experiment with pod affinity

kustomize/bases/nextcloud/kustomization.yaml

@@ -5,3 +5,11 @@ bases:
 resources:
   - nextcloud-deployment.yaml
   - nextcloud-ingress.yaml
+
+commonLabels:
+  app.kubernetes.io/name: nextcloud
+
+# TODO
+# patchesStrategicmerge:
+#   - patches/postgres-podaffinity-patch.yaml
+#   - patches/redis-podaffinity-patch.yaml

kustomize/bases/nextcloud/nextcloud-deployment.yaml

@@ -4,6 +4,7 @@ metadata:
   name: nextcloud
   labels:
     app.kubernetes.io/name: nextcloud
+    app.kubernetes.io/component: server
 spec:
   replicas: 1
   strategy:
@@ -11,22 +12,32 @@ spec:
   selector:
     matchLabels:
       app.kubernetes.io/name: nextcloud
+      app.kubernetes.io/component: server
   template:
     metadata:
       labels:
         app.kubernetes.io/name: nextcloud
+        app.kubernetes.io/component: server
     spec:
       affinity:
         nodeAffinity:
-          # prefer to not be on a server node (resource contention)
           preferredDuringSchedulingIgnoredDuringExecution:
             - weight: 1
               preference:
                 matchExpressions:
-                  - key: kubernetes.io/hostname
-                    operator: NotIn
-                    values:
-                      - k3s-s0
+                  - key: node-role.kubernetes.io/master
+                    operator: DoesNotExist
+        # podAffinity:
+        #   preferredDuringSchedulingIgnoredDuringExecution:
+        #     - weight: 2
+        #       podAffinityTerm:
+        #         labelSelector:
+        #           matchExpressions:
+        #             - key: app.kubernetes.io/name
+        #               operator: In
+        #               values:
+        #                 - nextcloud
+        #         topologyKey: kubernetes.io/hostname
       containers:
         - name: nextcloud
           image: nextcloud

kustomize/bases/nextcloud/patches/postgres-podaffinity-patch.yaml

@@ -0,0 +1,19 @@
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: postgres
+spec:
+  template:
+    spec:
+      affinity:
+        podAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 1
+              podAffinityTerm:
+                labelSelector:
+                  matchExpressions:
+                    - key: app.kubernetes.io/name
+                      operator: In
+                      values:
+                        - nextcloud
+                topologyKey: kubernetes.io/hostname

kustomize/bases/nextcloud/patches/redis-podaffinity-patch.yaml

@@ -0,0 +1,19 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: redis
+spec:
+  template:
+    spec:
+      affinity:
+        podAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 1
+              podAffinityTerm:
+                labelSelector:
+                  matchExpressions:
+                    - key: app.kubernetes.io/name
+                      operator: In
+                      values:
+                        - nextcloud
+                topologyKey: kubernetes.io/hostname

kustomize/bases/postgres/postgres-statefulset.yaml

@@ -3,17 +3,17 @@ kind: StatefulSet
 metadata:
   name: postgres
   labels:
-    app.kubernetes.io/name: postgres
+    app.kubernetes.io/component: postgres
 spec:
   serviceName: postgres
   selector:
     matchLabels:
-      app.kubernetes.io/name: postgres
+      app.kubernetes.io/component: postgres
   replicas: 1
   template:
     metadata:
       labels:
-        app.kubernetes.io/name: postgres
+        app.kubernetes.io/component: postgres
     spec:
       containers:
         - name: postgres

kustomize/bases/redis/redis-deployment.yaml

@@ -3,16 +3,16 @@ kind: Deployment
 metadata:
   name: redis
   labels:
-    app.kubernetes.io/name: redis
+    app.kubernetes.io/component: redis
 spec:
   replicas: 1
   selector:
     matchLabels:
-      app.kubernetes.io/name: redis
+      app.kubernetes.io/component: redis
   template:
     metadata:
       labels:
-        app.kubernetes.io/name: redis
+        app.kubernetes.io/component: redis
     spec:
       containers:
         - name: redis