implementation of server notices to alert on hitting resource limits

3 files changed, 190 insertions, 45 deletions

diff --git a/synapse/server_notices/resource_limits_server_notices.py b/synapse/server_notices/resource_limits_server_notices.py
index 33b1d80cd9..017828f81e 100644
--- a/synapse/server_notices/resource_limits_server_notices.py
+++ b/synapse/server_notices/resource_limits_server_notices.py
@@ -14,14 +14,9 @@
 # limitations under the License.
 import logging
 
-from six import iteritems, string_types
-
 from twisted.internet import defer
 
-from synapse.api.errors import SynapseError
-from synapse.api.urls import ConsentURIBuilder
-from synapse.config import ConfigError
-from synapse.types import get_localpart_from_id
+from synapse.api.errors import AuthError, SynapseError
 
 logger = logging.getLogger(__name__)
 
@@ -37,12 +32,12 @@ class ResourceLimitsServerNotices(object):
         """
         self._server_notices_manager = hs.get_server_notices_manager()
         self._store = hs.get_datastore()
-        self._api = hs.get_api()
+        self.auth = hs.get_auth()
         self._server_notice_content = hs.config.user_consent_server_notice_content
-        self._limit_usage_by_mau = config.limit_usage_by_mau = False
-        self._hs_disabled.config.hs_disabled = False
+        self._limit_usage_by_mau = hs.config.limit_usage_by_mau = False
+        self._hs_disabled = hs.config.hs_disabled
 
-        self._notified = set()
+        self._notified_of_blocking = set()
         self._resouce_limited = False
         # Config checks?
 
@@ -56,29 +51,49 @@ class ResourceLimitsServerNotices(object):
         Returns:
             Deferred
         """
-        if self._limit_usage_by_mau is False and self._hs_disabled is False:
-            # not enabled
+        if self._hs_disabled is True:
             return
 
-        timestamp = yield self.store.user_last_seen_monthly_active(user_id)
-        if timestamp is None:
-            # This user will be blocked from receiving the notice anyway
-            return
-        try:
-            yield self.api.check_auth_blocking()
-            if self._resouce_limited:
+        if self._limit_usage_by_mau is True:
+            timestamp = yield self._store.user_last_seen_monthly_active(user_id)
+            if timestamp is None:
+                # This user will be blocked from receiving the notice anyway.
+                # In practice, not sure we can ever get here
+                return
+            try:
+                yield self.auth.check_auth_blocking()
+                self._resouce_limited = False
                 # Need to start removing notices
-                pass
-        except AuthError as e:
-            # Need to start notifying of blocking
-            if not self._resouce_limited:
-                pass
+                if user_id in self._notified_of_blocking:
+                    # Send message to remove warning - needs updating
+                    content = "remove warning"
+                    self._send_server_notice(user_id, content)
+                    self._notified_of_blocking.remove(user_id)
 
-            # need to send a message.
-            try:
-                yield self._server_notices_manager.send_notice(
-                    user_id, content,
-                )
+            except AuthError:
+                # Need to start notifying of blocking
+
+                self._resouce_limited = True
+                if user_id not in self._notified_of_blocking:
+                    # Send message to add warning - needs updating
+                    content = "add warning"
+                    self._send_server_notice(user_id, content)
+                    self._notified_of_blocking.add(user_id)
 
-            except SynapseError as e:
-                logger.error("Error sending server notice about resource limits: %s", e)
+    @defer.inlineCallbacks
+    def _send_server_notice(self, user_id, content):
+        """Sends Server notice
+
+        Args:
+            user_id(str): The user to send to
+            content(str): The content of the message
+
+        Returns:
+            Deferred[]
+        """
+        try:
+            yield self._server_notices_manager.send_notice(
+                user_id, content,
+            )
+        except SynapseError as e:
+            logger.error("Error sending server notice about resource limits: %s", e)
diff --git a/synapse/server_notices/server_notices_sender.py b/synapse/server_notices/server_notices_sender.py
index 5d23965f34..6121b2f267 100644
--- a/synapse/server_notices/server_notices_sender.py
+++ b/synapse/server_notices/server_notices_sender.py
@@ -12,7 +12,12 @@
 # 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.
+from twisted.internet import defer
+
 from synapse.server_notices.consent_server_notices import ConsentServerNotices
+from synapse.server_notices.resource_limits_server_notices import (
+    ResourceLimitsServerNotices,
+)
 
 
 class ServerNoticesSender(object):
@@ -25,34 +30,34 @@ class ServerNoticesSender(object):
         Args:
             hs (synapse.server.HomeServer):
         """
-        # todo: it would be nice to make this more dynamic
-        self._consent_server_notices = ConsentServerNotices(hs)
+        self._server_notices = (
+            ConsentServerNotices(hs),
+            ResourceLimitsServerNotices(hs)
+        )
 
+    @defer.inlineCallbacks
     def on_user_syncing(self, user_id):
         """Called when the user performs a sync operation.
 
         Args:
             user_id (str): mxid of user who synced
-
-        Returns:
-            Deferred
         """
-        return self._consent_server_notices.maybe_send_server_notice_to_user(
-            user_id,
-        )
+        for sn in self._server_notices:
+            yield sn.maybe_send_server_notice_to_user(
+                user_id,
+            )
 
+    @defer.inlineCallbacks
     def on_user_ip(self, user_id):
         """Called on the master when a worker process saw a client request.
 
         Args:
             user_id (str): mxid
-
-        Returns:
-            Deferred
         """
         # The synchrotrons use a stubbed version of ServerNoticesSender, so
         # we check for notices to send to the user in on_user_ip as well as
         # in on_user_syncing
-        return self._consent_server_notices.maybe_send_server_notice_to_user(
-            user_id,
-        )
+        for sn in self._server_notices:
+            yield sn.maybe_send_server_notice_to_user(
+                user_id,
+            )
diff --git a/tests/server_notices/test_resource_limits_server_notices.py b/tests/server_notices/test_resource_limits_server_notices.py
new file mode 100644
index 0000000000..a69253f1b6
--- /dev/null
+++ b/tests/server_notices/test_resource_limits_server_notices.py
@@ -0,0 +1,125 @@
+from mock import Mock
+
+from twisted.internet import defer
+
+from synapse.api.errors import AuthError
+from synapse.handlers.auth import AuthHandler
+from synapse.server_notices.resource_limits_server_notices import (
+    ResourceLimitsServerNotices,
+)
+
+from tests import unittest
+from tests.utils import setup_test_homeserver
+
+
+class AuthHandlers(object):
+    def __init__(self, hs):
+        self.auth_handler = AuthHandler(hs)
+
+
+class TestResourceLimitsServerNotices(unittest.TestCase):
+    @defer.inlineCallbacks
+    def setUp(self):
+        self.hs = yield setup_test_homeserver(handlers=None)
+        self.hs.handlers = AuthHandlers(self.hs)
+        self.auth_handler = self.hs.handlers.auth_handler
+        self.server_notices_sender = self.hs.get_server_notices_sender()
+
+        # relying on [1] is far from ideal, but the only case where
+        # ResourceLimitsServerNotices class needs to be isolated is this test,
+        # general code should never have a reason to do so ...
+        self._rlsn = self.server_notices_sender._server_notices[1]
+        if not isinstance(self._rlsn, ResourceLimitsServerNotices):
+            raise Exception("Failed to find reference to ResourceLimitsServerNotices")
+
+        self._rlsn._store.user_last_seen_monthly_active = Mock(
+            return_value=defer.succeed(1000)
+        )
+        self._send_notice = self._rlsn._server_notices_manager.send_notice
+        self._rlsn._server_notices_manager.send_notice = Mock()
+        self._send_notice = self._rlsn._server_notices_manager.send_notice
+
+        self._rlsn._limit_usage_by_mau = True
+        self.user_id = "user_id"
+
+    @defer.inlineCallbacks
+    def test_maybe_send_server_notice_to_user_flag_off(self):
+        """Tests cases where the flags indicate nothing to do"""
+        # test hs disabled case
+        self._hs_disabled = True
+
+        yield self._rlsn.maybe_send_server_notice_to_user("user_id")
+
+        self._send_notice.assert_not_called()
+        # Test when mau limiting disabled
+        self._hs_disabled = False
+        self._rlsn._limit_usage_by_mau = False
+        yield self._rlsn.maybe_send_server_notice_to_user("user_id")
+
+        self._send_notice.assert_not_called()
+
+    @defer.inlineCallbacks
+    def test_maybe_send_server_notice_to_user_remove_blocked_notice(self):
+        """Test when user has blocked notice, but should have it removed"""
+
+        self._rlsn._notified_of_blocking.add(self.user_id)
+        self._rlsn.auth.check_auth_blocking = Mock()
+
+        yield self._rlsn.maybe_send_server_notice_to_user(self.user_id)
+        # "remove warning" obviously aweful, but test will start failing when code
+        # actually sends a real event, and then it can be updated
+
+        self._send_notice.assert_called_once_with(self.user_id, "remove warning")
+        self.assertFalse(self.user_id in self._rlsn._notified_of_blocking)
+
+    @defer.inlineCallbacks
+    def test_maybe_send_server_notice_to_user_remove_blocked_notice_noop(self):
+        """Test when user has blocked notice, but notice ought to be there (NOOP)"""
+        self._rlsn._notified_of_blocking.add(self.user_id)
+        self._rlsn.auth.check_auth_blocking = Mock(
+            side_effect=AuthError(403, 'foo')
+        )
+
+        yield self._rlsn.maybe_send_server_notice_to_user("user_id")
+
+        self._send_notice.assert_not_called()
+        self.assertTrue(self.user_id in self._rlsn._notified_of_blocking)
+
+    @defer.inlineCallbacks
+    def test_maybe_send_server_notice_to_user_add_blocked_notice(self):
+        """Test when user does not have blocked notice, but should have one"""
+
+        self._rlsn.auth.check_auth_blocking = Mock(side_effect=AuthError(403, 'foo'))
+        yield self._rlsn.maybe_send_server_notice_to_user("user_id")
+
+        # "add warning" obviously awful, but test will start failing when code
+        # actually sends a real event, and then it can be updated
+        self._send_notice.assert_called_once_with(self.user_id, "add warning")
+        self.assertTrue(self.user_id in self._rlsn._notified_of_blocking)
+
+    @defer.inlineCallbacks
+    def test_maybe_send_server_notice_to_user_add_blocked_notice_noop(self):
+        """Test when user does not have blocked notice, nor should they (NOOP)"""
+
+        self._rlsn.auth.check_auth_blocking = Mock()
+
+        yield self._rlsn.maybe_send_server_notice_to_user(self.user_id)
+
+        self._send_notice.assert_not_called()
+        self.assertFalse(self.user_id in self._rlsn._notified_of_blocking)
+
+    @defer.inlineCallbacks
+    def test_maybe_send_server_notice_to_user_not_in_mau_cohort(self):
+
+        """Test when user is not part of the MAU cohort - this should not ever
+        happen - but ...
+        """
+
+        self._rlsn.auth.check_auth_blocking = Mock()
+        self._rlsn._store.user_last_seen_monthly_active = Mock(
+            return_value=defer.succeed(None)
+        )
+        yield self._rlsn.maybe_send_server_notice_to_user(self.user_id)
+
+        self._send_notice.assert_not_called()
+        self.assertFalse(self.user_id in self._rlsn._notified_of_blocking)