Allow deleting node labels by their values

Usage for deleting node labels by value:
fuel2 node label delete (-n NODES [NODES ...] | --nodes-all)
(label | label=value) [(label | label=value)]

Change-Id: I119d137f3486c5692388a9ac08ae25df2f19ebee
Closes-Bug: #1477590

fuelclient/tests/v2/unit/cli/test_node.py

@@ -209,3 +209,28 @@ class TestNodeCommand(test_engine.BaseCLITest):
         self.m_get_client.assert_called_once_with('node', mock.ANY)
         self.m_client.delete_labels_for_nodes.assert_called_once_with(
             labels=None, node_ids=node_ids)
+
+    def test_node_label_delete_by_value(self):
+        labels = ['key_1', 'key_2=value2']
+        node_ids = ['42', '43']
+        args = 'node label delete -l {labels} --nodes {node_ids}'.format(
+            labels=' '.join(labels), node_ids=' '.join(node_ids))
+
+        self.exec_command(args)
+
+        self.m_get_client.assert_called_once_with('node', mock.ANY)
+        self.m_client.delete_labels_for_nodes.assert_called_once_with(
+            labels=labels, node_ids=node_ids)
+
+    def test_node_label_delete_by_value_with_whitespace(self):
+        labels = ['key_1', "'key_2   =value2'"]
+        labels_expected = [x.strip("'") for x in labels]
+        node_ids = ['42', '43']
+        args = 'node label delete -l {labels} --nodes {node_ids}'.format(
+            labels=' '.join(labels), node_ids=' '.join(node_ids))
+
+        self.exec_command(args)
+
+        self.m_get_client.assert_called_once_with('node', mock.ANY)
+        self.m_client.delete_labels_for_nodes.assert_called_once_with(
+            labels=labels_expected, node_ids=node_ids)

fuelclient/tests/v2/unit/lib/test_node.py

@@ -208,6 +208,36 @@ class TestNodeFacade(test_api.BaseLibTest):
         self.assertTrue(matcher_put.called)
         self.assertEqual(data, matcher_put.last_request.json())
 
+    def test_delete_labels_by_value(self):
+        labels = ['key_1=val_1', 'key_3=anothervalue', 'key_2']
+        node_ids = ['42']
+        result_labels = {'labels': {'key_3': 'val_3'}}
+        expected_uri = self.get_object_uri(self.res_uri, 42)
+
+        self.m_request.get(expected_uri, json=self.fake_node)
+        matcher_put = self.m_request.put(expected_uri, json=self.fake_node)
+
+        self.client.delete_labels_for_nodes(
+            labels=labels, node_ids=node_ids)
+
+        self.assertTrue(matcher_put.called)
+        self.assertEqual(result_labels, matcher_put.last_request.json())
+
+    def test_delete_labels_by_value_with_whitespace(self):
+        labels = ['key_1    =val_1', 'key_3=    anothervalue', 'key_2']
+        node_ids = ['42']
+        result_labels = {'labels': {'key_3': 'val_3'}}
+        expected_uri = self.get_object_uri(self.res_uri, 42)
+
+        self.m_request.get(expected_uri, json=self.fake_node)
+        matcher_put = self.m_request.put(expected_uri, json=self.fake_node)
+
+        self.client.delete_labels_for_nodes(
+            labels=labels, node_ids=node_ids)
+
+        self.assertTrue(matcher_put.called)
+        self.assertEqual(result_labels, matcher_put.last_request.json())
+
     def test_get_name_and_value_from_labels(self):
         for label in (
             'key=value',
@@ -265,6 +295,7 @@ class TestNodeFacade(test_api.BaseLibTest):
             ('label_B', 'label_C'),
             ('   label_B', 'label_C   '),
             ('label_B', 'label_C  ', 'unknown_label'),
+            ('label_A =   trololo', 'label_B=', 'label_C =C', 'label_D=value')
         ):
             result = self.client._labels_after_delete(
                 all_labels, labels_to_delete)

fuelclient/v1/node.py

@@ -146,21 +146,17 @@ class NodeClient(base_v1.BaseV1Client):
         data_to_return = []
 
         if node_ids:
-            for node_id in node_ids:
-                node = self._entity_wrapper(obj_id=node_id)
-                updated_labels = self._labels_after_delete(
-                    node.labels, labels)
-
-                result = self.update(node_id, **{'labels': updated_labels})
-                data_to_return.append(str(result.get('id')))
+            nodes = (self._entity_wrapper(obj_id=n_id).data
+                     for n_id in node_ids)
         else:
             nodes = self._entity_wrapper.get_all_data()
-            for node in nodes:
-                updated_labels = self._labels_after_delete(
-                    node['labels'], labels)
 
-                result = self.update(node['id'], **{'labels': updated_labels})
-                data_to_return.append(str(result.get('id')))
+        for node in nodes:
+            updated_labels = self._labels_after_delete(
+                node['labels'], labels)
+
+            result = self.update(node['id'], **{'labels': updated_labels})
+            data_to_return.append(str(result.get('id')))
 
         return data_to_return
 
@@ -178,15 +174,20 @@ class NodeClient(base_v1.BaseV1Client):
 
         return any(checking_list)
 
-    @staticmethod
-    def _labels_after_delete(labels, labels_to_delete):
+    @classmethod
+    def _labels_after_delete(cls, labels, labels_to_delete):
         if not labels_to_delete:
             return {}
 
         db_labels = copy.deepcopy(labels)
         for label in labels_to_delete:
             label = label.strip()
-            db_labels.pop(label, None)
+            sl = cls._split_label(label)
+            if sl.has_separator:
+                if sl.key in db_labels and db_labels[sl.key] == sl.value:
+                    db_labels.pop(sl.key)
+            else:
+                db_labels.pop(sl.key, None)
 
         return db_labels