lino.utils.daemoncommand¶

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Modifications by Luc Saffre :

fixed: Overriding default values in a subclass didn’t work. /blog/2010/1210
added DaemonCommand.preserve_loggers class variable and get_handlers() and get_logger_files(). /blog/2010/1214
when a pidfile is specified and a file of that name already exists, DaemonCommand now no longer waits forever but raises a LockTimeout See /blog/2011/0126 and http://packages.python.org/lockfile/lockfile.html#lockfile.FileLock.acquire.
now works with versions of daemon who use “pidfile” instead of “pidlockfile”.
20130610 Changes needed for Django 1.5: No longer overrides handle but execute. Converts any options ‘stdout’ and ‘stderr’ if given because Django expects them to be file-like objects (not names of files). Removed the stderr, stdout and stdin class attributes because they interferred with Django.
2016-06-07 converted from optparse to argparse (changes needed for Django 1.10)

DaemonCommand¶

Django Management Command for starting a daemon.

Use¶

Simple use of daemon command:

from daemonextension import DaemonCommand
from django.conf import settings
import os

class Command(DaemonCommand):

    stdout = os.path.join(settings.DIRNAME, "log/cubbyscott.out")
    stderr = os.path.join(settings.DIRNAME, "log/cubbyscott.err")
    pidfile = os.path.join(settings.DIRNAME, "pid/cb_link.pid")

    def handle_daemon(self, *args, **options):
        from flopsy import Connection, Consumer
        consumer = Consumer(connection=Connection())
        consumer.declare(queue='links',
                         exchange='cubbyscott',
                         routing_key='importer', auto_delete=False)

        def message_callback(message):
            print 'Recieved: ' + message.body
            consumer.channel.basic_ack(message.delivery_tag)

        consumer.register(message_callback)

        consumer.wait()

call:

python python manage.py linkconsumer

Functions

`get_handlers`(logger)
`get_logger_files`(loggers)	Return a list of the file handles used by the specified loggers.

Classes

DaemonCommand([stdout, stderr, no_color, ...])

If you have an existing Django management command, just rename it's handle method to handle_daemon and inherit from this instead of django.core.management.base.BaseCommand.

lino.utils.daemoncommand.get_logger_files(loggers)¶: Return a list of the file handles used by the specified loggers. Thanks to http://mail.python.org/pipermail/python-list/2010-April/1241406.html

class lino.utils.daemoncommand.DaemonCommand(stdout=None, stderr=None, no_color=False, force_color=False)¶

Bases: BaseCommand

If you have an existing Django management command, just rename it’s handle method to handle_daemon and inherit from this instead of django.core.management.base.BaseCommand.

help = 'Create a daemon'¶: The loggers to preserve. If not None, this should be a list of loggers (logging.Logger instances) whose file handles should not get closed.

execute(*args, **options)¶

Takes the options and starts a daemon context from them.

Example:

python manage.py linkconsumer --pidfile=/var/run/cb_link.pid
    --stdout=/var/log/cb/links.out --stderr=/var/log/cb/links.err