Add support for rbd volume resizing

[JrCs]

Can you add support for rbd volume resizing ?
See https://kubernetes.io/blog/2018/07/12/resizing-persistent-volumes-using-kubernetes/

[rootfs]

that has to wait till kubernetes csi volume plugin supports expandable volume, something like this

[aibarbetta]

CSI seems to be supporting volume expansion now:
https://github.com/container-storage-interface/spec/blob/master/spec.md#controllerexpandvolume
https://github.com/container-storage-interface/spec/blob/master/spec.md#nodeexpandvolume
Is anything else needed on the k8s side in order to implement this feature?

[gman0]

@abrden yes, something (external-provisioner) needs to implement the controller for expansion.

[rootfs]

will revisit this request once external-resizer is ready and able to provide all the info (e.g. secret) to resize rbd/cephfs PVs.

[rootfs]

now external-resize supports csi resize, we should pick it here.

cc @Madhu-1 @gman0 @humblec @j-griffith

[Madhu-1]

@rootfs does kube latest version supports volume expansion? , if yes i think we can take it, i was waiting for kube 1.14 release (i think it supports volume expansion) correct me if am wrong.

[Madhu-1]

/assign Madhu-1

[rootfs]

yes, k8s csi volume volume expansion is scheduled for k8s 1.14
kubernetes/kubernetes#74863

[humblec]

@rootfs sure, we will take care of it.. @Madhu-1 lets sync up ..

[sandromodarelli]

any news about this issue? plans of release?

[Madhu-1]

as humble is working on this one. assigning to humble
#331

[wavezhang]

Any progress on this?

[davi5e]

Besides any updates on the progress status, which would be the Kubernetes version this is being developed for? 1.14? 1.15?

[humblec]

Besides any updates on the progress status, which would be the Kubernetes version this is being developed for? 1.14? 1.15?

@wavezhang @davi5e we have a prototype on resize here #331, but has not completed as there were various changes happening on rbd code with other bug fixes and enhancements. This feature was planned for #393 , however deferred to v2.0.0 which is planned at 3rd week of September.

[Madhu-1]

closing this one as this is implemented in #331