title: How to use terraform output as input variable of another terraform template
body: <p>Is there any way I can use a Terraform template output to another Terraform template's input? </p>
  
  <p>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.</p>
  
  <p>I know I can use shell script to <code>grep</code> and feed in the ELB information, but I'm looking for some Terraform way to doing this.</p>