Feature/Add support for strategy on deployments

helm/README.md

@@ -0,0 +1,12 @@
+## Strategy + Azure storage
+
+### Why these errors happen (short)
+- `FailedAttachVolume` / `FailedVolumeAttach`: usually occurs when the PVC is backed by ReadWriteOnce (RWO) storage and Kubernetes attempts to start a new Pod before the old Pod has fully released/detached the volume.Because the same volume can’t be attached to two Pods/nodes at once, the attach step fails and the rollout can get stuck.
+- `database is locked` (SQLite): after switching the PVC `storageClass` to `azurefile-csi`, the app started hitting SQLite lock errors.
+
+We observed these issues during rollouts on Azure when multiple Pods briefly overlapped.
+
+### Current approach (what we use)
+We use `strategy.type: Recreate` so upgrades run only one Pod at a time:
+- switched back to the default storage class
+- `Recreate` avoids parallel Pod overlap, which prevents volume attach conflicts and reduces the chance of SQLite locking problems

helm/snapshots/alpha-1.yaml

@@ -103,6 +103,8 @@ metadata:
     app.kubernetes.io/managed-by: Helm
 spec:
   replicas: 1
+  strategy:
+    type: Recreate
   selector:
     matchLabels:
       app.kubernetes.io/name: cacheppuccino-helm

helm/snapshots/staging.yaml

@@ -46,9 +46,8 @@ metadata:
     app.kubernetes.io/version: "0.1.0"
     app.kubernetes.io/managed-by: Helm
 spec:
-  storageClassName: "azurefile-csi"
   accessModes:
-    - ReadWriteMany
+    - ReadWriteOnce
   resources:
     requests:
       storage: "512Mi"
@@ -90,6 +89,8 @@ metadata:
     app.kubernetes.io/managed-by: Helm
 spec:
   replicas: 1
+  strategy:
+    type: Recreate
   selector:
     matchLabels:
       app.kubernetes.io/name: cacheppuccino-helm

helm/templates/deployment.yaml

@@ -9,6 +9,8 @@ metadata:
     {{- include "cacheppuccino.labels" . | nindent 4 }}
 spec:
   replicas: {{ .Values.replicaCount }}
+  strategy:
+    type: Recreate
   selector:
     matchLabels:
       {{- include "cacheppuccino.selectorLabels" . | nindent 6 }}

helm/templates/pvc.yaml

@@ -10,7 +10,7 @@ spec:
   storageClassName: {{ .Values.sqlite.pvc.storageClassName | quote }}
   {{- end }}
   accessModes:
-    {{- toYaml .Values.sqlite.pvc.accessModes | nindent 4 }}
+    - ReadWriteOnce
   resources:
     requests:
       storage: {{ .Values.sqlite.pvc.size | quote }}

helm/values/go-deploy.yaml

@@ -11,9 +11,6 @@ ingress:
 sqlite:
   pvc:
     size: 512Mi
-    storageClassName: azurefile-csi
-    accessModes:
-      - ReadWriteMany
 
 serviceAccount:
   create: true