Terraform Advanced — Terragrunt Remote State Config

Terragrunt auto-generates backend configuration per directory — no more copy-pasting S3 keys.

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The Magic: path_relative_to_include()

# Root terragrunt.hcl
remote_state {
  backend = "s3"
  config = {
    bucket = "mycompany-terraform-state"
    key    = "${path_relative_to_include()}/terraform.tfstate"
    region = "us-east-1"
  }
}

This single line generates unique keys for every stack:

environments/dev/vpc/       → dev/vpc/terraform.tfstate
environments/dev/eks/       → dev/eks/terraform.tfstate
environments/prod/vpc/      → prod/vpc/terraform.tfstate
environments/prod/rds/      → prod/rds/terraform.tfstate

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Auto-Create Bucket and Table

remote_state {
  backend = "s3"
  generate = {
    path      = "backend.tf"
    if_exists = "overwrite_terragrunt"
  }
  config = {
    bucket         = "mycompany-terraform-state"
    key            = "${path_relative_to_include()}/terraform.tfstate"
    region         = "us-east-1"
    dynamodb_table = "terraform-locks"
    encrypt        = true

    # Terragrunt will create the bucket and table if they don't exist
    s3_bucket_tags = {
      ManagedBy = "terragrunt"
    }
    dynamodb_table_tags = {
      ManagedBy = "terragrunt"
    }
  }
}

💡 Production Tip: Terragrunt creates the S3 bucket and DynamoDB table automatically on first run — no bootstrap step needed.

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What’s Next?

Manage cross-stack dependencies.

← terragrunt.hcl Structure Dependency Blocks →