From fa10955e24cb07e0cdb80e84dd2138b840ae3a49 Mon Sep 17 00:00:00 2001
From: Jacob Nesbitt <jjnesbitt2@gmail.com>
Date: Thu, 30 Apr 2026 16:35:02 -0400
Subject: [PATCH 1/2] Increase CoreDNS replica count and resources

---
 terraform/modules/spack_aws_k8s/eks.tf | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/terraform/modules/spack_aws_k8s/eks.tf b/terraform/modules/spack_aws_k8s/eks.tf
index 2ad6a3102..a8fd5da7c 100644
--- a/terraform/modules/spack_aws_k8s/eks.tf
+++ b/terraform/modules/spack_aws_k8s/eks.tf
@@ -48,6 +48,21 @@ module "eks" {
     coredns = {
       # https://docs.aws.amazon.com/eks/latest/userguide/managing-coredns.html#coredns-versions
       addon_version = "v1.12.4-eksbuild.1"
+      # Based on this example of CoreDNS configuration
+      # https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/docs/faq.md#what-configuration-values-are-available-for-an-add-on
+      configuration_values = jsonencode({
+        replicaCount = 4,
+        resources = {
+          requests = {
+            cpu    = "200m"
+            memory = "128Mi"
+          },
+          limits = {
+            cpu    = "400m"
+            memory = "256Mi"
+          }
+        }
+      })
     }
     eks-pod-identity-agent = {
       addon_version = "v1.3.9-eksbuild.3"

From b7c14724fa4c26ae0526ba7f099612d53a07a715 Mon Sep 17 00:00:00 2001
From: Jacob Nesbitt <jjnesbitt2@gmail.com>
Date: Fri, 1 May 2026 10:42:04 -0400
Subject: [PATCH 2/2] Add CoreDNS autoscaling config

---
 terraform/modules/spack_aws_k8s/eks.tf | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/terraform/modules/spack_aws_k8s/eks.tf b/terraform/modules/spack_aws_k8s/eks.tf
index a8fd5da7c..2cd7cf94d 100644
--- a/terraform/modules/spack_aws_k8s/eks.tf
+++ b/terraform/modules/spack_aws_k8s/eks.tf
@@ -51,7 +51,11 @@ module "eks" {
       # Based on this example of CoreDNS configuration
       # https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/docs/faq.md#what-configuration-values-are-available-for-an-add-on
       configuration_values = jsonencode({
-        replicaCount = 4,
+        autoScaling = {
+          enabled     = true
+          minReplicas = 2
+          maxReplicas = 10
+        },
         resources = {
           requests = {
             cpu    = "200m"
@@ -61,7 +65,7 @@ module "eks" {
             cpu    = "400m"
             memory = "256Mi"
           }
-        }
+        },
       })
     }
     eks-pod-identity-agent = {