Handle slack payload metadata limit in paging command

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Handle slack metadata limit when creating paging command payload ([#2007](https://github.com/grafana/oncall/pull/2007))
 - Fix issue with sometimes cached final schedule not being refreshed after an update ([#2004](https://github.com/grafana/oncall/pull/2004))
 
 ## v1.2.28 (2023-05-24)

engine/apps/slack/constants.py

@@ -9,3 +9,5 @@
 SLACK_RATE_LIMIT_TIMEOUT = timezone.timedelta(minutes=5)
 SLACK_RATE_LIMIT_DELAY = 10
 CACHE_UPDATE_INCIDENT_SLACK_MESSAGE_LIFETIME = 60 * 10
+
+PRIVATE_METADATA_MAX_LENGTH = 3000

engine/apps/slack/scenarios/paging.py

@@ -10,6 +10,7 @@
     check_user_availability,
     direct_paging,
 )
+from apps.slack.constants import PRIVATE_METADATA_MAX_LENGTH
 from apps.slack.models import SlackChannel
 from apps.slack.scenarios import scenario_step
 from apps.slack.slack_client.exceptions import SlackAPIException
@@ -47,7 +48,10 @@
 def add_or_update_item(payload, key, item_pk, policy):
     metadata = json.loads(payload["view"]["private_metadata"])
     metadata[key][item_pk] = policy
-    payload["view"]["private_metadata"] = json.dumps(metadata)
+    updated_metadata = json.dumps(metadata)
+    if len(updated_metadata) > PRIVATE_METADATA_MAX_LENGTH:
+        raise ValueError("Cannot add entry, maximum exceeded")
+    payload["view"]["private_metadata"] = updated_metadata
     return payload
 
 
@@ -213,8 +217,13 @@ def process_scenario(self, slack_user_identity, slack_team_identity, payload):
             )
         else:
             # user is available to be paged
-            updated_payload = add_or_update_item(payload, USERS_DATA_KEY, selected_user.pk, DEFAULT_POLICY)
-            view = render_dialog(slack_user_identity, slack_team_identity, updated_payload)
+            error_msg = None
+            try:
+                updated_payload = add_or_update_item(payload, USERS_DATA_KEY, selected_user.pk, DEFAULT_POLICY)
+            except ValueError:
+                updated_payload = payload
+                error_msg = "Cannot add user, maximum responders exceeded"
+            view = render_dialog(slack_user_identity, slack_team_identity, updated_payload, error_msg=error_msg)
             self._slack_client.api_call(
                 "views.update",
                 trigger_id=payload["trigger_id"],
@@ -233,12 +242,17 @@ def _parse_action(self, payload):
     def process_scenario(self, slack_user_identity, slack_team_identity, payload, policy=None):
         policy, key, user_pk = self._parse_action(payload)
 
+        error_msg = None
         if policy == REMOVE_ACTION:
             updated_payload = remove_item(payload, key, user_pk)
         else:
-            updated_payload = add_or_update_item(payload, key, user_pk, policy)
+            try:
+                updated_payload = add_or_update_item(payload, key, user_pk, policy)
+            except ValueError:
+                updated_payload = payload
+                error_msg = "Cannot update policy, maximum responders exceeded"
 
-        view = render_dialog(slack_user_identity, slack_team_identity, updated_payload)
+        view = render_dialog(slack_user_identity, slack_team_identity, updated_payload, error_msg=error_msg)
         self._slack_client.api_call(
             "views.update",
             trigger_id=payload["trigger_id"],
@@ -269,8 +283,15 @@ def process_scenario(self, slack_user_identity, slack_team_identity, payload):
         }
         # add selected user
         selected_user = _get_selected_user_from_payload(previous_view_payload, private_metadata["input_id_prefix"])
-        updated_payload = add_or_update_item(previous_view_payload, USERS_DATA_KEY, selected_user.pk, DEFAULT_POLICY)
-        view = render_dialog(slack_user_identity, slack_team_identity, updated_payload)
+        error_msg = None
+        try:
+            updated_payload = add_or_update_item(
+                previous_view_payload, USERS_DATA_KEY, selected_user.pk, DEFAULT_POLICY
+            )
+        except ValueError:
+            updated_payload = payload
+            error_msg = "Cannot add user, maximum responders exceeded"
+        view = render_dialog(slack_user_identity, slack_team_identity, updated_payload, error_msg=error_msg)
         self._slack_client.api_call(
             "views.update",
             trigger_id=payload["trigger_id"],
@@ -291,8 +312,13 @@ def process_scenario(self, slack_user_identity, slack_team_identity, payload, ac
         if selected_schedule is None:
             return
 
-        updated_payload = add_or_update_item(payload, SCHEDULES_DATA_KEY, selected_schedule.pk, DEFAULT_POLICY)
-        view = render_dialog(slack_user_identity, slack_team_identity, updated_payload)
+        error_msg = None
+        try:
+            updated_payload = add_or_update_item(payload, SCHEDULES_DATA_KEY, selected_schedule.pk, DEFAULT_POLICY)
+        except ValueError:
+            updated_payload = payload
+            error_msg = "Cannot add schedule, maximum responders exceeded"
+        view = render_dialog(slack_user_identity, slack_team_identity, updated_payload, error_msg=error_msg)
         self._slack_client.api_call(
             "views.update",
             trigger_id=payload["trigger_id"],
@@ -306,7 +332,7 @@ def process_scenario(self, slack_user_identity, slack_team_identity, payload, ac
 DIVIDER_BLOCK = {"type": "divider"}
 
 
-def render_dialog(slack_user_identity, slack_team_identity, payload, initial=False):
+def render_dialog(slack_user_identity, slack_team_identity, payload, initial=False, error_msg=None):
     private_metadata = json.loads(payload["view"]["private_metadata"])
     submit_routing_uid = private_metadata.get("submit_routing_uid")
     if initial:
@@ -345,6 +371,18 @@ def render_dialog(slack_user_identity, slack_team_identity, payload, initial=Fal
     # blocks
     blocks = [organization_select, team_select, escalation_select, users_select, schedules_select]
 
+    if error_msg:
+        blocks += [
+            {
+                "type": "section",
+                "block_id": "error_message",
+                "text": {
+                    "type": "mrkdwn",
+                    "text": f":warning: {error_msg}",
+                },
+            }
+        ]
+
     # selected items
     selected_users = get_current_items(payload, USERS_DATA_KEY, selected_organization.users)
     selected_schedules = get_current_items(payload, SCHEDULES_DATA_KEY, selected_organization.oncall_schedules)

engine/apps/slack/tests/test_scenario_steps/test_paging.py

@@ -138,6 +138,63 @@ def test_add_user_no_warning(
     assert metadata[USERS_DATA_KEY] == {str(user.pk): DEFAULT_POLICY}
 
 
+@pytest.mark.django_db
+def test_add_user_maximum_exceeded(
+    make_organization_and_user_with_slack_identities, make_schedule, make_on_call_shift, make_user_notification_policy
+):
+    organization, user, slack_team_identity, slack_user_identity = make_organization_and_user_with_slack_identities()
+    # set up schedule: user is on call
+    schedule = make_schedule(
+        organization,
+        schedule_class=OnCallScheduleWeb,
+        team=None,
+    )
+    now = timezone.now().replace(hour=0, minute=0, second=0, microsecond=0)
+    start_date = now - timezone.timedelta(days=7)
+    data = {
+        "start": start_date,
+        "rotation_start": start_date,
+        "duration": timezone.timedelta(hours=23, minutes=59, seconds=59),
+        "priority_level": 1,
+        "frequency": CustomOnCallShift.FREQUENCY_DAILY,
+        "schedule": schedule,
+    }
+    on_call_shift = make_on_call_shift(
+        organization=organization, shift_type=CustomOnCallShift.TYPE_ROLLING_USERS_EVENT, **data
+    )
+    on_call_shift.add_rolling_users([[user]])
+    schedule.refresh_ical_file()
+    # setup notification policy
+    make_user_notification_policy(
+        user=user,
+        step=UserNotificationPolicy.Step.NOTIFY,
+        notify_by=UserNotificationPolicy.NotificationChannel.SMS,
+    )
+
+    payload = make_slack_payload(organization=organization, user=user)
+
+    step = OnPagingUserChange(slack_team_identity)
+    with patch("apps.slack.scenarios.paging.PRIVATE_METADATA_MAX_LENGTH", 100):
+        with patch.object(step._slack_client, "api_call") as mock_slack_api_call:
+            step.process_scenario(slack_user_identity, slack_team_identity, payload)
+
+    assert mock_slack_api_call.call_args.args == ("views.update",)
+    view_data = mock_slack_api_call.call_args.kwargs["view"]
+    metadata = json.loads(view_data["private_metadata"])
+    # metadata unchanged, ignoring the prefix
+    original_metadata = json.loads(payload["view"]["private_metadata"])
+    metadata.pop("input_id_prefix")
+    original_metadata.pop("input_id_prefix")
+    assert metadata == original_metadata
+    # error message is displayed
+    error_block = {
+        "type": "section",
+        "block_id": "error_message",
+        "text": {"type": "mrkdwn", "text": ":warning: Cannot add user, maximum responders exceeded"},
+    }
+    assert error_block in view_data["blocks"]
+
+
 @pytest.mark.django_db
 def test_add_user_raise_warning(make_organization_and_user_with_slack_identities):
     organization, user, slack_team_identity, slack_user_identity = make_organization_and_user_with_slack_identities()
@@ -247,6 +304,38 @@ def test_add_schedule(make_organization_and_user_with_slack_identities, make_sch
     assert metadata[USERS_DATA_KEY] == {str(user.pk): IMPORTANT_POLICY}
 
 
+@pytest.mark.django_db
+def test_add_schedule_responders_exceeded(make_organization_and_user_with_slack_identities, make_schedule):
+    organization, user, slack_team_identity, slack_user_identity = make_organization_and_user_with_slack_identities()
+    schedule = make_schedule(organization, schedule_class=OnCallScheduleWeb, team=None)
+    payload = make_slack_payload(
+        organization=organization,
+        schedule=schedule,
+        current_users={str(user.pk): IMPORTANT_POLICY},
+    )
+
+    step = OnPagingScheduleChange(slack_team_identity)
+    with patch("apps.slack.scenarios.paging.PRIVATE_METADATA_MAX_LENGTH", 100):
+        with patch.object(step._slack_client, "api_call") as mock_slack_api_call:
+            step.process_scenario(slack_user_identity, slack_team_identity, payload)
+
+    assert mock_slack_api_call.call_args.args == ("views.update",)
+    view_data = mock_slack_api_call.call_args.kwargs["view"]
+    metadata = json.loads(view_data["private_metadata"])
+    # metadata unchanged, ignoring the prefix
+    original_metadata = json.loads(payload["view"]["private_metadata"])
+    metadata.pop("input_id_prefix")
+    original_metadata.pop("input_id_prefix")
+    assert metadata == original_metadata
+    # error message is displayed
+    error_block = {
+        "type": "section",
+        "block_id": "error_message",
+        "text": {"type": "mrkdwn", "text": ":warning: Cannot add schedule, maximum responders exceeded"},
+    }
+    assert error_block in view_data["blocks"]
+
+
 @pytest.mark.django_db
 def test_change_schedule_policy(make_organization_and_user_with_slack_identities, make_schedule):
     organization, user, slack_team_identity, slack_user_identity = make_organization_and_user_with_slack_identities()