Resolves metadata field output on rest call to zone import and export

Earlier on REST API call to zones/tasks/imports or zones/tasks/exports,
metadata field was displayed with no key/val pair.
This patch makes {'total_count : #val'} to be be produced as
output in metadata field on execution of those REST API call.

Closes-Bug: #1532925

Change-Id: I566e370edce5f29aafe793d5fdf7fe2fb7b3a856

designate/storage/impl_sqlalchemy/__init__.py

@@ -1823,11 +1823,17 @@ class SQLAlchemyStorage(sqlalchemy_base.SQLAlchemy, storage_base.Storage):
         if not criterion:
             criterion = {}
         criterion['task_type'] = 'IMPORT'
-        return self._find(
+        zone_imports = self._find(
             context, tables.zone_tasks, objects.ZoneImport,
             objects.ZoneImportList, exceptions.ZoneImportNotFound, criterion,
             one, marker, limit, sort_key, sort_dir)
 
+        if not one:
+            zone_imports.total_count = self.count_zone_tasks(
+                context, criterion)
+
+        return zone_imports
+
     def create_zone_import(self, context, zone_import):
         return self._create(
             tables.zone_tasks, zone_import, exceptions.DuplicateZoneImport)
@@ -1863,10 +1869,15 @@ class SQLAlchemyStorage(sqlalchemy_base.SQLAlchemy, storage_base.Storage):
         if not criterion:
             criterion = {}
         criterion['task_type'] = 'EXPORT'
-        return self._find(
+        zone_exports = self._find(
             context, tables.zone_tasks, objects.ZoneExport,
             objects.ZoneExportList, exceptions.ZoneExportNotFound, criterion,
             one, marker, limit, sort_key, sort_dir)
+        if not one:
+            zone_exports.total_count = self.count_zone_tasks(
+                context, criterion)
+
+        return zone_exports
 
     def create_zone_export(self, context, zone_export):
         return self._create(
@@ -1897,6 +1908,20 @@ class SQLAlchemyStorage(sqlalchemy_base.SQLAlchemy, storage_base.Storage):
         return self._delete(context, tables.zone_tasks, zone_export,
                     exceptions.ZoneExportNotFound)
 
+    def count_zone_tasks(self, context, criterion=None):
+        query = select([func.count(tables.zone_tasks.c.id)])
+        query = self._apply_criterion(tables.zone_tasks, query, criterion)
+        query = self._apply_tenant_criteria(context, tables.zone_tasks, query)
+        query = self._apply_deleted_criteria(context, tables.zone_tasks, query)
+
+        resultproxy = self.session.execute(query)
+        result = resultproxy.fetchone()
+
+        if result is None:
+            return 0
+
+        return result[0]
+
     # diagnostics
     def ping(self, context):
         start_time = time.time()

designate/tests/__init__.py

@@ -284,6 +284,23 @@ class TestCase(base.BaseTestCase):
         'task_type': 'IMPORT'
     }]
 
+    zone_export_fixtures = [{
+        'status': 'PENDING',
+        'zone_id': None,
+        'message': None,
+        'task_type': 'EXPORT'
+    }, {
+        'status': 'ERROR',
+        'zone_id': None,
+        'message': None,
+        'task_type': 'EXPORT'
+    }, {
+        'status': 'COMPLETE',
+        'zone_id': '6ca6baef-3305-4ad0-a52b-a82df5752b62',
+        'message': None,
+        'task_type': 'EXPORT'
+    }]
+
     def setUp(self):
         super(TestCase, self).setUp()
 
@@ -580,6 +597,13 @@ class TestCase(base.BaseTestCase):
         _values.update(values)
         return _values
 
+    def get_zone_export_fixture(self, fixture=0, values=None):
+        values = values or {}
+
+        _values = copy.copy(self.zone_export_fixtures[fixture])
+        _values.update(values)
+        return _values
+
     def create_tld(self, **kwargs):
         context = kwargs.pop('context', self.admin_context)
         fixture = kwargs.pop('fixture', 0)
@@ -733,6 +757,16 @@ class TestCase(base.BaseTestCase):
         return self.storage.create_zone_import(
             context, objects.ZoneImport.from_dict(zone_import))
 
+    def create_zone_export(self, **kwargs):
+        context = kwargs.pop('context', self.admin_context)
+        fixture = kwargs.pop('fixture', 0)
+
+        zone_export = self.get_zone_export_fixture(fixture=fixture,
+                                               values=kwargs)
+
+        return self.storage.create_zone_export(
+            context, objects.ZoneExport.from_dict(zone_export))
+
     def wait_for_import(self, zone_import_id, errorok=False):
         """
            Zone imports spawn a thread to parse the zone file and

designate/tests/test_api/test_v2/test_import_export.py

@@ -133,3 +133,40 @@ class APIV2ZoneImportExportTest(ApiV2TestCase):
         exported.delete_rdataset(exported.origin, 'NS')
         imported.delete_rdataset('delegation', 'NS')
         self.assertEqual(imported, exported)
+
+    # Metadata tests
+    def test_metadata_exists_imports(self):
+        response = self.client.get('/zones/tasks/imports')
+
+        # Make sure the fields exist
+        self.assertIn('metadata', response.json)
+        self.assertIn('total_count', response.json['metadata'])
+
+    def test_metadata_exists_exports(self):
+        response = self.client.get('/zones/tasks/imports')
+
+        # Make sure the fields exist
+        self.assertIn('metadata', response.json)
+        self.assertIn('total_count', response.json['metadata'])
+
+    def test_total_count_imports(self):
+        response = self.client.get('/zones/tasks/imports')
+
+        # There are no imported zones by default
+        self.assertEqual(0, response.json['metadata']['total_count'])
+
+        # Create a zone import
+        response = self.client.post('/zones/tasks/imports',
+                                    self.get_zonefile_fixture(),
+                                    headers={'Content-type': 'text/dns'})
+
+        response = self.client.get('/zones/tasks/imports')
+
+        # Make sure total_count picked it up
+        self.assertEqual(1, response.json['metadata']['total_count'])
+
+    def test_total_count_exports(self):
+        response = self.client.get('/zones/tasks/exports')
+
+        # There are no exported zones by default
+        self.assertEqual(0, response.json['metadata']['total_count'])

designate/tests/test_storage/__init__.py

@@ -3091,6 +3091,33 @@ class StorageTestCase(object):
         self.assertEqual(zt_accept.id, result.id)
         self.assertEqual(zt_accept.zone_id, result.zone_id)
 
+    def test_count_zone_tasks(self):
+        # in the beginning, there should be nothing
+        zones = self.storage.count_zone_tasks(self.admin_context)
+        self.assertEqual(0, zones)
+
+        values = {
+            'status': 'PENDING',
+            'task_type': 'IMPORT'
+        }
+
+        self.storage.create_zone_import(
+            self.admin_context, objects.ZoneImport.from_dict(values))
+
+        # count imported zones
+        zones = self.storage.count_zone_tasks(self.admin_context)
+
+        # well, did we get 1?
+        self.assertEqual(1, zones)
+
+    def test_count_zone_tasks_none_result(self):
+        rp = mock.Mock()
+        rp.fetchone.return_value = None
+        with mock.patch.object(self.storage.session, 'execute',
+                               return_value=rp):
+            zones = self.storage.count_zone_tasks(self.admin_context)
+            self.assertEqual(0, zones)
+
     # Zone Import Tests
     def test_create_zone_import(self):
         values = {