What it does
Terragrunt is an open-source command-line orchestrator for Terraform and OpenTofu. It adds a terragrunt.hcl layer for shared configuration, automatic initialization, and multi-unit workflows, helping teams manage repeated infrastructure patterns and deploy related units in a controlled order. The quick start integrates it into an existing project with a small configuration file; users still install one of the underlying infrastructure-as-code engines.
The official quick-start tutorial's smallest adoption step is to add a terragrunt.hcl file beside an existing Terraform or OpenTofu configuration. Once Terragrunt and the underlying engine are installed, users can issue Terragrunt commands in place of the engine's commands; auto-init handles initialization when needed. The tutorial uses a local-file resource so a first example does not need a cloud subscription. Its terragrunt apply -auto-approve command is illustrative here. For larger projects, the site describes dividing infrastructure into units, reusing common provider and backend configuration, and ordering updates with a run queue or stacks. This is useful when separate environments or components have begun to drift, but Terragrunt remains an orchestration layer: the project still needs Terraform or OpenTofu and their provider configuration. The starter guide expects a Unix-like operating system and basic familiarity with one of those engines. It also documents how Terragrunt selects a binary when both are installed. The open-source CLI is MIT licensed; Terragrunt Scale and enterprise support are separate offerings and are not covered by this record.
Strengths
- An empty terragrunt.hcl can enable automatic initialization for an existing Terraform or OpenTofu project.
- The product documentation describes shared configuration, infrastructure units, run ordering, and stack operations for larger IaC layouts.
- The open-source CLI is published under the MIT License.
Watch out for
- Terragrunt requires Terraform or OpenTofu to be installed; it orchestrates those engines rather than replacing them.
- The documented starter tutorial assumes a Unix-like operating system and basic familiarity with Terraform or OpenTofu.
Best for
- Teams maintaining multiple Terraform or OpenTofu environments with repeated backend, provider, or input configuration.
- Platform engineers who need to break infrastructure into smaller units and coordinate their operations.
Sources
- Terragrunt | Orchestrate Terraform & OpenTofu at Scale (Oct 25, 2026)
- Quick Start | Terragrunt (Oct 25, 2026)
- MIT License (Oct 25, 2026)