How the kubernetes cinder volume plugin works?

Question

I'm new to k8s, and recently, I read the cinder volume plugin source code: cinder volume plugin .

I don't know how the plugin works, and how it communicates with cinder? And I don't find the request and response in code.

Does the cinder volume plugin call cinder API or other ways?

Answer 1

cinder volume is a persistent volume , more precisely one of the persistent volume storage classes .

Each StorageClass contains the fields provisioner and parameters, which are used when a PersistentVolume belonging to the class needs to be dynamically provisioned.

Cinder specifically is an Openstack volume type .
It is an OpenStack Block Storage Cinder , which:

• implements services and libraries to provide on demand, self-service access to Block Storage resources.
• Provides Software Defined Block Storage via abstraction and automation on top of various traditional backend block storage devices.

You can see how Kubernetes uses cinder in pkg/volume/cinder/cinder_test.go .
However, as mentioned in " Kubernetes Cinder volumes do not mount with cloud-provider=openstack ":

the the Cinder provisioner is not implemented yet, given the following statement in the docs ( StorageClasses Provisioner ):

During beta, the available provisioner types are kubernetes.io/aws-ebs and kubernetes.io/gce-pd

So no " kubernetes.io/cinder " yet.
Yet, Ewa mentions in the comments making it work: see " Kubernetes Cinder volumes do not mount with cloud-provider=openstack " as an example.

Answer 2

Check this question . Kubernetes has configuration( --cloud-config paramter) on how to connect cloud provider like OpenStack to operate Load Balance IP & Block Storage.