From 7721c5dc55d00d47f02c53c0215457cc1d868b66 Mon Sep 17 00:00:00 2001
From: nerahou <nrahou@synamedia.com>
Date: Tue, 16 Apr 2024 09:41:10 +0200
Subject: [PATCH] manage eniconfig labels

---
 main.tf                | 18 +++++++++++++++++-
 node_group_advanced.tf | 16 ++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/main.tf b/main.tf
index 576a1fe..fa515c8 100644
--- a/main.tf
+++ b/main.tf
@@ -25,7 +25,7 @@ locals {
   node_group_labels = [
     for key, node_group in var.node_groups :
     {
-      for k, v in lookup(node_group, "labels", {}) :
+      for k, v in lookup(node_group, "labels", { "k8s.amazonaws.com/eniConfig" : data.aws_subnet.subnets[key].availability_zone }) :
       key => {
         "k8s.io/cluster-autoscaler/node-template/label/${k}" : v
         (k) : v
@@ -65,6 +65,14 @@ data "aws_caller_identity" "current" {}
 # This datasource is used to get the region currently used by the AWS provider
 data "aws_region" "current" {}
 
+data "aws_subnet" "subnets" {
+  for_each = var.node_groups
+  filter {
+    name   = "subnet-id"
+    values = lookup(each.value, "subnet_ids", [])
+  }
+}
+
 # Cluster
 resource "aws_eks_cluster" "quortex" {
   name     = var.cluster_name
@@ -164,6 +172,10 @@ resource "aws_eks_node_group" "quortex" {
       "k8s.io/cluster-autoscaler/node-template/label/nodegroup" = each.key, # tag required for scaling to/from 0
     } : {},
     { "nodegroup" = each.key },
+    length(lookup(each.value, "subnet_ids", [])) == 1 ?
+    {
+      "k8s.amazonaws.com/eniConfig" : data.aws_subnet.subnets[each.key].availability_zone
+    } : {},
     lookup(each.value, "labels", {}),
     lookup(each.value, "tags", {}),
     var.tags
@@ -173,6 +185,10 @@ resource "aws_eks_node_group" "quortex" {
     {
       "nodegroup" = each.key
     },
+    length(lookup(each.value, "subnet_ids", [])) == 1 ?
+    {
+      "k8s.amazonaws.com/eniConfig" : data.aws_subnet.subnets[each.key].availability_zone
+    } : {},
     lookup(each.value, "labels", {})
   )
 
diff --git a/node_group_advanced.tf b/node_group_advanced.tf
index bc2d466..a483d02 100644
--- a/node_group_advanced.tf
+++ b/node_group_advanced.tf
@@ -35,6 +35,14 @@ locals {
   }
 }
 
+data "aws_subnet" "subnets_advanced" {
+  for_each = var.node_groups_advanced
+  filter {
+    name   = "subnet-id"
+    values = lookup(each.value, "subnet_ids", [])
+  }
+}
+
 # Get preferred instance types for node_groups_advanced with instance_filter preferred
 data "aws_ec2_instance_type_offering" "preferred" {
   for_each = local.filtered_nodegroups_advanced_preferred
@@ -115,6 +123,10 @@ resource "aws_launch_template" "quortex_launch_tpl" {
                     "eks.amazonaws.com/nodegroup"       = each.key,
                     "nodegroup"                         = each.key
                   },
+                  length(lookup(each.value, "subnet_ids", [])) == 1 ?
+                  {
+                    "k8s.amazonaws.com/eniConfig" : data.aws_subnet.subnets_advanced[each.key].availability_zone
+                  } : {},
                   # User-specified labels
                   lookup(each.value, "labels", {}),
                 )
@@ -274,6 +286,10 @@ resource "aws_autoscaling_group" "quortex_asg_advanced" {
       },
       # the following tags must be set on the ASG, and must match the k8s node labels/taints, for the autoscaler to be able to scale up from 0
       { for k, v in lookup(each.value, "labels", {}) : "k8s.io/cluster-autoscaler/node-template/label/${k}" => v },
+      length(lookup(each.value, "subnet_ids", [])) == 1 ?
+      {
+        "k8s.io/cluster-autoscaler/node-template/label/k8s.amazonaws.com/eniConfig" : data.aws_subnet.subnets_advanced[each.key].availability_zone
+      } : {},
       { for k, v in lookup(each.value, "taints", {}) : "k8s.io/cluster-autoscaler/node-template/taint/${k}" => v },
     ) : {}
     iterator = tag