#
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# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
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# software distributed under the License is distributed on an
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# KIND, either express or implied. See the License for the
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# under the License.
from __future__ import annotations
import os
from collections.abc import Iterable, Mapping
from contextlib import closing, contextmanager
from functools import cached_property
from io import StringIO
from pathlib import Path
from typing import TYPE_CHECKING, Any, Callable, TypeVar, overload
from urllib.parse import urlparse
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
from snowflake import connector
from snowflake.connector import DictCursor, SnowflakeConnection, util_text
from snowflake.sqlalchemy import URL
from sqlalchemy import create_engine
from airflow.exceptions import AirflowException
from airflow.providers.common.sql.hooks.sql import DbApiHook, return_single_query_results
from airflow.providers.snowflake.utils.openlineage import fix_snowflake_sqlalchemy_uri
from airflow.utils.strings import to_boolean
if TYPE_CHECKING:
from airflow.providers.openlineage.extractors import OperatorLineage
from airflow.providers.openlineage.sqlparser import DatabaseInfo
def _try_to_boolean(value: Any):
if isinstance(value, (str, type(None))):
return to_boolean(value)
return value
[docs]
class SnowflakeHook(DbApiHook):
"""
A client to interact with Snowflake.
This hook requires the snowflake_conn_id connection. The snowflake account, login,
and, password field must be setup in the connection. Other inputs can be defined
in the connection or hook instantiation.
:param snowflake_conn_id: Reference to
:ref:`Snowflake connection id<howto/connection:snowflake>`
:param account: snowflake account name
:param authenticator: authenticator for Snowflake.
'snowflake' (default) to use the internal Snowflake authenticator
'externalbrowser' to authenticate using your web browser and
Okta, ADFS or any other SAML 2.0-compliant identify provider
(IdP) that has been defined for your account
``https://<your_okta_account_name>.okta.com`` to authenticate
through native Okta.
:param warehouse: name of snowflake warehouse
:param database: name of snowflake database
:param region: name of snowflake region
:param role: name of snowflake role
:param schema: name of snowflake schema
:param session_parameters: You can set session-level parameters at
the time you connect to Snowflake
:param insecure_mode: Turns off OCSP certificate checks.
For details, see: `How To: Turn Off OCSP Checking in Snowflake Client Drivers - Snowflake Community
<https://community.snowflake.com/s/article/How-to-turn-off-OCSP-checking-in-Snowflake-client-drivers>`__
.. note::
``get_sqlalchemy_engine()`` depends on ``snowflake-sqlalchemy``
"""
[docs]
conn_name_attr = "snowflake_conn_id"
[docs]
default_conn_name = "snowflake_default"
[docs]
conn_type = "snowflake"
[docs]
hook_name = "Snowflake"
[docs]
supports_autocommit = True
_test_connection_sql = "select 1"
@classmethod
@classmethod
[docs]
def get_ui_field_behaviour(cls) -> dict[str, Any]:
"""Return custom field behaviour."""
import json
return {
"hidden_fields": ["port", "host"],
"relabeling": {},
"placeholders": {
"extra": json.dumps(
{
"authenticator": "snowflake oauth",
"private_key_file": "private key",
"session_parameters": "session parameters",
"client_request_mfa_token": "client request mfa token",
"client_store_temporary_credential": "client store temporary credential (externalbrowser mode)",
},
indent=1,
),
"schema": "snowflake schema",
"login": "snowflake username",
"password": "snowflake password",
"account": "snowflake account name",
"warehouse": "snowflake warehouse name",
"database": "snowflake db name",
"region": "snowflake hosted region",
"role": "snowflake role",
"private_key_file": "Path of snowflake private key (PEM Format)",
"private_key_content": "Content to snowflake private key (PEM format)",
"insecure_mode": "insecure mode",
},
}
def __init__(self, *args, **kwargs) -> None:
super().__init__(*args, **kwargs)
[docs]
self.account = kwargs.pop("account", None)
[docs]
self.warehouse = kwargs.pop("warehouse", None)
[docs]
self.database = kwargs.pop("database", None)
[docs]
self.region = kwargs.pop("region", None)
[docs]
self.role = kwargs.pop("role", None)
[docs]
self.schema = kwargs.pop("schema", None)
[docs]
self.authenticator = kwargs.pop("authenticator", None)
[docs]
self.session_parameters = kwargs.pop("session_parameters", None)
[docs]
self.client_request_mfa_token = kwargs.pop("client_request_mfa_token", None)
[docs]
self.client_store_temporary_credential = kwargs.pop("client_store_temporary_credential", None)
[docs]
self.query_ids: list[str] = []
def _get_field(self, extra_dict, field_name):
backcompat_prefix = "extra__snowflake__"
backcompat_key = f"{backcompat_prefix}{field_name}"
if field_name.startswith("extra__"):
raise ValueError(
f"Got prefixed name {field_name}; please remove the '{backcompat_prefix}' prefix "
f"when using this method."
)
if field_name in extra_dict:
import warnings
if backcompat_key in extra_dict:
warnings.warn(
f"Conflicting params `{field_name}` and `{backcompat_key}` found in extras. "
f"Using value for `{field_name}`. Please ensure this is the correct "
f"value and remove the backcompat key `{backcompat_key}`.",
UserWarning,
stacklevel=2,
)
return extra_dict[field_name] or None
return extra_dict.get(backcompat_key) or None
@cached_property
def _get_conn_params(self) -> dict[str, str | None]:
"""
Fetch connection params as a dict.
This is used in ``get_uri()`` and ``get_connection()``.
"""
conn = self.get_connection(self.snowflake_conn_id) # type: ignore[attr-defined]
extra_dict = conn.extra_dejson
account = self._get_field(extra_dict, "account") or ""
warehouse = self._get_field(extra_dict, "warehouse") or ""
database = self._get_field(extra_dict, "database") or ""
region = self._get_field(extra_dict, "region") or ""
role = self._get_field(extra_dict, "role") or ""
insecure_mode = _try_to_boolean(self._get_field(extra_dict, "insecure_mode"))
json_result_force_utf8_decoding = _try_to_boolean(
self._get_field(extra_dict, "json_result_force_utf8_decoding")
)
schema = conn.schema or ""
client_request_mfa_token = _try_to_boolean(self._get_field(extra_dict, "client_request_mfa_token"))
client_store_temporary_credential = _try_to_boolean(
self._get_field(extra_dict, "client_store_temporary_credential")
)
# authenticator and session_parameters never supported long name so we don't use _get_field
authenticator = extra_dict.get("authenticator", "snowflake")
session_parameters = extra_dict.get("session_parameters")
conn_config = {
"user": conn.login,
"password": conn.password or "",
"schema": self.schema or schema,
"database": self.database or database,
"account": self.account or account,
"warehouse": self.warehouse or warehouse,
"region": self.region or region,
"role": self.role or role,
"authenticator": self.authenticator or authenticator,
"session_parameters": self.session_parameters or session_parameters,
# application is used to track origin of the requests
"application": os.environ.get("AIRFLOW_SNOWFLAKE_PARTNER", "AIRFLOW"),
}
if insecure_mode:
conn_config["insecure_mode"] = insecure_mode
if json_result_force_utf8_decoding:
conn_config["json_result_force_utf8_decoding"] = json_result_force_utf8_decoding
if client_request_mfa_token:
conn_config["client_request_mfa_token"] = client_request_mfa_token
if client_store_temporary_credential:
conn_config["client_store_temporary_credential"] = client_store_temporary_credential
# If private_key_file is specified in the extra json, load the contents of the file as a private key.
# If private_key_content is specified in the extra json, use it as a private key.
# As a next step, specify this private key in the connection configuration.
# The connection password then becomes the passphrase for the private key.
# If your private key is not encrypted (not recommended), then leave the password empty.
private_key_file = self._get_field(extra_dict, "private_key_file")
private_key_content = self._get_field(extra_dict, "private_key_content")
private_key_pem = None
if private_key_content and private_key_file:
raise AirflowException(
"The private_key_file and private_key_content extra fields are mutually exclusive. "
"Please remove one."
)
if private_key_file:
private_key_file_path = Path(private_key_file)
if not private_key_file_path.is_file() or private_key_file_path.stat().st_size == 0:
raise ValueError("The private_key_file path points to an empty or invalid file.")
if private_key_file_path.stat().st_size > 4096:
raise ValueError("The private_key_file size is too big. Please keep it less than 4 KB.")
private_key_pem = Path(private_key_file_path).read_bytes()
elif private_key_content:
private_key_pem = private_key_content.encode()
if private_key_pem:
passphrase = None
if conn.password:
passphrase = conn.password.strip().encode()
p_key = serialization.load_pem_private_key(
private_key_pem, password=passphrase, backend=default_backend()
)
pkb = p_key.private_bytes(
encoding=serialization.Encoding.DER,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption(),
)
conn_config["private_key"] = pkb
conn_config.pop("password", None)
refresh_token = self._get_field(extra_dict, "refresh_token") or ""
if refresh_token:
conn_config["refresh_token"] = refresh_token
conn_config["authenticator"] = "oauth"
conn_config["client_id"] = conn.login
conn_config["client_secret"] = conn.password
conn_config.pop("login", None)
conn_config.pop("password", None)
# configure custom target hostname and port, if specified
snowflake_host = extra_dict.get("host")
snowflake_port = extra_dict.get("port")
if snowflake_host:
conn_config["host"] = snowflake_host
if snowflake_port:
conn_config["port"] = snowflake_port
# if a value for ocsp_fail_open is set, pass it along.
# Note the check is for `is not None` so that we can pass along `False` as a value.
ocsp_fail_open = extra_dict.get("ocsp_fail_open")
if ocsp_fail_open is not None:
conn_config["ocsp_fail_open"] = _try_to_boolean(ocsp_fail_open)
return conn_config
[docs]
def get_uri(self) -> str:
"""Override DbApiHook get_uri method for get_sqlalchemy_engine()."""
conn_params = self._get_conn_params
return self._conn_params_to_sqlalchemy_uri(conn_params)
def _conn_params_to_sqlalchemy_uri(self, conn_params: dict) -> str:
return URL(
**{
k: v
for k, v in conn_params.items()
if v
and k
not in [
"session_parameters",
"insecure_mode",
"private_key",
"client_request_mfa_token",
"client_store_temporary_credential",
"json_result_force_utf8_decoding",
"ocsp_fail_open",
]
}
)
[docs]
def get_conn(self) -> SnowflakeConnection:
"""Return a snowflake.connection object."""
conn_config = self._get_conn_params
conn = connector.connect(**conn_config)
return conn
[docs]
def get_sqlalchemy_engine(self, engine_kwargs=None):
"""
Get an sqlalchemy_engine object.
:param engine_kwargs: Kwargs used in :func:`~sqlalchemy.create_engine`.
:return: the created engine.
"""
engine_kwargs = engine_kwargs or {}
conn_params = self._get_conn_params
if "insecure_mode" in conn_params:
engine_kwargs.setdefault("connect_args", {})
engine_kwargs["connect_args"]["insecure_mode"] = True
if "json_result_force_utf8_decoding" in conn_params:
engine_kwargs.setdefault("connect_args", {})
engine_kwargs["connect_args"]["json_result_force_utf8_decoding"] = True
if "ocsp_fail_open" in conn_params:
engine_kwargs.setdefault("connect_args", {})
engine_kwargs["connect_args"]["ocsp_fail_open"] = conn_params["ocsp_fail_open"]
for key in ["session_parameters", "private_key"]:
if conn_params.get(key):
engine_kwargs.setdefault("connect_args", {})
engine_kwargs["connect_args"][key] = conn_params[key]
return create_engine(self._conn_params_to_sqlalchemy_uri(conn_params), **engine_kwargs)
[docs]
def get_snowpark_session(self):
"""
Get a Snowpark session object.
:return: the created session.
"""
from snowflake.snowpark import Session
from airflow import __version__ as airflow_version
from airflow.providers.snowflake import __version__ as provider_version
conn_config = self._get_conn_params
session = Session.builder.configs(conn_config).create()
# add query tag for observability
session.update_query_tag(
{
"airflow_version": airflow_version,
"airflow_provider_version": provider_version,
}
)
return session
[docs]
def set_autocommit(self, conn, autocommit: Any) -> None:
conn.autocommit(autocommit)
conn.autocommit_mode = autocommit
[docs]
def get_autocommit(self, conn):
return getattr(conn, "autocommit_mode", False)
@overload # type: ignore[override]
[docs]
def run(
self,
sql: str | Iterable[str],
autocommit: bool = ...,
parameters: Iterable | Mapping[str, Any] | None = ...,
handler: None = ...,
split_statements: bool = ...,
return_last: bool = ...,
return_dictionaries: bool = ...,
) -> None: ...
@overload
def run(
self,
sql: str | Iterable[str],
autocommit: bool = ...,
parameters: Iterable | Mapping[str, Any] | None = ...,
handler: Callable[[Any], T] = ...,
split_statements: bool = ...,
return_last: bool = ...,
return_dictionaries: bool = ...,
) -> tuple | list[tuple] | list[list[tuple] | tuple] | None: ...
def run(
self,
sql: str | Iterable[str],
autocommit: bool = False,
parameters: Iterable | Mapping[str, Any] | None = None,
handler: Callable[[Any], T] | None = None,
split_statements: bool = True,
return_last: bool = True,
return_dictionaries: bool = False,
) -> tuple | list[tuple] | list[list[tuple] | tuple] | None:
"""
Run a command or list of commands.
Pass a list of SQL statements to the SQL parameter to get them to
execute sequentially. The result of the queries is returned if the
``handler`` callable is set.
:param sql: The SQL string to be executed with possibly multiple
statements, or a list of sql statements to execute
:param autocommit: What to set the connection's autocommit setting to
before executing the query.
:param parameters: The parameters to render the SQL query with.
:param handler: The result handler which is called with the result of
each statement.
:param split_statements: Whether to split a single SQL string into
statements and run separately
:param return_last: Whether to return result for only last statement or
for all after split.
:param return_dictionaries: Whether to return dictionaries rather than
regular DBAPI sequences as rows in the result. The dictionaries are
of form ``{ 'column1_name': value1, 'column2_name': value2 ... }``.
:return: Result of the last SQL statement if *handler* is set.
*None* otherwise.
"""
self.query_ids = []
if isinstance(sql, str):
if split_statements:
split_statements_tuple = util_text.split_statements(StringIO(sql))
sql_list: Iterable[str] = [
sql_string for sql_string, _ in split_statements_tuple if sql_string
]
else:
sql_list = [self.strip_sql_string(sql)]
else:
sql_list = sql
if sql_list:
self.log.debug("Executing following statements against Snowflake DB: %s", sql_list)
else:
raise ValueError("List of SQL statements is empty")
with closing(self.get_conn()) as conn:
self.set_autocommit(conn, autocommit)
with self._get_cursor(conn, return_dictionaries) as cur:
results = []
for sql_statement in sql_list:
self._run_command(cur, sql_statement, parameters) # type: ignore[attr-defined]
if handler is not None:
result = self._make_common_data_structure(handler(cur)) # type: ignore[attr-defined]
if return_single_query_results(sql, return_last, split_statements):
_last_result = result
_last_description = cur.description
else:
results.append(result)
self.descriptions.append(cur.description) # type: ignore[has-type]
query_id = cur.sfqid
self.log.info("Rows affected: %s", cur.rowcount)
self.log.info("Snowflake query id: %s", query_id)
self.query_ids.append(query_id)
# If autocommit was set to False or db does not support autocommit, we do a manual commit.
if not self.get_autocommit(conn):
conn.commit()
if handler is None:
return None
if return_single_query_results(sql, return_last, split_statements):
self.descriptions = [_last_description]
return _last_result
return results
@contextmanager
def _get_cursor(self, conn: Any, return_dictionaries: bool):
cursor = None
try:
if return_dictionaries:
cursor = conn.cursor(DictCursor)
else:
cursor = conn.cursor()
yield cursor
finally:
if cursor is not None:
cursor.close()
[docs]
def get_openlineage_database_info(self, connection) -> DatabaseInfo:
from airflow.providers.openlineage.sqlparser import DatabaseInfo
database = self.database or self._get_field(connection.extra_dejson, "database")
return DatabaseInfo(
scheme=self.get_openlineage_database_dialect(connection),
authority=self._get_openlineage_authority(connection),
information_schema_columns=[
"table_schema",
"table_name",
"column_name",
"ordinal_position",
"data_type",
"table_catalog",
],
database=database,
is_information_schema_cross_db=True,
is_uppercase_names=True,
)
[docs]
def get_openlineage_database_dialect(self, _) -> str:
return "snowflake"
[docs]
def get_openlineage_default_schema(self) -> str | None:
return self._get_conn_params["schema"]
def _get_openlineage_authority(self, _) -> str | None:
uri = fix_snowflake_sqlalchemy_uri(self.get_uri())
return urlparse(uri).hostname
[docs]
def get_openlineage_database_specific_lineage(self, task_instance) -> OperatorLineage | None:
"""
Generate OpenLineage metadata for a Snowflake task instance based on executed query IDs.
If a single query ID is present, attach an `ExternalQueryRunFacet` to the lineage metadata.
If multiple query IDs are present, emits separate OpenLineage events for each query.
Note that `get_openlineage_database_specific_lineage` is usually called after task's execution,
so if multiple query IDs are present, both START and COMPLETE event for each query will be emitted
after task's execution. If we are able to query Snowflake for query execution metadata,
query event times will correspond to actual query's start and finish times.
Args:
task_instance: The Airflow TaskInstance object for which lineage is being collected.
Returns:
An `OperatorLineage` object if a single query ID is found; otherwise `None`.
"""
from airflow.providers.common.compat.openlineage.facet import ExternalQueryRunFacet
from airflow.providers.openlineage.extractors import OperatorLineage
from airflow.providers.openlineage.sqlparser import SQLParser
from airflow.providers.snowflake.utils.openlineage import (
emit_openlineage_events_for_snowflake_queries,
)
if not self.query_ids:
self.log.debug("openlineage: no snowflake query ids found.")
return None
self.log.debug("openlineage: getting connection to get database info")
connection = self.get_connection(self.get_conn_id())
namespace = SQLParser.create_namespace(self.get_openlineage_database_info(connection))
if len(self.query_ids) == 1:
self.log.debug("Attaching ExternalQueryRunFacet with single query_id to OpenLineage event.")
return OperatorLineage(
run_facets={
"externalQuery": ExternalQueryRunFacet(
externalQueryId=self.query_ids[0], source=namespace
)
}
)
self.log.info("Multiple query_ids found. Separate OpenLineage event will be emitted for each query.")
try:
from airflow.providers.openlineage.utils.utils import should_use_external_connection
use_external_connection = should_use_external_connection(self)
except ImportError:
# OpenLineage provider release < 1.8.0 - we always use connection
use_external_connection = True
emit_openlineage_events_for_snowflake_queries(
query_ids=self.query_ids,
query_source_namespace=namespace,
task_instance=task_instance,
hook=self if use_external_connection else None,
)
return None