Source code for airflow.sensors.bash

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you 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
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations

import os
from subprocess import PIPE, STDOUT, Popen
from tempfile import NamedTemporaryFile, TemporaryDirectory, gettempdir
from typing import TYPE_CHECKING, Sequence

from airflow.exceptions import AirflowFailException
from airflow.sensors.base import BaseSensorOperator

    from airflow.utils.context import Context

[docs]class BashSensor(BaseSensorOperator): """ Executes a bash command/script. Return 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. :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) :param output_encoding: output encoding of bash command. :param retry_exit_code: If task exits with this code, treat the sensor as not-yet-complete and retry the check later according to the usual retry/timeout settings. Any other non-zero return code will be treated as an error, and cause the sensor to fail. If set to ``None`` (the default), any non-zero exit code will cause a retry and the task will never raise an error except on time-out. .. seealso:: For more information on how to use this sensor,take a look at the guide: :ref:`howto/operator:BashSensor` """
[docs] template_fields: Sequence[str] = ("bash_command", "env")
def __init__( self, *, bash_command, env=None, output_encoding="utf-8", retry_exit_code: int | None = None, **kwargs ): super().__init__(**kwargs) self.bash_command = bash_command self.env = env self.output_encoding = output_encoding self.retry_exit_code = retry_exit_code
[docs] def poke(self, context: Context): """Execute the bash command in a temporary directory.""" bash_command = self.bash_command"Tmp dir root location: %s", gettempdir()) with TemporaryDirectory(prefix="airflowtmp") as tmp_dir, 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) with Popen( ["bash", fname], stdout=PIPE, stderr=STDOUT, close_fds=True, cwd=tmp_dir, env=self.env, preexec_fn=os.setsid, ) as resp: if resp.stdout:"Output:") for line in iter(resp.stdout.readline, b""): resp.wait()"Command exited with return code %s", resp.returncode) # zero code means success, the sensor can go green if resp.returncode == 0: return True # we have a retry exit code, sensor retries if return code matches, otherwise error elif self.retry_exit_code is not None: if resp.returncode == self.retry_exit_code:"Return code matches retry code, will retry later") return False else: raise AirflowFailException(f"Command exited with return code {resp.returncode}") # backwards compatibility: sensor retries no matter the error code else:"Non-zero return code and no retry code set, will retry later") return False

Was this entry helpful?