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Terragrunt

The Infracost breakdown and diff commands automatically detect Terragrunt projects, though we generally recommend setting up a config file for Terragrunt repos.

infracost breakdown --path=path/to/terragrunt/repo

The --exclude-path flag can be used to exclude any directories/modules that should not be run, for example:

infracost breakdown --path=. --exclude-path=dev --exclude-path=test

Usage file​

If your Terragrunt project has multiple modules and you want to specify different usage files for each module, you will need to add each Terragrunt subdirectory and usage file to the Infracost config file, see an example here.

If you have any feedback about how we should support multiple usage files with Terragrunt in the future, please comment on or follow this issue.

Source map​

The INFRACOST_TERRAFORM_SOURCE_MAP environment variable is useful when you want to replace module URLs used by Infracost (e.g. replace private URLs with public ones). See this docs section for more details.

How the Terragrunt integration works​

With v0.10, when the CLI's --path flag points to a Terragrunt directory:

  1. Infracost detects a Terragrunt project by checking for a Terragrunt config file in the specified path, which will be terragrunt.hcl, terragrunt.hcl.json or the value of the TERRAGRUNT_CONFIG environment variable. If Infracost does not detect your project as a Terragrunt project, make sure this file exists in the specified path or in any of the subdirectories with a depth less than 5.

  2. If Terragrunt is detected, Infracost downloads any required source files to an .infracost cache, detects Terragrunt defined inputs, then parses HCL directly.

  3. Infracost outputs a diff or breakdown for each Terragrunt module.