RFC for passing variables to dependencies

[juljaeg]

Description

In relation to #2674.

TODOs

Read the Gruntwork contribution guidelines.

• Update the docs.
• Run the relevant tests successfully, including pre-commit checks.
• Ensure any 3rd party code adheres with our license policy or delete this line if its not applicable.
• Include release notes. If this PR is backward incompatible, include a migration guide.

Release Notes (draft)

Added RFC for support for passing variables to terragrunt modules being included as dependencies.

Migration Guide

No migration needed.

[yhakbar]

Hey @juljaeg

I'm sorry we let this RFC go stale.

We have switched to a new process for RFCs which uses GitHub issues since you created this PR. You can start one by clicking this.

Some initial feedback I have for this PR is that I'm not sure why it's useful to segment state using environment variables with Terragrunt. Most users leverage separate terragrunt.hcl files in order to achieve this segmentation, so I'd like to better understand the value add here.

I'm going to close this PR, but please feel free to create an RFC issue if this is still something that's important to you. We can work to better understand why this is valuable, and not convenient/possible in modern Terragrunt.