Add example for IRSA and cluster-autoscaler (#710)

* Add example for IRSA

* remove unused SGs

* remove helm setup part

* simplification and use module

* fix fmt error

* remove unused resource

examples/irsa/main.tf

@@ -0,0 +1,82 @@
+terraform {
+  required_version = ">= 0.12.0"
+}
+
+provider "aws" {
+  version = ">= 2.28.1"
+  region  = var.region
+}
+
+provider "local" {
+  version = "~> 1.2"
+}
+
+provider "null" {
+  version = "~> 2.1"
+}
+
+provider "template" {
+  version = "~> 2.1"
+}
+
+data "aws_eks_cluster" "cluster" {
+  name = module.eks.cluster_id
+}
+
+data "aws_eks_cluster_auth" "cluster" {
+  name = module.eks.cluster_id
+}
+
+provider "kubernetes" {
+  host                   = data.aws_eks_cluster.cluster.endpoint
+  cluster_ca_certificate = base64decode(data.aws_eks_cluster.cluster.certificate_authority.0.data)
+  token                  = data.aws_eks_cluster_auth.cluster.token
+  load_config_file       = false
+  version                = "~> 1.10"
+}
+
+data "aws_availability_zones" "available" {}
+
+data "aws_caller_identity" "current" {}
+
+module "vpc" {
+  source               = "terraform-aws-modules/vpc/aws"
+  version              = "2.6.0"
+  name                 = "test-vpc"
+  cidr                 = "10.0.0.0/16"
+  azs                  = data.aws_availability_zones.available.names
+  public_subnets       = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
+  enable_dns_hostnames = true
+
+  tags = {
+    "kubernetes.io/cluster/${local.cluster_name}" = "shared"
+  }
+
+  public_subnet_tags = {
+    "kubernetes.io/cluster/${local.cluster_name}" = "shared"
+    "kubernetes.io/role/elb"                      = "1"
+  }
+}
+
+module "eks" {
+  source       = "../.."
+  cluster_name = local.cluster_name
+  subnets      = module.vpc.public_subnets
+  vpc_id       = module.vpc.vpc_id
+  enable_irsa  = true
+
+  worker_groups = [
+    {
+      name                 = "worker-group-1"
+      instance_type        = "t2.medium"
+      asg_desired_capacity = 1
+      tags = [
+        {
+          "key"                 = "k8s.io/cluster-autoscaler/enabled"
+          "propagate_at_launch" = "false"
+          "value"               = "true"
+        }
+      ]
+    }
+  ]
+}