feat: Add load_balancer_controller targetgroup binding only role (#199)

examples/iam-role-for-service-accounts-eks/README.md

@@ -38,6 +38,7 @@ No providers.
 | <a name="module_irsa_role"></a> [irsa\_role](#module\_irsa\_role) | ../../modules/iam-role-for-service-accounts-eks | n/a |
 | <a name="module_karpenter_controller_irsa_role"></a> [karpenter\_controller\_irsa\_role](#module\_karpenter\_controller\_irsa\_role) | ../../modules/iam-role-for-service-accounts-eks | n/a |
 | <a name="module_load_balancer_controller_irsa_role"></a> [load\_balancer\_controller\_irsa\_role](#module\_load\_balancer\_controller\_irsa\_role) | ../../modules/iam-role-for-service-accounts-eks | n/a |
+| <a name="module_load_balancer_controller_targetgroup_binding_only_irsa_role"></a> [load\_balancer\_controller\_targetgroup\_binding\_only\_irsa\_role](#module\_load\_balancer\_controller\_targetgroup\_binding\_only\_irsa\_role) | ../../modules/iam-role-for-service-accounts-eks | n/a |
 | <a name="module_node_termination_handler_irsa_role"></a> [node\_termination\_handler\_irsa\_role](#module\_node\_termination\_handler\_irsa\_role) | ../../modules/iam-role-for-service-accounts-eks | n/a |
 | <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 3.0 |
 | <a name="module_vpc_cni_ipv4_irsa_role"></a> [vpc\_cni\_ipv4\_irsa\_role](#module\_vpc\_cni\_ipv4\_irsa\_role) | ../../modules/iam-role-for-service-accounts-eks | n/a |

examples/iam-role-for-service-accounts-eks/main.tf

@@ -182,6 +182,22 @@ module "load_balancer_controller_irsa_role" {
   tags = local.tags
 }
 
+module "load_balancer_controller_targetgroup_binding_only_irsa_role" {
+  source = "../../modules/iam-role-for-service-accounts-eks"
+
+  role_name                                                       = "load_balancer_controller_targetgroup_binding_only"
+  attach_load_balancer_controller_targetgroup_binding_only_policy = true
+
+  oidc_providers = {
+    ex = {
+      provider_arn               = module.eks.oidc_provider_arn
+      namespace_service_accounts = ["kube-system:aws-load-balancer-controller"]
+    }
+  }
+
+  tags = local.tags
+}
+
 ################################################################################
 # Supporting Resources
 ################################################################################

modules/iam-role-for-service-accounts-eks/README.md

@@ -113,6 +113,7 @@ No modules.
 | [aws_iam_policy.external_dns](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy) | resource |
 | [aws_iam_policy.karpenter_controller](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy) | resource |
 | [aws_iam_policy.load_balancer_controller](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy) | resource |
+| [aws_iam_policy.load_balancer_controller_targetgroup_only](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy) | resource |
 | [aws_iam_policy.node_termination_handler](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy) | resource |
 | [aws_iam_policy.vpc_cni](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy) | resource |
 | [aws_iam_role.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role) | resource |
@@ -121,6 +122,7 @@ No modules.
 | [aws_iam_role_policy_attachment.external_dns](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
 | [aws_iam_role_policy_attachment.karpenter_controller](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
 | [aws_iam_role_policy_attachment.load_balancer_controller](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
+| [aws_iam_role_policy_attachment.load_balancer_controller_targetgroup_only](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
 | [aws_iam_role_policy_attachment.node_termination_handler](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
 | [aws_iam_role_policy_attachment.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
 | [aws_iam_role_policy_attachment.vpc_cni](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role_policy_attachment) | resource |
@@ -130,6 +132,7 @@ No modules.
 | [aws_iam_policy_document.external_dns](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
 | [aws_iam_policy_document.karpenter_controller](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
 | [aws_iam_policy_document.load_balancer_controller](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
+| [aws_iam_policy_document.load_balancer_controller_targetgroup_only](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
 | [aws_iam_policy_document.node_termination_handler](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
 | [aws_iam_policy_document.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
 | [aws_iam_policy_document.vpc_cni](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
@@ -145,6 +148,7 @@ No modules.
 | <a name="input_attach_external_dns_policy"></a> [attach\_external\_dns\_policy](#input\_attach\_external\_dns\_policy) | Determines whether to attach the External DNS IAM policy to the role | `bool` | `false` | no |
 | <a name="input_attach_karpenter_controller_policy"></a> [attach\_karpenter\_controller\_policy](#input\_attach\_karpenter\_controller\_policy) | Determines whether to attach the Karpenter Controller policy to the role | `bool` | `false` | no |
 | <a name="input_attach_load_balancer_controller_policy"></a> [attach\_load\_balancer\_controller\_policy](#input\_attach\_load\_balancer\_controller\_policy) | Determines whether to attach the Load Balancer Controller policy to the role | `bool` | `false` | no |
+| <a name="input_attach_load_balancer_controller_targetgroup_binding_only_policy"></a> [attach\_load\_balancer\_controller\_targetgroup\_binding\_only\_policy](#input\_attach\_load\_balancer\_controller\_targetgroup\_binding\_only\_policy) | Determines whether to attach the Load Balancer Controller policy for the TargetGroupBinding only | `bool` | `false` | no |
 | <a name="input_attach_node_termination_handler_policy"></a> [attach\_node\_termination\_handler\_policy](#input\_attach\_node\_termination\_handler\_policy) | Determines whether to attach the Node Termination Handler policy to the role | `bool` | `false` | no |
 | <a name="input_attach_vpc_cni_policy"></a> [attach\_vpc\_cni\_policy](#input\_attach\_vpc\_cni\_policy) | Determines whether to attach the VPC CNI IAM policy to the role | `bool` | `false` | no |
 | <a name="input_cluster_autoscaler_cluster_ids"></a> [cluster\_autoscaler\_cluster\_ids](#input\_cluster\_autoscaler\_cluster\_ids) | List of cluster IDs to appropriately scope permissions within the Cluster Autoscaler IAM policy | `list(string)` | `[]` | no |

modules/iam-role-for-service-accounts-eks/policies.tf

@@ -763,3 +763,47 @@ resource "aws_iam_role_policy_attachment" "load_balancer_controller" {
   role       = aws_iam_role.this[0].name
   policy_arn = aws_iam_policy.load_balancer_controller[0].arn
 }
+
+################################################################################
+# AWS Load Balancer Controller TargetGroup Binding Only Policy
+################################################################################
+
+# https://kubernetes-sigs.github.io/aws-load-balancer-controller/v2.4/guide/targetgroupbinding/targetgroupbinding/#reference
+# https://kubernetes-sigs.github.io/aws-load-balancer-controller/v2.4/deploy/installation/#setup-iam-manually
+data "aws_iam_policy_document" "load_balancer_controller_targetgroup_only" {
+  count = var.create_role && var.attach_load_balancer_controller_targetgroup_binding_only_policy ? 1 : 0
+
+  statement {
+    actions = [
+      "ec2:DescribeSecurityGroups",
+      "ec2:DescribeInstances",
+      "ec2:DescribeVpcs",
+      "elasticloadbalancing:DescribeTargetGroups",
+      "elasticloadbalancing:DescribeTargetHealth",
+      "elasticloadbalancing:ModifyTargetGroup",
+      "elasticloadbalancing:ModifyTargetGroupAttributes",
+      "elasticloadbalancing:RegisterTargets",
+      "elasticloadbalancing:DeregisterTargets"
+    ]
+
+    resources = ["*"]
+  }
+}
+
+resource "aws_iam_policy" "load_balancer_controller_targetgroup_only" {
+  count = var.create_role && var.attach_load_balancer_controller_targetgroup_binding_only_policy ? 1 : 0
+
+  name_prefix = "AmazonEKS_AWS_Load_Balancer_Controller_TargetGroup_Only-"
+  path        = var.role_path
+  description = "Provides permissions for AWS Load Balancer Controller addon in TargetGroup binding only scenario."
+  policy      = data.aws_iam_policy_document.load_balancer_controller_targetgroup_only[0].json
+
+  tags = var.tags
+}
+
+resource "aws_iam_role_policy_attachment" "load_balancer_controller_targetgroup_only" {
+  count = var.create_role && var.attach_load_balancer_controller_targetgroup_binding_only_policy ? 1 : 0
+
+  role       = aws_iam_role.this[0].name
+  policy_arn = aws_iam_policy.load_balancer_controller_targetgroup_only[0].arn
+}

modules/iam-role-for-service-accounts-eks/variables.tf

@@ -177,3 +177,11 @@ variable "attach_load_balancer_controller_policy" {
   type        = bool
   default     = false
 }
+
+# https://kubernetes-sigs.github.io/aws-load-balancer-controller/v2.4/guide/targetgroupbinding/targetgroupbinding/#reference
+# https://kubernetes-sigs.github.io/aws-load-balancer-controller/v2.4/deploy/installation/#setup-iam-manually
+variable "attach_load_balancer_controller_targetgroup_binding_only_policy" {
+  description = "Determines whether to attach the Load Balancer Controller policy for the TargetGroupBinding only"
+  type        = bool
+  default     = false
+}