# -*- coding: utf-8 -*-
#
# Licensed 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 logging
import tempfile
from airflow.hooks.hive_hooks import HiveServer2Hook
from airflow.hooks.samba_hook import SambaHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
[docs]class Hive2SambaOperator(BaseOperator):
"""
Executes hql code in a specific Hive database and loads the
results of the query as a csv to a Samba location.
:param hql: the hql to be exported
:type hql: string
:param hiveserver2_conn_id: reference to the hiveserver2 service
:type hiveserver2_conn_id: string
:param samba_conn_id: reference to the samba destination
:type samba_conn_id: string
"""
template_fields = ('hql', 'destination_filepath')
template_ext = ('.hql', '.sql',)
@apply_defaults
def __init__(
self, hql,
destination_filepath,
samba_conn_id='samba_default',
hiveserver2_conn_id='hiveserver2_default',
*args, **kwargs):
super(Hive2SambaOperator, self).__init__(*args, **kwargs)
self.hiveserver2_conn_id = hiveserver2_conn_id
self.samba_conn_id = samba_conn_id
self.destination_filepath = destination_filepath
self.hql = hql.strip().rstrip(';')
def execute(self, context):
samba = SambaHook(samba_conn_id=self.samba_conn_id)
hive = HiveServer2Hook(hiveserver2_conn_id=self.hiveserver2_conn_id)
tmpfile = tempfile.NamedTemporaryFile()
logging.info("Fetching file from Hive")
hive.to_csv(hql=self.hql, csv_filepath=tmpfile.name)
logging.info("Pushing to samba")
samba.push_from_local(self.destination_filepath, tmpfile.name)