How to use terraform output as input variable of another terraform template

Question

Is there any way I can use a Terraform template output to another Terraform template's input?

Ex: I have a Terraform template which creates an ELB and I have another Terraform template which is going to create an auto scale group which need the ELB information as an input variable.

I know I can use shell script to grep and feed in the ELB information, but I'm looking for some Terraform way to doing this.

Answer 1

Have you tried using remote state to populate your second template?

Declare it like this:

resource "terraform_remote_state" "your_state" {
  backend = "s3"
  config {
    bucket = "${var.your_bucket}"
    region = "${var.your_region}"
    key = "${var.your_state_file}"
  }
}

And then you should be able to pull out your resource directly like this:

your_elb = "${terraform_remote_state.your_state.output.your_output_resource}"

If this doesn't work for you, have you tried implementing your ELB in a module and then just using the output?

https://github.com/terraform-community-modules/tf_aws_elb is a good example of how to structure the module.