Source code for airflow.contrib.operators.oracle_to_azure_data_lake_transfer
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from airflow.hooks.oracle_hook import OracleHook
from airflow.contrib.hooks.azure_data_lake_hook import AzureDataLakeHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
from airflow.utils.file import TemporaryDirectory
import unicodecsv as csv
import os
[docs]class OracleToAzureDataLakeTransfer(BaseOperator):
"""
Moves data from Oracle to Azure Data Lake. The operator runs the query against
Oracle and stores the file locally before loading it into Azure Data Lake.
:param filename: file name to be used by the csv file.
:type filename: str
:param azure_data_lake_conn_id: destination azure data lake connection.
:type azure_data_lake_conn_id: str
:param azure_data_lake_path: destination path in azure data lake to put the file.
:type azure_data_lake_path: str
:param oracle_conn_id: source Oracle connection.
:type oracle_conn_id: str
:param sql: SQL query to execute against the Oracle database. (templated)
:type sql: str
:param sql_params: Parameters to use in sql query. (templated)
:type sql_params: str
:param delimiter: field delimiter in the file.
:type delimiter: str
:param encoding: encoding type for the file.
:type encoding: str
:param quotechar: Character to use in quoting.
:type quotechar: str
:param quoting: Quoting strategy. See unicodecsv quoting for more information.
:type quoting: str
"""
[docs] template_fields = ('filename', 'sql', 'sql_params')
@apply_defaults
def __init__(
self,
filename,
azure_data_lake_conn_id,
azure_data_lake_path,
oracle_conn_id,
sql,
sql_params=None,
delimiter=",",
encoding="utf-8",
quotechar='"',
quoting=csv.QUOTE_MINIMAL,
*args, **kwargs):
super(OracleToAzureDataLakeTransfer, self).__init__(*args, **kwargs)
if sql_params is None:
sql_params = {}
self.filename = filename
self.oracle_conn_id = oracle_conn_id
self.sql = sql
self.sql_params = sql_params
self.azure_data_lake_conn_id = azure_data_lake_conn_id
self.azure_data_lake_path = azure_data_lake_path
self.delimiter = delimiter
self.encoding = encoding
self.quotechar = quotechar
self.quoting = quoting
[docs] def _write_temp_file(self, cursor, path_to_save):
with open(path_to_save, 'wb') as csvfile:
csv_writer = csv.writer(csvfile, delimiter=self.delimiter,
encoding=self.encoding, quotechar=self.quotechar,
quoting=self.quoting)
csv_writer.writerow(map(lambda field: field[0], cursor.description))
csv_writer.writerows(cursor)
csvfile.flush()
[docs] def execute(self, context):
oracle_hook = OracleHook(oracle_conn_id=self.oracle_conn_id)
azure_data_lake_hook = AzureDataLakeHook(
azure_data_lake_conn_id=self.azure_data_lake_conn_id)
self.log.info("Dumping Oracle query results to local file")
conn = oracle_hook.get_conn()
cursor = conn.cursor()
cursor.execute(self.sql, self.sql_params)
with TemporaryDirectory(prefix='airflow_oracle_to_azure_op_') as temp:
self._write_temp_file(cursor, os.path.join(temp, self.filename))
self.log.info("Uploading local file to Azure Data Lake")
azure_data_lake_hook.upload_file(os.path.join(temp, self.filename),
os.path.join(self.azure_data_lake_path,
self.filename))
cursor.close()
conn.close()