deleting snapshotclass is marking volumesnapshot readyToUse as false

[Madhu-1]

deleting the snapshot class which is used to create volume snapshots is leading to marking all volume snapshot readyToUse as false

steps to reproduce:-

• create volumesnapshotclass
• create volumesnapshot
• wait till readyToUse is set to true
• Now delete the volumesnapshotclass
• check readyToUse on volumesnapshot

logs of snapshot controller

I1201 04:44:46.953076       1 reflector.go:369] github.com/kubernetes-csi/external-snapshotter/client/v3/informers/externalversions/factory.go:117: forcing resync
I1201 04:44:46.953295       1 snapshot_controller_base.go:158] enqueued "default/rbd-pvc-snapshot" for sync
I1201 04:44:46.953349       1 snapshot_controller_base.go:202] syncSnapshotByKey[default/rbd-pvc-snapshot]
I1201 04:44:46.953366       1 snapshot_controller_base.go:205] snapshotWorker: snapshot namespace [default] name [rbd-pvc-snapshot]
I1201 04:44:46.953381       1 snapshot_controller_base.go:328] checkAndUpdateSnapshotClass [rbd-pvc-snapshot]: VolumeSnapshotClassName [csi-rbdplugin-snapclass]
I1201 04:44:46.953393       1 snapshot_controller.go:1178] getSnapshotClass: VolumeSnapshotClassName [csi-rbdplugin-snapclass]
E1201 04:44:46.953415       1 snapshot_controller.go:1182] failed to retrieve snapshot class csi-rbdplugin-snapclass from the informer: "volumesnapshotclass.snapshot.storage.k8s.io \"csi-rbdplugin-snapclass\" not found"
E1201 04:44:46.953477       1 snapshot_controller_base.go:331] checkAndUpdateSnapshotClass failed to getSnapshotClass volumesnapshotclass.snapshot.storage.k8s.io "csi-rbdplugin-snapclass" not found
I1201 04:44:46.953525       1 snapshot_controller.go:721] updateSnapshotStatusWithEvent[default/rbd-pvc-snapshot]
I1201 04:44:46.953539       1 snapshot_controller.go:724] updateSnapshotStatusWithEvent[rbd-pvc-snapshot]: the same error &{2020-12-01 04:37:46 +0000 UTC 0xc0004baf90} is already set
I1201 04:44:46.953602       1 snapshot_controller_base.go:192] Failed to sync snapshot "default/rbd-pvc-snapshot", will retry again: volumesnapshotclass.snapshot.storage.k8s.io "csi-rbdplugin-snapclass" not found
I1201 04:45:46.894293       1 reflector.go:369] github.com/kubernetes-csi/external-snapshotter/client/v3/informers/externalversions/factory.go:117: forcing resync
I1201 04:45:46.894521       1 snapshot_controller_base.go:175] enqueued "snapcontent-7a477074-ecd2-464c-a925-1892e8b2f419" for sync
I1201 04:45:46.894710       1 snapshot_controller_base.go:277] syncContentByKey[snapcontent-7a477074-ecd2-464c-a925-1892e8b2f419]
I1201 04:45:46.894864       1 util.go:264] storeObjectUpdate updating content "snapcontent-7a477074-ecd2-464c-a925-1892e8b2f419" with version 102029
I1201 04:45:46.895012       1 snapshot_controller.go:86] synchronizing VolumeSnapshotContent[snapcontent-7a477074-ecd2-464c-a925-1892e8b2f419]: content is bound to snapshot default/rbd-pvc-snapshot
I1201 04:45:46.895148       1 snapshot_controller.go:88] syncContent[snapcontent-7a477074-ecd2-464c-a925-1892e8b2f419]: check if we should add invalid label on content
I1201 04:45:46.895289       1 snapshot_controller.go:1370] getSnapshotFromStore: snapshot default/rbd-pvc-snapshot found
I1201 04:45:46.895453       1 snapshot_controller.go:991] needsUpdateSnapshotStatus[default/rbd-pvc-snapshot]
I1201 04:45:46.895740       1 snapshot_controller.go:143] synchronizing VolumeSnapshotContent for snapshot [default/rbd-pvc-snapshot]: update snapshot status to true if needed.
I1201 04:45:46.895980       1 snapshot_controller_base.go:202] syncSnapshotByKey[default/rbd-pvc-snapshot]
I1201 04:45:46.897389       1 snapshot_controller_base.go:205] snapshotWorker: snapshot namespace [default] name [rbd-pvc-snapshot]
I1201 04:45:46.897424       1 snapshot_controller_base.go:328] checkAndUpdateSnapshotClass [rbd-pvc-snapshot]: VolumeSnapshotClassName [csi-rbdplugin-snapclass]
I1201 04:45:46.897431       1 snapshot_controller.go:1178] getSnapshotClass: VolumeSnapshotClassName [csi-rbdplugin-snapclass]
E1201 04:45:46.897448       1 snapshot_controller.go:1182] failed to retrieve snapshot class csi-rbdplugin-snapclass from the informer: "volumesnapshotclass.snapshot.storage.k8s.io \"csi-rbdplugin-snapclass\" not found"
E1201 04:45:46.897523       1 snapshot_controller_base.go:331] checkAndUpdateSnapshotClass failed to getSnapshotClass volumesnapshotclass.snapshot.storage.k8s.io "csi-rbdplugin-snapclass" not found
I1201 04:45:46.897545       1 snapshot_controller.go:721] updateSnapshotStatusWithEvent[default/rbd-pvc-snapshot]
I1201 04:45:46.897554       1 snapshot_controller.go:724] updateSnapshotStatusWithEvent[rbd-pvc-snapshot]: the same error &{2020-12-01 04:37:46 +0000 UTC 0xc0004baf90} is already set
I1201 04:45:46.897624       1 snapshot_controller_base.go:192] Failed to sync snapshot "default/rbd-pvc-snapshot", will retry again: volumesnapshotclass.snapshot.storage.k8s.io "csi-rbdplugin-snapclass" not found
I1201 04:45:46.955714       1 reflector.go:369] github.com/kubernetes-csi/external-snapshotter/client/v3/informers/externalversions/factory.go:117: forcing resync
I1201 04:45:46.955856       1 snapshot_controller_base.go:158] enqueued "default/rbd-pvc-snapshot" for sync
I1201 04:45:46.955909       1 snapshot_controller_base.go:202] syncSnapshotByKey[default/rbd-pvc-snapshot]
I1201 04:45:46.955925       1 snapshot_controller_base.go:205] snapshotWorker: snapshot namespace [default] name [rbd-pvc-snapshot]
I1201 04:45:46.955938       1 snapshot_controller_base.go:328] checkAndUpdateSnapshotClass [rbd-pvc-snapshot]: VolumeSnapshotClassName [csi-rbdplugin-snapclass]
I1201 04:45:46.955947       1 snapshot_controller.go:1178] getSnapshotClass: VolumeSnapshotClassName [csi-rbdplugin-snapclass]
E1201 04:45:46.955963       1 snapshot_controller.go:1182] failed to retrieve snapshot class csi-rbdplugin-snapclass from the informer: "volumesnapshotclass.snapshot.storage.k8s.io \"csi-rbdplugin-snapclass\" not found"
E1201 04:45:46.956023       1 snapshot_controller_base.go:331] checkAndUpdateSnapshotClass failed to getSnapshotClass volumesnapshotclass.snapshot.storage.k8s.io "csi-rbdplugin-snapclass" not found
I1201 04:45:46.956043       1 snapshot_controller.go:721] updateSnapshotStatusWithEvent[default/rbd-pvc-snapshot]
I1201 04:45:46.956068       1 snapshot_controller.go:724] updateSnapshotStatusWithEvent[rbd-pvc-snapshot]: the same error &{2020-12-01 04:37:46 +0000 UTC 0xc0004baf90} is already set
I1201 04:45:46.956135       1 snapshot_controller_base.go:192] Failed to sync snapshot "default/rbd-pvc-snapshot", will retry again: volumesnapshotclass.snapshot.storage.k8s.io "csi-rbdplugin-snapclass" not found

[Madhu-1]

cc @xing-yang

[xing-yang]

@Madhu-1 which version of external-snapshotter are you testing with?

[xing-yang]

Current fix: Update updateSnapshotStatusWithEvent to include a "setReadyToFalse bool" input parameter. If false, ReadyToUse will not be changed.

• If snapshot class is not found, ReadyToUse will not be changed.
• If updateSnapshotStatus failed, ReadyToUse will not be changed.
• For all other cases, the code stays the same as before, meaning ReadyToUse will be False.