refactor: Refactoring to match the rest of terraform-aws-modules (#1583)

examples/bottlerocket/main.tf

@@ -1,31 +1,27 @@
-terraform {
-  required_version = ">= 0.13.0"
+provider "aws" {
+  region = local.region
 }
 
-resource "tls_private_key" "nodes" {
-  algorithm = "RSA"
-}
-
-resource "aws_key_pair" "nodes" {
-  key_name   = "bottlerocket-nodes"
-  public_key = tls_private_key.nodes.public_key_openssh
+locals {
+  region      = "eu-west-1"
+  k8s_version = "1.21"
 }
 
 module "eks" {
-  source          = "../.."
-  cluster_name    = "bottlerocket"
-  cluster_version = var.k8s_version
-  subnets         = data.aws_subnet_ids.default.ids
+  source = "../.."
 
-  vpc_id = data.aws_vpc.default.id
+  cluster_name    = "bottlerocket-${random_string.suffix.result}"
+  cluster_version = local.k8s_version
+
+  vpc_id  = data.aws_vpc.default.id
+  subnets = data.aws_subnet_ids.default.ids
 
   write_kubeconfig = false
   manage_aws_auth  = false
 
   worker_groups_launch_template = [
     {
-      name = "bottlerocket-nodes"
-      # passing bottlerocket ami id
+      name                 = "bottlerocket-nodes"
       ami_id               = data.aws_ami.bottlerocket_ami.id
       instance_type        = "t3a.small"
       asg_desired_capacity = 2
@@ -42,9 +38,9 @@ module "eks" {
       # we are using this section to pass additional arguments for
       # userdata template rendering
       userdata_template_extra_args = {
-        enable_admin_container   = var.enable_admin_container
-        enable_control_container = var.enable_control_container
-        aws_region               = data.aws_region.current.name
+        enable_admin_container   = false
+        enable_control_container = true
+        aws_region               = local.region
       }
       # example of k8s/kubelet configuration via additional_userdata
       additional_userdata = <<EOT
@@ -59,5 +55,41 @@ EOT
 # https://github.com/bottlerocket-os/bottlerocket/blob/develop/QUICKSTART-EKS.md#enabling-ssm
 resource "aws_iam_role_policy_attachment" "ssm" {
   role       = module.eks.worker_iam_role_name
-  policy_arn = data.aws_iam_policy.ssm.arn
+  policy_arn = "arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore"
+}
+
+################################################################################
+# Supporting Resources
+################################################################################
+
+data "aws_vpc" "default" {
+  default = true
+}
+
+data "aws_subnet_ids" "default" {
+  vpc_id = data.aws_vpc.default.id
+}
+
+data "aws_ami" "bottlerocket_ami" {
+  most_recent = true
+  owners      = ["amazon"]
+
+  filter {
+    name   = "name"
+    values = ["bottlerocket-aws-k8s-${local.k8s_version}-x86_64-*"]
+  }
+}
+
+resource "random_string" "suffix" {
+  length  = 8
+  special = false
+}
+
+resource "tls_private_key" "nodes" {
+  algorithm = "RSA"
+}
+
+resource "aws_key_pair" "nodes" {
+  key_name   = "bottlerocket-nodes-${random_string.suffix.result}"
+  public_key = tls_private_key.nodes.public_key_openssh
 }