This repo contains [Container Storage Interface(CSI)] (https://github.com/container-storage-interface/) Unity CSI driver for DellEMC.
Unity CSI plugins implement an interface between CSI enabled Container Orchestrator(CO) and Unity Storage Array. It allows dynamically provisioning Unity volumes and attaching them to workloads.
The CSI Driver For Dell EMC Unity conforms to CSI spec 1.1
- Support for Kubernetes 1.14
- Will add support for other orchestrators over time
- The CSI specification is documented here: https://github.com/container-storage-interface/spec. The driver uses CSI v1.1.
CSI Driver For Dell EMC Unity Capabilities
|Provisioning||Persistent volumes creation, deletion, mounting, unmounting, listing||Volume expand|
|Export, Mount||Mount volume as file system||Raw volumes, Topology|
|Data protection||Creation of snapshots||Cloning, Create volume from snapshots|
|Types of volumes||Static, Dynamic|
|Access mode||Single Node read/write||Multi Node access modes|
|Kubernetes||v1.14||V1.13 or previous versions|
|OS||RHEL 7.5, 7.6. CentOs 7.6||Ubuntu, other Linux variants|
|Unity||OE 5.0||Previous versions|
The Helm chart installs CSI Driver for Unity using a shell script (helm/install.unity). This script installs the CSI driver container image along with the required Kubernetes sidecar containers.
The controller section of the Helm chart installs the following components in a Stateful Set in the namespace unity:
- CSI Driver for Unity
- Kubernetes Provisioner, which provisions the provisioning volumes
- Kubernetes Attacher, which attaches the volumes to the containers
- Kubernetes Snapshotter, which provides snapshot support
The node section of the Helm chart installs the following component in a Daemon Set in the namespace unity:
- CSI Driver for Unity
- Kubernetes Registrar, which handles the driver registration
Before you install CSI Driver for Unity, verify the requirements that are mentioned in this topic are installed and configured.
- Install Kubernetes.
- Enable the Kubernetes feature gates
- Configure Docker service
- Install Helm and Tiller with a service account
- Deploy Unity using Helm
Enable Kubernetes feature gates
The Kubernetes feature gates must be enabled before installing CSI Driver for Unity.
About Enabling Kubernetes feature gates
The Feature Gates section of Kubernetes home page lists the Kubernetes feature gates. The following Kubernetes feature gates must be enabled:
On each master and node of Kubernetes, edit /var/lib/kubelet/config.yaml and append the following lines at the end to set feature-gate settings for the kubelets: /var/lib/kubelet/config.yaml
VolumeSnapshotDataSource: true KubeletPluginsWatcher: true CSINodeInfo: true CSIDriverRegistry: true BlockVolume: true CSIBlockVolume: true ExpandCSIVolumes: true
On the master node, set the feature gate settings of the kube-apiserver.yaml, kube-controllermanager.yaml and kube-scheduler.yaml file as follows:
/etc/kubernetes/manifests/kube-apiserver.yaml /etc/kubernetes/manifests/kube-controller-manager.yaml /etc/kubernetes/manifests/kube-scheduler.yaml
On each node (including master), edit the variable KUBELET_KUBECONFIG_ARGS of /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf file as follows:
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --feature-gates=VolumeSnapshotDataSource=true,KubeletPluginsWatcher=true,CSINodeInfo=true,CSIDriverRegistry=true,BlockVolume=true,CSIBlockVolume=true,ExpandCSIVolumes=true"
Restart the kublet on all nodes.
systemctl daemon-reload systemctl restart kubelet
Configure Docker service
The mount propagation in Docker must be configured on all Kubernetes nodes before installing CSI Driver for Unity.
Edit the service section of /etc/systemd/system/multi-user.target.wants/docker.service file as follows:
[Service] ... MountFlags=shared
Restart the Docker service with systemctl daemon-reload and
systemctl daemon-reload systemctl restart docker
Install CSI Driver for Unity
Install CSI Driver for Unity using this procedure.
Before you begin
- You must have the downloaded files, including the Helm chart from the source git repository, ready for this procedure.
- In the top-level helm directory, there should be two shell scripts, install.unity and uninstall.unity. These scripts handle some of the pre and post operations that cannot be performed in the helm chart, such as creating Custom Resource Definitions (CRDs), if needed.
Collect information from the Unity System like IP address, username and password. Make a note of the value for these parameters as they must be entered in the myvalues.yaml file.
Copy the csi-unity/values.yaml into a file in the same directory as the install.unity named myvalues.yaml, to customize settings for installation.
Edit myvalues.yaml to set the following parameters for your installation:
The following table lists the primary configurable parameters of the Unity driver chart and their default values. More detailed information can be found in the
values.yamlfile in this repository.
Parameter Description Required Default systemName Name of the Unity system false unity restGateway REST API gateway HTTPS endpoint Unity system true - storagePool Unity Storage Pool CLI ID to use with in the Kubernetes storage class true - unityUsername Username for accessing unity system true - unityPassword Password for accessing unity system true - volumeNamePrefix String to prepend to any volumes created by the driver false csivol storageClass.name Name of the storage class to be defined false unity storageClass.isDefault Whether or not to make this storage class the default false true storageClass.reclaimPolicy What should happen when a volume is removed false Delete Storage Class parameters Following parameters are not present in values.yaml FsType To set File system type. Possible values are ext3,ext4,xfs false ext4 volumeThinProvisioned To set volume thinProvisioned false true isVolumeDataReductionEnabled To set volume data reduction false false volumeTieringPolicy To set volume tiering policy false 0 hostIOLimitName To set unity host IO limit false "" Snapshot Class parameters Following parameters are not present in values.yaml snapshotRetentionDuration TO set snapshot retention duration. Format:"1:23:52:50" (number of days:hours:minutes:sec) false ""
Use the following command to convert username/password to base64 encoded string
echo -n 'admin' | base64 echo -n 'password' | base64
storagePool: pool_1 restGateway: "https://<Ip of Unity system>" unityUsername: <Base64 encoded string> unityPassword: <Base64 encoded string> images: driver: <docker image>
sh install.unitycommand to proceed with the installation.
A successful installation should emit messages that look similar to the following samples:
sh install.unity Kubernetes version v1.14.2 Kubernetes master nodes: 10.*.*.* Kubernetes minion nodes: Verifying the feature gates. NAME: unity LAST DEPLOYED: Wed Aug 14 01:23:35 2019 NAMESPACE: unity STATUS: DEPLOYED [....] NAME READY STATUS RESTARTS AGE unity-controller-0 4/4 Running 0 21s unity-node-kzv49 2/2 Running 0 21s CSIDrivers: No resources found. CSINodeInfos: No resources found. StorageClasses: NAME PROVISIONER AGE unity (default) csi-unity 21s
Results At the end of the script, the kubectl get pods -n unity is called to GET the status of the pods and you will see the following:
- unity-controller-0 with 4/4 containers ready, and status displayed as Running.
- Agent pods with 2/2 containers and the status displayed as Running.
Finally, the script lists the created storageclasses such as, "unity". Additional storage classes can be created for different combinations of file system types and Unity storage pools. The script also creates volumesnapshotclass "unity-snapclass".
Test deploying a simple pod with Unity storage
Test the deployment workflow of a simple pod on Unity storage.
Verify Unity system for Host
After helm deployment
CSI Driver for Nodewill create new Host(s) in the Unity system depending on the number of node in kubernetes cluster. Verify Unity system for new Hosts and Initattors
Creating a volume:
Create a file (
pvc.yaml) with the following content
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: testvolclaim1 spec: accessModes: - ReadWriteOnce resources: requests: storage: 5Gi storageClassName: unity
Execute the following command to create volume
kubectl create -f $PWD/pvc.yaml
Result: After executing the above command PVC will be created in the default namespace, and the user can see the pvc by executing
kubectl get pvc. Note: Verify unity system for the new volume
Attach the volume to Host
To attach a volume to a host, create a new application(Pod) and use the PVC created above in the Pod. This scenario is explained using the Nginx application. Create
nginx.yamlwith the following content.
apiVersion: v1 kind: Pod metadata: name: ngnix-pv-pod spec: containers: - name: task-pv-container image: nginx ports: - containerPort: 80 name: "http-server" volumeMounts: - mountPath: "/usr/share/nginx/html" name: task-pv-storage volumes: - name: task-pv-storage persistentVolumeClaim: claimName: testvolclaim1
Execute the following command to mount the volume to kubernetes node
kubectl create -f $PWD/nginx.yaml
Result: After executing the above command, new nginx pod will be successfully created and started in the default namespace. Note: Verify unity system for volume to be attached to the Host where the nginx container is running
The following procedure will create a snapshot of the volume in the container using VolumeSnapshot objects defined in snap.yaml. The following are the contents of snap.yaml.
apiVersion: snapshot.storage.k8s.io/v1alpha1 kind: VolumeSnapshot metadata: name: testvolclaim1-snap1 spec: snapshotClassName: unity-snapclass source: name: testvolclaim1 kind: PersistentVolumeClaim
Execute the following command to create snapshot
kubectl create -f $PWD/snap.yaml
The spec.source section contains the volume that will be snapped in the default namespace. For example, if the volume to be snapped is testvolclaim1, then the created snapshot is named testvolclaim1-snap1. Verify the unity system for new snapshot under the lun section.
- User can see the snapshots using
kubectl get volumesnapshot
- Notice that this VolumeSnapshot class has a reference to a snapshotClassName:unity-snapclass. The CSI Driver for Unity installation creates this class as its default snapshot class.
- You can see its definition using
kubectl get volumesnapshotclasses unity-snapclass -o yaml.
- User can see the snapshots using
Execute the following command to delete the snapshot
kubectl get volumesnapshot kubectl delete volumesnapshot testvolclaim1-snap1
To Unattach the volume from Host
Delete the nginx application to unattach the volume from host
kubectl delete -f nginx.yaml
To delete the volume
kubectl get pvc kubectl delete pvc testvolclaim1 kubectl get pvc
The CSI Driver for Dell EMC Unity image available on Dockerhub is officially supported by Dell EMC.
The source code available on Github is unsupported and provided solely under the terms of the license attached to the source code. For clarity, Dell EMC does not provide support for any source code modifications.
For any CSI driver setup, configuration issues, questions or feedback, join the Dell EMC Container community athttps://www.dell.com/community/Containers/bd-p/Containers
For any Dell EMC storage issues, please contact Dell support at: https://www.dell.com/support.