util: add support for the nsenter

add support to run rbd map and mount -t
commands with the nsenter.

complete design of pod/multus network
is added here https://github.com/rook/rook/
blob/master/design/ceph/multus-network.md#csi-pods

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

charts/ceph-csi-cephfs/templates/nodeplugin-daemonset.yaml

@@ -31,6 +31,7 @@ spec:
       priorityClassName: {{ .Values.nodeplugin.priorityClassName }}
 {{- end }}
       hostNetwork: true
+      hostPID: true
       # to use e.g. Rook orchestrated cluster, and mons' FQDN is
       # resolved through k8s service, set dns policy to cluster first
       dnsPolicy: ClusterFirstWithHostNet

charts/ceph-csi-cephfs/values.yaml

@@ -27,6 +27,7 @@ serviceAccounts:
 #       - "<MONValue2>"
 #     cephFS:
 #       subvolumeGroup: "csi"
+#     netNamespaceFilePath: "{{ .kubeletDir }}/plugins/{{ .driverName }}/net"
 csiConfig: []
 
 # Set logging level for csi containers.

charts/ceph-csi-rbd/values.yaml

@@ -25,6 +25,7 @@ serviceAccounts:
 #     monitors:
 #       - "<MONValue1>"
 #       - "<MONValue2>"
+#     netNamespaceFilePath: "{{ .kubeletDir }}/plugins/{{ .driverName }}/net"
 csiConfig: []
 
 # Configuration details of clusterID,PoolID and FscID mapping