Add docs for usage show/list

Change-Id: Iaf911d69a0b63d705f8789a4640018a428b87be6

Author: Steve Martinelli

doc/source/command-objects/usage.rst

@@ -0,0 +1,50 @@
+=====
+usage
+=====
+
+Compute v2
+
+usage list
+----------
+
+List resource usage per project
+
+.. program:: usage list
+.. code:: bash
+
+    os usage list
+        --start <start>
+        --end <end>
+
+.. option:: --start <start>
+
+    Usage range start date, ex 2012-01-20 (default: 4 weeks ago).
+
+.. option:: --end <end>
+
+    Usage range end date, ex 2012-01-20 (default: tomorrow)
+
+usage show
+----------
+
+Show resource usage for a single project.
+
+.. program:: usage show
+.. code:: bash
+
+    os usage show
+        --project <project>
+        --start <start>
+        --end <end>
+
+.. option:: --project <project>
+
+    Name or ID of project to show usage for.
+
+.. option:: --start <start>
+
+    Usage range start date, ex 2012-01-20 (default: 4 weeks ago).
+
+.. option:: --end <end>
+
+    Usage range end date, ex 2012-01-20 (default: tomorrow)

doc/source/commands.rst

@@ -107,6 +107,7 @@ referring to both Compute and Volume quotas.
 * ``service``: Identity - a cloud service
 * ``snapshot``: Volume - a point-in-time copy of a volume
 * ``token``: (**Identity**) a bearer token managed by Identity service
+* ``usage``: (**Compute**) display host resources being consumed
 * ``user``: (**Identity**) individual cloud resources users
 * ``user role``: (**Identity**) roles assigned to a user
 * ``volume``: Volume - block volumes

openstackclient/compute/v2/usage.py

@@ -125,6 +125,12 @@ class ShowUsage(show.ShowOne):
 
     def get_parser(self, prog_name):
         parser = super(ShowUsage, self).get_parser(prog_name)
+        parser.add_argument(
+            "--project",
+            metavar="<project>",
+            default=None,
+            help="Name or ID of project to show usage for."
+        )
         parser.add_argument(
             "--start",
             metavar="<start>",
@@ -138,12 +144,6 @@ def get_parser(self, prog_name):
             default=None,
             help="Usage range end date, ex 2012-01-20 (default: tomorrow)."
         )
-        parser.add_argument(
-            "--project",
-            metavar="<project>",
-            default=None,
-            help="Name or ID of project to show usage for."
-        )
         return parser
 
     def take_action(self, parsed_args):