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import snowflake.connector
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)
[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)
conn_config = {
"user": conn.login,
"password": conn.password or '',
"schema": conn.schema or '',
"database": self.database or database or '',
"account": self.account or account or '',
"warehouse": self.warehouse or warehouse or ''
}
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}'
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)