azurelustre

func (*Driver) ControllerGetCapabilities ¶

func (d *Driver) ControllerGetCapabilities(
	_ context.Context,
	_ *csi.ControllerGetCapabilitiesRequest,
) (*csi.ControllerGetCapabilitiesResponse, error)

ControllerGetCapabilities returns the capabilities of the Controller plugin

func (*Driver) CreateVolume ¶

func (d *Driver) CreateVolume(
	_ context.Context,
	req *csi.CreateVolumeRequest,
) (*csi.CreateVolumeResponse, error)

CreateVolume provisions a volume

func (*Driver) DeleteVolume ¶

func (d *Driver) DeleteVolume(
	_ context.Context, req *csi.DeleteVolumeRequest,
) (*csi.DeleteVolumeResponse, error)

DeleteVolume delete a volume

func (*Driver) GetPluginCapabilities ¶

func (f *Driver) GetPluginCapabilities(_ context.Context, _ *csi.GetPluginCapabilitiesRequest) (*csi.GetPluginCapabilitiesResponse, error)

GetPluginCapabilities returns the capabilities of the plugin

func (*Driver) GetPluginInfo ¶

func (f *Driver) GetPluginInfo(_ context.Context, _ *csi.GetPluginInfoRequest) (*csi.GetPluginInfoResponse, error)

GetPluginInfo return the version and name of the plugin

func (*Driver) NodeGetCapabilities ¶

func (d *Driver) NodeGetCapabilities(
	_ context.Context, _ *csi.NodeGetCapabilitiesRequest,
) (*csi.NodeGetCapabilitiesResponse, error)

NodeGetCapabilities return the capabilities of the Node plugin

func (*Driver) NodeGetInfo ¶

func (d *Driver) NodeGetInfo(
	_ context.Context,
	_ *csi.NodeGetInfoRequest,
) (*csi.NodeGetInfoResponse, error)

NodeGetInfo return info of the node on which this plugin is running

func (*Driver) NodeGetVolumeStats ¶

func (d *Driver) NodeGetVolumeStats(
	_ context.Context,
	req *csi.NodeGetVolumeStatsRequest,
) (*csi.NodeGetVolumeStatsResponse, error)

NodeGetVolumeStats get volume stats

func (*Driver) NodePublishVolume ¶

func (d *Driver) NodePublishVolume(
	_ context.Context,
	req *csi.NodePublishVolumeRequest,
) (*csi.NodePublishVolumeResponse, error)

NodePublishVolume mount the volume from staging to target path

func (*Driver) NodeStageVolume ¶ added in v0.1.13

func (d *Driver) NodeStageVolume(_ context.Context, _ *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error)

Staging and Unstaging is not able to be supported with how Lustre is mounted

This was discovered during a proof of concept implementation and the issue is as follows:

When the kubelet process attempts to unstage / unmount a Lustre mount that has been staged to a global mount point, it performs extra checks to ensure that the same device is not mounted anywhere else in the filesystem. For usual configurations, this would be a reasonable check to ensure that we aren't trying to remove something that is still in use elsewhere in the system. However, the way Lustre mounts are configured is not compatible with the check it performs.

The kubelet process does this by checking all of the mount points on the node to see if any have the following: 1) The same 'root' value of the mount that is being cleaned 2) The same device number of the mount that is being cleaned And that those mounts are in a different path tree. If so, it returns this error: "the device mount path %q is still mounted by other references %v", deviceMountPath, refs) and fails the unmount. See pkg/volume/util/operationexecutor/operation_generator.go calling GetDeviceMountRefs(deviceMountPath) around line 947.

All Lustre mounts on a system, no matter where in the lustrefs they are mounted to, all have '/' as the root and they all have the same major and minor device numbers, so as far as this check is concerned, every lustre mount is the same device, even though individual Lustre mount points can be unmounted without affecting others and should not be a concern.

With a single Lustre volume mount, this works fine. It stages to a globalpath dir, pods can bind mount into that, and when the last pod is done, unstage is called and the global mount point can be cleaned up, because that is the only lustre mount so kubelet has no issue with 'other mounts' on the same node.

The problem occurs when two different volumes are trying to mount a Lustre cluster. In that case, pods for the first volume can come up as expected with their global mount path, then pods for the second volume with their global mount path. The error occurs when the pods for one of these volumes are deleted and an unstage action should occur, because the other volume has its own Lustre mount, so it fails this check. For example, it's trying to unmount /var/...<firstvolume>.../globalpath, but there's another volume at /var/...<secondvolume>.../globalpath with the same root '/' and major and minor device numbers.

It errors out, fails the unmount, and never calls unstage, even though all of the pods using that volume have already been deleted. This leaves the box with as many global mount directories still mounted to the Lustre cluster as you've ever staged, but without any way to see this other than looking at the mounts on the node or in the kubelet logs.

func (*Driver) NodeUnpublishVolume ¶

func (d *Driver) NodeUnpublishVolume(
	_ context.Context,
	req *csi.NodeUnpublishVolumeRequest,
) (*csi.NodeUnpublishVolumeResponse, error)

NodeUnpublishVolume unmount the volume from the target path

func (*Driver) NodeUnstageVolume ¶ added in v0.1.13

func (d *Driver) NodeUnstageVolume(_ context.Context, _ *csi.NodeUnstageVolumeRequest) (*csi.NodeUnstageVolumeResponse, error)

Staging and Unstaging is not able to be supported with how Lustre is mounted

See NodeStageVolume for more details

func (*Driver) Probe ¶

func (f *Driver) Probe(_ context.Context, _ *csi.ProbeRequest) (*csi.ProbeResponse, error)

Probe check whether the plugin is running or not. This method does not need to return anything. Currently the spec does not dictate what you should return either. Hence, return an empty response

func (*Driver) Run ¶

func (d *Driver) Run(endpoint string, testBool bool)

Run driver initialization

func (*Driver) ValidateVolumeCapabilities ¶

func (d *Driver) ValidateVolumeCapabilities(
	_ context.Context,
	req *csi.ValidateVolumeCapabilitiesRequest,
) (*csi.ValidateVolumeCapabilitiesResponse, error)

ValidateVolumeCapabilities return the capabilities of the volume