Source code for airflow.operators.bash_operator

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from builtins import bytes
import os
import signal
from subprocess import Popen, STDOUT, PIPE
from tempfile import gettempdir, NamedTemporaryFile

from airflow.exceptions import AirflowException
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
from airflow.utils.file import TemporaryDirectory


[docs]class BashOperator(BaseOperator): """ Execute a Bash script, command or set of commands. :param bash_command: The command, set of commands or reference to a bash script (must be '.sh') to be executed. (templated) :type bash_command: string :param xcom_push: If xcom_push is True, the last line written to stdout will also be pushed to an XCom when the bash command completes. :type xcom_push: bool :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 :type output_encoding: output encoding of bash command """ template_fields = ('bash_command', 'env') template_ext = ('.sh', '.bash',) ui_color = '#f0ede4' @apply_defaults def __init__( self, bash_command, xcom_push=False, env=None, output_encoding='utf-8', *args, **kwargs): super(BashOperator, self).__init__(*args, **kwargs) self.bash_command = bash_command self.env = env self.xcom_push_flag = xcom_push self.output_encoding = output_encoding
[docs] def execute(self, context): """ Execute the bash command in a temporary directory which will be cleaned afterwards """ self.log.info("Tmp dir root location: \n %s", gettempdir()) self.lineage_data = self.bash_command with TemporaryDirectory(prefix='airflowtmp') as tmp_dir: with NamedTemporaryFile(dir=tmp_dir, prefix=self.task_id) as f: f.write(bytes(self.bash_command, 'utf_8')) f.flush() fname = f.name script_location = os.path.abspath(fname) self.log.info( "Temporary script location: %s", script_location ) def pre_exec(): # Restore default signal disposition and invoke setsid for sig in ('SIGPIPE', 'SIGXFZ', 'SIGXFSZ'): if hasattr(signal, sig): signal.signal(getattr(signal, sig), signal.SIG_DFL) os.setsid() self.log.info("Running command: %s", self.bash_command) sp = Popen( ['bash', fname], stdout=PIPE, stderr=STDOUT, cwd=tmp_dir, env=self.env, preexec_fn=pre_exec) self.sp = sp self.log.info("Output:") line = '' for line in iter(sp.stdout.readline, b''): line = line.decode(self.output_encoding).rstrip() self.log.info(line) sp.wait() self.log.info( "Command exited with return code %s", sp.returncode ) if sp.returncode: raise AirflowException("Bash command failed") if self.xcom_push_flag: return line
def on_kill(self): self.log.info('Sending SIGTERM signal to bash process group') os.killpg(os.getpgid(self.sp.pid), signal.SIGTERM)