Update mounter interface in volume manager's ActualStateOfWorld every time.
Otherwise kubelet uses the first mounter it gets, which may not have the
latest information.
This fixes set up of CSI volumes, which store information about SELinux
support in their `mounter` interface implementation. With each MountVolume()
retry, a new mounter is instantiated and only the final mounter that succeeds
has the right info if the volume supports SELinux or not and can later
return the right attributes on GetAttributes() call.
desiredStateOfWorldPopulator.findAndRemoveDeletedPods() should remove
volumes from DSW when a pod is deleted on the API server and the volume is
uncertain in ASW.
podVolumesExist() should consider also uncertain volumes (where kubelet
does not know if a volume was fully unmounted) when checking for pod's
volumes. Added GetPossiblyMountedVolumesForPod for that.
Adding uncertain mounts to GetMountedVolumesForPod would potentially break
other callers (e.g. `verifyVolumesMountedFunc`).
As discussed during the alpha review, the ReadOnly field is not really
needed because volume mounts can also be read-only. It's a historical
oddity that can be avoided for generic ephemeral volumes as part
of the promotion to beta.
Silently ignoring the unsupported volume type leads to:
Warning FailedMount 8s kubelet Unable to attach or mount volumes: unmounted volumes=[my-csi-volume default-token-bsnbz], unattached volumes=[my-csi-volume default-token-bsnbz]: failed to get Plugin from volumeSpec for volume "my-csi-volume" err=no volume plugin matched
The new message is easier to understand:
Warning FailedMount 6s (x5 over 49s) kubelet Unable to attach or mount volumes: unmounted volumes=[my-csi-volume], unattached volumes=[my-csi-volume default-token-rwlpp]: volume my-csi-volume is a generic ephemeral volume, but that feature is disabled in kubelet
fakeVolumeHost previously implemented both the KubeletVolumeHost and
AttachDetachVolumeHost interfaces. This design makes it difficult to test the
CSIAttacher since it behaves differently depending on what type of
VolumeHost is supplied.
The implementation consists of
- identifying all places where VolumeSource.PersistentVolumeClaim has
a special meaning and then ensuring that the same code path is taken
for an ephemeral volume, with the ownership check
- adding a controller that produces the PVCs for each embedded
VolumeSource.EphemeralVolume
- relaxing the PVC protection controller such that it removes
the finalizer already before the pod is deleted (only
if the GenericEphemeralVolume feature is enabled): this is
needed to break a cycle where foreground deletion of the pod
blocks on removing the PVC, which waits for deletion of the pod
The controller was derived from the endpointslices controller.