Improve messages for validation

Change-Id: Icce40f843e97ffff11c6f7e26438e94d7fed247b
Closes-bug: #1283289

sahara/service/validations/base.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import collections
 import operator
 
 import novaclient.exceptions as nova_ex
@@ -49,6 +50,17 @@ def _get_plugin_configs(plugin_name, hadoop_version, scope=None):
     return pl_confs
 
 
+def _check_duplicates(lst, message):
+    invalid = []
+    lst = collections.Counter(lst)
+    for (key, value) in lst.iteritems():
+        if value > 1:
+            invalid.append(key)
+
+    if len(invalid) > 0:
+        raise ex.InvalidDataException(message % invalid)
+
+
 # Common validation checks
 
 def check_plugin_name_exists(name):
@@ -181,25 +193,30 @@ def check_floatingip_pool_exists(ng_name, pool_id):
 
 
 def check_node_processes(plugin_name, version, node_processes):
-    if len(set(node_processes)) != len(node_processes):
-        raise ex.InvalidDataException(
-            _("Duplicates in node processes have been detected"))
+    _check_duplicates(node_processes, _("Duplicates in node processes have "
+                                        "been detected: %s"))
+
     plugin_processes = []
     for process in plugin_base.PLUGINS.get_plugin(
             plugin_name).get_node_processes(version).values():
         plugin_processes += process
+    plugin_processes = set(plugin_processes)
 
-    if not set(node_processes).issubset(set(plugin_processes)):
+    invalid_processes = []
+    for node_process in node_processes:
+        if node_process not in plugin_processes:
+            invalid_processes.append(node_process)
+
+    if len(invalid_processes) > 0:
         raise ex.InvalidReferenceException(
-            _("Plugin supports the following node procesess: %s")
-            % sorted(plugin_processes))
+            _("Plugin doesn't support the following node processes: %s")
+            % sorted(invalid_processes))
 
 
 def check_duplicates_node_groups_names(node_groups):
     ng_names = [ng['name'] for ng in node_groups]
-    if len(set(ng_names)) < len(node_groups):
-        raise ex.InvalidDataException(
-            _("Duplicates in node group names are detected"))
+    _check_duplicates(
+        ng_names, _("Duplicates in node group names are detected: %s"))
 
 
 def check_availability_zone_exist(az):

sahara/tests/unit/service/validation/test_cluster_scaling_validation.py

@@ -37,6 +37,8 @@ class TestScalingValidation(u.ValidationTestCase):
         super(TestScalingValidation, self).setUp()
         api.plugin_base.setup_plugins()
         self._create_object_fun = mock.Mock()
+        self.duplicates_detected = ("Duplicates in node group names are"
+                                    " detected: ['a']")
 
     @mock.patch('sahara.service.api.get_cluster')
     @mock.patch('sahara.plugins.base.PluginManager.get_plugin')
@@ -101,8 +103,7 @@ class TestScalingValidation(u.ValidationTestCase):
         ]})
         self._assert_check_scaling(
             data=data, cluster=cluster,
-            expected_message='Duplicates in node '
-                             'group names are detected',
+            expected_message=self.duplicates_detected,
             expected_exception=ex.InvalidDataException)
 
     @mock.patch("sahara.service.api.OPS")
@@ -128,8 +129,7 @@ class TestScalingValidation(u.ValidationTestCase):
         }
         self._assert_check_scaling(
             data=data, cluster=cluster,
-            expected_message='Duplicates in node '
-                             'group names are detected',
+            expected_message=self.duplicates_detected,
             expected_exception=ex.InvalidDataException)
         data = {
             'add_node_groups': [

sahara/tests/unit/service/validation/test_ng_template_validation_create.py

@@ -101,9 +101,8 @@ class TestNGTemplateCreateValidation(u.ValidationTestCase):
                 'node_processes': ['wrong_process']
             },
             bad_req_i=(1, 'INVALID_REFERENCE',
-                       "Plugin supports the following node procesess: ["
-                       "'datanode', 'hiveserver', 'jobtracker', 'namenode', "
-                       "'oozie', 'secondarynamenode', 'tasktracker']")
+                       "Plugin doesn't support the following node processes: "
+                       "['wrong_process']")
         )
 
     def test_ng_template_create_v_right(self):