Source code for airflow.contrib.hooks.snowflake_hook
# -*- coding: utf-8 -*-
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# 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
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
import snowflake.connector
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
from airflow.hooks.dbapi_hook import DbApiHook
[docs]class SnowflakeHook(DbApiHook):
"""
Interact with Snowflake.
get_sqlalchemy_engine() depends on snowflake-sqlalchemy
"""
[docs] conn_name_attr = 'snowflake_conn_id'
[docs] default_conn_name = 'snowflake_default'
[docs] supports_autocommit = True
def __init__(self, *args, **kwargs):
super(SnowflakeHook, self).__init__(*args, **kwargs)
self.account = kwargs.pop("account", None)
self.warehouse = kwargs.pop("warehouse", None)
self.database = kwargs.pop("database", None)
self.region = kwargs.pop("region", None)
self.role = kwargs.pop("role", None)
self.schema = kwargs.pop("schema", None)
self.authenticator = kwargs.pop("authenticator", None)
[docs] def _get_conn_params(self):
"""
one method to fetch connection params as a dict
used in get_uri() and get_connection()
"""
conn = self.get_connection(self.snowflake_conn_id)
account = conn.extra_dejson.get('account', None)
warehouse = conn.extra_dejson.get('warehouse', None)
database = conn.extra_dejson.get('database', None)
region = conn.extra_dejson.get("region", None)
role = conn.extra_dejson.get('role', None)
authenticator = conn.extra_dejson.get('authenticator', 'snowflake')
conn_config = {
"user": conn.login,
"password": conn.password or '',
"schema": self.schema or conn.schema or '',
"database": self.database or database or '',
"account": self.account or account or '',
"warehouse": self.warehouse or warehouse or '',
"region": self.region or region or '',
"role": self.role or role,
"authenticator": self.authenticator or authenticator
}
"""
If private_key_file is specified in the extra json, load the contents of the file as a private
key and specify that in the connection configuration. The connection password then becomes the
passphrase for the private key. If your private key file is not encrypted (not recommended), then
leave the password empty.
"""
private_key_file = conn.extra_dejson.get('private_key_file', None)
if private_key_file:
with open(private_key_file, "rb") as key:
passphrase = None
if conn.password:
passphrase = conn.password.strip().encode()
p_key = serialization.load_pem_private_key(
key.read(),
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)
return conn_config
[docs] def get_uri(self):
"""
override DbApiHook get_uri method for get_sqlalchemy_engine()
"""
conn_config = self._get_conn_params()
uri = 'snowflake://{user}:{password}@{account}/{database}/'
uri += '{schema}?warehouse={warehouse}&role={role}&authenticator={authenticator}'
return uri.format(**conn_config)
[docs] def get_conn(self):
"""
Returns a snowflake.connection object
"""
conn_config = self._get_conn_params()
conn = snowflake.connector.connect(**conn_config)
return conn
[docs] def _get_aws_credentials(self):
"""
returns aws_access_key_id, aws_secret_access_key
from extra
intended to be used by external import and export statements
"""
if self.snowflake_conn_id:
connection_object = self.get_connection(self.snowflake_conn_id)
if 'aws_secret_access_key' in connection_object.extra_dejson:
aws_access_key_id = connection_object.extra_dejson.get(
'aws_access_key_id')
aws_secret_access_key = connection_object.extra_dejson.get(
'aws_secret_access_key')
return aws_access_key_id, aws_secret_access_key
[docs] def set_autocommit(self, conn, autocommit):
conn.autocommit(autocommit)