feat: Longhorn S3 backup to MinIO (daily, retain 7)

apps/longhorn-backup/recurring-job.yaml

@@ -0,0 +1,12 @@
+apiVersion: longhorn.io/v1beta2
+kind: RecurringJob
+metadata:
+  name: daily-backup
+  namespace: longhorn-system
+spec:
+  cron: "0 4 * * *"
+  task: backup
+  groups:
+    - default
+  retain: 7
+  concurrency: 1

argocd-apps/longhorn-backup.yaml

@@ -0,0 +1,20 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: longhorn-backup
+  namespace: argocd
+  finalizers:
+    - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  source:
+    repoURL: http://10.10.10.1:3000/claude/k8s-apps.git
+    targetRevision: main
+    path: apps/longhorn-backup
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: longhorn-system
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true

argocd-apps/longhorn.yaml

@@ -17,6 +17,8 @@ spec:
           defaultReplicaCount: 2
           defaultDataPath: /var/lib/longhorn
           guaranteedInstanceManagerCPU: 5
+          backupTarget: "s3://longhorn-backups@us-east-1/"
+          backupTargetCredentialSecret: minio-secret
         persistence:
           defaultClass: true
           defaultClassReplicaCount: 2