Adding support for existing cluster

truefoundry · Nov 21, 2024 · 03a30af · 03a30af
1 parent 3dd19cd
commit 03a30af
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Showing 8 changed files with 195 additions and 35 deletions.
diff --git a/data.tf b/data.tf
@@ -0,0 +1,7 @@
+data "aws_eks_cluster" "eks_cluster" {
+  count = var.use_existing_cluster ? 1 : 0
+  name  = var.cluster_name
+}
+
+# To do
+# apply data block for openid_connect_provider to fetch openid arn directly using eks cluster oidc[0].issuer[0].url
diff --git a/eks.tf b/eks.tf
@@ -3,6 +3,7 @@
 ###################################################################################
 
 module "aws-eks-kubernetes-cluster" {
+  count                                 = var.use_existing_cluster ? 0 : 1
   source                                = "terraform-aws-modules/eks/aws"
   version                               = "v20.17.2"
   cluster_name                          = var.cluster_name

diff --git a/eks_addons.tf b/eks_addons.tf
@@ -3,13 +3,14 @@
 ###################################################################################
 
 module "eks_blueprints_addons" {
+  count   = var.use_existing_cluster ? 0 : 1
   source  = "aws-ia/eks-blueprints-addons/aws"
   version = "1.16.3"
 
-  cluster_name      = module.aws-eks-kubernetes-cluster.cluster_name
-  cluster_endpoint  = module.aws-eks-kubernetes-cluster.cluster_endpoint
-  cluster_version   = module.aws-eks-kubernetes-cluster.cluster_version
-  oidc_provider_arn = module.aws-eks-kubernetes-cluster.oidc_provider_arn
+  cluster_name      = module.aws-eks-kubernetes-cluster[0].cluster_name
+  cluster_endpoint  = module.aws-eks-kubernetes-cluster[0].cluster_endpoint
+  cluster_version   = module.aws-eks-kubernetes-cluster[0].cluster_version
+  oidc_provider_arn = module.aws-eks-kubernetes-cluster[0].oidc_provider_arn
 
   eks_addons = {
     coredns = {

diff --git a/locals.tf b/locals.tf
@@ -104,4 +104,30 @@ locals {
   } : {})
 
   karpenter_profile_name = "${var.cluster_name}-karpenter"
+
+  // this is used when use_existing_cluster is set to true, so that we don't have to modify eks_managed_node_groups
+  output_eks_managed_node_groups = tomap({
+    "initial" = {
+      autoscaling_group_schedule_arns    = {}
+      iam_role_arn                       = var.existing_cluster_node_role_arn
+      iam_role_unique_id                 = {}
+      launch_template_arn                = ""
+      launch_template_id                 = ""
+      autoscaling_group_schedule_arns    = {}
+      iam_role_name                      = ""
+      iam_role_unique_id                 = ""
+      launch_template_arn                = ""
+      launch_template_id                 = ""
+      launch_template_latest_version     = 0
+      launch_template_name               = ""
+      node_group_arn                     = ""
+      node_group_autoscaling_group_names = []
+      node_group_id                      = ""
+      node_group_labels                  = {}
+      node_group_resources               = []
+      node_group_status                  = ""
+      node_group_taints                  = []
+      platform                           = ""
+    }
+  })
 }
diff --git a/output.tf b/output.tf
@@ -3,50 +3,55 @@
 ################################################################################
 # Cluster
 ################################################################################
+output "use_existing_cluster" {
+  description = "Flag to check if you are using an alreday existing cluster"
+  value       = var.use_existing_cluster
+}
 
 output "cluster_arn" {
   description = "The Amazon Resource Name (ARN) of the cluster"
-  value       = module.aws-eks-kubernetes-cluster.cluster_arn
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].arn : module.aws-eks-kubernetes-cluster[0].cluster_arn
 }
 
 output "cluster_certificate_authority_data" {
   description = "Base64 encoded certificate data required to communicate with the cluster"
-  value       = module.aws-eks-kubernetes-cluster.cluster_certificate_authority_data
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].certificate_authority[0].data : module.aws-eks-kubernetes-cluster[0].cluster_certificate_authority_data
 }
 
 output "cluster_endpoint" {
   description = "Endpoint for your Kubernetes API server"
-  value       = module.aws-eks-kubernetes-cluster.cluster_endpoint
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].endpoint : module.aws-eks-kubernetes-cluster[0].cluster_endpoint
 }
 
 output "cluster_id" {
   description = "DEPRECATED - Use cluster_name"
-  value       = module.aws-eks-kubernetes-cluster.cluster_name
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].id : module.aws-eks-kubernetes-cluster[0].cluster_name
 }
 
 output "cluster_name" {
   description = "The name/id of the EKS cluster. Will block on cluster creation until the cluster is really ready"
-  value       = module.aws-eks-kubernetes-cluster.cluster_name
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].name : module.aws-eks-kubernetes-cluster[0].cluster_name
 }
 
 output "cluster_oidc_issuer_url" {
   description = "The URL on the EKS cluster for the OpenID Connect identity provider"
-  value       = module.aws-eks-kubernetes-cluster.cluster_oidc_issuer_url
+  # value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].identity[0].oidc[0].issuer : module.aws-eks-kubernetes-cluster[0].cluster_oidc_issuer_url
+  value = var.use_existing_cluster ? var.existing_cluster_oidc_issuer_url : module.aws-eks-kubernetes-cluster[0].cluster_oidc_issuer_url
 }
 
 output "cluster_platform_version" {
   description = "Platform version for the cluster"
-  value       = module.aws-eks-kubernetes-cluster.cluster_platform_version
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].platform_version : module.aws-eks-kubernetes-cluster[0].cluster_platform_version
 }
 
 output "cluster_status" {
   description = "Status of the EKS cluster. One of `CREATING`, `ACTIVE`, `DELETING`, `FAILED`"
-  value       = module.aws-eks-kubernetes-cluster.cluster_status
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].status : module.aws-eks-kubernetes-cluster[0].cluster_status
 }
 
 output "cluster_primary_security_group_id" {
   description = "Cluster security group that was created by Amazon EKS for the cluster. Managed node groups use this security group for control-plane-to-data-plane communication. Referred to as 'Cluster security group' in the EKS console"
-  value       = module.aws-eks-kubernetes-cluster.cluster_primary_security_group_id
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].vpc_config[0].cluster_security_group_id : module.aws-eks-kubernetes-cluster[0].cluster_primary_security_group_id
 }
 
 ################################################################################
@@ -55,12 +60,12 @@ output "cluster_primary_security_group_id" {
 
 output "cluster_security_group_arn" {
   description = "Amazon Resource Name (ARN) of the cluster security group"
-  value       = module.aws-eks-kubernetes-cluster.cluster_security_group_arn
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].cluster_security_group_arn
 }
 
 output "cluster_security_group_id" {
   description = "ID of the cluster security group"
-  value       = module.aws-eks-kubernetes-cluster.cluster_security_group_id
+  value       = var.use_existing_cluster ? data.aws_eks_cluster.eks_cluster[0].vpc_config[0].cluster_security_group_id : module.aws-eks-kubernetes-cluster[0].cluster_security_group_id
 }
 
 ################################################################################
@@ -69,21 +74,21 @@ output "cluster_security_group_id" {
 
 output "node_security_group_arn" {
   description = "Amazon Resource Name (ARN) of the node shared security group"
-  value       = module.aws-eks-kubernetes-cluster.node_security_group_arn
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].node_security_group_arn
 }
 
 output "node_security_group_id" {
   description = "ID of the node shared security group"
-  value       = module.aws-eks-kubernetes-cluster.node_security_group_id
+  value       = var.use_existing_cluster ? var.existing_cluster_node_security_group_id : module.aws-eks-kubernetes-cluster[0].node_security_group_id
 }
 
 ################################################################################
 # IRSA
 ################################################################################
 
 output "oidc_provider_arn" {
-  description = "The ARN of the OIDC Provider if `enable_irsa = true`"
-  value       = module.aws-eks-kubernetes-cluster.oidc_provider_arn
+  description = "The ARN of the OIDC Provider"
+  value       = var.use_existing_cluster ? var.existing_cluster_oidc_issuer_arn : module.aws-eks-kubernetes-cluster[0].oidc_provider_arn
 }
 
 ################################################################################
@@ -92,17 +97,17 @@ output "oidc_provider_arn" {
 
 output "cluster_iam_role_name" {
   description = "IAM role name of the EKS cluster"
-  value       = module.aws-eks-kubernetes-cluster.cluster_iam_role_name
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].cluster_iam_role_name
 }
 
 output "cluster_iam_role_arn" {
   description = "IAM role ARN of the EKS cluster"
-  value       = module.aws-eks-kubernetes-cluster.cluster_iam_role_arn
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].cluster_iam_role_arn
 }
 
 output "cluster_iam_role_unique_id" {
   description = "Stable and unique string identifying the IAM role"
-  value       = module.aws-eks-kubernetes-cluster.cluster_iam_role_unique_id
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].cluster_iam_role_unique_id
 }
 
 ################################################################################
@@ -111,7 +116,7 @@ output "cluster_iam_role_unique_id" {
 
 output "cluster_addons" {
   description = "Map of attribute maps for all EKS cluster addons enabled"
-  value       = module.eks_blueprints_addons.eks_addons
+  value       = var.use_existing_cluster ? {} : module.eks_blueprints_addons[0].eks_addons
 }
 
 ################################################################################
@@ -120,7 +125,7 @@ output "cluster_addons" {
 
 output "cluster_identity_providers" {
   description = "Map of attribute maps for all EKS identity providers enabled"
-  value       = module.aws-eks-kubernetes-cluster.cluster_identity_providers
+  value       = var.use_existing_cluster ? {} : module.aws-eks-kubernetes-cluster[0].cluster_identity_providers
   sensitive   = true
 }
 
@@ -130,12 +135,12 @@ output "cluster_identity_providers" {
 
 output "cloudwatch_log_group_name" {
   description = "Name of cloudwatch log group created"
-  value       = module.aws-eks-kubernetes-cluster.cloudwatch_log_group_name
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].cloudwatch_log_group_name
 }
 
 output "cloudwatch_log_group_arn" {
   description = "Arn of cloudwatch log group created"
-  value       = module.aws-eks-kubernetes-cluster.cloudwatch_log_group_arn
+  value       = var.use_existing_cluster ? "" : module.aws-eks-kubernetes-cluster[0].cloudwatch_log_group_arn
 }
 
 ################################################################################
@@ -144,7 +149,7 @@ output "cloudwatch_log_group_arn" {
 
 output "fargate_profiles" {
   description = "Map of attribute maps for all EKS Fargate Profiles created"
-  value       = module.aws-eks-kubernetes-cluster.fargate_profiles
+  value       = var.use_existing_cluster ? {} : module.aws-eks-kubernetes-cluster[0].fargate_profiles
 }
 
 ################################################################################
@@ -153,7 +158,7 @@ output "fargate_profiles" {
 
 output "eks_managed_node_groups" {
   description = "Map of attribute maps for all EKS managed node groups created"
-  value       = module.aws-eks-kubernetes-cluster.eks_managed_node_groups
+  value       = var.use_existing_cluster ? local.output_eks_managed_node_groups : module.aws-eks-kubernetes-cluster[0].eks_managed_node_groups
 }
 
 ################################################################################
@@ -162,7 +167,7 @@ output "eks_managed_node_groups" {
 
 output "self_managed_node_groups" {
   description = "Map of attribute maps for all self managed node groups created"
-  value       = module.aws-eks-kubernetes-cluster.self_managed_node_groups
+  value       = var.use_existing_cluster ? {} : module.aws-eks-kubernetes-cluster[0].self_managed_node_groups
 }
 
 ################################################################################
@@ -171,5 +176,5 @@ output "self_managed_node_groups" {
 
 output "aws_access_entries" {
   description = "Access entries for the EKS cluster security group"
-  value       = module.aws-eks-kubernetes-cluster.access_entries
+  value       = var.use_existing_cluster ? {} : module.aws-eks-kubernetes-cluster[0].access_entries
 }