CODEWITHSUNDEEP
kubernetesgoogle-kubernetes-enginekubernetes-helm
Yogesh
Yogesh

Reputation: 4784

Helm deletes StorageClass but keeps Persistent volume claims

I am using helm to deploy StatefulSet, below is yaml

---
kind: StorageClass
apiVersion: storage.k8s.io/v1beta1
metadata:
  name: {{ .Values.database.mongo.storageClassName }}
  labels:
    for: for-mongo-statefulset
provisioner: kubernetes.io/gce-pd
parameters:
  type: pd-ssd
reclaimPolicy: Retain
---
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
  name: mongo
spec:
  serviceName: {{ .Values.database.mongo.serviceName }}
  replicas: {{ .Values.database.mongo.replicas }}
  template:
    metadata:
      labels:
        role: mongo
        environment: prod
    spec:
      serviceAccountName: {{ .Values.serviceAccount }}
      terminationGracePeriodSeconds: 10
      containers:
        - name: mongo
          image: mongo
          command:
            - mongod
            - "--bind_ip"
            - 0.0.0.0
            - "--replSet"
            - {{ .Values.database.mongo.replicaSet }}
            - "--smallfiles"
            - "--noprealloc"
          ports:
            - containerPort: {{ .Values.database.mongo.port }}
          volumeMounts:
            - name: {{ .Values.database.mongo.storageName }}
              mountPath: /data/db
        - name: mongo-sidecar
          image: cvallance/mongo-k8s-sidecar
          env:
            - name: MONGO_SIDECAR_POD_LABELS
              value: "role=mongo,environment=prod"
            - name: KUBERNETES_MONGO_SERVICE_NAME
              value: {{ .Values.database.mongo.serviceName }}
  volumeClaimTemplates:
  - metadata:
      name: {{ .Values.database.mongo.storageName }}
    spec:
      storageClassName: {{ .Values.database.mongo.storageClassName }}
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 100Gi

On helm install . -n release-name it creates StorageClass, PersistentVolume & PersistentVolumeClaim.

If I delete the release helm delete release-name --purge it keeps pv and pvc which is fine. But it deletes the StorageClass even though I have specified reclaimPolicy: Retain on sc.

Is this expected behaviour?

Helm version

Client: v2.10.0+g9ad53aa
Server: v2.10.0+g9ad53aa

Kubernetes version

Client Version: v1.11.1
Server Version: v1.9.7-gke.5

Update

I assumed reclaimPolicy was for both StorageClass and PV/PVC, Thanks to @Pablo for clearing my understanding regarding reclaimPolicy

Reclaim Policy

Persistent Volumes that are dynamically created by a storage class will have the reclaim policy specified in the reclaimPolicy field of the class, which can be either Delete or Retain. If no reclaimPolicy is specified when a StorageClass object is created, it will default to Delete

Is there anything similar to reclaimPolicy which will tell helm/kubernetes to not delete StorageClass when performing helm delete release-name --purge?

Upvotes: 1

Views: 3790

Answers (3)

Vikas Rathore
Vikas Rathore

Reputation: 8801

The annotation "helm.sh/resource-policy": keep instructs Tiller to skip this resource during a helm delete operation. However, this resource becomes orphaned. Helm will no longer manage it in any way. This can lead to problems if using helm install —replace on a release that has already been deleted, but has kept resources.

To explicitly opt into resource deletion, for example when overriding a chart’s default annotations, set the resource policy annotation value to delete.

Upvotes: 1

Alberto Fojo
Alberto Fojo

Reputation: 48

Try setting Delete on StorageClass reclaimPolicy

https://kubernetes.io/docs/concepts/storage/storage-classes/#reclaim-policy

kind: StorageClass
apiVersion: storage.k8s.io/v1beta1
metadata:
  name: {{ .Values.database.mongo.storageClassName }}
  labels:
    for: for-mongo-statefulset
provisioner: kubernetes.io/gce-pd
parameters:
  type: pd-ssd
reclaimPolicy: Delete

Upvotes: 1

Pablo Marti Cordero
Pablo Marti Cordero

Reputation: 1145

The reclaim policy listed in the StorageClass object is used for the persistent volumes not the storage class it self. Meaning that the pvs and pvcs that are created using that storage class will inherit the reclaim policy set in the storage class.

You can find more info on that here: https://kubernetes.io/docs/concepts/storage/storage-classes/

Upvotes: 3

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