How to write markers inside a for_each’d module#

Instances of a for_each’d module share one HCL body for tags, so no single literal address is correct for all of them and auto-stamping cannot reach inside. choudoufu leaves such a resource alone when it already declares tags, and raises a must-stamp error when it declares none and its type needs discovery.

Thread the module’s own each.key through and build the address from it.

# root module: the call passes its own each.key through
module "wrapped" {
  source   = "./wrapped"
  for_each = toset(["a", "b"])
  key      = each.key
}

# wrapped module: receives it as a variable
variable "key" {
  type = string
}

# wrapped module: builds its own address from the variable
resource "aws_eip" "app" {
  tags = {
    tofu-estate  = local.estate_tag
    tofu-address = "module.wrapped[\"${var.key}\"].aws_eip.app"
  }
}

live/e2e/estate-module-keyed/ is the two-instance fixture this is drawn from, proven against a live emulator.

See Compatibility reference for the module forms this pattern applies to.