Use NFS Storage as a backend storage for docker registry

[kwiatekus]

Description Use NFS Storage as a backend storage for docker registry

AC

• [ ] User can configure a docker registry storage using an NFS storage class via DockerRegistry CR
• [ ] User can deduct that a NFS storage is used based on the docker registry status
• [ ] Document how to configure NFS storage as a backend for docker registry ( incl prerequisite: link to cloud manager tutorial)
• [ ] Operator should resolve CR into warning state in case reference storage class doesnt exist on the cluster

Test Strategy Full integration test incl. cloud manager should be performed manually. A new unit test should be added (testing which flags are passed to the helm chart based on DockerRegistry CR).

Reason Using Network File System Storage class will be a great addition to the already provided storage options of docker registry. When mounted into docker registry pod, it could serve as a highly available storage resource, the content of which is not purged upon unmounting.

Attachments https://kubernetes.io/docs/concepts/storage/volumes/#nfs https://github.com/kyma-project/cloud-manager/blob/main/docs/user/README.md#features https://github.com/kyma-project/cloud-manager/tree/main/docs/user/tutorials

[halamix2]

We'll support nfs through PersistentVolumeClaim, as there is an existing support for providing existing PVC; and also because pvc supports more storage options than just nfs