feat(alerts): apply SQL limit to all alerts

superset/reports/commands/alert.py

@@ -36,6 +36,9 @@
 logger = logging.getLogger(__name__)
 
 
+ALERT_SQL_LIMIT = 2
+# All sql statements have an applied LIMIT,
+# to avoid heavy loads done by a user mistake
 OPERATOR_FUNCTIONS = {">=": ge, ">": gt, "<=": le, "<": lt, "==": eq, "!=": ne}
 
 
@@ -117,7 +120,10 @@ def validate(self) -> None:
         )
         rendered_sql = sql_template.process_template(self._report_schedule.sql)
         try:
-            df = self._report_schedule.database.get_df(rendered_sql)
+            limited_rendered_sql = self._report_schedule.database.apply_limit_to_sql(
+                rendered_sql, ALERT_SQL_LIMIT
+            )
+            df = self._report_schedule.database.get_df(limited_rendered_sql)
         except Exception as ex:
             raise AlertQueryError(message=str(ex))
 

tests/reports/commands_tests.py

@@ -17,7 +17,7 @@
 import json
 from datetime import datetime, timedelta
 from typing import List, Optional
-from unittest.mock import patch
+from unittest.mock import Mock, patch
 
 import pytest
 from contextlib2 import contextmanager
@@ -49,10 +49,17 @@
 )
 from superset.reports.commands.execute import AsyncExecuteReportScheduleCommand
 from superset.utils.core import get_example_database
+from tests.fixtures.world_bank_dashboard import (
+    load_world_bank_dashboard_with_slices_module_scope,
+)
 from tests.reports.utils import insert_report_schedule
 from tests.test_app import app
 from tests.utils import read_fixture
 
+pytestmark = pytest.mark.usefixtures(
+    "load_world_bank_dashboard_with_slices_module_scope"
+)
+
 
 def get_target_from_report_schedule(report_schedule) -> List[str]:
     return [
@@ -129,6 +136,22 @@ def cleanup_report_schedule(report_schedule: ReportSchedule) -> None:
     db.session.commit()
 
 
+@contextmanager
+def create_test_table_context(database: Database):
+    database.get_sqla_engine().execute(
+        "CREATE TABLE test_table AS SELECT 1 as first, 2 as second"
+    )
+    database.get_sqla_engine().execute(
+        "INSERT INTO test_table (first, second) VALUES (1, 2)"
+    )
+    database.get_sqla_engine().execute(
+        "INSERT INTO test_table (first, second) VALUES (3, 4)"
+    )
+
+    yield db.session
+    database.get_sqla_engine().execute("DROP TABLE test_table")
+
+
 @pytest.yield_fixture()
 def create_report_email_chart():
     with app.app_context():
@@ -233,7 +256,7 @@ def create_alert_slack_chart_grace():
 
 
 @pytest.yield_fixture(
-    params=["alert1", "alert2", "alert3", "alert4", "alert5", "alert6", "alert7"]
+    params=["alert1", "alert2", "alert3", "alert4", "alert5", "alert6", "alert7",]
 )
 def create_alert_email_chart(request):
     param_config = {
@@ -276,35 +299,22 @@ def create_alert_email_chart(request):
     with app.app_context():
         chart = db.session.query(Slice).first()
         example_database = get_example_database()
+        with create_test_table_context(example_database):
 
-        report_schedule = create_report_notification(
-            email_target="target@email.com",
-            chart=chart,
-            report_type=ReportScheduleType.ALERT,
-            database=example_database,
-            sql=param_config[request.param]["sql"],
-            validator_type=param_config[request.param]["validator_type"],
-            validator_config_json=param_config[request.param]["validator_config_json"],
-        )
-        yield report_schedule
-
-        cleanup_report_schedule(report_schedule)
-
-
-@contextmanager
-def create_test_table_context(database: Database):
-    database.get_sqla_engine().execute(
-        "CREATE TABLE test_table AS SELECT 1 as first, 2 as second"
-    )
-    database.get_sqla_engine().execute(
-        "INSERT INTO test_table (first, second) VALUES (1, 2)"
-    )
-    database.get_sqla_engine().execute(
-        "INSERT INTO test_table (first, second) VALUES (3, 4)"
-    )
+            report_schedule = create_report_notification(
+                email_target="target@email.com",
+                chart=chart,
+                report_type=ReportScheduleType.ALERT,
+                database=example_database,
+                sql=param_config[request.param]["sql"],
+                validator_type=param_config[request.param]["validator_type"],
+                validator_config_json=param_config[request.param][
+                    "validator_config_json"
+                ],
+            )
+            yield report_schedule
 
-    yield db.session
-    database.get_sqla_engine().execute("DROP TABLE test_table")
+            cleanup_report_schedule(report_schedule)
 
 
 @pytest.yield_fixture(
@@ -373,12 +383,12 @@ def create_no_alert_email_chart(request):
 def create_mul_alert_email_chart(request):
     param_config = {
         "alert1": {
-            "sql": "SELECT first from test_table",
+            "sql": "SELECT first, second from test_table",
             "validator_type": ReportScheduleValidatorType.OPERATOR,
             "validator_config_json": '{"op": "<", "threshold": 10}',
         },
         "alert2": {
-            "sql": "SELECT first, second from test_table",
+            "sql": "SELECT first from test_table",
             "validator_type": ReportScheduleValidatorType.OPERATOR,
             "validator_config_json": '{"op": "<", "threshold": 10}',
         },
@@ -626,6 +636,28 @@ def test_report_schedule_success_grace_end(create_alert_slack_chart_grace):
     assert create_alert_slack_chart_grace.last_state == ReportState.NOOP
 
 
+@pytest.mark.usefixtures("create_alert_email_chart")
+@patch("superset.reports.notifications.email.send_email_smtp")
+@patch("superset.utils.screenshots.ChartScreenshot.compute_and_cache")
+def test_alert_limit_is_applied(screenshot_mock, email_mock, create_alert_email_chart):
+    """
+    ExecuteReport Command: Test that all alerts apply a SQL limit to stmts
+    """
+
+    with patch.object(
+        create_alert_email_chart.database.db_engine_spec, "execute", return_value=None
+    ) as execute_mock:
+        with patch.object(
+            create_alert_email_chart.database.db_engine_spec,
+            "fetch_data",
+            return_value=None,
+        ) as fetch_data_mock:
+            AsyncExecuteReportScheduleCommand(
+                create_alert_email_chart.id, datetime.utcnow()
+            ).run()
+            assert "LIMIT 2" in execute_mock.call_args[0][1]
+
+
 @pytest.mark.usefixtures("create_report_email_dashboard")
 @patch("superset.reports.notifications.email.send_email_smtp")
 @patch("superset.utils.screenshots.DashboardScreenshot.compute_and_cache")