Chapter 7. Requesting persistent storage for workspaces
Chapter 7. Requesting persistent storage for workspaces OpenShift Dev Spaces workspaces and workspace data are ephemeral and are lost when the workspace stops. To preserve the workspace state in persistent storage while the workspace is stopped, request a Kubernetes PersistentVolume (PV) for the Dev Workspace containers in the OpenShift cluster of your organization's OpenShift Dev Spaces instance. You can request a PV by using the devfile or a Kubernetes PersistentVolumeClaim (PVC). An example of a PV is the /projects/ directory of a workspace, which is mounted by default for non-ephemeral workspaces. Persistent Volumes come at a cost: attaching a persistent volume slows workspace startup. Warning Starting another, concurrently running workspace with a ReadWriteOnce PV might fail. Additional resources Red Hat OpenShift Documentation: Understanding persistent storage Kubernetes Documentation: Persistent Volumes 7.1. Requesting persistent storage in a devfile When a workspace requires its own persistent storage, request a PersistentVolume (PV) in the devfile, and OpenShift Dev Spaces will automatically manage the necessary PersistentVolumeClaims. Prerequisites You have not started the workspace. Procedure Add a volume component in the devfile: ... components: ... - name: <chosen_volume_name> volume: size: <requested_volume_size> G ... Add a volumeMount for the relevant container in the devfile: ... components: - name: ... container: ... volumeMounts: - name: <chosen_volume_name_from_previous_step> path: <path_where_to_mount_the_PV> ... Example 7.1. A devfile that provisions a PV for a workspace to a container When a workspace is started with the following devfile, the cache PV is provisioned to the golang container in the ./cache container path: schemaVersion: 2.1.0 metadata: name: mydevfile components: - name: golang container: image: golang memoryLimit: 512Mi mountSources: true command: ['sleep', 'infinity'] volumeMounts: - name: cache path: /.cache - name: cache volume: size: 2Gi 7.2. Requesting persistent storage in a PVC You can opt to apply a PersistentVolumeClaim (PVC) to request a PersistentVolume (PV) for your workspaces in the following cases: Not all developers of the project need the PV. The PV lifecycle goes beyond the lifecycle of a single workspace. The data included in the PV are shared across workspaces. Tip You can apply a PVC to the Dev Workspace containers even if the workspace is ephemeral and its devfile contains the controller.devfile.io/storage-type: ephemeral attribute. Prerequisites You have not started the workspace. An active oc session with administrative permissions to the destination OpenShift cluster. See Getting started with the CLI . A PVC is created in your user project to mount to all Dev Workspace containers. Procedure Add the controller.devfile.io/mount-to-devworkspace: true label to the PVC. Optional: Use the annotations to configure how the PVC is mounted: Table 7.1. Optional annotations Annotation Description controller.devfile.io/mount-path: The mount path for the PVC. Defaults to /tmp/ <PVC_name> . controller.devfile.io/read-only: Set to 'true' or 'false' to specify whether the PVC is to be mounted as read-only. Defaults to 'false' , resulting in the PVC mounted as read/write. Example 7.2. Mounting a read-only PVC apiVersion: v1 kind: PersistentVolumeClaim metadata: name: <pvc_name> labels: controller.devfile.io/mount-to-devworkspace: 'true' annotations: controller.devfile.io/mount-path: </example/directory> 1 controller.devfile.io/read-only: 'true' spec: accessModes: - ReadWriteOnce resources: requests: storage: 3Gi 2 storageClassName: <storage_class_name> 3 volumeMode: Filesystem 1 The mounted PV is available at </example/directory> in the workspace. 2 Example size value of the requested storage. 3 The name of the StorageClass required by the claim. Remove this line if you want to use a default StorageClass.
components: - name: <chosen_volume_name> volume: size: <requested_volume_size> G components: - name: container: volumeMounts: - name: <chosen_volume_name_from_previous_step> path: <path_where_to_mount_the_PV> schemaVersion: 2.1.0 metadata: name: mydevfile components: - name: golang container: image: golang memoryLimit: 512Mi mountSources: true command: ['sleep', 'infinity'] volumeMounts: - name: cache path: /.cache - name: cache volume: size: 2Gi oc label persistentvolumeclaim <PVC_name> \ controller.devfile.io/mount-to-devworkspace=true apiVersion: v1 kind: PersistentVolumeClaim metadata: name: <pvc_name> labels: controller.devfile.io/mount-to-devworkspace: 'true' annotations: controller.devfile.io/mount-path: </example/directory> 1 controller.devfile.io/read-only: 'true' spec: accessModes: - ReadWriteOnce resources: requests: storage: 3Gi 2 storageClassName: <storage_class_name> 3 volumeMode: Filesystem