text: # -*- coding: utf-8 -*-
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  # Licensed to the Apache Software Foundation (ASF) under one
  # or more contributor license agreements.  See the NOTICE file
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  # 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
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
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  # software distributed under the License is distributed on an
  # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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  # specific language governing permissions and limitations
  # under the License.
  
  
  import os
  import signal
  from subprocess import PIPE, STDOUT, Popen
  from tempfile import TemporaryDirectory, gettempdir
  from typing import Dict, Optional
  
  from airflow.exceptions import AirflowException
  from airflow.models import BaseOperator
  from airflow.utils.decorators import apply_defaults
  from airflow.utils.operator_helpers import context_to_airflow_vars
  
  
  class BashOperator(BaseOperator):
      """
      Execute a Bash script, command or set of commands.
  
      .. seealso::
          For more information on how to use this operator, take a look at the guide:
          :ref:`howto/operator:BashOperator`
  
      If BaseOperator.do_xcom_push is True, the last line written to stdout
      will also be pushed to an XCom when the bash command completes
  
      :param bash_command: The command, set of commands or reference to a
          bash script (must be '.sh') to be executed. (templated)
      :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
  
      On execution of this operator the task will be up for retry
      when exception is raised. However, if a sub-command exits with non-zero
      value Airflow will not recognize it as failure unless the whole shell exits
      with a failure. The easiest way of achieving this is to prefix the command
      with ``set -e;``
      Example:
  
      .. code-block:: python
  
          bash_command = "set -e; python3 script.py '{{ next_execution_date }}'"
      """
      template_fields = ('bash_command', 'env')
      template_ext = ('.sh', '.bash',)
      ui_color = '#f0ede4'
  
      @apply_defaults
      def __init__(
              self,
              bash_command: str,
              env: Optional[Dict[str, str]] = None,
              output_encoding: str = 'utf-8',
              *args, **kwargs) -> None:
  
          super().__init__(*args, **kwargs)
          self.bash_command = bash_command
          self.env = env
          self.output_encoding = output_encoding
          if kwargs.get('xcom_push') is not None:
              raise AirflowException("'xcom_push' was deprecated, use 'BaseOperator.do_xcom_push' instead")
          self.sub_process = None
  
      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())
  
          # Prepare env for child process.
          env = self.env
          if env is None:
              env = os.environ.copy()
  
          airflow_context_vars = context_to_airflow_vars(context, in_env_var_format=True)
          self.log.debug('Exporting the following env vars:\n%s',
                         '\n'.join(["{}={}".format(k, v)
                                    for k, v in airflow_context_vars.items()]))
          env.update(airflow_context_vars)
  
          self.lineage_data = self.bash_command
  
          with TemporaryDirectory(prefix='airflowtmp') as tmp_dir:
  
              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)
  
              self.sub_process = Popen(
                  ['bash', "-c", self.bash_command],
                  stdout=PIPE,
                  stderr=STDOUT,
                  cwd=tmp_dir,
                  env=env,
                  preexec_fn=pre_exec)
  
              self.log.info('Output:')
              line = ''
              for raw_line in iter(self.sub_process.stdout.readline, b''):
                  line = raw_line.decode(self.output_encoding).rstrip()
                  self.log.info("%s", line)
  
              self.sub_process.wait()
  
              self.log.info('Command exited with return code %s', self.sub_process.returncode)
  
              if self.sub_process.returncode != 0:
                  raise AirflowException('Bash command failed. The command returned a non-zero exit code.')
  
          return line
  
      def on_kill(self):
          self.log.info('Sending SIGTERM signal to bash process group')
          if self.sub_process and hasattr(self.sub_process, 'pid'):
              os.killpg(os.getpgid(self.sub_process.pid), signal.SIGTERM)
  