juicefs-csi-driver

JuiceFS CSI Driver

The JuiceFS Container Storage Interface (CSI) Driver implements the CSI specification for container orchestrators to manage the lifecycle of JuiceFS file system.

Prerequisites

• Kubernetes 1.14+

Installation

Installation with 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 values.yaml file with access information about metadata engine (e.g. Redis) and object storage. If already formatted a volume, only name and metaurl is required. You can specify CPU/memory limits and requests of mount pod for pods using this driver.

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>"

1. Install

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

1. 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

Installation with kubectl

Deploy the driver:

kubectl apply -f https://raw.githubusercontent.com/juicedata/juicefs-csi-driver/master/deploy/k8s.yaml

If the CSI driver couldn't be discovered by Kubernetes and the error like this: driver name csi.juicefs.com not found in the list of registered CSI drivers, check the root directory path of kubelet. Run the following command on any non-master node in your Kubernetes cluster:

ps -ef | grep kubelet | grep root-dir

If the result isn't empty, modify the CSI driver deployment k8s.yaml file with the new path and redeploy the CSI driver again.

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 -

Replace {{KUBELET_DIR}} with your own --root-dir value in above command.

Upgrade CSI Driver

v0.10+

Juicefs CSI Driver separated JuiceFS client from CSI Driver since v0.10.0, CSI Driver upgrade will not interrupt existing PVs. If CSI Driver version >= v0.10.0, do operations below:

• If you're using latest tag, simple run kubectl rollout restart -f k8s.yaml and make sure juicefs-csi-controller and juicefs-csi-node pods are restarted.
• If you have pinned to a specific version, modify your k8s.yaml to a newer version, then run kubectl apply -f k8s.yaml.
• Alternatively, if JuiceFS CSI driver is installed using Helm, you can also use Helm to upgrade it.

If you want to upgrade CSI Driver from v0.9.0 to v0.10.0+, follow "How to upgrade CSI Driver from v0.9.0 to v0.10.0+".

Before v0.10

Upgrade of CSI Driver requires restart the DaemonSet, which has all the JuiceFS client running inside. The restart will cause all PVs become unavailable, so we need to stop all the application pod first.

1. Stop all pods using this driver.
2. Upgrade driver:
   • If you're using latest tag, simple run kubectl rollout restart -f k8s.yaml and make sure juicefs-csi-controller and juicefs-csi-node pods are restarted.
   • If you have pinned to a specific version, modify your k8s.yaml to a newer version, then run kubectl apply -f k8s.yaml.
   • Alternatively, if JuiceFS CSI driver is installed using Helm, you can also use Helm to upgrade it.
3. Start all the application pods.

We are working on launching the JuiceFS client in separate container, so the upgrade will NOT interrupt existing PVs. Before that, we can upgrade the JuiceFS client without upgrading the CSI driver, please follow this workaround.

Visit Docker Hub for more versions.

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.

Example links

• Basic
• Static provisioning
  • Mount options
  • Read write many
  • Sub path
  • Mount resources
  • Config and env
• Dynamic provisioning

Notes:

• 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.
• kustomize 3.x is required to build some examples.

CSI Specification Compatibility

JuiceFS CSI Driver \ CSI Version	v0.3	v1.0
master branch	no	yes

Interfaces

The following CSI interfaces are implemented:

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

Troubleshooting

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

JuiceFS CSI Driver on Kubernetes

The following sections are Kubernetes specific. If you are a Kubernetes user, use this for driver features, installation steps and examples.

Kubernetes Version Compatibility

JuiceFS CSI Driver is compatible with Kubernetes v1.14+

Container Images

JuiceFS CSI Driver Version	Image
master branch	juicedata/juicefs-csi-driver:latest

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

Validation

JuiceFS CSI driver has been validated in the following Kubernetes version

Kubernetes	master
v1.19.2 / minikube v1.16.0	Yes
v1.20.2 / minikube v1.16.0	Yes

Known issues

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

Miscellaneous

• Access ceph cluster with librados

Develop

See DEVELOP document.

License

This library is licensed under the Apache 2.0 License.