# -*- coding: utf-8 -*-
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# Licensed to the Apache Software Foundation (ASF) under one
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# 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
#
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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
[docs] def on_kill(self):
self.log.info('Sending SIGTERM signal to bash process group')
os.killpg(os.getpgid(self.sp.pid), signal.SIGTERM)