Terraform, creating a CloudFront distributon reusable module with and without multiples Origins

Question

I have an application that needs CloudFront + s3. I want to create a CloudFront module and make it reusable for others applications.

My problem is that I have one application that needs two Origins ( s3_origin_config and a custom_origin_config) AND other application that needs ONLY s3_origin_config.

The question is: How can I have a module that handles application that needs two Origins and another that needs only one Origin.

Below an example of my code:

resource "aws_cloudfront_distribution" "s3_distribution" {
  origin {
    domain_name = "${var.domain_name}"
    origin_id   = "${var.app_name}-${var.environment}"
    origin_path = "/${var.environment}/${var.setup}/public"
    s3_origin_config {
       origin_access_identity = ${aws_cloudfront_origin_access_identity.origin_access_identity.cloudfront_access_identity_path}"
       }
  }


#HERE, I would like something like if $second_origin, then:
#I know there is no if in terraform, just to have an example ;)
origin {             
   domain_name = "${var.second_origin_domain_name}"
   origin_id   = "Custom-${var.second_origin_domain_name}"
   custom_origin_config {
      http_port              = "80"
      https_port             = "443"
      origin_protocol_policy = "https-only"
      origin_ssl_protocols   = ["TLSv1", "TLSv1.1", "TLSv1.2"]
    }
  custom_header {
    name  = "${var.second_origin_header_name}"
    value = "${var.second_origin_header_key}"
  }
}...

Thanks!

Answer 1

You need to create two cloudfront resources with different origin requirements. Using count, you can enable one resource and disable another resource at same time. This will allow you to use same module for different origin requirements.

Here is simple example.

resource "aws_cloudfront_distribution" "cf_app1" {
  count = "${var.something ? 1 : 0}"
}

resource "aws_cloudfront_distribution" "cf_app2" {
  count = "${var.something ? 0 : 1}"
}