Source code for airflow.sensors.bash

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

from airflow.sensors.base import BaseSensorOperator
from airflow.utils.context import Context


[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.

    :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.
    """

[docs]    template_fields: Sequence[str] = ('bash_command', 'env')

    def __init__(self, *, bash_command, env=None, output_encoding='utf-8', **kwargs):
        super().__init__(**kwargs)
        self.bash_command = bash_command
        self.env = env
        self.output_encoding = output_encoding

[docs]    def poke(self, context: 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)

                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:
                        self.log.info("Output:")
                        for line in iter(resp.stdout.readline, b''):
                            self.log.info(line.decode(self.output_encoding).strip())
                    resp.wait()
                    self.log.info("Command exited with return code %s", resp.returncode)

                    return not resp.returncode