Support persistent home directory for common and per-workspace storag…

…e strategies

Fix devfile#1097

Signed-off-by: Andrew Obuchowicz <aobuchow@redhat.com>

pkg/provision/storage/commonStorage.go

@@ -80,7 +80,17 @@ func (p *CommonStorageProvisioner) ProvisionStorage(podAdditions *v1alpha1.PodAd
 		pvcName = commonPVC.Name
 	}
 
-	if err := p.rewriteContainerVolumeMounts(workspace.Status.DevWorkspaceId, pvcName, podAdditions, &workspace.Spec.Template); err != nil {
+	if shouldPersistHomeDirectory(workspace) {
+		err := addHomeVolumeMount(workspace, pvcName, podAdditions)
+		if err != nil {
+			return &dwerrors.FailError{
+				Err:     err,
+				Message: "Could not add persistent home directory",
+			}
+		}
+	}
+
+	if err := p.rewriteContainerVolumeMounts(workspace.Status.DevWorkspaceId, pvcName, podAdditions, workspace); err != nil {
 		return &dwerrors.FailError{
 			Err:     err,
 			Message: "Could not rewrite container volume mounts",
@@ -125,11 +135,11 @@ func (p *CommonStorageProvisioner) CleanupWorkspaceStorage(workspace *common.Dev
 // (i.e. all volume mounts are subpaths into a common PVC used by all workspaces in the namespace).
 //
 // Also adds appropriate k8s Volumes to PodAdditions to accomodate the rewritten VolumeMounts.
-func (p *CommonStorageProvisioner) rewriteContainerVolumeMounts(workspaceId, pvcName string, podAdditions *v1alpha1.PodAdditions, workspace *dw.DevWorkspaceTemplateSpec) error {
+func (p *CommonStorageProvisioner) rewriteContainerVolumeMounts(workspaceId, pvcName string, podAdditions *v1alpha1.PodAdditions, workspace *common.DevWorkspaceWithConfig) error {
 	devfileVolumes := map[string]dw.VolumeComponent{}
 
 	// Construct map of volume name -> volume Component
-	for _, component := range workspace.Components {
+	for _, component := range workspace.Spec.Template.Components {
 		if component.Volume != nil {
 			if _, exists := devfileVolumes[component.Name]; exists {
 				return fmt.Errorf("volume component '%s' is defined multiple times", component.Name)
@@ -144,6 +154,12 @@ func (p *CommonStorageProvisioner) rewriteContainerVolumeMounts(workspaceId, pvc
 		additionalVolumes[additionalVolume.Name] = true
 	}
 
+	// When we persist the home directory, a volumeMount is created that references the PVC volume.
+	// This volumeMount should not be rewritten
+	if shouldPersistHomeDirectory(workspace) {
+		additionalVolumes[pvcName] = true
+	}
+
 	// Add implicit projects volume to support mountSources, if needed
 	if _, exists := devfileVolumes[devfileConstants.ProjectsVolumeName]; !exists {
 		projectsVolume := dw.VolumeComponent{}

pkg/provision/storage/perWorkspaceStorage.go

@@ -70,8 +70,18 @@ func (p *PerWorkspaceStorageProvisioner) ProvisionStorage(podAdditions *v1alpha1
 		}
 	}
 
+	if shouldPersistHomeDirectory(workspace) {
+		err := addHomeVolumeMount(workspace, pvcName, podAdditions)
+		if err != nil {
+			return &dwerrors.FailError{
+				Err:     err,
+				Message: "Could not add persistent home directory",
+			}
+		}
+	}
+
 	// Rewrite container volume mounts
-	if err := p.rewriteContainerVolumeMounts(workspace.Status.DevWorkspaceId, pvcName, podAdditions, &workspace.Spec.Template); err != nil {
+	if err := p.rewriteContainerVolumeMounts(workspace.Status.DevWorkspaceId, pvcName, podAdditions, workspace); err != nil {
 		return &dwerrors.FailError{
 			Err:     err,
 			Message: "Could not rewrite container volume mounts",
@@ -90,11 +100,11 @@ func (*PerWorkspaceStorageProvisioner) CleanupWorkspaceStorage(workspace *common
 // (i.e. all volume mounts are subpaths into a PVC used by a single workspace in the namespace).
 //
 // Also adds appropriate k8s Volumes to PodAdditions to accomodate the rewritten VolumeMounts.
-func (p *PerWorkspaceStorageProvisioner) rewriteContainerVolumeMounts(workspaceId, pvcName string, podAdditions *v1alpha1.PodAdditions, workspace *dw.DevWorkspaceTemplateSpec) error {
+func (p *PerWorkspaceStorageProvisioner) rewriteContainerVolumeMounts(workspaceId, pvcName string, podAdditions *v1alpha1.PodAdditions, workspace *common.DevWorkspaceWithConfig) error {
 	devfileVolumes := map[string]dw.VolumeComponent{}
 
 	// Construct map of volume name -> volume Component
-	for _, component := range workspace.Components {
+	for _, component := range workspace.Spec.Template.Components {
 		if component.Volume != nil {
 			if _, exists := devfileVolumes[component.Name]; exists {
 				return fmt.Errorf("volume component '%s' is defined multiple times", component.Name)
@@ -109,6 +119,12 @@ func (p *PerWorkspaceStorageProvisioner) rewriteContainerVolumeMounts(workspaceI
 		additionalVolumes[additionalVolume.Name] = true
 	}
 
+	// When we persist the home directory, a volumeMount is created that references the PVC volume.
+	// This volumeMount should not be rewritten
+	if shouldPersistHomeDirectory(workspace) {
+		additionalVolumes[pvcName] = true
+	}
+
 	// Add implicit projects volume to support mountSources, if needed
 	if _, exists := devfileVolumes[devfileConstants.ProjectsVolumeName]; !exists {
 		projectsVolume := dw.VolumeComponent{}

pkg/provision/storage/shared.go

@@ -277,3 +277,32 @@ func checkPVCTerminating(name, namespace string, api sync.ClusterAPI) (bool, err
 	}
 	return pvc.DeletionTimestamp != nil, nil
 }
+
+func shouldPersistHomeDirectory(workspace *common.DevWorkspaceWithConfig) bool {
+	return workspace.Config.Workspace.PersistUserHome != nil && workspace.Config.Workspace.PersistUserHome.Enabled != nil && *workspace.Config.Workspace.PersistUserHome.Enabled
+}
+
+// Adds a home volume mount to the given set of Pod Additions.
+// The home volume mount is mounted to the given PVC at the path `/home/user/`.
+// If a Devfile volume already mounts to `/home/user/`, an error is returned.
+func addHomeVolumeMount(workspace *common.DevWorkspaceWithConfig, pvcName string, podAdditions *v1alpha1.PodAdditions) error {
+	homeUserDirPath := "/home/user/"
+	homeVolumeMount := corev1.VolumeMount{
+		Name:      pvcName,
+		MountPath: homeUserDirPath,
+		SubPath:   fmt.Sprintf("%s/home/user/", workspace.Status.DevWorkspaceId),
+	}
+
+	// Check if we are already trying to mount a volume to /home/user/ in one of the containers
+	for cIdx := range podAdditions.Containers {
+		for vmIdx := range podAdditions.Containers[cIdx].VolumeMounts {
+			if podAdditions.Containers[cIdx].VolumeMounts[vmIdx].MountPath == homeUserDirPath {
+				containerName := podAdditions.Containers[cIdx].Name
+				volumeMountName := podAdditions.Containers[cIdx].VolumeMounts[vmIdx].Name
+				return fmt.Errorf("volumeMount '%s' for container '%s' already mounts to %s", volumeMountName, containerName, homeUserDirPath)
+			}
+		}
+		podAdditions.Containers[cIdx].VolumeMounts = append(podAdditions.Containers[cIdx].VolumeMounts, homeVolumeMount)
+	}
+	return nil
+}