This section of documentation covers use of the Rancher orchestrator as a Kubernetes provisioner.
Rancher with StorageOS
StorageOS installation in Rancher deployed clusters is fully supported.
Kubernetes API controller and StorageOS communicate with each other to perform actions such as creation, deletion or mounting of volumes. The standard communication procedure uses REST API calls. However, StorageOS also implements communication using CSI. By using CSI, Kubernetes and StorageOS communicates via a Linux socket. That socket is handled by the Kubelet in the Host.
CSI (Container Storage Interface) Note
CSI is the future standard that enables storage drivers to release on their own schedule. This allows storage vendors to upgrade, update, and enhance their drivers without the need to update Kubernetes source code, or follow Kubernetes release cycles.
CSI 1.0.0 is released with Kubernetes 1.13. Its use is recommended only if the user is aware of its particularities.
CSI communication between StorageOS and Kubernetes is currently not possible when using RancherOS because of restricted access to the Linux Socket created by the Kubelet.
CSI communication is fully supported by StorageOS if the Kubernetes cluster is deployed with another supported Linux Distribution.