docs: clarify compute service --service option

The compute service commands emit a "Binary" in the output but
the --service filter option isn't as clear that it's the binary
(for set it is but not list) nor do the docs give an example
of a binary (typically nova-compute but could be others like
nova-conductor, nova-scheduler, etc). This simply mentions that
the --service option is the binary for "compute service list"
and gives an example value for the option in both list and set
help.

Change-Id: If87fc37352c3a251cc89041723adbe04dedf4f8a

Author: mriedem

doc/source/cli/command-objects/compute-service.rst

@@ -39,7 +39,8 @@ List compute services
 
 .. option:: --service <service>
 
-    List only specified service (name only)
+    List only specified service binaries (name only). For example,
+    ``nova-compute``, ``nova-conductor``, etc.
 
 .. option:: --long
 
@@ -86,4 +87,4 @@ Set compute service properties
 
 .. describe:: <service>
 
-    Name of service (Binary name)
+    Name of service (Binary name), for example ``nova-compute``

openstackclient/compute/v2/service.py

@@ -72,7 +72,8 @@ def get_parser(self, prog_name):
         parser.add_argument(
             "--service",
             metavar="<service>",
-            help=_("List only specified service (name only)")
+            help=_("List only specified service binaries (name only). For "
+                   "example, ``nova-compute``, ``nova-conductor``, etc.")
         )
         parser.add_argument(
             "--long",
@@ -126,7 +127,8 @@ def get_parser(self, prog_name):
         parser.add_argument(
             "service",
             metavar="<service>",
-            help=_("Name of service (Binary name)")
+            help=_("Name of service (Binary name), for example "
+                   "``nova-compute``")
         )
         enabled_group = parser.add_mutually_exclusive_group()
         enabled_group.add_argument(