add antiAffinity rules

cluster/apps/pihole/pihole.yml

@@ -16,6 +16,15 @@ spec:
         app: pihole
     spec:
       hostNetwork: true
+      affinity:
+        nodeAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            nodeSelectorTerms:
+            - matchExpressions:
+              - key: kubernetes.io/hostname
+                operator: In
+                values:
+                - kube-01
       containers:
       - name: pihole
         image: pihole/pihole@sha256:90a1412b3d3037d1c22131402bde19180d898255b584d685c84d943cf9c14821