# -*- coding: utf-8 -*-
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# to you under the Apache License, Version 2.0 (the
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#
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import ftplib
import re
from airflow.contrib.hooks.ftp_hook import FTPHook, FTPSHook
from airflow.sensors.base_sensor_operator import BaseSensorOperator
from airflow.utils.decorators import apply_defaults
[docs]class FTPSensor(BaseSensorOperator):
"""
Waits for a file or directory to be present on FTP.
"""
[docs] template_fields = ('path',)
"""Errors that are transient in nature, and where action can be retried"""
[docs] transient_errors = [421, 425, 426, 434, 450, 451, 452]
[docs] error_code_pattern = re.compile(r"([\d]+)")
@apply_defaults
def __init__(
self,
path,
ftp_conn_id='ftp_default',
fail_on_transient_errors=True,
*args,
**kwargs):
"""
Create a new FTP sensor
:param path: Remote file or directory path
:type path: str
:param fail_on_transient_errors: Fail on all errors,
including 4xx transient errors. Default True.
:type fail_on_transient_errors: bool
:param ftp_conn_id: The connection to run the sensor against
:type ftp_conn_id: str
"""
super(FTPSensor, self).__init__(*args, **kwargs)
self.path = path
self.ftp_conn_id = ftp_conn_id
self.fail_on_transient_errors = fail_on_transient_errors
[docs] def _create_hook(self):
"""Return connection hook."""
return FTPHook(ftp_conn_id=self.ftp_conn_id)
[docs] def _get_error_code(self, e):
"""Extract error code from ftp exception"""
try:
matches = self.error_code_pattern.match(str(e))
code = int(matches.group(0))
return code
except ValueError:
return e
[docs] def poke(self, context):
with self._create_hook() as hook:
self.log.info('Poking for %s', self.path)
try:
hook.get_mod_time(self.path)
except ftplib.error_perm as e:
self.log.info('Ftp error encountered: %s', str(e))
error_code = self._get_error_code(e)
if ((error_code != 550) and
(self.fail_on_transient_errors or
(error_code not in self.transient_errors))):
raise e
return False
return True
[docs]class FTPSSensor(FTPSensor):
"""Waits for a file or directory to be present on FTP over SSL."""
[docs] def _create_hook(self):
"""Return connection hook."""
return FTPSHook(ftp_conn_id=self.ftp_conn_id)