Add podAntiAffinity to node-healthceck-controller-manager deployment to improve HA

Use preferred podAntiAffinity for node-healthcheck-controller-manager to improve HA by avoiding co-scheduling of replicas on the same node.

Signed-off-by: Katsuya Kawakami <[email protected]>

Author: kattz-kawa

bundle/manifests/node-healthcheck-operator.clusterserviceversion.yaml

@@ -452,6 +452,21 @@ spec:
                       - key: node-role.kubernetes.io/control-plane
                         operator: Exists
                     weight: 1
+                podAntiAffinity:
+                  preferredDuringSchedulingIgnoredDuringExecution:
+                  - podAffinityTerm:
+                      labelSelector:
+                        matchExpressions:
+                        - key: app.kubernetes.io/component
+                          operator: In
+                          values:
+                          - controller-manager
+                        - key: app.kubernetes.io/name
+                          operator: In
+                          values:
+                          - node-healthcheck-operator
+                      topologyKey: kubernetes.io/hostname
+                    weight: 100
               containers:
               - args:
                 - --secure-listen-address=0.0.0.0:8443

config/patches/affinity/kustomization.yaml

@@ -4,3 +4,7 @@ patches:
 - path: node_affinity_patch.yaml
   target:
     kind: Deployment
+- path: podantiaffinity_patch.yaml
+  target:
+    kind: Deployment
+    name: controller-manager

config/patches/affinity/podantiaffinity_patch.yaml

@@ -0,0 +1,23 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: n/a
+spec:
+  template:
+    spec:
+      affinity:
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 100
+              podAffinityTerm:
+                labelSelector:
+                  matchExpressions:
+                    - key: app.kubernetes.io/component
+                      operator: In
+                      values:
+                        - controller-manager
+                    - key: app.kubernetes.io/name
+                      operator: In
+                      values:
+                        - node-healthcheck-operator
+                topologyKey: kubernetes.io/hostname