Enhances client to support unique meter retrieval

meter list API is enhanced to support a unique param
If specified as True, it returns a unique list of
meters.

This patch enhances the ceilometer-client to support
the unique argument in the shell and the client bindings.

DocImpact
Closes-Bug: #1506959

Change-Id: I011ca725c25e1cdbe9891c3719f13f5cd34142ea
(cherry picked from commit c45000c759)

ceilometerclient/tests/unit/v2/test_shell.py

@@ -1846,6 +1846,7 @@ class ShellMeterListCommandTest(utils.BaseTestCase):
         self.cc.meters.list = mock.Mock()
         self.args = mock.MagicMock()
         self.args.limit = None
+        self.args.unique = False
 
     @mock.patch('sys.stdout', new=six.StringIO())
     def test_meter_list(self):
@@ -1853,7 +1854,26 @@ class ShellMeterListCommandTest(utils.BaseTestCase):
         self.cc.meters.list.return_value = [meter]
 
         ceilometer_shell.do_meter_list(self.cc, self.args)
-        self.cc.meters.list.assert_called_once_with(q=[], limit=None)
+        self.cc.meters.list.assert_called_once_with(q=[], limit=None,
+                                                    unique=False)
+
+        self.assertEqual('''\
++-------+-------+-------+-------------+---------+------------+
+| Name  | Type  | Unit  | Resource ID | User ID | Project ID |
++-------+-------+-------+-------------+---------+------------+
+| image | gauge | image | resource-id |         | project    |
++-------+-------+-------+-------------+---------+------------+
+''', sys.stdout.getvalue())
+
+    @mock.patch('sys.stdout', new=six.StringIO())
+    def test_unique_meter_list(self):
+        self.args.unique = True
+        meter = meters.Meter(mock.Mock(), self.METER)
+        self.cc.meters.list.return_value = [meter]
+
+        ceilometer_shell.do_meter_list(self.cc, self.args)
+        self.cc.meters.list.assert_called_once_with(q=[], limit=None,
+                                                    unique=True)
 
         self.assertEqual('''\
 +-------+-------+-------+-------------+---------+------------+

ceilometerclient/v2/meters.py

@@ -25,7 +25,14 @@ class Meter(base.Resource):
 class MeterManager(base.Manager):
     resource_class = Meter
 
-    def list(self, q=None, limit=None):
+    def list(self, q=None, limit=None, unique=False):
         path = '/v2/meters'
-        params = ['limit=%s' % limit] if limit else None
+        params = []
+
+        if limit:
+            params.append('limit=%s' % limit)
+
+        if unique:
+            params.append('unique=%s' % str(unique))
+
         return self._list(options.build_url(path, q, params))

ceilometerclient/v2/shell.py

@@ -266,10 +266,14 @@ def do_sample_create(cc, args={}):
                 'but if supplied must be string, integer, float, or boolean.')
 @utils.arg('-l', '--limit', metavar='<NUMBER>',
            help='Maximum number of meters to return. %s' % DEFAULT_API_LIMIT)
+@utils.arg('--unique', dest='unique',
+           metavar='{True|False}',
+           type=lambda v: strutils.bool_from_string(v, True),
+           help='Retrieves unique list of meters.')
 def do_meter_list(cc, args={}):
     """List the user's meters."""
     meters = cc.meters.list(q=options.cli_to_array(args.query),
-                            limit=args.limit)
+                            limit=args.limit, unique=args.unique)
     field_labels = ['Name', 'Type', 'Unit', 'Resource ID', 'User ID',
                     'Project ID']
     fields = ['name', 'type', 'unit', 'resource_id', 'user_id',