Reusing locals in the tree

[pritho]

Describe the solution you'd like
Having a older structure like this:

├── dev
│   ├── stage.hcl
│   └── app1
│       └── bucket
│           └── terragrunt.hcl
├── qual
│   ├── stage.hcl
│   └── app1
│       └── bucket
│           └── terragrunt.hcl
├── global.hcl
└── terragrunt.hcl

I end up having this redundant code in every single terragrunt.hcl file:

locals {
  stage_vars          = read_terragrunt_config(find_in_parent_folders("stage.hcl"))
  resource_group_name = local.stage_vars.locals.resource_group_name
  stage_name = local.stage_vars.locals.stage_name
}

I would like to define said code once in the root terragrunt.hcl file

Describe alternatives you've considered
The docs regarding globally-defined-locals also is more or less the same and doesn't help.

Additional context
Is there already WIP where I could maybe participate?
Or did I miss a specific feature solving my use-case?

[denis256]

Hi,
can be used include with merge_strategy = "deep"

# dev/app1/terragrunt.hcl
include "root" {
  path = find_in_parent_folders()
  merge_strategy = "deep"
}

# parent terragrunt.hcl

locals {
  stage_vars          = read_terragrunt_config(find_in_parent_folders("stage.hcl"))
  resource_group_name = local.stage_vars.locals.resource_group_name
  stage_name = local.stage_vars.locals.stage_name
}

Simplified example in: https://github.com/denis256/terragrunt-tests/tree/master/reuse-locals

[pritho]

perfect, thanks so much.
I created a documentation PR for this: #3070