Instances without Internet (using terraform-aws-modules: asg, vpc, alb)

terraform - (82 lines, pastebin)

Using the referenced terraform I’m able to successfully build an alb, asg, target groups, instances, etc. However, the instances are unable to
reach Internet and unable to complete executing user-data. This results in the apply hanging until timeout, troubleshooting, and trying again.

To correct this I understand I need a NAT Gateway and routes from the private subnets to the NAT Gateway. That being the case I’ve
made adjustments to the vpc block:

  manage_default_route_table    = true
  enable_nat_gateway = true
  single_nat_gateway = true

Yet this does not work as expected. I will continue to read through docs and try a few more modifications but I would be most grateful
if someone here were to offer guidance.