'Not a valid output for module' when using output variable with terraform

Question

I\'m trying to setup some IaC for a new project using Hashicorp Terraform on AWS. I\'m using modules because I want to be able to reuse stuff across multiple environments (s

Answer 1

Outputs need to be passed up through each module explicitly each time.

For example if you wanted to output a variable to the screen from a module nested below another module you would need something like this:

child-module.tf

output "child_foo" {
  value = "foobar"
}

parent-module.tf

module "child" {
  source = "path/to/child"
}

output "parent_foo" {
  value = "${module.child.child_foo}"
}

main.tf

module "parent" {
  source = "path/to/parent"
}

output "main_foo" {
  value = "${module.parent.parent_foo}"
}