title: Passing parameters to modules in dev and prod clusters
body: <p>Hi how should i pass the variable to only one environment.</p>
  
  <p>I have a logging parameter defined and i want to pass this variable only to my prod redshift and not to the dev redshift. The dev redshift cluster should not have logging parameter defined.</p>
  
  <p>I am stuck on how to pass inside a module, i have separate modules for prod and dev redshift cluster.</p>
  
  <pre><code>variable "logging" {
       target_bucket= "xxxx"
  }
  
  resource "aws_s3_bucket" "log_bucket" {
    bucket = "${var.bucket}-${var.env}"
    logging = ["${var.logging}"]
  
  
  module "redshift-dev" {
    source                      = "../modules/xxxx"
    env                         = "dev"
    region                      = "us-east-1"
    logging                     = {}
  
  module "redshift-prod" {
    source                      = "../modules/xxxx"
    env                         = "prod"
    region                      = "us-east-1"
    logging                     = {
       target_bucket= "xxxx"
  }
  </code></pre>