Gruntwork Patcher now natively supports Terragrunt Stacks. Stacks help you manage infrastructure at scale by logically grouping OpenTofu/Terraform units into versioned entities, keeping your IaC DRY and your blast radius small. For a detailed overview, see our announcement blog post.

Now, when you release new versions of your unit and stack definitions, Patcher automatically detects these changes and ensures all stacks referencing previous versions receive the corresponding updates. Specifically, Patcher will:

1. Update the version of a unit definition specified as a source in a terragrunt.stack.hcl file in your catalog repo when a new unit version is released
2. Update the version of a stack definition specified as a source in a terragrunt.stack.hcl file in your catalog repo when a new stack version is released
3. Update the version of a unit specified as a source in a terragrunt.stack.hcl file in your live infrastructure repo when a new unit version is released
4. Update the version of a stack specified as a source in a terragrunt.stack.hcl file in your live infrastructure repo when a new stack version is released

This functionality is available now. Using Patcher with Terragrunt Stacks lets you maintain DRY code while preserving flexibility in which versions deploy to each environment, and we now recommend versioned stacks over the _envcommon pattern. Refer to the migration guide for more information on using versioned stacks.