ec2.tf

data "template_file" "userdata" {
  template = file("${path.module}/userdata.sh.tpl")

  vars = {
    SrcEFS       = var.SrcEFS
    DstEFS       = aws_efs_file_system.dst.id
    IntervalTag  = var.IntervalTag
    Retain       = var.Retain
    FolderLabel  = var.FolderLabel
    BackupPrefix = var.BackupPrefix
  }
}

resource "aws_launch_configuration" "backup_instance" {
  name_prefix          = "${var.name}-"
  image_id             = data.aws_ami.efs_backup.id
  security_groups      = [aws_security_group.efs.id]
  instance_type        = local.instance_type
  iam_instance_profile = aws_iam_instance_profile.ec2.name
  user_data            = data.template_file.userdata.rendered

  lifecycle {
    create_before_destroy = true
  }
}

module "asg_tags" {
  source  = "github.com/rhythmictech/terraform-aws-asg-tag-transform?ref=1.0.0"
  tag_map = merge(
    local.tags,
    var.tags,
    {
      Name = "${var.name}-asg"
    }
  )
}

resource "aws_autoscaling_group" "backup_instances" {
  name_prefix          = "${var.name}-"
  max_size             = 1
  min_size             = 0
  desired_capacity     = 0
  vpc_zone_identifier  = var.Subnets
  launch_configuration = aws_launch_configuration.backup_instance.name
  tags                 = module.asg_tags.tag_list
}

resource "random_uuid" "lifecycle_hook_name" {}

resource "aws_autoscaling_lifecycle_hook" "backup_instances" {
  name                   = "${var.name}-${random_uuid.lifecycle_hook_name.result}"
  autoscaling_group_name = aws_autoscaling_group.backup_instances.name
  heartbeat_timeout      = 3600
  lifecycle_transition   = "autoscaling:EC2_INSTANCE_TERMINATING"
}