Use Cases

HashiCorp Terraform is an infrastructure as code (IaC) tool that lets you define infrastructure resources in human-readable configuration files that you can version, reuse, and share. You can then use a consistent workflow to safely and efficiently provision and manage your infrastructure throughout its lifecycle.

This page describes popular Terraform use cases and provides related resources that you can use to create Terraform configurations and workflows.

Codify your infrastructure

By capturing and building your infrastructure as code, you make your deployments faster, repeatable, and easier to collaborate on. Terraform codifies cloud APIs into declarative configuration files using HashiCorp Configuration Language (HCL). You define the desired state of your infrastructure in HCL, and Terraform deploys and configures resources to match your configuration.

In addition to configuring your networks, servers, and databases, you can also use Terraform to manage other resources like containers, machine images, web services, and observability services.

Resources

• Get started with Terraform on AWS, Azure, Google Cloud, or Docker.
• Read HashiCorp's Well-Architected Framework to learn how to codify your infrastructure with Terraform.

Multi-cloud deployment

Provisioning infrastructure across multiple clouds increases fault-tolerance, allowing for more graceful recovery from cloud provider outages. However, multi-cloud deployments add complexity because each provider has its own interfaces, tools, and workflows. Terraform lets you use the same workflow to manage multiple providers and handle cross-cloud dependencies. This simplifies management and orchestration for large-scale, multi-cloud infrastructures.

Resources

• Learn how to [standardize artifacts across multiple cloud providers] with Terraform and Packer.
• Try our Deploy Federated Multi-Cloud Kubernetes Clusters tutorial to provision Kubernetes clusters in both Azure and AWS environments, configure Consul federation with mesh gateways across the two clusters, and deploy microservices across the two clusters to verify federation.
• Browse the Terraform Registry to find thousands of publicly available providers.

Multi-environment deployments

Application development workflows can depend on multiple environments to test features, such as QA and staging, before releasing them to production. As production grows more complex, it becomes increasingly difficult to synchronize deployments and keep them up-to-date for each stage of the development process.

Terraform Stacks let you split your Terraform configuration into components and then deploy and manage those components across multiple environments. You can manage the lifecycle of each deployment separately, making it easy to validate changes throughout your deployments.

Resources

• Read the Deploy a Stack with HCP Terraform tutorial to get hands-on experience. You will create a Terraform Stack that deploys an AWS Lambda function across a development, test, and production environment.

Application infrastructure deployment, scaling, and monitoring tools

You can use Terraform to efficiently deploy, release, scale, and monitor infrastructure for multi-tier applications. N-tier application architecture lets you scale application components independently and provides a separation of concerns. An application could consist of a pool of web servers that use a database tier, with additional tiers for API servers, caching servers, and routing meshes. Terraform allows you to manage the resources in each tier together, and automatically handles dependencies between tiers. For example, Terraform will deploy a database tier before provisioning the web servers that depend on it.

Resources

• Try our Automate Monitoring with the Terraform Datadog Provider tutorial to deploy a demo Nginx application to a Kubernetes cluster with Helm and install the Datadog agent across the cluster. The Datadog agent reports the cluster health back to your Datadog dashboard.
• Try our Use Application Load Balancers for Blue-Green and Canary Deployments tutorial. You will provision the blue and green environments, add feature toggles to your Terraform configuration to define a list of potential deployment strategies, conduct a canary test, and incrementally promote your green environment.
• Read the HashiCorp Well-Architected Framework recommendations for managing infrastructure and service monitoring

Self-service infrastructure

At a large organization, your centralized operations team may get many repetitive infrastructure requests. You can use Terraform to build a "self-serve" infrastructure model that lets product teams manage their own infrastructure independently. You can create and use Terraform modules that codify the standards for deploying and managing services in your organization, allowing teams to efficiently deploy services in compliance with your organization's practices. HCP Terraform can also integrate with ticketing systems like ServiceNow to automatically generate new infrastructure requests.

Resources

• Try the Use Modules from the Registry tutorial to get started using public modules in your Terraform configuration. Try the Build and Use a Local Module tutorial to create a module to manage AWS S3 buckets.
• Follow these ServiceNow Service Catalog Integration Setup Instructions to connect ServiceNow to HCP Terraform.

Policy compliance and management

Terraform can help you enforce policies on the types of resources teams can provision and use. Ticket-based review processes are a bottleneck that can slow down development. Instead, you can use Sentinel, a policy-as-code framework, to automatically enforce compliance and governance policies before Terraform makes infrastructure changes. Sentinel policies are available in Terraform Enterprise and HCP Terraform.

Resources

• Try the Control Costs with Policies tutorial to estimate the cost of infrastructure changes and define policy to limit it.
• The Sentinel documentation provides more in-depth information and a list of example policies that you can adapt for your use cases.

Software defined networking

Terraform can interact with Software Defined Networks (SDNs) to automatically configure the network according to the needs of the applications running in it. This lets you move from a ticket-based workflow to an automated one, reducing deployment times.

For example, when a service registers with HashiCorp Consul, Consul-Terraform-Sync can automatically generate Terraform configuration to expose appropriate ports and adjust network settings for any SDN that has an associated Terraform provider. Network Infrastructure Automation (NIA) allows you to safely approve the changes that your applications require without having to manually translate tickets from developers into the changes you think their applications need.

Resources

• Try the Network Infrastructure Automation with Consul-Terraform-Sync Intro tutorial to install Consul-Terraform-Sync on a node. You will then configure it to communicate with a Consul datacenter, react to service changes, and execute an example task.
• Try the Consul-Terraform-Sync and Terraform Enterprise/Cloud Integration tutorial to configure Consul-Terraform-Sync to interact with Terraform Enterprise and HCP Terraform.

Kubernetes

Kubernetes is an open-source workload scheduler for containerized applications. Terraform lets you both deploy a Kubernetes cluster and manage its resources (e.g., pods, deployments, services, etc.). You can also use the Kubernetes Operator for Terraform to manage cloud and on-prem infrastructure through a Kubernetes Custom Resource Definition (CRD) and HCP Terraform.

Resources

• Learn how to provision a Kubernetes cluster in AWS, Google Cloud Platform, and Azure.
• Try the Manage Kubernetes Resources via Terraform tutorial. You will use Terraform to schedule and expose a NGINX deployment on a Kubernetes cluster.
• Learn how to deploy applications with the Helm provider.
• Try the Deploy Infrastructure with the HCP Terraform Operator for Kubernetes tutorial. You will configure and deploy the Operator to a Kubernetes cluster and use it to create an HCP Terraform workspace and provision a message queue for an example application.