kubernetes provisioning while automating the deployment of applications in a cluster.
What is Terraform used for?
Terraform can be used for a wide range of infrastructure management tasks including:
- Resource management: Terraform supports public and private cloud infrastructure and works with network appliances and SaaS deployments.
- Automating infrastructure management: Terraform provides a powerful automation engine that enables teams to automate the provisioning and management infrastructure resources for faster and more reliable changes.
- Self-service clusters: Public registries provide prepacked configurations that can be used as or is or change to meet particular needs.
- Scheduling: Terraform modules make it possible to to stop and start resources from cloud providers and can help Kubernetes schedule containers.
- Expendable environments: Modules make it possible to create ad hoc test environments for code before it has to go into production.
What are the challenges of using Terraform?
Terraform is a powerful tool but it doesn’t come without challenges. Consider that IaC is not something that everyone has experience with, which means a steep learning curve. Users need to learn Terraform syntax, understand the different resource types, and become familiar with various cloud APIs. It can also be very complex. Users need to be able to understand and manage relationships between different resources and ensure configurations are both correct and complete. This also requires an understanding of resource dependencies. Cloud providers can change their APIs frequently, causing compatibility issues if Terraform configurations are not kept up to date. Then there are third-party module dependencies that often introduce even more complexity. And we can’t forget about state management, which can get increasingly hard to manage as the number of resources and environments increase.
What is the future of Terraform and DevOps?
The future of Terraform and DevOps is promising, as both are poised to be integral in the future of software development and operations. Here are few things we may look forward to:
- Greater focus on automation: As DevOps practices continue to permeate across teams and organizations, the focus on automation will likely increase. Automation reduces the risk of errors and inconsistencies, and allows teams to focus on strategic work.
- More multicloud environments: We’ve gone from dabbling to cloud to employing several depending on use case. Terraform will continue to be popular for companies leveraging several varied cloud infrastructure and services.
- Edge computing: More and more, organizations are processing information closer to the source instead of sending it all back to their data centers. Terraform will be key in managing resources in edge environments.
- More security: Terraform is compliant and secure, making it a great tool for organizations that have to prioritize security.