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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
#
# Unless required by applicable law or agreed to in writing,
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# KIND, either express or implied.   See the License for the
# specific language governing permissions and limitations
# under the License. 

"""Scheduler command"""
import signal

import daemon
from daemon.pidfile import TimeoutPIDLockFile

from airflow import settings
from airflow.jobs.scheduler_job import SchedulerJob
from airflow.utils import cli as cli_utils
from airflow.utils.cli import process_subdir, setup_locations, setup_logging, sigint_handler, sigquit_handler


@cli_utils.action_logging
def scheduler(args):
    """Starts Airflow Scheduler"""
    print(settings. HEADER)
    job = SchedulerJob(
        dag_id=args.dag_id,
        subdir=process_subdir(args.subdir),
        num_runs=args.num_runs,
        do_pickle=args.do_pickle)

    if args.daemon:
        pid, stdout, stderr, log_file = setup_locations("scheduler",
                                                        args.pid,
                                                        args.stdout,
                                                        args.stderr,
                                                        args.log_file)
        handle = setup_logging(log_file)
        stdout = open(stdout, 'w+')
        stderr = open(stderr, 'w+')

        ctx = daemon. DaemonContext(
            pidfile=TimeoutPIDLockFile(pid, -1),
            files_preserve=[handle],
            stdout=stdout,
            stderr=stderr,
        )
        with ctx:
            job.run()

        stdout.close()
        stderr.close()
    else:
        signal.signal(signal. SIGINT, sigint_handler)
        signal.signal(signal. SIGTERM, sigint_handler)
        signal.signal(signal. SIGQUIT, sigquit_handler)
        job.run()
