doc: Add rados namespace to option to csi-configs

A minimal documentation on how to use a rados namespace with rbd.

Signed-off-by: Mehdy Khoshnoody <mehdy.khoshnoody@gmail.com>

examples/csi-config-map-sample.yaml

@@ -12,6 +12,12 @@ kind: ConfigMap
 # each such cluster in use.
 # To add more clusters or edit MON addresses in an existing configmap, use
 # the `kubectl replace` command.
+# The <rados-namespace> is optional and represents a radosNamespace in the pool.
+# If any given all the of the rbd images, snapshots and other metadata
+# will be store within the radosNamespace.
+# NOTE: The given radosNamespace must already exists in the pool.
+# NOTE: Make sure you don't add radosNamespace option to a currently in use
+# configuration as it will cause issues.
 # The field "cephFS.subvolumeGroup" is optional and defaults to "csi".
 # NOTE: Changes to the configmap is automatically updated in the running pods,
 # thus restarting existing pods using the configmap is NOT required on edits
@@ -21,6 +27,7 @@ data:
     [
       {
         "clusterID": "<cluster-id>",
+        "radosNamespace": "<rados-namespace>",
         "monitors": [
           "<MONValue1>",
           "<MONValue2>",

internal/util/csiconfig.go

@@ -37,7 +37,7 @@ const (
 type ClusterInfo struct {
 	// ClusterID is used for unique identification
 	ClusterID string `json:"clusterID"`
-	// Namespace is the namespace in the pool
+	// RadosNamespace is a rados namespace in the pool
 	RadosNamespace string `json:"radosNamespace"`
 	// Monitors is monitor list for corresponding cluster ID
 	Monitors []string `json:"monitors"`
@@ -52,7 +52,7 @@ type ClusterInfo struct {
 // [
 // 	{
 // 		"clusterID": "<cluster-id>",
-//		"namespace": "<namespace>",
+//		"radosNamespace": "<rados-namespace>",
 // 		"monitors":
 // 			[
 // 				"<monitor-value>",