From 2a08898a23e77e1eb10c01bffa0ba7d9b4849b9d Mon Sep 17 00:00:00 2001
From: Ultradesu <ultradesu@hexor.cy>
Date: Wed, 14 Oct 2026 13:57:36 +0100
Subject: [PATCH] Configure three CoreDNS replicas on core nodes

---
 k8s-ng/core-state/templates/applications.yaml |  3 +++
 k8s-ng/core-state/values.yaml                 |  5 +++++
 k8s-ng/core/coredns-config/deployment.yaml    | 22 +++++++++++++++++++
 k8s-ng/core/coredns-config/kustomization.yaml |  5 +++++
 4 files changed, 35 insertions(+)
 create mode 100644 k8s-ng/core/coredns-config/deployment.yaml
 create mode 100644 k8s-ng/core/coredns-config/kustomization.yaml

diff --git a/k8s-ng/core-state/templates/applications.yaml b/k8s-ng/core-state/templates/applications.yaml
index 8438561..85df577 100644
--- a/k8s-ng/core-state/templates/applications.yaml
+++ b/k8s-ng/core-state/templates/applications.yaml
@@ -23,6 +23,9 @@ spec:
     syncOptions:
       - CreateNamespace=true
       - ServerSideApply=true
+      {{- if and (hasKey . "validate") (not .validate) }}
+      - Validate=false
+      {{- end }}
       {{- if .skipDryRunOnMissingResource }}
       - SkipDryRunOnMissingResource=true
       {{- end }}
diff --git a/k8s-ng/core-state/values.yaml b/k8s-ng/core-state/values.yaml
index 36b4e50..027c327 100644
--- a/k8s-ng/core-state/values.yaml
+++ b/k8s-ng/core-state/values.yaml
@@ -24,6 +24,11 @@ apps:
     path: k8s-ng/core/traefik-config
     namespace: kube-system
     wave: 1
+  - name: coredns-config
+    path: k8s-ng/core/coredns-config
+    namespace: kube-system
+    wave: 1
+    validate: false # partial Deployment: only the fields we manage
   - name: reloader
     path: k8s-ng/core/reloader
     namespace: reloader
diff --git a/k8s-ng/core/coredns-config/deployment.yaml b/k8s-ng/core/coredns-config/deployment.yaml
new file mode 100644
index 0000000..ee708cc
--- /dev/null
+++ b/k8s-ng/core/coredns-config/deployment.yaml
@@ -0,0 +1,22 @@
+# K3s owns the CoreDNS Deployment. Apply only the fields customized here so
+# upstream image, probes, Corefile mounts and topology spread stay intact.
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system
+  annotations:
+    argocd.argoproj.io/sync-options: Prune=false,Delete=false
+spec:
+  replicas: 3
+  template:
+    spec:
+      affinity:
+        nodeAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            nodeSelectorTerms:
+              - matchExpressions:
+                  - key: homelab.hexor.cy/pool
+                    operator: In
+                    values:
+                      - core
diff --git a/k8s-ng/core/coredns-config/kustomization.yaml b/k8s-ng/core/coredns-config/kustomization.yaml
new file mode 100644
index 0000000..88a04b5
--- /dev/null
+++ b/k8s-ng/core/coredns-config/kustomization.yaml
@@ -0,0 +1,5 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - deployment.yaml