Source code for airflow.contrib.sensors.bash_sensor

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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"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 = script_location = tmp_dir + "/" + fname"Temporary script location: %s", script_location)"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"Output:") line = '' for line in iter(sp.stdout.readline, b''): line = line.decode(self.output_encoding).strip() sp.wait()"Command exited with return code %s", sp.returncode) return not sp.returncode