This PR also looses the check to allow zero since the API doc has
explained that value zero indicates no waiting.
Signed-off-by: Dave Chen <dave.chen@arm.com>
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.
This uses the information provided by a CSI driver deployment for
checking whether a node has access to enough storage to create the
currently unbound volumes, if the CSI driver opts into that checking
with CSIDriver.Spec.VolumeCapacity != false.
This resolves a TODO from commit 95b530366a.
Previously, separate interfaces were defined for Reserve and Unreserve
plugins. However, in nearly all cases, a plugin that allocates a
resource using Reserve will likely want to register itself for Unreserve
as well in order to free the allocated resource at the end of a failed
scheduling/binding cycle. Having separate plugins for Reserve and
Unreserve also adds unnecessary config toil. To that end, this patch
aims to merge the two plugins into a single interface called a
ReservePlugin that requires implementing both the Reserve and Unreserve
methods.
The scheduler doesn't really need to know in detail which reasons
rendered a node unusable for a node. All it needs from the volume
binder is a list of reasons that it then can present to the user.
This seems a bit cleaner. But the main reason for the change is that
it simplifies the checking of CSI inline volumes and perhaps later
capacity checking. Both will lead to new failure reasons, which then
can be added without changing the interface.
