[fix] Add FoundationDB chart retention guardrails

helm-charts/doris-foundationdb/README.md

@@ -22,4 +22,22 @@ The foundationdb cluster is a practice for doris.
 4. Install doris-foundationdb
    ```Bash
    $ helm install doris-foundationdb selectdb/doris-foundationdb
-   ```
+   ```
+
+## Data safety notes
+
+- Keep FoundationDB in a dedicated Helm or Flux release. Doris configMap or compute-group changes should not rebuild the FoundationDB release.
+- This chart keeps the `FoundationDBCluster` resource by default with `helm.sh/resource-policy: keep` to reduce accidental metadata loss during Helm uninstall or release replacement.
+- Use a `StorageClass` with `reclaimPolicy=Retain` for FoundationDB metadata volumes. The PVC template controls claim shape, but the `StorageClass` controls PV retention behavior.
+
+Example values:
+
+```yaml
+keepClusterResource: true
+volumeClaimTemplate:
+  spec:
+    storageClassName: retain-sc
+    resources:
+      requests:
+        storage: 50G
+```

helm-charts/doris-foundationdb/templates/foundationdb.yaml

@@ -19,6 +19,10 @@ apiVersion: apps.foundationdb.org/v1beta2
 kind: FoundationDBCluster
 metadata:
   name: {{ include "foundationdb.clusterName" . }}
+  {{- if .Values.keepClusterResource }}
+  annotations:
+    helm.sh/resource-policy: keep
+  {{- end }}
 spec:
   databaseConfiguration:
     redundancy_mode: {{ template "foundationdb.redundancyMode" }}

helm-charts/doris-foundationdb/values.yaml

@@ -1,6 +1,11 @@
 # specify the foundationdb cluster name
 name: test-cluster
 
+# Keep the FoundationDBCluster object during Helm uninstall or release
+# replacement so that unrelated Doris chart changes do not implicitly tear
+# down the metadata cluster.
+keepClusterResource: true
+
 #specify the data replicas. enum: single, double, triple
 redundancy_mode: "double"
 
@@ -34,8 +39,11 @@ resources:
 
 # VolumeClaimTemplate allows customizing the persistent volume claim for the pod.
 # this config reference the kubernetes doc about statefulset volumeClaimTemplate: https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/
+# Production metadata volumes should use a StorageClass with
+# reclaimPolicy=Retain. PVC template fields alone do not control PV retention.
 volumeClaimTemplate:
   spec:
+    # storageClassName: retain-sc
     resources:
       requests:
         storage: 50G