feat: add support for coredns_affinity (#11994)

Signed-off-by: Ho Kim <ho.kim@ulagbulag.io>
Co-authored-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>

roles/kubernetes-apps/ansible/defaults/main.yml

@@ -13,6 +13,17 @@ dns_prevent_single_point_failure: "{{ 'true' if dns_min_replicas | int > 1 else
 enable_coredns_reverse_dns_lookups: true
 coredns_ordinal_suffix: ""
 # dns_extra_tolerations: [{effect: NoSchedule, operator: "Exists"}]
+coredns_affinity:
+  podAntiAffinity:
+    preferredDuringSchedulingIgnoredDuringExecution:
+    - weight: 100
+      podAffinityTerm:
+        labelSelector:
+          matchExpressions:
+          - key: k8s-app
+            operator: In
+            values: ["kube-dns"]
+        topologyKey: kubernetes.io/hostname
 coredns_deployment_nodeselector: "kubernetes.io/os: linux"
 coredns_default_zone_cache_block: |
   cache 30