github
/
k3s
mirror of https://github.com/k3s-io/k3s
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge pull request #53098 from gnufied/add-volume-expand-comments 

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add documentation comments for volume expand controller

These comments help clear out some of the design choices made
in code.

cc @kubernetes/sig-storage-pr-reviews @NickrenREN
pull/6/head
Kubernetes Submit Queue 2017-09-28 10:12:20 -07:00 committed by GitHub
parent 208ae55f6d 0ad846cb18
commit bfaaa77263
3 changed files with 15 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
pkg/controller/volume/expand/cache/volume_resize_map.go vendored
View File

@ -88,6 +88,11 @@ func NewVolumeResizeMap(kubeClient clientset.Interface) VolumeResizeMap {
}
// AddPVCUpdate adds pvc for resizing
// This function intentionally allows addition of PVCs for which pv.Spec.Size >= pvc.Spec.Size,
// the reason being - lack of transaction in k8s means after successful resize, we can't guarantee that when we update PV,
// pvc update will be successful too and after resize we alyways update PV first.
// If for some reason we weren't able to update PVC after successful resize, then we are going to reprocess
// the PVC and hopefully after a no-op resize in volume plugin, PVC will be updated with right values as well.
func (resizeMap *volumeResizeMap) AddPVCUpdate(pvc *v1.PersistentVolumeClaim, pv *v1.PersistentVolume) {
if pv.Spec.ClaimRef == nil || pvc.Namespace != pv.Spec.ClaimRef.Namespace || pvc.Name != pv.Spec.ClaimRef.Name {
glog.V(4).Infof("Persistent Volume is not bound to PVC being updated : %s", util.ClaimToClaimKey(pvc))

5
pkg/controller/volume/expand/pvc_populator.go
View File

@ -80,6 +80,11 @@ func (populator *pvcPopulator) Sync() {
glog.V(5).Infof("Error getting persistent volume for pvc %q : %v", pvc.UID, err)
continue
}
// We are only going to add PVCs which are:
// - bound
// - pvc.Spec.Size > pvc.Status.Size
// These 2 checks are already performed in AddPVCUpdate function before adding pvc for resize
// and hence we do not repeat those checks here.
populator.resizeMap.AddPVCUpdate(pvc, pv)
}
}

5
pkg/volume/util/operationexecutor/operation_generator.go
View File

@ -756,6 +756,9 @@ func (og *operationGenerator) GenerateExpandVolumeFunc(
return expandErr
}
newSize = updatedSize
// k8s doesn't have transactions, we can't guarantee that after updating PV - updating PVC will be
// successful, that is why all PVCs for which pvc.Spec.Size > pvc.Status.Size must be reprocessed
// until they reflect user requested size in pvc.Status.Size
updateErr := resizeMap.UpdatePVSize(pvcWithResizeRequest, newSize)
if updateErr != nil {
@ -766,6 +769,8 @@ func (og *operationGenerator) GenerateExpandVolumeFunc(
}
// No Cloudprovider resize needed, lets mark resizing as done
// Rest of the volume expand controller code will assume PVC as *not* resized until pvc.Status.Size
// reflects user requested size.
if !volumePlugin.RequiresFSResize() {
glog.V(4).Infof("Controller resizing done for PVC %s", pvcWithResizeRequest.QualifiedName())
err := resizeMap.MarkAsResized(pvcWithResizeRequest, newSize)