terragrunt

Terraform wrapper for DRY configurations

TLDR

Initialize modules

$ terragrunt init

Plan changes

$ terragrunt plan

Apply changes

$ terragrunt apply

Destroy infrastructure

$ terragrunt destroy

Run on all modules

$ terragrunt run-all apply

Plan all modules

$ terragrunt run-all plan

Show outputs

$ terragrunt output

Graph dependencies

$ terragrunt graph-dependencies

SYNOPSIS

terragrunt [init] [plan] [apply] [destroy] [run-all] [options]

terragrunt is a thin wrapper for Terraform that provides extra tools for keeping configurations DRY and managing multiple modules.DRY configuration avoids repetition across environments. Common settings are defined once and inherited by modules.Remote state configuration is centralized. Backend settings don't need repetition in every module.Dependencies between modules are managed automatically. run-all executes commands across multiple modules in dependency order.Before and after hooks run custom commands around Terraform operations. This enables validation, notifications, and cleanup.Lock file management handles concurrent access. Multiple team members can work safely on shared infrastructure.

PARAMETERS

init

Initialize Terraform.

plan

Show execution plan.

apply

Apply changes.

destroy

Destroy infrastructure.

output

Show outputs.

run-all CMD

Run command on all modules.

graph-dependencies

Show dependency graph.

--terragrunt-config FILE

Config file.

--terragrunt-working-dir DIR

Working directory.

--terragrunt-source SOURCE

Module source override.

--terragrunt-non-interactive

Non-interactive mode.

--terragrunt-parallelism N

Parallel operations.

CONFIGURATION

terragrunt.hcl

Module-level configuration file defining Terraform source, inputs, dependencies, and backend settings

TERRAGRUNT_CONFIG

Environment variable to override the default configuration file path

TERRAGRUNT_DOWNLOAD

Environment variable to set the directory where Terragrunt downloads Terraform source code

INSTALL

sudo pacman -S terragrunt

sudo zypper install terragrunt

brew install terragrunt

nix profile install nixpkgs#terragrunt

CAVEATS

Adds complexity over plain Terraform. Learning curve for configuration syntax. Some Terraform features need workarounds.

HISTORY

Terragrunt was created by Gruntwork around 2016 to address pain points in managing Terraform at scale. It's widely used for multi-environment, multi-account infrastructure management.