Depuis Terragrunt v0.10.0, la configuration S3 et DynamoDB permettant de gérer les states et lock Terraform se trouve dans terraform.tfvarsau lieu de .terragrunt.

Exemple de configuration avec un repo de configuration et un repos module:

• arborescence:

* terraform-configuration-repo
    |- dev
    |- test
    |- prod
         |- application
         |    |- terraform.tfvars
         |    |- main.tfvars (symlink -> ../main.tfvars)
         |- terraform.tfvars
         |- main.tfvars

* terraform-module-application-repo
    |- main.tf
    |- vars.tf
    |- ...

• terragrunt configuration spécifique to application:

# terraform-configuration/prod/application/terraform.tfvars
terragrunt = {
  terraform {
    source = "git@github.com:myuser/tf-modules-application-repo.git///ref=1.0.0"
    extra_arguments "main" {
      arguments = [
        "-var-file=main.tfvars",
        "-var-file=terraform.tfvars"
      ]
      commands = [
        "plan",
        "apply"
      ]
    }
  }

  include {
    path = "${find_in_parent_folders()}"
  }
}

# variables specifics to application module
var1 = "XXX"
var2 = "YYY"
# var3 can override var3 from main.tfvars environment variables
var3 = "BBB"
...

• terragrunt configuration spécifique to prod environnement:

# terraform-configuration/prod/terraform.tfvars
terragrunt = {
  # Configure Terragrunt to use DynamoDB for locking
  lock = {
    backend = "dynamodb"
    config {
      state_file_id = "prod"
    }
  }

  # Configure Terragrunt to automatically store tfstate files in an S3 bucket
  remote_state = {
    backend = "s3"
    config {
      encrypt = "true"
      bucket = "s3-terraform-states"
      key = "prod/${path_relative_to_include()}/terraform.tfstate"
    }
  }
}

• global variables for prod environment:

# terraform-configuration/prod/main.tfvars
# variables specifics to prod environment

var3 = "ZZZ"
var4 = "AAA"