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JuiceFS CSI Driver

The JuiceFS CSI Driver implements the CSI specification for container orchestrators to manage the lifecycle of JuiceFS file system.

Prerequisites

  • Kubernetes 1.14+

Installation

There are two ways to install JuiceFS CSI Driver.

1. Install via Helm

Prerequisites

  • Helm 3.1.0+

Install Helm

Helm is a tool for managing Kubernetes charts. Charts are packages of pre-configured Kubernetes resources.

To install Helm, refer to the Helm install guide and ensure that the helm binary is in the PATH of your shell.

Using Helm To Deploy

  1. Prepare a YAML file

    Create a configuration file, for example: values.yaml, copy and complete the following configuration information. Among them, the backend part is the information related to the JuiceFS file system, you can refer to JuiceFS Quick Start Guide for more information. If you are using a JuiceFS volume that has been created, you only need to fill in the two items name and metaurl. The mountPod part can specify CPU/memory limits and requests of mount pod for pods using this driver. Unneeded items should be deleted, or its value should be left blank.

    storageClasses:
    - name: juicefs-sc
      enabled: true
      reclaimPolicy: Retain
      backend:
        name: "<name>"
        metaurl: "<meta-url>"
        storage: "<storage-type>"
        accessKey: "<access-key>"
        secretKey: "<secret-key>"
        bucket: "<bucket>"
      mountPod:
        resources:
          limits:
            cpu: "<cpu-limit>"
            memory: "<memory-limit>"
          requests:
            cpu: "<cpu-request>"
            memory: "<memory-request>"

  2. Check and update kubelet root directory

    Execute the following command.

    $ ps -ef | grep kubelet | grep root-dir

    If the result is not empty, it means that the root directory (--root-dir) of kubelet is not the default value (/var/lib/kubelet) and you need to set kubeletDir to the current root directly of kubelet in the configuration file values.yaml prepared in the first step.

    kubeletDir: <kubelet-dir>

  3. Deploy

    helm repo add juicefs-csi-driver https://juicedata.github.io/juicefs-csi-driver/
    helm repo update
    helm install juicefs-csi-driver juicefs-csi-driver/juicefs-csi-driver -n kube-system -f ./values.yaml

  4. Check the deployment

    • Check pods are running: the deployment will launch a StatefulSet named juicefs-csi-controller with replica 1 and a DaemonSet named juicefs-csi-node, so run kubectl -n kube-system get pods -l app.kubernetes.io/name=juicefs-csi-driver should see n+1 (where n is the number of worker nodes of the Kubernetes cluster) pods is running. For example:

      $ kubectl -n kube-system get pods -l app.kubernetes.io/name=juicefs-csi-driver
      NAME                       READY   STATUS    RESTARTS   AGE
      juicefs-csi-controller-0   3/3     Running   0          22m
      juicefs-csi-node-v9tzb     3/3     Running   0          14m

    • Check secret: kubectl -n kube-system describe secret juicefs-sc-secret will show the secret with above backend fields in values.yaml:

      Name:         juicefs-sc-secret
      Namespace:    kube-system
      Labels:       app.kubernetes.io/instance=juicefs-csi-driver
                    app.kubernetes.io/managed-by=Helm
                    app.kubernetes.io/name=juicefs-csi-driver
                    app.kubernetes.io/version=0.7.0
                    helm.sh/chart=juicefs-csi-driver-0.1.0
      Annotations:  meta.helm.sh/release-name: juicefs-csi-driver
                    meta.helm.sh/release-namespace: default

      Type:  Opaque

      Data
      ====
      access-key:  0 bytes
      bucket:      47 bytes
      metaurl:     54 bytes
      name:        4 bytes
      secret-key:  0 bytes
      storage:     2 bytes

    • Check storage class: kubectl get sc juicefs-sc will show the storage class like this:

      NAME         PROVISIONER       RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
      juicefs-sc   csi.juicefs.com   Retain          Immediate           false                  69m

2. Install via kubectl

Since Kubernetes will deprecate some old APIs when a new version is released, you need to choose the appropriate deployment configuration file.

  1. Check the root directory path of kubelet.

    Execute the following command on any non-Master node in the Kubernetes cluster.

    $ ps -ef | grep kubelet | grep root-dir

  2. Deploy

    If the check command returns a non-empty result, it means that the root directory (--root-dir) of the kubelet is not the default (/var/lib/kubelet), so you need to update the kubeletDir path in the CSI Driver's deployment file and deploy.

    # Kubernetes version >= v1.18
    curl -sSL https://raw.githubusercontent.com/juicedata/juicefs-csi-driver/master/deploy/k8s.yaml | sed 's@/var/lib/kubelet@{{KUBELET_DIR}}@g' | kubectl apply -f -

    # Kubernetes version < v1.18
    curl -sSL https://raw.githubusercontent.com/juicedata/juicefs-csi-driver/master/deploy/k8s_before_v1_18.yaml | sed 's@/var/lib/kubelet@{{KUBELET_DIR}}@g' | kubectl apply -f -
    note

    Please replace {{KUBELET_DIR}} in the above command with the actual root directory path of kubelet.

    If the check command returns an empty result, you can deploy directly without modifying the configuration:

    # Kubernetes version >= v1.18
    kubectl apply -f https://raw.githubusercontent.com/juicedata/juicefs-csi-driver/master/deploy/k8s.yaml

    # Kubernetes version < v1.18
    kubectl apply -f https://raw.githubusercontent.com/juicedata/juicefs-csi-driver/master/deploy/k8s_before_v1_18.yaml

Troubleshooting & FAQs

If you encounter any issue, please refer to Troubleshooting or FAQ document.

Upgrade CSI Driver

Refer to Upgrade CSI Driver document.

Examples

Before the example, you need to:

  • Get yourself familiar with how to setup Kubernetes and how to use JuiceFS file system.
  • Make sure JuiceFS is accessible from Kuberenetes cluster. It is recommended to create the file system inside the same region as Kubernetes cluster.
  • Install JuiceFS CSI driver following the Installation steps.
info

Since JuiceFS is an elastic file system it doesn't really enforce any file system capacity. The actual storage capacity value in PersistentVolume and PersistentVolumeClaim is not used when creating the file system. However, since the storage capacity is a required field by Kubernetes, you must specify the value and you can use any valid value e.g. 10Pi for the capacity.

CSI Specification Compatibility

JuiceFS CSI Driver \ CSI Versionv0.3v1.0
master branchnoyes

Interfaces

The following CSI interfaces are implemented:

  • Node Controller: CreateVolume, DeleteVolume
  • Node Service: NodePublishVolume, NodeUnpublishVolume, NodeGetCapabilities, NodeGetInfo, NodeGetId
  • Identity Service: GetPluginInfo, GetPluginCapabilities, Probe

Kubernetes

The following sections are Kubernetes specific.

Kubernetes Version Compatibility

JuiceFS CSI Driver is compatible with Kubernetes v1.14+

Container Images

JuiceFS CSI Driver VersionImage
master branchjuicedata/juicefs-csi-driver:<latest-release>

Features

  • Static provisioning: JuiceFS file system needs to be created manually first, then it could be mounted inside container as a PersistentVolume (PV) using the driver.
  • Mount options: CSI volume attributes can be specified in the PersistentVolume (PV) to define how the volume should be mounted.
  • Read write many: Support ReadWriteMany access mode
  • Sub path: provision PersistentVolume with subpath in JuiceFS file system
  • Mount resources: CSI volume attributes can be specified in the PersistentVolume (PV) to define CPU/memory limits/requests of mount pod.
  • Config files & env in mount pod: Support set config files and envs in mount pod.
  • Dynamic provisioning: allows storage volumes to be created on-demand

Known issues

  • The mount option --cache-dir in JuiceFS CSI driver (>=v0.10.0) does not support wildcards currently.

Further Readings