SNOW-910685: Support creating session from default configuration file (…

…#1041)

CHANGELOG.md

@@ -7,6 +7,11 @@
 - Added support for VOLATILE/IMMUTABLE keyword when registering UDFs.
 - Added support for specifying clustering keys when saving dataframes using `DataFrame.save_as_table`.
 - Accept `Iterable` objects input for `schema` when creating dataframes using `Session.create_dataframe`.
+- Added support for creating a Snowpark session from a configuration file or environment variables.
+
+### Dependency updates
+
+- Updated ``snowflake-connector-python`` to 3.2.0.
 
 ### Bug Fixes
 

setup.py

@@ -10,7 +10,7 @@
 THIS_DIR = os.path.dirname(os.path.realpath(__file__))
 SRC_DIR = os.path.join(THIS_DIR, "src")
 SNOWPARK_SRC_DIR = os.path.join(SRC_DIR, "snowflake", "snowpark")
-CONNECTOR_DEPENDENCY_VERSION = ">=3.0.4, <4.0.0"
+CONNECTOR_DEPENDENCY_VERSION = ">=3.2.0, <4.0.0"
 REQUIRED_PYTHON_VERSION = ">=3.8, <3.11"
 if os.getenv("SNOWFLAKE_IS_PYTHON_RUNTIME_TEST", False):
     REQUIRED_PYTHON_VERSION = ">=3.8"

src/snowflake/snowpark/session.py

@@ -21,6 +21,7 @@
 import pkg_resources
 
 from snowflake.connector import ProgrammingError, SnowflakeConnection
+from snowflake.connector.config_manager import _get_default_connection_params
 from snowflake.connector.options import installed_pandas, pandas
 from snowflake.connector.pandas_tools import write_pandas
 from snowflake.snowpark._internal.analyzer.analyzer import Analyzer
@@ -328,6 +329,11 @@ def getOrCreate(self) -> "Session":
         def _create_internal(
             self, conn: Optional[SnowflakeConnection] = None
         ) -> "Session":
+            # If no connection object and no connection parameter is provided,
+            # we read from the default config file
+            if not conn and not self._options:
+                self._options = _get_default_connection_params()
+
             # Set paramstyle to qmark by default to be consistent with previous behavior
             if "paramstyle" not in self._options:
                 self._options["paramstyle"] = "qmark"

tests/integ/test_session.py

@@ -550,3 +550,26 @@ def test_sql_simplifier_disabled_on_session(db_parameters):
     }
     with Session.builder.configs(parameters).create() as new_session2:
         assert new_session2.sql_simplifier_enabled is False
+
+
+@pytest.mark.skipif(IS_IN_STORED_PROC, reason="Cannot create session in SP")
+def test_create_session_from_default_config_file(monkeypatch, db_parameters):
+    import tomlkit
+
+    doc = tomlkit.document()
+    default_con = tomlkit.table()
+    try:
+        # If anything unexpected fails here, don't want to expose password
+        for k, v in db_parameters.items():
+            default_con[k] = v
+        doc["default"] = default_con
+        with monkeypatch.context() as m:
+            m.setenv("SNOWFLAKE_CONNECTIONS", tomlkit.dumps(doc))
+            m.setenv("SNOWFLAKE_DEFAULT_CONNECTION_NAME", "default")
+            with Session.builder.create() as new_session:
+                _ = new_session.sql("select 1").collect()[0][0]
+    except Exception:
+        # This is my way of guaranteeing that we'll not expose the
+        # sensitive information that this test needs to handle.
+        # db_parameter contains passwords.
+        pytest.fail("something failed", pytrace=False)