Add the actual main.py for edit monitor

# Copyright 2024, The Android Open Source Project

#

# Licensed 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

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

import argparse

import logging

import os

import signal

import sys

import tempfile

from edit_monitor import daemon_manager

from edit_monitor import edit_monitor

def create_arg_parser():

  """Creates an instance of the default arg parser."""

  parser = argparse.ArgumentParser(

      description=(

          'Monitors edits in Android source code and uploads the edit logs.'

      ),

      add_help=True,

      formatter_class=argparse.RawDescriptionHelpFormatter,

  )

  parser.add_argument(

      '--path',

      type=str,

      required=True,

      help='Root path to monitor the edit events.',

  )

  parser.add_argument(

      '--force_cleanup',

      action='store_true',

      help=(

          'Instead of start a new edit monitor, force stop all existing edit'

          ' monitors in the system. This option is only used in emergent cases'

          ' when we want to prevent user damage by the edit monitor.'

      ),

  )

  return parser

def configure_logging():

  root_logging_dir = tempfile.mkdtemp(prefix='edit_monitor_')

  _, log_path = tempfile.mkstemp(dir=root_logging_dir, suffix='.log')

  log_fmt = '%(asctime)s %(filename)s:%(lineno)s:%(levelname)s: %(message)s'

  date_fmt = '%Y-%m-%d %H:%M:%S'

  logging.basicConfig(

      filename=log_path, level=logging.DEBUG, format=log_fmt, datefmt=date_fmt

  )

  print(f'logging to file {log_path}')

def term_signal_handler(_signal_number, _frame):

  logging.info('Process %d received SIGTERM, Terminating...', os.getpid())

  sys.exit(0)

def main(argv: list[str]):

  args = create_arg_parser().parse_args(argv[1:])

  dm = daemon_manager.DaemonManager(

      binary_path=argv[0],

      daemon_target=edit_monitor.start,

      daemon_args=(args.path,),

  )

  if args.force_cleanup:

    dm.cleanup()

  try:

    dm.start()

    dm.monitor_daemon()

  except Exception:

    logging.exception('Unexpected exception raised when run daemon.')

  finally:

    dm.stop()

if __name__ == '__main__':

  signal.signal(signal.SIGTERM, term_signal_handler)

  configure_logging()

  main(sys.argv)