Outputs not displaying when using modules

Question

I have a outputs.tf file under my module directory. And I have a Main.tf file. When I create a resource and Terraform Apply, the outputs does not display. However, if I don't use modules and create my resources strictly from the Main.tf file, the outputs shows fine. Is there any different I need to do for my outputs to display when using modules and a separate outputs.tf file?

    Terraform v0.11.14
+ provider.aws v2.19.0

However, if I don't use modules and create my resources strictly from the Main.tf file, the outputs shows fine.

main.tf

module "identity-provider" {
  source = "./modules/identity-provider"
}



module "saml-role1" {
  source = "./modules/saml-roles/"
}

===============

module file

resource "aws_iam_role" "role1" {
  name                 = "saml-role1"
  description          = "Blah Blah"
  path                 = "/"
  assume_role_policy   = "${data.aws_iam_policy_document.assume_role.json}"
  permissions_boundary = ""
  max_session_duration = 43200



resource "aws_iam_role_policy_attachment" "Read-Only" {
  role       = "${aws_iam_role.role1.name}"
  policy_arn = "arn:aws:iam::aws:policy/ReadOnlyAccess"
}

=================

outputs.tf

output "Role1-ARN" {
  value = "${module.saml-role1.arn}"
}

Answer 1

You also need an another output.tf file along with your main.tf file to capture the output from your module.

Below is the content of the output.tf file.

output "Role1-ARN" {
  value = "${module.saml-role1.Role1-ARN}"
}

Regards,

Vinoth

Answer 2

Only the outputs of the root module are captured and displayed by Terraform. If you need to pass outputs from a module to the root module you have to do it explicitly (e.g. you do not have access to all the resources created by a module from the root ONLY the values specified as outputs). If you include an output in your module file like this:

resource "aws_iam_role" "role1" {
  name                 = "saml-role1"
  description          = "Blah Blah"
  path                 = "/"
  assume_role_policy   = "${data.aws_iam_policy_document.assume_role.json}"
  permissions_boundary = ""
  max_session_duration = 43200



resource "aws_iam_role_policy_attachment" "Read-Only" {
  role       = "${aws_iam_role.role1.name}"
  policy_arn = "arn:aws:iam::aws:policy/ReadOnlyAccess"
}

output "saml-role1-arn" {
    value = "aws_iam_role.role1.arn"
}

Then from within the root module you can access the output:

module "saml-role1" {
  source = "./modules/saml-roles/"
}

output "saml-role1-arn" {
    value = "${module.saml-role1.saml-role1-arn}"
}