Invalid Terraform Syntax For ASG Launch Template 'version' Field

[Michael Price]

I've recently encountered the following errors when provisioning this module into our AWS account:

Error: Error creating AutoScaling Group: ValidationError: Invalid launch template version: either '$Default', '$Latest', or a numeric version are allowed.
	status code: 400, request id: 91aedde0-b2e2-11e9-a1aa-af17fe228806

  on ../terraform-aws-concourse/asg.tf line 44, in resource "aws_autoscaling_group" "web_asg":
  44: resource "aws_autoscaling_group" "web_asg" {

Error: Error creating AutoScaling Group: ValidationError: Invalid launch template version: either '$Default', '$Latest', or a numeric version are allowed.
	status code: 400, request id: 91af04b7-b2e2-11e9-8042-cf7640053d0d

  on ../terraform-aws-concourse/asg.tf line 120, in resource "aws_autoscaling_group" "worker_asg":
 120: resource "aws_autoscaling_group" "worker_asg" {

I have tried using terraform version 0.12.4 and 0.12.5 although get the same results (I can see the required version in the module set to >=0.12.3). I am using version 1.0.0 of the module.

It looks like the Terraform syntax is incorrect for the web & worker ASG's launch template config:
https://github.com/7Factor/terraform-aws-concourse/blob/v1.0.0/asg.tf#L55
https://github.com/7Factor/terraform-aws-concourse/blob/v1.0.0/asg.tf#L129

According to the TF docs the value should be $Latest instead of $$Latest:
https://www.terraform.io/docs/providers/aws/r/autoscaling_group.html#launch_template-1

Happy to raise a PR you agree

[Richard Dohn]

Thanks for raising this issue, it has been updated on master :)