Feature Request: Support for Terragrunt Units & Stacks

[ddroessler-ext]

Overview

First of all thanks a lot for this awesome Action!
I am using Terraform Module Releaser in a larger mono-repo with custom Terraform Modules and Terragrunt Units+Stacks. It works like a charm for Terraform Modules. Unfortunately it does not natively support Terragrunt Units and Stacks.

Suggested Feature

Add support for Terragrunt Units & Stacks. Extend the current implementation to also generate tags & wiki entries for Terragrunt Units (found in files named terragrunt.hcl) and Terragrunt Stacks (found in files named terragrunt.stack.hcl). I managed to get the tag creation working by patching the file regex to include || file === 'terragrunt.hcl' || file === 'terragrunt.stack.hcl', but I do not know TypeScript well enough for anything more than that.

Benefits

Teams can maintain Terragrunt Units and Stacks side-by-side to Terraform Modules in a single mono-repo.

Implementation Ideas

• Update file regex in ‎src/utils/file.ts to include Terragrunt-specific file names terragrunt.hcl and terragrunt.stack.hcl
• Update wiki generation to differentiate between Terraform Modules, Terragrunt Units and Terragrunt Stacks, e.g., by file type/name (*.tf, or terragrunt.hcl or terragrunt.stack.hcl)
• Update individual wiki entry generation to produce a correct Usage entry for Terragrunt Units starting with unit "<unit_name>" { ... } instead of module
• Update individual wiki entry generation to produce a correct Usage entry for Terragrunt Stacks starting with stack"<stack_name>" { ... } instead of module
• Optional: Generate attributes (requirements, providers, modules, inputs, outputs) for Terragrunt Units based on the referenced Terraform Module
• Optional: Generate attributes (requirements, providers, modules, inputs, outputs) for Terragrunt Stacks based on the referenced Terragrunt Units

[virgofx]

Thanks for the detailed feature request! A few clarifying questions:

1. Mono-repo structure confirmation

Just to confirm — your use case is a single mono-repo containing all three side by side, something like:

modules/
  vpc/              # Terraform Module (*.tf files)
  s3-bucket/        # Terraform Module (*.tf files)
units/
  app-network/      # Terragrunt Unit (terragrunt.hcl)
  app-database/     # Terragrunt Unit (terragrunt.hcl)
stacks/
  full-env/         # Terragrunt Stack (terragrunt.stack.hcl)

Is that roughly representative of your layout, or do you nest them differently? Any details here would be helpful to plan this accordingly.

2. Wiki documentation for Terragrunt Units & Stacks

For Terraform modules, we generate wiki pages with Usage, Attributes (via terraform-docs), and Changelog sections. Since terraform-docs doesn't apply to Terragrunt files, the Attributes section (requirements, providers, inputs, outputs) wouldn't be generated for units/stacks.

• Do you have an example of what ideal wiki documentation for a Terragrunt Unit or Stack would look like? If there are any existing repos, blog posts, or screenshots showing Terragrunt-specific documentation, that would help us nail the format.

• For the Usage block, we're thinking something like:

  Terragrunt Unit:

  unit "app_network" {
    source = "git::https://github.com/owner/repo.git?ref=units/app-network/v1.0.0"
  }

  Terragrunt Stack:

  stack "full_env" {
    source = "git::https://github.com/owner/repo.git?ref=stacks/full-env/v1.0.0"
  }

  Does that match how you'd reference these in practice? Is unit {} / stack {} the correct HCL block syntax, or would it just be a source attribute in the terragrunt.hcl?

3. Opt-in behavior

Since many existing repos may have terragrunt.hcl files in deployment/live directories that are not intended to be versioned and released, we're planning to make this opt-in via an enable-terragrunt input (default: false). That way existing users aren't surprised by new module discovery. Does that sound reasonable for your workflow?

4. Anything beyond tagging + wiki?

You mentioned you got tagging working with a regex patch — great! Beyond tags, releases, and wiki pages, is there anything else specific to Terragrunt that you'd want the action to handle differently? For example:

• Should the PR release plan comment visually distinguish between Terraform modules, Terragrunt units, and Terragrunt stacks?
• Any difference in how changelogs should be generated?

[ddroessler-ext]

Thanks a lot for the extensive reply. I will try to answer as much as I can below

1. Mono-repo structure confirmation

Spot-on, this is exactly how I structured my repository

2. Wiki documentation for Terragrunt Units & Stacks

• I unfortunately do not have any example that I can share, but I think this would require something like terraform-docs to exist for terragrunt first to be able to use it here.
• The usage block examples are exactly how I am currently referencing my units and stacks, so this is perfect for me

3. Opt-in behavior

I fully agree, making this an opt-in feature that is disabled by default follows the principle of least surprise.

4. Anything beyond tagging + wiki?

• I did not think about this before, but now that you mentioned it I think it is probably a good idea. In my case the name of the module/unit/stack always starts with modules/ or units/ or stacks/ so it is clear from the naming alone, but others might use a different setup so I guess it makes sense to add some information about whether it is a module, unit or stack to the release plan table (e.g., extra column)
• Similar for the changelog probably, maybe adding the type in the sub-title of each entry?