feat(db_engine): Implement user impersonation support for StarRocks

superset/db_engine_specs/README.md

@@ -95,7 +95,7 @@ The table below (generated via `python superset/db_engine_specs/lib.py`) summari
 | Masks/unmasks encrypted_extra | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | True | True | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False |
 | Has column type mappings | False | False | False | False | False | True | False | False | False | False | True | False | True | True | True | True | True | True | False | False | True | False | False | False | False | False | False | False | False | False | False | False | False | False | True | True | True | False | False | False | True | True | False | False | False | False | False | True | False | True | False | True |
 | Returns a list of function names | False | False | False | False | False | True | False | False | False | False | True | False | False | False | False | True | True | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | True | True | False | False | False | True | False | True |
-| Supports user impersonation | False | False | False | True | False | True | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | True | False | False |
+| Supports user impersonation | False | False | False | True | False | True | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | True | False | True | False | False |
 | Support file upload | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | False | False | True | True | True | True | True | True | True | True | True | True | True | True | True | False | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True | True |
 | Returns extra table metadata | False | False | False | False | False | True | False | False | False | False | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | True | True | False | False | False | False | False | False | False | False | False | True | False | False | False | False | False | False | False | False | True | False | False |
 | Maps driver exceptions to Superset exceptions | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False | False |

superset/db_engine_specs/base.py

@@ -1408,6 +1408,7 @@ def adjust_engine_params(  # pylint: disable=unused-argument
     @classmethod
     def get_prequeries(
         cls,
+        database: Database,  # pylint: disable=unused-argument
         catalog: str | None = None,  # pylint: disable=unused-argument
         schema: str | None = None,  # pylint: disable=unused-argument
     ) -> list[str]:

superset/db_engine_specs/databricks.py

@@ -458,6 +458,7 @@ def get_default_catalog(
     @classmethod
     def get_prequeries(
         cls,
+        database: Database,
         catalog: str | None = None,
         schema: str | None = None,
     ) -> list[str]:

superset/db_engine_specs/db2.py

@@ -21,6 +21,7 @@
 
 from superset.constants import TimeGrain
 from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod
+from superset.models.core import Database
 from superset.sql_parse import Table
 
 logger = logging.getLogger(__name__)
@@ -93,6 +94,7 @@ def get_table_comment(
     @classmethod
     def get_prequeries(
         cls,
+        database: Database,
         catalog: Union[str, None] = None,
         schema: Union[str, None] = None,
     ) -> list[str]:

superset/db_engine_specs/postgres.py

@@ -322,6 +322,7 @@ def get_default_catalog(cls, database: Database) -> str | None:
     @classmethod
     def get_prequeries(
         cls,
+        database: Database,
         catalog: str | None = None,
         schema: str | None = None,
     ) -> list[str]:

superset/db_engine_specs/starrocks.py

@@ -18,7 +18,7 @@
 import logging
 import re
 from re import Pattern
-from typing import Any, Optional
+from typing import Any, Optional, Union
 from urllib import parse
 
 from flask_babel import gettext as __
@@ -28,6 +28,7 @@
 
 from superset.db_engine_specs.mysql import MySQLEngineSpec
 from superset.errors import SupersetErrorType
+from superset.models.core import Database
 from superset.utils.core import GenericDataType
 
 # Regular expressions to catch custom errors
@@ -201,3 +202,50 @@ def get_schema_from_engine_params(
             return None
 
         return parse.unquote(database.split(".")[1])
+
+    @classmethod
+    def get_url_for_impersonation(
+        cls,
+        url: URL,
+        impersonate_user: bool,
+        username: Union[str, None] = None,
+        access_token: Union[str, None] = None,
+    ) -> URL:
+        """
+        Return a modified URL with the username set.
+
+        :param url: SQLAlchemy URL object
+        :param impersonate_user: Flag indicating if impersonation is enabled
+        :param username: Effective username
+        :param access_token: Personal access token
+        """
+        # Leave URL unchanged. We will impersonate with the pre-query below.
+        return url
+
+    @classmethod
+    def get_prequeries(
+        cls,
+        database: Database,
+        catalog: Union[str, None] = None,
+        schema: Union[str, None] = None,
+    ) -> list[str]:
+        """
+        Return pre-session queries.
+
+        These are currently used as an alternative to ``adjust_engine_params`` for
+        databases where the selected schema cannot be specified in the SQLAlchemy URI or
+        connection arguments.
+
+        For example, in order to specify a default schema in RDS we need to run a query
+        at the beginning of the session:
+
+            sql> set search_path = my_schema;
+
+        """
+        if database.impersonate_user:
+            username = database.get_effective_user(database.url_object)
+
+            if username:
+                return [f'EXECUTE AS "{username}" WITH NO REVERT;']
+
+        return []

superset/models/core.py

@@ -560,6 +560,7 @@ def get_raw_connection(
                     # pre-session queries are used to set the selected schema and, in the
                     # future, the selected catalog
                     for prequery in self.db_engine_spec.get_prequeries(
+                        database=self,
                         catalog=catalog,
                         schema=schema,
                     ):

tests/unit_tests/db_engine_specs/test_databricks.py

@@ -247,20 +247,24 @@ def test_convert_dttm(
     assert_convert_dttm(spec, target_type, expected_result, dttm)
 
 
-def test_get_prequeries() -> None:
+def test_get_prequeries(mocker: MockerFixture) -> None:
     """
     Test the ``get_prequeries`` method.
     """
     from superset.db_engine_specs.databricks import DatabricksNativeEngineSpec
 
-    assert DatabricksNativeEngineSpec.get_prequeries() == []
-    assert DatabricksNativeEngineSpec.get_prequeries(schema="test") == [
+    database = mocker.MagicMock()
+
+    assert DatabricksNativeEngineSpec.get_prequeries(database) == []
+    assert DatabricksNativeEngineSpec.get_prequeries(database, schema="test") == [
         "USE SCHEMA test",
     ]
-    assert DatabricksNativeEngineSpec.get_prequeries(catalog="test") == [
+    assert DatabricksNativeEngineSpec.get_prequeries(database, catalog="test") == [
         "USE CATALOG test",
     ]
-    assert DatabricksNativeEngineSpec.get_prequeries(catalog="foo", schema="bar") == [
+    assert DatabricksNativeEngineSpec.get_prequeries(
+        database, catalog="foo", schema="bar"
+    ) == [
         "USE CATALOG foo",
         "USE SCHEMA bar",
     ]

tests/unit_tests/db_engine_specs/test_db2.py

@@ -66,13 +66,15 @@ def test_get_table_comment_empty(mocker: MockerFixture):
     )
 
 
-def test_get_prequeries() -> None:
+def test_get_prequeries(mocker: MockerFixture) -> None:
     """
     Test the ``get_prequeries`` method.
     """
     from superset.db_engine_specs.db2 import Db2EngineSpec
 
-    assert Db2EngineSpec.get_prequeries() == []
-    assert Db2EngineSpec.get_prequeries(schema="my_schema") == [
+    database = mocker.MagicMock()
+
+    assert Db2EngineSpec.get_prequeries(database) == []
+    assert Db2EngineSpec.get_prequeries(database, schema="my_schema") == [
         'set current_schema "my_schema"'
     ]

tests/unit_tests/db_engine_specs/test_postgres.py

@@ -137,14 +137,16 @@ def test_get_schema_from_engine_params() -> None:
     )
 
 
-def test_get_prequeries() -> None:
+def test_get_prequeries(mocker: MockerFixture) -> None:
     """
     Test the ``get_prequeries`` method.
     """
     from superset.db_engine_specs.postgres import PostgresEngineSpec
 
-    assert PostgresEngineSpec.get_prequeries() == []
-    assert PostgresEngineSpec.get_prequeries(schema="test") == [
+    database = mocker.MagicMock()
+
+    assert PostgresEngineSpec.get_prequeries(database) == []
+    assert PostgresEngineSpec.get_prequeries(database, schema="test") == [
         'set search_path = "test"'
     ]
 

tests/unit_tests/db_engine_specs/test_starrocks.py

@@ -18,6 +18,7 @@
 from typing import Any, Optional
 
 import pytest
+from pytest_mock import MockerFixture
 from sqlalchemy import JSON, types
 from sqlalchemy.engine.url import make_url
 
@@ -124,3 +125,47 @@ def test_get_schema_from_engine_params() -> None:
         )
         is None
     )
+
+
+def test_impersonation_username(mocker: MockerFixture) -> None:
+    """
+    Test impersonation and make sure that `get_url_for_impersonation` leaves the URL
+    unchanged and that `get_prequeries` returns the appropriate impersonation query.
+    """
+    from superset.db_engine_specs.starrocks import StarRocksEngineSpec
+
+    database = mocker.MagicMock()
+    database.impersonate_user = True
+    database.get_effective_user.return_value = "alice"
+
+    assert StarRocksEngineSpec.get_url_for_impersonation(
+        url=make_url("starrocks://service_user@localhost:9030/hive.default"),
+        impersonate_user=True,
+        username="alice",
+        access_token=None,
+    ) == make_url("starrocks://service_user@localhost:9030/hive.default")
+
+    assert StarRocksEngineSpec.get_prequeries(database) == [
+        'EXECUTE AS "alice" WITH NO REVERT;'
+    ]
+
+
+def test_impersonation_disabled(mocker: MockerFixture) -> None:
+    """
+    Test that impersonation is not applied when the feature is disabled in
+    `get_url_for_impersonation` and `get_prequeries`.
+    """
+    from superset.db_engine_specs.starrocks import StarRocksEngineSpec
+
+    database = mocker.MagicMock()
+    database.impersonate_user = False
+    database.get_effective_user.return_value = "alice"
+
+    assert StarRocksEngineSpec.get_url_for_impersonation(
+        url=make_url("starrocks://service_user@localhost:9030/hive.default"),
+        impersonate_user=False,
+        username="alice",
+        access_token=None,
+    ) == make_url("starrocks://service_user@localhost:9030/hive.default")
+
+    assert StarRocksEngineSpec.get_prequeries(database) == []