The 'model_update' helper has been added.

* it's now used to make cluster status changes easier
* it'll be potentially used to set cluster status + status description
  in the following way:
  context.model_update(obj, status='X', status_description='XXX')

Change-Id: I656f3f94b3dce697e060ed2ca2d4ad8f5c955794

savanna/context.py

@@ -94,6 +94,23 @@ def model_save(model, context=None):
     return model
 
 
+def model_update(model, context=None, **kwargs):
+    if not hasattr(model, '__table__'):
+        # TODO(slikjanov): replace with specific exception
+        raise RuntimeError("Specified object isn't model, class: %s"
+                           % model.__class__.__name__)
+    columns = model.__table__.columns
+    for prop in kwargs:
+        if prop not in columns:
+            # TODO(slukjanov): replace with specific exception
+            raise RuntimeError(
+                "Model class '%s' doesn't contains specified property '%s'"
+                % (model.__class__.__name__, prop))
+        setattr(model, prop, kwargs[prop])
+
+    return model_save(model, context)
+
+
 def spawn(func, *args, **kwargs):
     ctx = current().clone()
 

savanna/service/api.py

@@ -48,14 +48,12 @@ def scale_cluster(cluster_id, data):
     additional = construct_ngs_for_scaling(additional_node_groups)
 
     try:
-        cluster.status = 'Validating'
-        context.model_save(cluster)
+        context.model_update(cluster, status='Validating')
         _validate_cluster(cluster, plugin, additional)
         plugin.validate_scaling(cluster, to_be_enlarged, additional)
     except Exception:
         with excutils.save_and_reraise_exception():
-            cluster.status = 'Active'
-            context.model_save(cluster)
+            context.model_update(cluster, status='Active')
 
     # If we are here validation is successful.
     # So let's update bd and to_be_enlarged map:
@@ -77,13 +75,11 @@ def create_cluster(values):
 
     # validating cluster
     try:
-        cluster.status = 'Validating'
-        context.model_save(cluster)
+        context.model_update(cluster, status='Validating')
         plugin.validate(cluster)
     except Exception:
         with excutils.save_and_reraise_exception():
-            cluster.status = 'Error'
-            context.model_save(cluster)
+            context.model_update(cluster, status='Error')
 
     context.spawn(_provision_cluster, cluster.id)
 
@@ -95,18 +91,15 @@ def _provision_nodes(cluster_id, node_group_names_map):
     cluster = get_cluster(id=cluster_id)
     plugin = plugin_base.PLUGINS.get_plugin(cluster.plugin_name)
 
-    cluster.status = 'Scaling'
-    context.model_save(cluster)
+    context.model_update(cluster, status='Scaling')
     instances = i.scale_cluster(cluster, node_group_names_map)
 
     if instances:
-        cluster.status = 'Configuring'
-        context.model_save(cluster)
+        context.model_update(cluster, status='Configuring')
         plugin.scale_cluster(cluster, instances)
 
     # cluster is now up and ready
-    cluster.status = 'Active'
-    context.model_save(cluster)
+    context.model_update(cluster, status='Active')
 
 
 def _provision_cluster(cluster_id):
@@ -114,34 +107,29 @@ def _provision_cluster(cluster_id):
     plugin = plugin_base.PLUGINS.get_plugin(cluster.plugin_name)
 
     # updating cluster infra
-    cluster.status = 'InfraUpdating'
-    context.model_save(cluster)
+    context.model_update(cluster, status='InfraUpdating')
     plugin.update_infra(cluster)
 
     # creating instances and configuring them
     i.create_cluster(cluster)
 
     # configure cluster
-    cluster.status = 'Configuring'
-    context.model_save(cluster)
+    context.model_update(cluster, status='Configuring')
     plugin.configure_cluster(cluster)
 
     # starting prepared and configured cluster
-    cluster.status = 'Starting'
-    context.model_save(cluster)
+    context.model_update(cluster, status='Starting')
     plugin.start_cluster(cluster)
 
     # cluster is now up and ready
-    cluster.status = 'Active'
-    context.model_save(cluster)
+    context.model_update(cluster, status='Active')
 
     return cluster
 
 
 def terminate_cluster(**args):
     cluster = get_cluster(**args)
-    cluster.status = 'Deleting'
-    context.model_save(cluster)
+    context.model_update(cluster, status='Deleting')
 
     plugin = plugin_base.PLUGINS.get_plugin(cluster.plugin_name)
     plugin.on_terminate_cluster(cluster)

savanna/service/instances.py

@@ -28,27 +28,23 @@ LOG = logging.getLogger(__name__)
 def create_cluster(cluster):
     try:
         # create all instances
-        cluster.status = 'Spawning'
-        context.model_save(cluster)
+        context.model_update(cluster, status='Spawning')
         _create_instances(cluster)
 
         # wait for all instances are up and accessible
-        cluster.status = 'Waiting'
-        context.model_save(cluster)
+        context.model_update(cluster, status='Waiting')
         _await_instances(cluster)
 
         # attach volumes
         volumes.attach(cluster)
 
         # prepare all instances
-        cluster.status = 'Preparing'
-        context.model_save(cluster)
+        context.model_update(cluster, status='Preparing')
         _configure_instances(cluster)
     except Exception as ex:
         LOG.warn("Can't start cluster '%s' (reason: %s)", cluster.name, ex)
         with excutils.save_and_reraise_exception():
-            cluster.status = 'Error'
-            context.model_save(cluster)
+            context.model_update(cluster, status='Error')
             _rollback_cluster_creation(cluster, ex)
 
 

savanna/tests/unit/test_context.py

@@ -0,0 +1,59 @@
+# Copyright (c) 2013 Mirantis Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import sqlalchemy as sa
+
+from savanna import context
+from savanna.db import model_base as mb
+from savanna.tests.unit import base
+
+
+class TestModel(mb.SavannaBase, mb.IdMixin):
+    test_field = sa.Column(sa.String(80))
+
+
+def _insert_test_object():
+    t = TestModel()
+    t.test_field = 123
+    context.model_save(t)
+
+    return t
+
+
+class ModelHelpersTest(base.DbTestCase):
+    def test_model_save(self):
+        self.assertEqual(0, len(context.model_query(TestModel).all()))
+
+        t = _insert_test_object()
+
+        self.assertEqual(1, len(context.model_query(TestModel).all()))
+
+        db_t = context.model_query(TestModel).first()
+
+        self.assertEqual(t.id, db_t.id)
+        self.assertEqual(t.test_field, db_t.test_field)
+
+    def test_model_update(self):
+        _insert_test_object()
+
+        t = context.current().session.query(TestModel).first()
+
+        context.model_update(t, test_field=42)
+
+        db_t = context.model_query(TestModel).first()
+
+        self.assertEqual(t.id, db_t.id)
+        self.assertEqual(42, db_t.test_field)