fix: adding tags to auto scaling groups (PSCLOUD-3) (#415)

Author: lohitdave

locals.tf

@@ -130,7 +130,6 @@ locals {
       launch_template_name            = "${local.cluster_name}-default-lt"
       launch_template_use_name_prefix = true
       launch_template_tags            = { Name = "${local.cluster_name}-default" }
-      tags                            = var.autoscaling_enabled ? merge(local.tags, { "k8s.io/cluster-autoscaler/${local.cluster_name}" = "owned", propagate_at_launch = true }, { "k8s.io/cluster-autoscaler/enabled" = "true", propagate_at_launch = true }) : local.tags
 
       # Node Pool IAM Configuration
       iam_role_use_name_prefix = false
@@ -181,7 +180,6 @@ locals {
       launch_template_name            = "${local.cluster_name}-${key}-lt"
       launch_template_use_name_prefix = true
       launch_template_tags            = { Name = "${local.cluster_name}-${key}" }
-      tags                            = var.autoscaling_enabled ? merge(local.tags, { "k8s.io/cluster-autoscaler/${local.cluster_name}" = "owned", propagate_at_launch = true }, { "k8s.io/cluster-autoscaler/enabled" = "true", propagate_at_launch = true }) : local.tags
       # Node Pool IAM Configuration
       iam_role_use_name_prefix = false
       iam_role_name            = "${var.prefix}-${key}-eks-node-group"
@@ -224,4 +222,24 @@ locals {
     }
   } : {}
 
+  # Used while tagging the EKS created ASGs with our user specified set of tags
+  node_group_names = keys(local.node_groups)
+  # Merge user tags with autoscaler tags when autoscaling is enabled
+  all_node_group_tags = var.autoscaling_enabled ? merge(
+    local.tags,
+    {
+      "k8s.io/cluster-autoscaler/${local.cluster_name}" = "owned"
+      "k8s.io/cluster-autoscaler/enabled"               = "true"
+    }
+  ) : local.tags
+  node_group_tags = flatten([
+    for ng_name in local.node_group_names : [
+      for tag_key, tag_value in local.all_node_group_tags : {
+        node_group = ng_name
+        key        = tag_key
+        value      = tag_value
+      }
+    ]
+  ])
+
 }

main.tf

@@ -183,12 +183,35 @@ module "eks" {
     # BYO - EKS Workers IAM Role
     create_iam_role = var.workers_iam_role_arn == null ? true : false
     iam_role_arn    = var.workers_iam_role_arn
+
+    # Tags to propagate to node groups and their Auto Scaling Groups
+    tags = local.tags
   }
 
   ## Any individual Node Group customizations should go here
   eks_managed_node_groups = local.node_groups # Node group definitions (from locals)
 }
 
+# Tag the EKS created ASGs - ensures tags are explicitly applied to AutoScalingGroups
+# This is more reliable than relying solely on EKS module propagation
+resource "aws_autoscaling_group_tag" "node_group_tags" {
+  # The for_each loop results in one resource created per node group per tag
+  for_each = {
+    for item in local.node_group_tags :
+    "${item.node_group}-${item.key}" => item
+  }
+  # Reference the single ASG for this node group
+  autoscaling_group_name = module.eks.eks_managed_node_groups[each.value.node_group].node_group_autoscaling_group_names[0]
+
+  tag {
+    key                 = each.value.key
+    value               = each.value.value
+    propagate_at_launch = true
+  }
+
+  depends_on = [module.eks]
+}
+
 # Resource to create EKS access entries for admin IAM roles. Used for EKS RBAC.
 resource "aws_eks_access_entry" "instance" {
   for_each = toset(coalesce(var.admin_access_entry_role_arns, []))