This document describes the current stable version of Celery (5.2). For development docs, go here.
Source code for celery.bin.multi
"""Start multiple worker instances from the command-line.
.. program:: celery multi
Examples
========
.. code-block:: console
$ # Single worker with explicit name and events enabled.
$ celery multi start Leslie -E
$ # Pidfiles and logfiles are stored in the current directory
$ # by default. Use --pidfile and --logfile argument to change
$ # this. The abbreviation %n will be expanded to the current
$ # node name.
$ celery multi start Leslie -E --pidfile=/var/run/celery/%n.pid
--logfile=/var/log/celery/%n%I.log
$ # You need to add the same arguments when you restart,
$ # as these aren't persisted anywhere.
$ celery multi restart Leslie -E --pidfile=/var/run/celery/%n.pid
--logfile=/var/log/celery/%n%I.log
$ # To stop the node, you need to specify the same pidfile.
$ celery multi stop Leslie --pidfile=/var/run/celery/%n.pid
$ # 3 workers, with 3 processes each
$ celery multi start 3 -c 3
celery worker -n celery1@myhost -c 3
celery worker -n celery2@myhost -c 3
celery worker -n celery3@myhost -c 3
$ # override name prefix when using range
$ celery multi start 3 --range-prefix=worker -c 3
celery worker -n worker1@myhost -c 3
celery worker -n worker2@myhost -c 3
celery worker -n worker3@myhost -c 3
$ # start 3 named workers
$ celery multi start image video data -c 3
celery worker -n image@myhost -c 3
celery worker -n video@myhost -c 3
celery worker -n data@myhost -c 3
$ # specify custom hostname
$ celery multi start 2 --hostname=worker.example.com -c 3
celery worker -n celery1@worker.example.com -c 3
celery worker -n celery2@worker.example.com -c 3
$ # specify fully qualified nodenames
$ celery multi start foo@worker.example.com bar@worker.example.com -c 3
$ # fully qualified nodenames but using the current hostname
$ celery multi start foo@%h bar@%h
$ # Advanced example starting 10 workers in the background:
$ # * Three of the workers processes the images and video queue
$ # * Two of the workers processes the data queue with loglevel DEBUG
$ # * the rest processes the default' queue.
$ celery multi start 10 -l INFO -Q:1-3 images,video -Q:4,5 data
-Q default -L:4,5 DEBUG
$ # You can show the commands necessary to start the workers with
$ # the 'show' command:
$ celery multi show 10 -l INFO -Q:1-3 images,video -Q:4,5 data
-Q default -L:4,5 DEBUG
$ # Additional options are added to each celery worker's command,
$ # but you can also modify the options for ranges of, or specific workers
$ # 3 workers: Two with 3 processes, and one with 10 processes.
$ celery multi start 3 -c 3 -c:1 10
celery worker -n celery1@myhost -c 10
celery worker -n celery2@myhost -c 3
celery worker -n celery3@myhost -c 3
$ # can also specify options for named workers
$ celery multi start image video data -c 3 -c:image 10
celery worker -n image@myhost -c 10
celery worker -n video@myhost -c 3
celery worker -n data@myhost -c 3
$ # ranges and lists of workers in options is also allowed:
$ # (-c:1-3 can also be written as -c:1,2,3)
$ celery multi start 5 -c 3 -c:1-3 10
celery worker -n celery1@myhost -c 10
celery worker -n celery2@myhost -c 10
celery worker -n celery3@myhost -c 10
celery worker -n celery4@myhost -c 3
celery worker -n celery5@myhost -c 3
$ # lists also works with named workers
$ celery multi start foo bar baz xuzzy -c 3 -c:foo,bar,baz 10
celery worker -n foo@myhost -c 10
celery worker -n bar@myhost -c 10
celery worker -n baz@myhost -c 10
celery worker -n xuzzy@myhost -c 3
"""
import os
import signal
import sys
from functools import wraps
import click
from kombu.utils.objects import cached_property
from celery import VERSION_BANNER
from celery.apps.multi import Cluster, MultiParser, NamespacedOptionParser
from celery.bin.base import CeleryCommand, handle_preload_options
from celery.platforms import EX_FAILURE, EX_OK, signals
from celery.utils import term
from celery.utils.text import pluralize
__all__ = ('MultiTool',)
USAGE = """\
usage: {prog_name} start <node1 node2 nodeN|range> [worker options]
{prog_name} stop <n1 n2 nN|range> [-SIG (default: -TERM)]
{prog_name} restart <n1 n2 nN|range> [-SIG] [worker options]
{prog_name} kill <n1 n2 nN|range>
{prog_name} show <n1 n2 nN|range> [worker options]
{prog_name} get hostname <n1 n2 nN|range> [-qv] [worker options]
{prog_name} names <n1 n2 nN|range>
{prog_name} expand template <n1 n2 nN|range>
{prog_name} help
additional options (must appear after command name):
* --nosplash: Don't display program info.
* --quiet: Don't show as much output.
* --verbose: Show more output.
* --no-color: Don't display colors.
"""
def main():
sys.exit(MultiTool().execute_from_commandline(sys.argv))
def splash(fun):
@wraps(fun)
def _inner(self, *args, **kwargs):
self.splash()
return fun(self, *args, **kwargs)
return _inner
def using_cluster(fun):
@wraps(fun)
def _inner(self, *argv, **kwargs):
return fun(self, self.cluster_from_argv(argv), **kwargs)
return _inner
def using_cluster_and_sig(fun):
@wraps(fun)
def _inner(self, *argv, **kwargs):
p, cluster = self._cluster_from_argv(argv)
sig = self._find_sig_argument(p)
return fun(self, cluster, sig, **kwargs)
return _inner
class TermLogger:
splash_text = 'celery multi v{version}'
splash_context = {'version': VERSION_BANNER}
#: Final exit code.
retcode = 0
def setup_terminal(self, stdout, stderr,
nosplash=False, quiet=False, verbose=False,
no_color=False, **kwargs):
self.stdout = stdout or sys.stdout
self.stderr = stderr or sys.stderr
self.nosplash = nosplash
self.quiet = quiet
self.verbose = verbose
self.no_color = no_color
def ok(self, m, newline=True, file=None):
self.say(m, newline=newline, file=file)
return EX_OK
def say(self, m, newline=True, file=None):
print(m, file=file or self.stdout, end='\n' if newline else '')
def carp(self, m, newline=True, file=None):
return self.say(m, newline, file or self.stderr)
def error(self, msg=None):
if msg:
self.carp(msg)
self.usage()
return EX_FAILURE
def info(self, msg, newline=True):
if self.verbose:
self.note(msg, newline=newline)
def note(self, msg, newline=True):
if not self.quiet:
self.say(str(msg), newline=newline)
@splash
def usage(self):
self.say(USAGE.format(prog_name=self.prog_name))
def splash(self):
if not self.nosplash:
self.note(self.colored.cyan(
self.splash_text.format(**self.splash_context)))
@cached_property
def colored(self):
return term.colored(enabled=not self.no_color)
[docs]class MultiTool(TermLogger):
"""The ``celery multi`` program."""
MultiParser = MultiParser
OptionParser = NamespacedOptionParser
reserved_options = [
('--nosplash', 'nosplash'),
('--quiet', 'quiet'),
('-q', 'quiet'),
('--verbose', 'verbose'),
('--no-color', 'no_color'),
]
def __init__(self, env=None, cmd=None,
fh=None, stdout=None, stderr=None, **kwargs):
# fh is an old alias to stdout.
self.env = env
self.cmd = cmd
self.setup_terminal(stdout or fh, stderr, **kwargs)
self.fh = self.stdout
self.prog_name = 'celery multi'
self.commands = {
'start': self.start,
'show': self.show,
'stop': self.stop,
'stopwait': self.stopwait,
'stop_verify': self.stopwait, # compat alias
'restart': self.restart,
'kill': self.kill,
'names': self.names,
'expand': self.expand,
'get': self.get,
'help': self.help,
}
[docs] def execute_from_commandline(self, argv, cmd=None):
# Reserve the --nosplash|--quiet|-q/--verbose options.
argv = self._handle_reserved_options(argv)
self.cmd = cmd if cmd is not None else self.cmd
self.prog_name = os.path.basename(argv.pop(0))
if not self.validate_arguments(argv):
return self.error()
return self.call_command(argv[0], argv[1:])
[docs] def call_command(self, command, argv):
try:
return self.commands[command](*argv) or EX_OK
except KeyError:
return self.error(f'Invalid command: {command}')
def _handle_reserved_options(self, argv):
argv = list(argv) # don't modify callers argv.
for arg, attr in self.reserved_options:
if arg in argv:
setattr(self, attr, bool(argv.pop(argv.index(arg))))
return argv
[docs] @splash
@using_cluster
def start(self, cluster):
self.note('> Starting nodes...')
return int(any(cluster.start()))
[docs] @splash
@using_cluster_and_sig
def stop(self, cluster, sig, **kwargs):
return cluster.stop(sig=sig, **kwargs)
[docs] @splash
@using_cluster_and_sig
def stopwait(self, cluster, sig, **kwargs):
return cluster.stopwait(sig=sig, **kwargs)
stop_verify = stopwait # compat
[docs] @splash
@using_cluster_and_sig
def restart(self, cluster, sig, **kwargs):
return int(any(cluster.restart(sig=sig, **kwargs)))
[docs] def get(self, wanted, *argv):
try:
node = self.cluster_from_argv(argv).find(wanted)
except KeyError:
return EX_FAILURE
else:
return self.ok(' '.join(node.argv))
[docs] @using_cluster
def show(self, cluster):
return self.ok('\n'.join(
' '.join(node.argv_with_executable)
for node in cluster
))
[docs] def expand(self, template, *argv):
return self.ok('\n'.join(
node.expander(template)
for node in self.cluster_from_argv(argv)
))
def _find_sig_argument(self, p, default=signal.SIGTERM):
args = p.args[len(p.values):]
for arg in reversed(args):
if len(arg) == 2 and arg[0] == '-':
try:
return int(arg[1])
except ValueError:
pass
if arg[0] == '-':
try:
return signals.signum(arg[1:])
except (AttributeError, TypeError):
pass
return default
def _nodes_from_argv(self, argv, cmd=None):
cmd = cmd if cmd is not None else self.cmd
p = self.OptionParser(argv)
p.parse()
return p, self.MultiParser(cmd=cmd).parse(p)
[docs] def cluster_from_argv(self, argv, cmd=None):
_, cluster = self._cluster_from_argv(argv, cmd=cmd)
return cluster
def _cluster_from_argv(self, argv, cmd=None):
p, nodes = self._nodes_from_argv(argv, cmd=cmd)
return p, self.Cluster(list(nodes), cmd=cmd)
[docs] def Cluster(self, nodes, cmd=None):
return Cluster(
nodes,
cmd=cmd,
env=self.env,
on_stopping_preamble=self.on_stopping_preamble,
on_send_signal=self.on_send_signal,
on_still_waiting_for=self.on_still_waiting_for,
on_still_waiting_progress=self.on_still_waiting_progress,
on_still_waiting_end=self.on_still_waiting_end,
on_node_start=self.on_node_start,
on_node_restart=self.on_node_restart,
on_node_shutdown_ok=self.on_node_shutdown_ok,
on_node_status=self.on_node_status,
on_node_signal_dead=self.on_node_signal_dead,
on_node_signal=self.on_node_signal,
on_node_down=self.on_node_down,
on_child_spawn=self.on_child_spawn,
on_child_signalled=self.on_child_signalled,
on_child_failure=self.on_child_failure,
)
[docs] def on_send_signal(self, node, sig):
self.note('\t> {0.name}: {1} -> {0.pid}'.format(node, sig))
[docs] def on_still_waiting_for(self, nodes):
num_left = len(nodes)
if num_left:
self.note(self.colored.blue(
'> Waiting for {} {} -> {}...'.format(
num_left, pluralize(num_left, 'node'),
', '.join(str(node.pid) for node in nodes)),
), newline=False)
[docs] def on_node_signal_dead(self, node):
self.note(
'Could not signal {0.name} ({0.pid}): No such process'.format(
node))
[docs] def on_node_restart(self, node):
self.note(self.colored.blue(
f'> Restarting node {node.name}: '), newline=False)
[docs] def on_node_signal(self, node, sig):
self.note('Sending {sig} to node {0.name} ({0.pid})'.format(
node, sig=sig))
[docs] def on_child_signalled(self, node, signum):
self.note(f'* Child was terminated by signal {signum}')
[docs] def on_child_failure(self, node, retcode):
self.note(f'* Child terminated with exit code {retcode}')
@cached_property
def OK(self):
return str(self.colored.green('OK'))
@cached_property
def FAILED(self):
return str(self.colored.red('FAILED'))
@cached_property
def DOWN(self):
return str(self.colored.magenta('DOWN'))
@click.command(
cls=CeleryCommand,
context_settings={
'allow_extra_args': True,
'ignore_unknown_options': True
}
)
@click.pass_context
@handle_preload_options
def multi(ctx):
"""Start multiple worker instances."""
cmd = MultiTool(quiet=ctx.obj.quiet, no_color=ctx.obj.no_color)
# In 4.x, celery multi ignores the global --app option.
# Since in 5.0 the --app option is global only we
# rearrange the arguments so that the MultiTool will parse them correctly.
args = sys.argv[1:]
args = args[args.index('multi'):] + args[:args.index('multi')]
return cmd.execute_from_commandline(args)
