Making containerized kubelets use host iSCSI initiator

Kubernetes flavours which use containerized kubelets tend to have 2 sets of iSCSI initiator packages available to them:

1. Those on the host machine
2. Those on the kubelet container

This causes conflict for Jiva/cStor storage engine pods trying to use an initiator.

CSI-volumes use the initiators on the host, and not inside the kubelet container. Going forward, the host initiators will have to be the initiators of choice. This will require us to do the following:

1. Install iSCSI initiator packages on the host (if not present)
2. Mount /etc/iscsi, /sbin/iscsiadm, /var/lib/iscsi, /lib/modules on to the kubelet container
3. Make the host initiator start with the init system to make the changes persistent.

For Rancher, this will involve making changes to cluster.yml (for rke cli setups) and making changes to the cluster config on the GUI based Rancher setup.

The issue identifies cluster.yml for RKE CLI setups and the cluster configuration in Rancher’s GUI as the entry points. Start by tracing how those configurations provision kubelets and host iSCSI services. Done means host initiator packages and startup are configured, the listed host paths are mounted into the kubelet container, and CSI volumes use the host initiator.