Merge "Enable localizable REST API responses via the Accept-Language header"

neutron/api/v2/resource.py

@@ -23,6 +23,7 @@ import webob.exc
 
 from neutron.api.v2 import attributes
 from neutron.common import exceptions
+from neutron.openstack.common import gettextutils
 from neutron.openstack.common import log as logging
 from neutron import wsgi
 
@@ -70,6 +71,7 @@ def Resource(controller, faults=None, deserializers=None, serializers=None):
         action = args.pop('action', None)
         content_type = format_types.get(fmt,
                                         request.best_match_content_type())
+        language = request.best_match_language()
         deserializer = deserializers.get(content_type)
         serializer = serializers.get(content_type)
 
@@ -83,6 +85,7 @@ def Resource(controller, faults=None, deserializers=None, serializers=None):
         except (exceptions.NeutronException,
                 netaddr.AddrFormatError) as e:
             LOG.exception(_('%s failed'), action)
+            e = translate(e, language)
             body = serializer.serialize({'NeutronError': e})
             kwargs = {'body': body, 'content_type': content_type}
             for fault in faults:
@@ -91,10 +94,12 @@ def Resource(controller, faults=None, deserializers=None, serializers=None):
             raise webob.exc.HTTPInternalServerError(**kwargs)
         except webob.exc.HTTPException as e:
             LOG.exception(_('%s failed'), action)
+            translate(e, language)
             e.body = serializer.serialize({'NeutronError': e})
             e.content_type = content_type
             raise
         except NotImplementedError as e:
+            e = translate(e, language)
             # NOTE(armando-migliaccio): from a client standpoint
             # it makes sense to receive these errors, because
             # extensions may or may not be implemented by
@@ -111,6 +116,7 @@ def Resource(controller, faults=None, deserializers=None, serializers=None):
             # Do not expose details of 500 error to clients.
             msg = _('Request Failed: internal server error while '
                     'processing your request.')
+            msg = translate(msg, language)
             body = serializer.serialize({'NeutronError': msg})
             kwargs = {'body': body, 'content_type': content_type}
             raise webob.exc.HTTPInternalServerError(**kwargs)
@@ -126,3 +132,24 @@ def Resource(controller, faults=None, deserializers=None, serializers=None):
                               content_type=content_type,
                               body=body)
     return resource
+
+
+def translate(translatable, locale):
+    """Translates the object to the given locale.
+
+    If the object is an exception its translatable elements are translated
+    in place, if the object is a translatable string it is translated and
+    returned. Otherwise, the object is returned as-is.
+
+    :param translatable: the object to be translated
+    :param locale: the locale to translate to
+    :returns: the translated object, or the object as-is if it
+              was not translated
+    """
+    localize = gettextutils.get_localized_message
+    if isinstance(translatable, Exception):
+        translatable.message = localize(translatable.message, locale)
+        if isinstance(translatable, webob.exc.HTTPError):
+            translatable.detail = localize(translatable.detail, locale)
+        return translatable
+    return localize(translatable, locale)

neutron/server/__init__.py

@@ -27,6 +27,9 @@ from oslo.config import cfg
 from neutron.common import config
 from neutron import service
 
+from neutron.openstack.common import gettextutils
+gettextutils.install('neutron', lazy=True)
+
 
 def main():
     eventlet.monkey_patch()

neutron/tests/unit/test_api_v2_resource.py

@@ -25,6 +25,7 @@ import webtest
 from neutron.api.v2 import resource as wsgi_resource
 from neutron.common import exceptions as q_exc
 from neutron import context
+from neutron.openstack.common import gettextutils
 from neutron.tests import base
 from neutron import wsgi
 
@@ -98,8 +99,23 @@ class RequestTestCase(base.BaseTestCase):
     def test_context_without_neutron_context(self):
         self.assertTrue(self.req.context.is_admin)
 
+    def test_best_match_language(self):
+        # Here we test that we are actually invoking language negotiation
+        # by webop and also that the default locale always available is en-US
+        request = wsgi.Request.blank('/')
+        gettextutils.get_available_languages = mock.MagicMock()
+        gettextutils.get_available_languages.return_value = ['known-language',
+                                                             'es', 'zh']
+        request.headers['Accept-Language'] = 'known-language'
+        language = request.best_match_language()
+        self.assertEqual(language, 'known-language')
+        request.headers['Accept-Language'] = 'unknown-language'
+        language = request.best_match_language()
+        self.assertEqual(language, 'en_US')
+
 
 class ResourceTestCase(base.BaseTestCase):
+
     def test_unmapped_neutron_error_with_json(self):
         msg = u'\u7f51\u7edc'
 
@@ -136,6 +152,29 @@ class ResourceTestCase(base.BaseTestCase):
         self.assertEqual(wsgi.XMLDeserializer().deserialize(res.body),
                          expected_res)
 
+    @mock.patch('neutron.openstack.common.gettextutils.Message.data',
+                new_callable=mock.PropertyMock)
+    def test_unmapped_neutron_error_localized(self, mock_translation):
+        gettextutils.install('blaa', lazy=True)
+        msg_translation = 'Translated error'
+        mock_translation.return_value = msg_translation
+        msg = _('Unmapped error')
+
+        class TestException(q_exc.NeutronException):
+            message = msg
+
+        controller = mock.MagicMock()
+        controller.test.side_effect = TestException()
+        resource = webtest.TestApp(wsgi_resource.Resource(controller))
+
+        environ = {'wsgiorg.routing_args': (None, {'action': 'test',
+                                                   'format': 'json'})}
+
+        res = resource.get('', extra_environ=environ, expect_errors=True)
+        self.assertEqual(res.status_int, exc.HTTPInternalServerError.code)
+        self.assertIn(msg_translation,
+                      str(wsgi.JSONDeserializer().deserialize(res.body)))
+
     def test_mapped_neutron_error_with_json(self):
         msg = u'\u7f51\u7edc'
 
@@ -176,6 +215,31 @@ class ResourceTestCase(base.BaseTestCase):
         self.assertEqual(wsgi.XMLDeserializer().deserialize(res.body),
                          expected_res)
 
+    @mock.patch('neutron.openstack.common.gettextutils.Message.data',
+                new_callable=mock.PropertyMock)
+    def test_mapped_neutron_error_localized(self, mock_translation):
+        gettextutils.install('blaa', lazy=True)
+        msg_translation = 'Translated error'
+        mock_translation.return_value = msg_translation
+        msg = _('Unmapped error')
+
+        class TestException(q_exc.NeutronException):
+            message = msg
+
+        controller = mock.MagicMock()
+        controller.test.side_effect = TestException()
+        faults = {TestException: exc.HTTPGatewayTimeout}
+        resource = webtest.TestApp(wsgi_resource.Resource(controller,
+                                                          faults=faults))
+
+        environ = {'wsgiorg.routing_args': (None, {'action': 'test',
+                                                   'format': 'json'})}
+
+        res = resource.get('', extra_environ=environ, expect_errors=True)
+        self.assertEqual(res.status_int, exc.HTTPGatewayTimeout.code)
+        self.assertIn(msg_translation,
+                      str(wsgi.JSONDeserializer().deserialize(res.body)))
+
     def test_http_error(self):
         controller = mock.MagicMock()
         controller.test.side_effect = exc.HTTPGatewayTimeout()

neutron/wsgi.py

@@ -37,6 +37,7 @@ import webob.exc
 from neutron.common import constants
 from neutron.common import exceptions as exception
 from neutron import context
+from neutron.openstack.common import gettextutils
 from neutron.openstack.common import jsonutils
 from neutron.openstack.common import log as logging
 
@@ -299,6 +300,12 @@ class Request(webob.Request):
             return _type
         return None
 
+    def best_match_language(self):
+        """Determine language for returned response."""
+        all_languages = gettextutils.get_available_languages('neutron')
+        return self.accept_language.best_match(all_languages,
+                                               default_match='en_US')
+
     @property
     def context(self):
         if 'neutron.context' not in self.environ: