Forwarding module outputs for remote state or `terraform output`

example.tf

// Foo has outputs "bar" and "baz"
module "foo" {
  source = "..."
  arg1 = "spam"
  arg2 = "eggs"
}

// If you want `terraform output` or your remote state to show the outputs of
// `module.foo` you need to "forward" them along here:
output "bar" { value = "${module.foo.bar}" }
output "baz" { value = "${module.foo.baz}" }