main.tf

data "aws_partition" "current" {}
data "aws_caller_identity" "current" {}

################################################################################
# User Data
################################################################################

module "user_data" {
  source = "../_user_data"

  create   = var.create
  platform = var.platform

  cluster_name        = var.cluster_name
  cluster_endpoint    = var.cluster_endpoint
  cluster_auth_base64 = var.cluster_auth_base64

  cluster_service_ipv4_cidr = var.cluster_service_ipv4_cidr

  enable_bootstrap_user_data = var.enable_bootstrap_user_data
  pre_bootstrap_user_data    = var.pre_bootstrap_user_data
  post_bootstrap_user_data   = var.post_bootstrap_user_data
  bootstrap_extra_args       = var.bootstrap_extra_args
  user_data_template_path    = var.user_data_template_path
}

################################################################################
# Launch template
################################################################################

locals {
  launch_template_name = coalesce(var.launch_template_name, "${var.name}-eks-node-group")
  security_group_ids   = compact(concat([var.cluster_primary_security_group_id], var.vpc_security_group_ids))
}

resource "aws_launch_template" "this" {
  count = var.create && var.create_launch_template && var.use_custom_launch_template ? 1 : 0

  dynamic "block_device_mappings" {
    for_each = var.block_device_mappings

    content {
      device_name = try(block_device_mappings.value.device_name, null)

      dynamic "ebs" {
        for_each = try([block_device_mappings.value.ebs], [])

        content {
          delete_on_termination = try(ebs.value.delete_on_termination, null)
          encrypted             = try(ebs.value.encrypted, null)
          iops                  = try(ebs.value.iops, null)
          kms_key_id            = try(ebs.value.kms_key_id, null)
          snapshot_id           = try(ebs.value.snapshot_id, null)
          throughput            = try(ebs.value.throughput, null)
          volume_size           = try(ebs.value.volume_size, null)
          volume_type           = try(ebs.value.volume_type, null)
        }
      }

      no_device    = try(block_device_mappings.value.no_device, null)
      virtual_name = try(block_device_mappings.value.virtual_name, null)
    }
  }

  dynamic "capacity_reservation_specification" {
    for_each = length(var.capacity_reservation_specification) > 0 ? [var.capacity_reservation_specification] : []

    content {
      capacity_reservation_preference = try(capacity_reservation_specification.value.capacity_reservation_preference, null)

      dynamic "capacity_reservation_target" {
        for_each = try([capacity_reservation_specification.value.capacity_reservation_target], [])

        content {
          capacity_reservation_id                 = try(capacity_reservation_target.value.capacity_reservation_id, null)
          capacity_reservation_resource_group_arn = try(capacity_reservation_target.value.capacity_reservation_resource_group_arn, null)
        }
      }
    }
  }

  dynamic "cpu_options" {
    for_each = length(var.cpu_options) > 0 ? [var.cpu_options] : []

    content {
      core_count       = try(cpu_options.value.core_count, null)
      threads_per_core = try(cpu_options.value.threads_per_core, null)
    }
  }

  dynamic "credit_specification" {
    for_each = length(var.credit_specification) > 0 ? [var.credit_specification] : []

    content {
      cpu_credits = try(credit_specification.value.cpu_credits, null)
    }
  }

  default_version         = var.launch_template_default_version
  description             = var.launch_template_description
  disable_api_termination = var.disable_api_termination
  ebs_optimized           = var.ebs_optimized

  dynamic "elastic_gpu_specifications" {
    for_each = var.elastic_gpu_specifications

    content {
      type = elastic_gpu_specifications.value.type
    }
  }

  dynamic "elastic_inference_accelerator" {
    for_each = length(var.elastic_inference_accelerator) > 0 ? [var.elastic_inference_accelerator] : []

    content {
      type = elastic_inference_accelerator.value.type
    }
  }

  dynamic "enclave_options" {
    for_each = length(var.enclave_options) > 0 ? [var.enclave_options] : []

    content {
      enabled = enclave_options.value.enabled
    }
  }

  # Set on EKS managed node group, will fail if set here
  # https://docs.aws.amazon.com/eks/latest/userguide/launch-templates.html#launch-template-basics
  # dynamic "hibernation_options" {
  #   for_each = length(var.hibernation_options) > 0 ? [var.hibernation_options] : []

  #   content {
  #     configured = hibernation_options.value.configured
  #   }
  # }

  # Set on EKS managed node group, will fail if set here
  # https://docs.aws.amazon.com/eks/latest/userguide/launch-templates.html#launch-template-basics
  # dynamic "iam_instance_profile" {
  #   for_each = [var.iam_instance_profile]
  #   content {
  #     name = lookup(var.iam_instance_profile, "name", null)
  #     arn  = lookup(var.iam_instance_profile, "arn", null)
  #   }
  # }

  image_id = var.ami_id
  # Set on EKS managed node group, will fail if set here
  # https://docs.aws.amazon.com/eks/latest/userguide/launch-templates.html#launch-template-basics
  # instance_initiated_shutdown_behavior = var.instance_initiated_shutdown_behavior

  dynamic "instance_market_options" {
    for_each = length(var.instance_market_options) > 0 ? [var.instance_market_options] : []

    content {
      market_type = try(instance_market_options.value.market_type, null)

      dynamic "spot_options" {
        for_each = try([instance_market_options.value.spot_options], [])

        content {
          block_duration_minutes         = try(spot_options.value.block_duration_minutes, null)
          instance_interruption_behavior = try(spot_options.value.instance_interruption_behavior, null)
          max_price                      = try(spot_options.value.max_price, null)
          spot_instance_type             = try(spot_options.value.spot_instance_type, null)
          valid_until                    = try(spot_options.value.valid_until, null)
        }
      }
    }
  }

  # # Set on node group instead
  # instance_type = var.launch_template_instance_type
  kernel_id = var.kernel_id
  key_name  = var.key_name

  dynamic "license_specification" {
    for_each = length(var.license_specifications) > 0 ? var.license_specifications : {}

    content {
      license_configuration_arn = license_specifications.value.license_configuration_arn
    }
  }

  dynamic "maintenance_options" {
    for_each = length(var.maintenance_options) > 0 ? [var.maintenance_options] : []

    content {
      auto_recovery = try(maintenance_options.value.auto_recovery, null)
    }
  }

  dynamic "metadata_options" {
    for_each = length(var.metadata_options) > 0 ? [var.metadata_options] : []

    content {
      http_endpoint               = try(metadata_options.value.http_endpoint, null)
      http_protocol_ipv6          = try(metadata_options.value.http_protocol_ipv6, null)
      http_put_response_hop_limit = try(metadata_options.value.http_put_response_hop_limit, null)
      http_tokens                 = try(metadata_options.value.http_tokens, null)
      instance_metadata_tags      = try(metadata_options.value.instance_metadata_tags, null)
    }
  }

  dynamic "monitoring" {
    for_each = var.enable_monitoring ? [1] : []

    content {
      enabled = var.enable_monitoring
    }
  }

  name        = var.launch_template_use_name_prefix ? null : local.launch_template_name
  name_prefix = var.launch_template_use_name_prefix ? "${local.launch_template_name}-" : null

  dynamic "network_interfaces" {
    for_each = var.network_interfaces
    content {
      associate_carrier_ip_address = try(network_interfaces.value.associate_carrier_ip_address, null)
      associate_public_ip_address  = try(network_interfaces.value.associate_public_ip_address, null)
      delete_on_termination        = try(network_interfaces.value.delete_on_termination, null)
      description                  = try(network_interfaces.value.description, null)
      device_index                 = try(network_interfaces.value.device_index, null)
      interface_type               = try(network_interfaces.value.interface_type, null)
      ipv4_address_count           = try(network_interfaces.value.ipv4_address_count, null)
      ipv4_addresses               = try(network_interfaces.value.ipv4_addresses, [])
      ipv4_prefix_count            = try(network_interfaces.value.ipv4_prefix_count, null)
      ipv4_prefixes                = try(network_interfaces.value.ipv4_prefixes, null)
      ipv6_address_count           = try(network_interfaces.value.ipv6_address_count, null)
      ipv6_addresses               = try(network_interfaces.value.ipv6_addresses, [])
      ipv6_prefix_count            = try(network_interfaces.value.ipv6_prefix_count, null)
      ipv6_prefixes                = try(network_interfaces.value.ipv6_prefixes, [])
      network_card_index           = try(network_interfaces.value.network_card_index, null)
      network_interface_id         = try(network_interfaces.value.network_interface_id, null)
      private_ip_address           = try(network_interfaces.value.private_ip_address, null)
      # Ref: https://github.com/hashicorp/terraform-provider-aws/issues/4570
      security_groups = compact(concat(try(network_interfaces.value.security_groups, []), local.security_group_ids))
      # Set on EKS managed node group, will fail if set here
      # https://docs.aws.amazon.com/eks/latest/userguide/launch-templates.html#launch-template-basics
      # subnet_id       = try(network_interfaces.value.subnet_id, null)
    }
  }

  dynamic "placement" {
    for_each = length(var.placement) > 0 ? [var.placement] : []

    content {
      affinity                = try(placement.value.affinity, null)
      availability_zone       = try(placement.value.availability_zone, null)
      group_name              = try(placement.value.group_name, null)
      host_id                 = try(placement.value.host_id, null)
      host_resource_group_arn = try(placement.value.host_resource_group_arn, null)
      partition_number        = try(placement.value.partition_number, null)
      spread_domain           = try(placement.value.spread_domain, null)
      tenancy                 = try(placement.value.tenancy, null)
    }
  }

  dynamic "private_dns_name_options" {
    for_each = length(var.private_dns_name_options) > 0 ? [var.private_dns_name_options] : []

    content {
      enable_resource_name_dns_aaaa_record = try(private_dns_name_options.value.enable_resource_name_dns_aaaa_record, null)
      enable_resource_name_dns_a_record    = try(private_dns_name_options.value.enable_resource_name_dns_a_record, null)
      hostname_type                        = try(private_dns_name_options.value.hostname_type, null)
    }
  }

  ram_disk_id = var.ram_disk_id

  dynamic "tag_specifications" {
    for_each = toset(var.tag_specifications)

    content {
      resource_type = tag_specifications.key
      tags          = merge(var.tags, { Name = var.name }, var.launch_template_tags)
    }
  }

  update_default_version = var.update_launch_template_default_version
  user_data              = module.user_data.user_data
  vpc_security_group_ids = length(var.network_interfaces) > 0 ? [] : local.security_group_ids

  tags = var.tags

  # Prevent premature access of policies by pods that
  # require permissions on create/destroy that depend on nodes
  depends_on = [
    aws_iam_role_policy_attachment.this,
  ]

  lifecycle {
    create_before_destroy = true
  }
}

################################################################################
# Node Group
################################################################################

locals {
  launch_template_id = var.create && var.create_launch_template ? try(aws_launch_template.this[0].id, null) : var.launch_template_id
  # Change order to allow users to set version priority before using defaults
  launch_template_version = coalesce(var.launch_template_version, try(aws_launch_template.this[0].default_version, "$Default"))
}

resource "aws_eks_node_group" "this" {
  count = var.create ? 1 : 0

  # Required
  cluster_name  = var.cluster_name
  node_role_arn = var.create_iam_role ? aws_iam_role.this[0].arn : var.iam_role_arn
  subnet_ids    = var.subnet_ids

  scaling_config {
    min_size     = var.min_size
    max_size     = var.max_size
    desired_size = var.desired_size
  }

  # Optional
  node_group_name        = var.use_name_prefix ? null : var.name
  node_group_name_prefix = var.use_name_prefix ? "${var.name}-" : null

  # https://docs.aws.amazon.com/eks/latest/userguide/launch-templates.html#launch-template-custom-ami
  ami_type        = var.ami_id != "" ? null : var.ami_type
  release_version = var.ami_id != "" ? null : var.ami_release_version
  version         = var.ami_id != "" ? null : var.cluster_version

  capacity_type        = var.capacity_type
  disk_size            = var.use_custom_launch_template ? null : var.disk_size # if using a custom LT, set disk size on custom LT or else it will error here
  force_update_version = var.force_update_version
  instance_types       = var.instance_types
  labels               = var.labels

  dynamic "launch_template" {
    for_each = var.use_custom_launch_template ? [1] : []

    content {
      id      = local.launch_template_id
      version = local.launch_template_version
    }
  }

  dynamic "remote_access" {
    for_each = length(var.remote_access) > 0 ? [var.remote_access] : []

    content {
      ec2_ssh_key               = try(remote_access.value.ec2_ssh_key, null)
      source_security_group_ids = try(remote_access.value.source_security_group_ids, [])
    }
  }

  dynamic "taint" {
    for_each = var.taints

    content {
      key    = taint.value.key
      value  = try(taint.value.value, null)
      effect = taint.value.effect
    }
  }

  dynamic "update_config" {
    for_each = length(var.update_config) > 0 ? [var.update_config] : []

    content {
      max_unavailable_percentage = try(update_config.value.max_unavailable_percentage, null)
      max_unavailable            = try(update_config.value.max_unavailable, null)
    }
  }

  timeouts {
    create = lookup(var.timeouts, "create", null)
    update = lookup(var.timeouts, "update", null)
    delete = lookup(var.timeouts, "delete", null)
  }

  lifecycle {
    create_before_destroy = true
    ignore_changes = [
      scaling_config[0].desired_size,
    ]
  }

  tags = merge(
    var.tags,
    { Name = var.name }
  )
}

################################################################################
# IAM Role
################################################################################

locals {
  iam_role_name          = coalesce(var.iam_role_name, "${var.name}-eks-node-group")
  iam_role_policy_prefix = "arn:${data.aws_partition.current.partition}:iam::aws:policy"
  cni_policy             = var.cluster_ip_family == "ipv6" ? "arn:${data.aws_partition.current.partition}:iam::${data.aws_caller_identity.current.account_id}:policy/AmazonEKS_CNI_IPv6_Policy" : "${local.iam_role_policy_prefix}/AmazonEKS_CNI_Policy"
}

data "aws_iam_policy_document" "assume_role_policy" {
  count = var.create && var.create_iam_role ? 1 : 0

  statement {
    sid     = "EKSNodeAssumeRole"
    actions = ["sts:AssumeRole"]

    principals {
      type        = "Service"
      identifiers = ["ec2.${data.aws_partition.current.dns_suffix}"]
    }
  }
}

resource "aws_iam_role" "this" {
  count = var.create && var.create_iam_role ? 1 : 0

  name        = var.iam_role_use_name_prefix ? null : local.iam_role_name
  name_prefix = var.iam_role_use_name_prefix ? "${local.iam_role_name}-" : null
  path        = var.iam_role_path
  description = var.iam_role_description

  assume_role_policy    = data.aws_iam_policy_document.assume_role_policy[0].json
  permissions_boundary  = var.iam_role_permissions_boundary
  force_detach_policies = true

  tags = merge(var.tags, var.iam_role_tags)
}

# Policies attached ref https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/eks_node_group
resource "aws_iam_role_policy_attachment" "this" {
  for_each = { for k, v in toset(compact([
    "${local.iam_role_policy_prefix}/AmazonEKSWorkerNodePolicy",
    "${local.iam_role_policy_prefix}/AmazonEC2ContainerRegistryReadOnly",
    var.iam_role_attach_cni_policy ? local.cni_policy : "",
  ])) : k => v if var.create && var.create_iam_role }

  policy_arn = each.value
  role       = aws_iam_role.this[0].name
}

resource "aws_iam_role_policy_attachment" "additional" {
  for_each = { for k, v in var.iam_role_additional_policies : k => v if var.create && var.create_iam_role }

  policy_arn = each.value
  role       = aws_iam_role.this[0].name
}