subpath.md

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Mount Subdirectory

How to mount subdirectory in Kubernetes

This document shows how to mount with subdirectory in Kubernetes.

Using subPath

The community edition and the cloud service edition are used in the same way.

You can use subPath in PV:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: juicefs-pv
  labels:
    juicefs-name: ten-pb-fs
spec:
  capacity:
    storage: 10Pi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  csi:
    driver: csi.juicefs.com
    volumeHandle: test-bucket
    fsType: juicefs
    nodePublishSecretRef:
      name: juicefs-secret
      namespace: default
    volumeAttributes:
      subPath: fluentd

Apply PVC and sample pod as follows:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: juicefs-pvc
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  volumeMode: Filesystem
  storageClassName: ""
  resources:
    requests:
      storage: 10Pi
  selector:
    matchLabels:
      juicefs-name: ten-pb-fs
---
apiVersion: v1
kind: Pod
metadata:
  name: juicefs-app-subpath
  namespace: default
spec:
  containers:
    - args:
        - -c
        - while true; do echo $(date -u) >> /data/out.txt; sleep 5; done
      command:
        - /bin/sh
      image: centos
      name: app
      volumeMounts:
        - mountPath: /data
          name: data
      resources:
        requests:
          cpu: 10m
  volumes:
    - name: data
      persistentVolumeClaim:
        claimName: juicefs-pvc

After the configuration is applied, verify that pod is running:

kubectl get pods juicefs-app-subpath

Also you can verify that data is written onto JuiceFS file system:

kubectl exec -ti juicefs-app-subpath -- tail -f /data/out.txt

Using subdir

If you are using the cloud service edition, and the token you use only has permission for subdirectory, you can use the following methods, only need to specify subdir=xxx in mountOptions:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: juicefs-pv
  labels:
    juicefs-name: ten-pb-fs
spec:
  capacity:
    storage: 10Pi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  csi:
    driver: csi.juicefs.com
    volumeHandle: test-bucket
    fsType: juicefs
    nodePublishSecretRef:
      name: juicefs-secret
      namespace: default
  mountOptions:
    - subdir=/test

Apply PVC and sample pod as follows:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: juicefs-pvc
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  volumeMode: Filesystem
  storageClassName: ""
  resources:
    requests:
      storage: 10Pi
  selector:
    matchLabels:
      juicefs-name: ten-pb-fs
---
apiVersion: v1
kind: Pod
metadata:
  name: juicefs-app-subpath
  namespace: default
spec:
  containers:
    - args:
        - -c
        - while true; do echo $(date -u) >> /data/out.txt; sleep 5; done
      command:
        - /bin/sh
      image: centos
      name: app
      volumeMounts:
        - mountPath: /data
          name: data
      resources:
        requests:
          cpu: 10m
  volumes:
    - name: data
      persistentVolumeClaim:
        claimName: juicefs-pvc