outgoing_webhook: Fix broken way of accessing realm.uri.

Previously, this accessed realm.uri via trying to use
zulip_default_context.  That doesn't make any sense, because
zulip_default_context expects an HttpRequest object, and those are
nowhere in sight in the code path.  We do, however, have the outgoing
webhook bot user involved in the event, and that's the object to
access realm.uri from here.

zerver/lib/outgoing_webhook.py

@@ -13,7 +13,6 @@ from requests import Response
 
 from django.utils.translation import ugettext as _
 
-from zerver.context_processors import zulip_default_context
 from zerver.models import Realm, UserProfile, get_user_profile_by_id, get_client, \
     GENERIC_INTERFACE, Service, SLACK_INTERFACE, email_to_domain, get_service_profile
 from zerver.lib.actions import check_send_message
@@ -186,6 +185,8 @@ def do_rest_call(rest_operation, request_data, event, service_handler, timeout=N
     if error:
         raise JsonableError(error)
 
+    bot_user = get_user_profile_by_id(event['user_profile_id'])
+
     http_method = rest_operation['method']
     final_url = urllib.parse.urljoin(rest_operation['base_url'], rest_operation['relative_url_path'])
     request_kwargs = rest_operation['request_kwargs']
@@ -198,9 +199,8 @@ def do_rest_call(rest_operation, request_data, event, service_handler, timeout=N
             if response_message is not None:
                 succeed_with_message(event, response_message)
         else:
-            context = zulip_default_context(request_data)
             message_url = ("%(server)s/#narrow/stream/%(stream)s/subject/%(subject)s/near/%(id)s"
-                           % {'server': context['realm_uri'],
+                           % {'server': bot_user.realm.uri,
                               'stream': event['message']['display_recipient'],
                               'subject': event['message']['subject'],
                               'id': str(event['message']['id'])})

zerver/tests/test_outgoing_webhook_system.py

@@ -9,19 +9,9 @@ from requests import Response
 
 from zerver.lib.outgoing_webhook import do_rest_call, OutgoingWebhookServiceInterface
 from zerver.lib.test_classes import ZulipTestCase
+from zerver.models import get_realm, get_user
 from builtins import object
 
-mock_event = {'message': {'display_recipient': '',
-                          'subject': '',
-                          'id': ''},
-              'command': '',
-              'service_name': ''}
-
-rest_operation = {'method': "POST",
-                  'relative_url_path': "",
-                  'request_kwargs': {},
-                  'base_url': ""}
-
 class ResponseMock(object):
     def __init__(self, status_code, data, content):
         # type: (int, Any, str) -> None
@@ -45,12 +35,28 @@ class MockServiceHandler(OutgoingWebhookServiceInterface):
 service_handler = MockServiceHandler(None, None, None, None)
 
 class DoRestCallTests(ZulipTestCase):
+    def setUp(self):
+        # type: () -> None
+        realm = get_realm("zulip")
+        user_profile = get_user("outgoing-webhook@zulip.com", realm)
+        self.mock_event = {'message': {'display_recipient': '',
+                                       'subject': '',
+                                       'id': ''},
+                           'user_profile_id': user_profile.id,
+                           'command': '',
+                           'service_name': ''}
+
+        self.rest_operation = {'method': "POST",
+                               'relative_url_path': "",
+                               'request_kwargs': {},
+                               'base_url': ""}
+
     @mock.patch('zerver.lib.outgoing_webhook.succeed_with_message')
     def test_successful_request(self, mock_succeed_with_message):
         # type: (mock.Mock) -> None
         response = ResponseMock(200, {"message": "testing"}, '')
         with mock.patch('requests.request', return_value=response):
-            do_rest_call(rest_operation, None, None, service_handler, None)
+            do_rest_call(self.rest_operation, None, self.mock_event, service_handler, None)
             self.assertTrue(mock_succeed_with_message.called)
 
     @mock.patch('zerver.lib.outgoing_webhook.request_retry')
@@ -58,7 +64,7 @@ class DoRestCallTests(ZulipTestCase):
         # type: (mock.Mock) -> None
         response = ResponseMock(500, {"message": "testing"}, '')
         with mock.patch('requests.request', return_value=response):
-            do_rest_call(rest_operation, None, mock_event, service_handler, None)
+            do_rest_call(self.rest_operation, None, self.mock_event, service_handler, None)
             self.assertTrue(mock_request_retry.called)
 
     @mock.patch('zerver.lib.outgoing_webhook.fail_with_message')
@@ -66,7 +72,7 @@ class DoRestCallTests(ZulipTestCase):
         # type: (mock.Mock) -> None
         response = ResponseMock(400, {"message": "testing"}, '')
         with mock.patch('requests.request', return_value=response):
-            do_rest_call(rest_operation, None, mock_event, service_handler, None)
+            do_rest_call(self.rest_operation, None, self.mock_event, service_handler, None)
             self.assertTrue(mock_fail_with_message.called)
 
     @mock.patch('logging.info')
@@ -74,7 +80,7 @@ class DoRestCallTests(ZulipTestCase):
     @mock.patch('zerver.lib.outgoing_webhook.request_retry')
     def test_timeout_request(self, mock_request_retry, mock_requests_request, mock_logger):
         # type: (mock.Mock, mock.Mock, mock.Mock) -> None
-        do_rest_call(rest_operation, None, mock_event, service_handler, None)
+        do_rest_call(self.rest_operation, None, self.mock_event, service_handler, None)
         self.assertTrue(mock_request_retry.called)
 
     @mock.patch('logging.exception')
@@ -82,5 +88,5 @@ class DoRestCallTests(ZulipTestCase):
     @mock.patch('zerver.lib.outgoing_webhook.fail_with_message')
     def test_request_exception(self, mock_fail_with_message, mock_requests_request, mock_logger):
         # type: (mock.Mock, mock.Mock, mock.Mock) -> None
-        do_rest_call(rest_operation, None, mock_event, service_handler, None)
+        do_rest_call(self.rest_operation, None, self.mock_event, service_handler, None)
         self.assertTrue(mock_fail_with_message.called)