Add preparation for asynchronous instance faults

Add InstanceFault model
Migration for new instance_faults table
Functions to add and get instance faults
A single example of how faults should be added

Change-Id: I439e2419240de24a728045046153451eb8a0d267

nova/tests/test_compute.py

@@ -21,6 +21,7 @@ Tests For Compute
 """
 
 from copy import copy
+from webob import exc
 
 import mox
 
@@ -1063,6 +1064,60 @@ class ComputeTestCase(BaseTestCase):
         self.assertEqual(len(instances), 1)
         self.assertEqual(power_state.NOSTATE, instances[0]['power_state'])
 
+    def test_add_instance_fault(self):
+        instance_uuid = str(utils.gen_uuid())
+
+        def fake_db_fault_create(ctxt, values):
+            expected = {
+                'code': 404,
+                'message': 'HTTPNotFound',
+                'details': 'Error Details',
+                'instance_uuid': instance_uuid,
+            }
+            self.assertEquals(expected, values)
+
+        self.stubs.Set(nova.db, 'instance_fault_create', fake_db_fault_create)
+
+        ctxt = context.get_admin_context()
+        self.compute.add_instance_fault(ctxt, instance_uuid, 404,
+                                        'HTTPNotFound', 'Error Details')
+
+    def test_add_instance_fault_error(self):
+        instance_uuid = str(utils.gen_uuid())
+
+        def fake_db_fault_create(ctxt, values):
+            expected = {
+                'code': 500,
+                'message': 'NotImplementedError',
+                'details': '',
+                'instance_uuid': instance_uuid,
+            }
+            self.assertEquals(expected, values)
+
+        self.stubs.Set(nova.db, 'instance_fault_create', fake_db_fault_create)
+
+        ctxt = context.get_admin_context()
+        self.compute.add_instance_fault_from_exc(ctxt, instance_uuid,
+                                                 NotImplementedError())
+
+    def test_add_instance_fault_http_exception(self):
+        instance_uuid = str(utils.gen_uuid())
+
+        def fake_db_fault_create(ctxt, values):
+            expected = {
+                'code': 404,
+                'message': 'HTTPNotFound',
+                'details': 'Error Details',
+                'instance_uuid': instance_uuid,
+            }
+            self.assertEquals(expected, values)
+
+        self.stubs.Set(nova.db, 'instance_fault_create', fake_db_fault_create)
+
+        ctxt = context.get_admin_context()
+        self.compute.add_instance_fault_from_exc(ctxt, instance_uuid,
+                                        exc.HTTPNotFound("Error Details"))
+
 
 class ComputeAPITestCase(BaseTestCase):
 

nova/tests/test_db_api.py

@@ -24,6 +24,7 @@ from nova import test
 from nova import context
 from nova import db
 from nova import flags
+from nova import utils
 
 FLAGS = flags.FLAGS
 
@@ -192,3 +193,74 @@ class DbApiTestCase(test.TestCase):
         # Retrieve the metadata to ensure it was successfully updated
         instance_meta = db.instance_metadata_get(ctxt, instance.id)
         self.assertEqual('bar', instance_meta['host'])
+
+    def test_instance_fault_create(self):
+        """Ensure we can create an instance fault"""
+        ctxt = context.get_admin_context()
+        uuid = str(utils.gen_uuid())
+
+        # Create a fault
+        fault_values = {
+            'message': 'message',
+            'details': 'detail',
+            'instance_uuid': uuid,
+            'code': 404,
+        }
+        db.instance_fault_create(ctxt, fault_values)
+
+        # Retrieve the fault to ensure it was successfully added
+        instance_fault = db.instance_fault_get_by_instance(ctxt, uuid)
+        self.assertEqual(404, instance_fault['code'])
+
+    def test_instance_fault_get_by_instance(self):
+        """ ensure we can retrieve an instance fault by  instance UUID """
+        ctxt = context.get_admin_context()
+
+        # Create faults
+        uuid = str(utils.gen_uuid())
+        fault_values = {
+            'message': 'message',
+            'details': 'detail',
+            'instance_uuid': uuid,
+            'code': 404,
+        }
+        db.instance_fault_create(ctxt, fault_values)
+
+        uuid2 = str(utils.gen_uuid())
+        fault_values = {
+            'message': 'message',
+            'details': 'detail',
+            'instance_uuid': uuid2,
+            'code': 500,
+        }
+        db.instance_fault_create(ctxt, fault_values)
+
+        # Retrieve the fault to ensure it was successfully added
+        instance_fault = db.instance_fault_get_by_instance(ctxt, uuid2)
+        self.assertEqual(500, instance_fault['code'])
+
+    def test_instance_fault_get_by_instance_first_fault(self):
+        """Instance_fault_get_by_instance should return the latest fault """
+        ctxt = context.get_admin_context()
+
+        # Create faults
+        uuid = str(utils.gen_uuid())
+        fault_values = {
+            'message': 'message',
+            'details': 'detail',
+            'instance_uuid': uuid,
+            'code': 404,
+        }
+        db.instance_fault_create(ctxt, fault_values)
+
+        fault_values = {
+            'message': 'message',
+            'details': 'detail',
+            'instance_uuid': uuid,
+            'code': 500,
+        }
+        db.instance_fault_create(ctxt, fault_values)
+
+        # Retrieve the fault to ensure it was successfully added
+        instance_fault = db.instance_fault_get_by_instance(ctxt, uuid)
+        self.assertEqual(500, instance_fault['code'])