Branch 04_02 - request for update to latest autoscaling parameters

[guteksan]

From version 9.0.0, alb does not output target_group_arns and autoscaling does not accept such input parameters. Please update the lesson, or at least the code, to use the latest versions of load balancers and autoscaling groups.

https://registry.terraform.io/modules/terraform-aws-modules/autoscaling/aws/8.0.1?tab=inputs
https://registry.terraform.io/modules/terraform-aws-modules/alb/aws/9.13.0?tab=inputs

[thatnerdjoe]

Took a bit of tinkering, but I found the solution as of ALB v9.13.0 and ASG v8.1.0.

module "blog"
  source  = "terraform-aws-modules/autoscaling/aws"
  version = "8.1.0"
 
  ...snip...

  vpc_zone_identifier   = module.blog_vpc.public_subnets
  security_groups       = [module.blog_sg.security_group_id]
  traffic_source_attachments = {
    blog_alb = {
      traffic_source_identifier = module.blog_alb.target_groups["blog_asg"].arn
      traffic_source_type = "elbv2"
    }
  }
}

module "blog_alb"
  source = "terraform-aws-modules/alb/aws"
  version = "9.13.0"

  ...snip...

  listeners = {
    blog_http = {
      port     = 80
      protocol = "HTTP"
    
      forward = {
        target_group_key = "blog_asg"
      }
    }
  }
    
  target_groups = {
    blog_asg = {
      name_prefix      = "blog-"
      protocol         = "HTTP"
      port             = 80
      target_type      = "instance"
      # Required argument to attach to the ASG later.
      create_attachment = false
    }
 }

Source: https://github.com/terraform-aws-modules/terraform-aws-autoscaling/blob/v8.1.0/examples/complete/main.tf