Terragrunt

Orchestration tool for Infrastructure as Code written in Terraform or OpenTofu. Lets you keep Terraform configurations DRY, manage remote state across many modules, enforce dependency order, and run hooks before or after apply. Wraps Terraform and OpenTofu without replacing them.

Developed by Gruntwork and widely adopted for multi-environment and multi-account setups. Terragrunt reduces duplication of provider configs, backends, and module inputs by centralizing shared settings and referencing them from each environment. Unlike plain Terraform, it generates backend blocks dynamically and supports cross-module dependencies so you can deploy in the right order.

Key capabilities:

• DRY configuration with includes: reuse backend, provider, and input definitions across modules
• Remote state generation and locking without boilerplate per environment
• Dependency graph and run queue for controlled, ordered updates
• Before and after hooks for logging, validation, or policy enforcement
• Units and stacks to segment infrastructure into independently updatable pieces

Teams use Terragrunt to manage dev, staging, and production with minimal duplicated code, deploy the same infrastructure across multiple cloud accounts, and scale from a handful of modules to hundreds. Hooks codify steps like running security scans before apply or triggering post-deploy notifications. The run queue avoids all-or-nothing updates by controlling exactly what runs and in what order.