main.tf

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT-0

# Amazon EKS cluster data
data "aws_eks_cluster" "selected" {
  name = var.eks_cluster_name
}


# EC2 instance type data
data "aws_ec2_instance_type" "selected" {
  instance_type = var.instance_type
}


resource "aws_autoscaling_group" "eks_self_managed_node_group" {
  name = "${var.eks_cluster_name}-${local.node_group_name}"

  desired_capacity = var.desired_capacity
  min_size         = var.min_size
  max_size         = var.max_size

  vpc_zone_identifier = var.subnets

  launch_template {
    id      = aws_launch_template.eks_self_managed_nodes.id
    version = "$Latest"
  }

  tags = concat(
    [
      for tag, value in var.tags : {
        key                 = tag
        value               = value
        propagate_at_launch = true
      }
    ],
    [
      {
        key                 = "Name"
        value               = "${var.eks_cluster_name}-${local.node_group_name}"
        propagate_at_launch = true
      },
      {
        key                 = "kubernetes.io/cluster/${var.eks_cluster_name}"
        value               = "owned"
        propagate_at_launch = true
      },
    ]
  )


  # Ensure the IAM role has been created (and the policies have been attached)
  # before creating the auto-scaling group.
  depends_on = [
    aws_iam_role_policy_attachment.amazon_eks_worker_node_policy,
    aws_iam_role_policy_attachment.amazon_eks_cni_policy,
    aws_iam_role_policy_attachment.amazon_ec2_container_registry_read_only,
  ]
}


resource "aws_launch_template" "eks_self_managed_nodes" {
  name_prefix = "${var.eks_cluster_name}-${local.node_group_name}"
  description = "Amazon EKS self-managed nodes"

  instance_type          = var.instance_type
  image_id               = data.aws_ami.selected_eks_optimized_ami.id
  ebs_optimized          = data.aws_ec2_instance_type.selected.ebs_optimized_support == "default" ? true : false
  key_name               = var.key_name
  update_default_version = true

  vpc_security_group_ids = concat(
    [data.aws_eks_cluster.selected.vpc_config[0].cluster_security_group_id],
    var.security_group_ids
  )

  iam_instance_profile {
    arn = aws_iam_instance_profile.eks_self_managed_node_group.arn
  }

  block_device_mappings {
    device_name = local.root_block_device_mapping.device_name

    ebs {
      snapshot_id = local.root_block_device_mapping.ebs.snapshot_id

      encrypted  = coalesce(var.ebs_encrypted, local.root_block_device_mapping.ebs.encrypted)
      kms_key_id = var.ebs_kms_key_arn

      volume_size = coalesce(var.ebs_volume_size, local.root_block_device_mapping.ebs.volume_size)
      volume_type = coalesce(var.ebs_volume_type, local.root_block_device_mapping.ebs.volume_type)
      iops        = contains(["io1", "io2"], var.ebs_volume_type) ? var.ebs_iops : null
      throughput  = var.ebs_volume_type == "gp3" ? var.ebs_throughput : null

      delete_on_termination = coalesce(var.ebs_delete_on_termination, local.root_block_device_mapping.ebs.delete_on_termination)
    }
  }

  user_data = base64encode(templatefile("${path.module}/user_data.sh", {
    cluster_name = var.eks_cluster_name
    node_labels  = var.node_labels
  }))

  tags = var.tags
}

locals {
  ami_block_device_mappings = {
    for bdm in data.aws_ami.selected_eks_optimized_ami.block_device_mappings : bdm.device_name => bdm
  }
  root_block_device_mapping = local.ami_block_device_mappings[data.aws_ami.selected_eks_optimized_ami.root_device_name]
}