PV controller should send events to PVCs and not PVs when a PVC requests PV
that's either too small or has mismatching StorageClass.
Regular users can't see events on PVs so `kubectl describe pvc` is the only
way how to tell user that something is wrong.
Automatic merge from submit-queue
Add storageClass.mountOptions and use it in all applicable plugins
split off from https://github.com/kubernetes/kubernetes/pull/50919 and still dependent on it. cc @gnufied
issue: https://github.com/kubernetes/features/issues/168
```release-note
Add mount options field to StorageClass. The options listed there are automatically added to PVs provisioned using the class.
```
When API server crashes *after* saving a provisioned PV and before sending
200 OK, the controller tries to save the PV again. In this case, it gets
AlreadyExists error, which should be interpreted as success and not as error.
Especially, a volume that corresponds to the PV should not be deleted in the
underlying storage.
Automatic merge from submit-queue (batch tested with PRs 51441, 51356, 51460)
Don't update pvc.status.capacity if pvc is already Bound
As discussed here https://github.com/kubernetes/community/pull/657#discussion_r128008128, in order for `pvc.status.Capacity < pv.Spec.Capcity` to be the mechanism for volume filesystem* resize, the pv controller should stop updating pvc.status.Capacity every resync period.
/assign @jsafrane
/sig storage
```release-note
NONE
```
Automatic merge from submit-queue
Add volume operation metrics to operation executor and PV controller
This PR implements the proposal for high level volume metrics https://github.com/kubernetes/community/pull/809
**Special notes for your reviewer**:
~Differences from proposal:~ all resolved
~"verify_volume" is now "verify_volumes_are_attached" + "verify_volumes_are_attached_per_node" + "verify_controller_attached_volume." Which of them do we want?~
~There is no "mount_device" metric because the MountVolume operation combines MountDevice and mount (plugin.Setup). Do we want to extract the mount_device metric or is it okay to keep mountvolume as one? For attachable volumes, MountDevice is the actual mount and Setup is a bindmount + setvolumeownership. For unattachable, mountDevice does not occur and Setup is an actual mount + setvolumeownership.~
~PV controller metrics I did not implement following the proposal at all. I did not change goroutinemap nor scheduleOperation. Because provisionClaimOperation does not return an error, so it's impossible for the caller to know if there is actually a failure worth reporting. So I manually create a new metric inside the function according to some conditions.~
@gnufied
I have tested the operationexecutor metrics but not provision & delete. Sample:

**Release note**:
```release-note
Add error count and time-taken metrics for storage operations such as mount and attach, per-volume-plugin.
```
We want relatively short resync period of PV/PVCs and at the same time we
don't want to force such short resync to all shared informer consumers.
Therefore we need to make our own periodic resync.
Automatic merge from submit-queue
Remove alphaProvisioner in PVController and AlphaStorageClassAnnotation
remove alpha annotation and alphaProvisioner
**Release note**:
```release-note
NONE
```
check if the volume requested by the claim satisfies the requirements of the claim before binding when
syncUnboundClaim and claim.Spec.VolumeName is not set
Automatic merge from submit-queue
Make Constants Public so that They Can Be Used in an Ext. Provisioner
Out-of-tree external provisioners have the same purpose as in-tree provisioners. As external provisioners work with PV and PVC datastructures it's an advantage to import certain Kubernetes packages instead of copy-pasting the Kubernetes code.
That's why the constants are made public so that they can be used in an external provisioner.
@jsafrane @kubernetes/sig-storage-pr-reviews
```
NONE
```
When ctrl.kubeClient.Core().PersistentVolumes().Create(volume) returns no err, but storeVolumeUpdate() failed, we save PV sucessfully ,but here err is not nil,
we should not run the codes next in block if err != nil {}
same in the deletion retries below
Automatic merge from submit-queue (batch tested with PRs 42522, 42545, 42556, 42006, 42631)
optimize the binding logic of bindClaimToVolume
extract var shouldSetBoundByController and do not need to judge volumename twice
**Release note**:
```release-note
NONE
```
Out-of-tree external provisioners have the same purpose as in-tree provisioners. As external provisioners work with PV and PVC datastructures it's an advantage to import certain Kubernetes packages instead of copy-pasting the Kubernetes code.
That's why the constants are made public so that they can be used in an external provisioner.
Automatic merge from submit-queue (batch tested with PRs 41814, 41922, 41957, 41406, 41077)
pv_controller: Do not report exponential backoff as error.
It's not an error when recycle/delete/provision operation cannot be started
because it has failed recently. It will be restarted automatically when
backoff expires.
This just pollutes logs without any useful information:
```
E0214 08:00:30.428073 77288 pv_controller.go:1410] error scheduling operaion "delete-pvc-1fa0e8b4-f2b5-11e6-a8bb-fa163ecb84eb[1fbd52ee-f2b5-11e6-a8bb-fa163ecb84eb]": Failed to create operation with name "delete-pvc-1fa0e8b4-f2b5-11e6-a8bb-fa163ecb84eb[1fbd52ee-f2b5-11e6-a8bb-fa163ecb84eb]". An operation with that name failed at 2017-02-14 08:00:15.631133152 -0500 EST. No retries permitted until 2017-02-14 08:00:31.631133152 -0500 EST (16s). Last error: "Cannot delete the volume \"11a4faea-bfc7-4713-88b3-dec492480dba\", it's still attached to a node".
```
```release-note
NONE
```
@kubernetes/sig-storage-pr-reviews
Automatic merge from submit-queue (batch tested with PRs 41364, 40317, 41326, 41783, 41782)
changes to cleanup the volume plugin for recycle
**What this PR does / why we need it**:
Code cleanup. Changing from creating a new interface from the plugin, that then calls a function to recycle a volume, to adding the function to the plugin itself.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#26230
**Special notes for your reviewer**:
Took same approach from closed PR #28432.
Do you want the approach to be the same for NewDeleter(), NewMounter(), NewUnMounter() and should they be in this same PR or submit different PR's for those?
**Release note**:
```NONE
```
Automatic merge from submit-queue
Remove alpha provisioning
This is the first part of https://github.com/kubernetes/features/issues/36
@kubernetes/sig-storage-misc
**Release note**:
```release-note
Alpha version of dynamic volume provisioning is removed in this release. Annotation
"volume.alpha.kubernetes.io/storage-class" does not have any special meaning. A default storage class
and DefaultStorageClass admission plugin can be used to preserve similar behavior of Kubernetes cluster,
see https://kubernetes.io/docs/user-guide/persistent-volumes/#class-1 for details.
```
It's not an error when recycle/delete/provision operation cannot be started
because it has failed recently. It will be restarted automatically when
backoff expires.