# -*- coding: utf-8 -*-
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# to you under the Apache License, Version 2.0 (the
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from builtins import bytes
import os
from subprocess import Popen, STDOUT, PIPE
from tempfile import gettempdir, NamedTemporaryFile
from airflow.utils.decorators import apply_defaults
from airflow.sensors.base_sensor_operator import BaseSensorOperator
from airflow.utils.file import TemporaryDirectory
[docs]class BashSensor(BaseSensorOperator):
"""
Executes a bash command/script and returns True if and only if the
return code is 0.
:param bash_command: The command, set of commands or reference to a
bash script (must be '.sh') to be executed.
:type bash_command: str
:param env: If env is not None, it must be a mapping that defines the
environment variables for the new process; these are used instead
of inheriting the current process environment, which is the default
behavior. (templated)
:type env: dict
:param output_encoding: output encoding of bash command.
:type output_encoding: str
"""
[docs] template_fields = ('bash_command', 'env')
@apply_defaults
def __init__(self,
bash_command,
env=None,
output_encoding='utf-8',
*args, **kwargs):
super(BashSensor, self).__init__(*args, **kwargs)
self.bash_command = bash_command
self.env = env
self.output_encoding = output_encoding
[docs] def poke(self, context):
"""
Execute the bash command in a temporary directory
which will be cleaned afterwards
"""
bash_command = self.bash_command
self.log.info("Tmp dir root location: \n %s", gettempdir())
with TemporaryDirectory(prefix='airflowtmp') as tmp_dir:
with NamedTemporaryFile(dir=tmp_dir, prefix=self.task_id) as f:
f.write(bytes(bash_command, 'utf_8'))
f.flush()
fname = f.name
script_location = tmp_dir + "/" + fname
self.log.info("Temporary script location: %s", script_location)
self.log.info("Running command: %s", bash_command)
sp = Popen(
['bash', fname],
stdout=PIPE, stderr=STDOUT,
close_fds=True, cwd=tmp_dir,
env=self.env, preexec_fn=os.setsid)
self.sp = sp
self.log.info("Output:")
line = ''
for line in iter(sp.stdout.readline, b''):
line = line.decode(self.output_encoding).strip()
self.log.info(line)
sp.wait()
self.log.info("Command exited with return code %s", sp.returncode)
return not sp.returncode