Mini Shell

"""Beat command-line program.

This module is the 'program-version' of :mod:`celery.beat`.

It does everything necessary to run that module
as an actual application, like installing signal handlers
and so on.
"""
from __future__ import annotations

import numbers
import socket
import sys
from datetime import datetime
from signal import Signals
from types import FrameType
from typing import Any

from celery import VERSION_BANNER, Celery, beat, platforms
from celery.utils.imports import qualname
from celery.utils.log import LOG_LEVELS, get_logger
from celery.utils.time import humanize_seconds

__all__ = ('Beat',)

STARTUP_INFO_FMT = """
LocalTime -> {timestamp}
Configuration ->
    . broker -> {conninfo}
    . loader -> {loader}
    . scheduler -> {scheduler}
{scheduler_info}
    . logfile -> {logfile}@%{loglevel}
    . maxinterval -> {hmax_interval} ({max_interval}s)
""".strip()

logger = get_logger('celery.beat')


class Beat:
    """Beat as a service."""

    Service = beat.Service
    app: Celery = None

    def __init__(self, max_interval: int | None = None, app: Celery | None = None,
                 socket_timeout: int = 30, pidfile: str | None = None, no_color: bool | None = None,
                 loglevel: str = 'WARN', logfile: str | None = None, schedule: str | None = None,
                 scheduler: str | None = None,
                 scheduler_cls: str | None = None,  # XXX use scheduler
                 redirect_stdouts: bool | None = None,
                 redirect_stdouts_level: str | None = None,
                 quiet: bool = False, **kwargs: Any) -> None:
        self.app = app = app or self.app
        either = self.app.either
        self.loglevel = loglevel
        self.logfile = logfile
        self.schedule = either('beat_schedule_filename', schedule)
        self.scheduler_cls = either(
            'beat_scheduler', scheduler, scheduler_cls)
        self.redirect_stdouts = either(
            'worker_redirect_stdouts', redirect_stdouts)
        self.redirect_stdouts_level = either(
            'worker_redirect_stdouts_level', redirect_stdouts_level)
        self.quiet = quiet

        self.max_interval = max_interval
        self.socket_timeout = socket_timeout
        self.no_color = no_color
        self.colored = app.log.colored(
            self.logfile,
            enabled=not no_color if no_color is not None else no_color,
        )
        self.pidfile = pidfile
        if not isinstance(self.loglevel, numbers.Integral):
            self.loglevel = LOG_LEVELS[self.loglevel.upper()]

    def run(self) -> None:
        if not self.quiet:
            print(str(self.colored.cyan(
                f'celery beat v{VERSION_BANNER} is starting.')))
        self.init_loader()
        self.set_process_title()
        self.start_scheduler()

    def setup_logging(self, colorize: bool | None = None) -> None:
        if colorize is None and self.no_color is not None:
            colorize = not self.no_color
        self.app.log.setup(self.loglevel, self.logfile,
                           self.redirect_stdouts, self.redirect_stdouts_level,
                           colorize=colorize)

    def start_scheduler(self) -> None:
        if self.pidfile:
            platforms.create_pidlock(self.pidfile)
        service = self.Service(
            app=self.app,
            max_interval=self.max_interval,
            scheduler_cls=self.scheduler_cls,
            schedule_filename=self.schedule,
        )

        if not self.quiet:
            print(self.banner(service))

        self.setup_logging()
        if self.socket_timeout:
            logger.debug('Setting default socket timeout to %r',
                         self.socket_timeout)
            socket.setdefaulttimeout(self.socket_timeout)
        try:
            self.install_sync_handler(service)
            service.start()
        except Exception as exc:
            logger.critical('beat raised exception %s: %r',
                            exc.__class__, exc,
                            exc_info=True)
            raise

    def banner(self, service: beat.Service) -> str:
        c = self.colored
        return str(
            c.blue('__    ', c.magenta('-'),
                   c.blue('    ... __   '), c.magenta('-'),
                   c.blue('        _\n'),
                   c.reset(self.startup_info(service))),
        )

    def init_loader(self) -> None:
        # Run the worker init handler.
        # (Usually imports task modules and such.)
        self.app.loader.init_worker()
        self.app.finalize()

    def startup_info(self, service: beat.Service) -> str:
        scheduler = service.get_scheduler(lazy=True)
        return STARTUP_INFO_FMT.format(
            conninfo=self.app.connection().as_uri(),
            timestamp=datetime.now().replace(microsecond=0),
            logfile=self.logfile or '[stderr]',
            loglevel=LOG_LEVELS[self.loglevel],
            loader=qualname(self.app.loader),
            scheduler=qualname(scheduler),
            scheduler_info=scheduler.info,
            hmax_interval=humanize_seconds(scheduler.max_interval),
            max_interval=scheduler.max_interval,
        )

    def set_process_title(self) -> None:
        arg_start = 'manage' in sys.argv[0] and 2 or 1
        platforms.set_process_title(
            'celery beat', info=' '.join(sys.argv[arg_start:]),
        )

    def install_sync_handler(self, service: beat.Service) -> None:
        """Install a `SIGTERM` + `SIGINT` handler saving the schedule."""
        def _sync(signum: Signals, frame: FrameType) -> None:
            service.sync()
            raise SystemExit()
        platforms.signals.update(SIGTERM=_sync, SIGINT=_sync)