data "template_file" "user_data" {
  template = file("${path.module}/user_data.tpl")
  vars = {
    aws_region         = var.aws_region_name
  }
}

resource "aws_launch_configuration" "lcfg" {
  name_prefix                 = "${var.name}.LCFG-"
  image_id                    = var.ami
  instance_type               = var.instance_type
  iam_instance_profile        = var.iam_instance_profile_id
  key_name                    = var.key_name
  security_groups             = var.security_groups
  associate_public_ip_address = var.associate_public_ip_address
  user_data                   = data.template_file.user_data.rendered

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_autoscaling_group" "asg" {
  name                      = "${var.name}.ASG"
  launch_configuration      = aws_launch_configuration.lcfg.name
  vpc_zone_identifier       = var.subnets
  max_size                  = var.max_size
  min_size                  = 0
  desired_capacity          = var.server_count
  load_balancers            = var.load_balancers
  health_check_grace_period = 60
  termination_policies      = ["OldestLaunchConfiguration", "OldestInstance"]
  suspended_processes       = ["AZRebalance"]

  tag {
    key                 = "Name"
    propagate_at_launch = true
    value               = "${var.name}.ASG"
  }

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_launch_template" "launchtemplate" {
  name_prefix                 = "${var.name}.launchtemplate-"
  image_id                    = var.ami
  instance_type               = var.instance_type
  update_default_version      = true
  iam_instance_profile        {
    name = var.iam_instance_profile_id
  }
  key_name                    = var.key_name
  network_interfaces {
    security_groups = var.security_groups
    associate_public_ip_address = var.associate_public_ip_address
  }
  user_data                   = base64encode(templatefile(
    "${path.module}/user_data.tpl",
    {
      aws_region         = var.aws_region_name
    }
  ))

  lifecycle {
    create_before_destroy = true
  }

  tag_specifications {
    resource_type = "instance"

    tags = {
      profile = var.titan_profile_name
    }
  }
}

resource "aws_autoscaling_group" "asg" {
  name                      = "${var.name}.ASG"
  launch_template           {
    name = aws_launch_template.launchtemplate.name
  }
  vpc_zone_identifier       = var.subnets
  max_size                  = var.max_size
  min_size                  = 0
  desired_capacity          = var.server_count
  load_balancers            = var.load_balancers
  health_check_grace_period = 60
  termination_policies      = ["OldestLaunchConfiguration", "OldestInstance"]
  suspended_processes       = ["AZRebalance"]

  tag {
    key                 = "Name"
    propagate_at_launch = true
    value               = "${var.name}.ASG"
  }

  lifecycle {
    create_before_destroy = true
  }
}