kubernetes : dynamic persistent volume provisioning using iSCSI and NFS

Question

I am using Kubernetes 1.4 persistent volume support, iSCSI/NFS PV and PVC successfully, in my containers. However it needs to first provision the storage by specifying the capacity both at PV creation and during claiming the storage.

My requirement is to just provide storage to cluster(and don't want to mention the capacity of storage) and let users/developers claim the storage based on their requirements. So need to use dynamic provisioning using StorageClass. Just declare the storage with details and let developers claim it based on their needs.

However got confused about using dynamic volume provisioning for iSCSI and NFS using Storage class and not getting exact steps to follow. As per documentation i need to use external volume plugin for both these types and it has already been made available as a part of incubator project - https://github.com/kubernetes-incubator/external-storage/ . But i am not getting how to load/run that external provisioner(i need to run it as a container itself??i guess) and then write storage class with details of iSCSI/NFS storage.

Can somebody who has already done/used it can guide/provide pointers on this?

Thanks in advance, picku

Answer 1

The project you pointed to is specific to iSCSI targets running targetd. You basically download the YAML files here https://github.com/kubernetes-incubator/external-storage/tree/master/iscsi/targetd/kubernetes , modify them with your storage provider's parameters and deploy the pods using kubectl create. In your pods you need to specify the a storageclass. The storageclass then specifies a the iSCSI provisioner. There are more steps but that's the gist of it.

See this link for more detailed instructions https://github.com/kubernetes-incubator/external-storage/tree/master/iscsi/targetd

Answer 2

the OpenEBS community has folks running this way afaik. There is a blog here for example explaining one approach supporting WordPress: https://blog.openebs.io/setting-up-persistent-volumes-in-rwx-mode-using-openebs-142632244cb2