Improve help text for libvirt options

This patch improves help text for libvirt_volume_net_opts,
libvirt_volume_nfs_opts, libvirt_volume_quobyte_opts,
libvirt_volume_scality_opts.

Blueprint centralize-config-options-ocata

Change-Id: Ie89f1b1a7795d73fff9341fbdf1268fb3df7a20d

diff --git a/nova/conf/libvirt.py b/nova/conf/libvirt.py
index 722f55069b2d2b2adcdb708ccde63d2becd8d1b4..029ef726a188dbe769914b74e14f76c55c903168 100644 (file)
--- a/nova/conf/libvirt.py
+++ b/nova/conf/libvirt.py
@@ -607,37 +607,88 @@ libvirt_volume_iser_opts = [
 
 libvirt_volume_net_opts = [
     cfg.StrOpt('rbd_user',
-               help='The RADOS client name for accessing rbd volumes'),
+               help="""
+The RADOS client name for accessing rbd(RADOS Block Devices) volumes.
+
+Libvirt will refer to this user when connecting and authenticating with
+the Ceph RBD server.
+"""),
     cfg.StrOpt('rbd_secret_uuid',
-               help='The libvirt UUID of the secret for the rbd_user'
-                    ' volumes'),
+               help="""
+The libvirt UUID of the secret for the rbd_user volumes.
+"""),
 ]
 
 libvirt_volume_nfs_opts = [
     cfg.StrOpt('nfs_mount_point_base',
                default=paths.state_path_def('mnt'),
-               help='Directory where the NFS volume is mounted on the'
-                    ' compute node'),
+               help="""
+Directory where the NFS volume is mounted on the compute node.
+The default is 'mnt' directory of the location where nova's Python module
+is installed.
+
+NFS provides shared storage for the OpenStack Block Storage service.
+
+Possible values:
+
+* A string representing absolute path of mount point.
+"""),
     cfg.StrOpt('nfs_mount_options',
-               help='Mount options passed to the NFS client. See section '
-                    'of the nfs man page for details'),
+               help="""
+Mount options passed to the NFS client. See section of the nfs man page
+for details.
+
+Mount options controls the way the filesystem is mounted and how the
+NFS client behaves when accessing files on this mount point.
+
+Possible values:
+
+* Any string representing mount options seperated by commas.
+* Example string: vers=3,lookupcache=pos
+"""),
 ]
 
 libvirt_volume_quobyte_opts = [
     cfg.StrOpt('quobyte_mount_point_base',
                default=paths.state_path_def('mnt'),
-               help='Directory where the Quobyte volume is mounted on the '
-                    'compute node'),
+               help="""
+Directory where the Quobyte volume is mounted on the compute node.
+
+Nova supports Quobyte volume driver that enables storing Block Storage
+service volumes on a Quobyte storage back end. This Option sepcifies the
+path of the directory where Quobyte volume is mounted.
+
+Possible values:
+
+* A string representing absolute path of mount point.
+"""),
     cfg.StrOpt('quobyte_client_cfg',
                help='Path to a Quobyte Client configuration file.'),
 ]
 
 libvirt_volume_scality_opts = [
     cfg.StrOpt('scality_sofs_config',
-               help='Path or URL to Scality SOFS configuration file'),
+               help="""
+Path or URL to Scality SOFS(Scale-Out File Server) configuration file.
+
+The Scality SOFS provides OpenStack users the option of storing their
+data on a high capacity, replicated, highly available Scality Ring object
+storage cluster.
+"""),
     cfg.StrOpt('scality_sofs_mount_point',
                default='$state_path/scality',
-               help='Base dir where Scality SOFS shall be mounted'),
+               help="""
+Base dir where Scality SOFS shall be mounted.
+
+The Scality volume driver in Nova mounts SOFS and lets the hypervisor access
+the volumes.
+
+Possible values:
+
+* $state_path/scality where state_path is a config option that specifies
+  the top-level directory for maintaining nova's state or Any string
+  containing the full directory path.
+"""),
 ]
 
 libvirt_volume_smbfs_opts = [