celery/celery/bin/base.py

# -*- coding: utf-8 -*-
"""

.. _preload-options:

Preload Options
---------------

These options are supported by all commands,
and usually parsed before command-specific arguments.

.. cmdoption:: -A, --app

    app instance to use (e.g. module.attr_name)

.. cmdoption:: -b, --broker

    url to broker.  default is 'amqp://guest@localhost//'

.. cmdoption:: --loader

    name of custom loader class to use.

.. cmdoption:: --config

    Name of the configuration module

.. _daemon-options:

Daemon Options
--------------

These options are supported by commands that can detach
into the background (daemon).  They will be present
in any command that also has a `--detach` option.

.. cmdoption:: -f, --logfile

    Path to log file. If no logfile is specified, `stderr` is used.

.. cmdoption:: --pidfile

    Optional file used to store the process pid.

    The program will not start if this file already exists
    and the pid is still alive.

.. cmdoption:: --uid

    User id, or user name of the user to run as after detaching.

.. cmdoption:: --gid

    Group id, or group name of the main group to change to after
    detaching.

.. cmdoption:: --umask

    Effective umask of the process after detaching. Default is 0.

.. cmdoption:: --workdir

    Optional directory to change to after detaching.

"""
from __future__ import absolute_import, print_function

import os
import re
import socket
import sys
import warnings
import json

from collections import defaultdict
from heapq import heappush
from inspect import getargspec
from optparse import OptionParser, IndentedHelpFormatter, make_option as Option
from pprint import pformat
from types import ModuleType

import celery
from celery.exceptions import CDeprecationWarning, CPendingDeprecationWarning
from celery.five import items, string, string_t, values
from celery.platforms import (
    EX_FAILURE, EX_OK, EX_USAGE,
    maybe_patch_concurrency,
)
from celery.utils import term
from celery.utils import text
from celery.utils.imports import symbol_by_name, import_from_cwd

# always enable DeprecationWarnings, so our users can see them.
for warning in (CDeprecationWarning, CPendingDeprecationWarning):
    warnings.simplefilter('once', warning, 0)

ARGV_DISABLED = """
Unrecognized command-line arguments: {0}

Try --help?
"""

find_long_opt = re.compile(r'.+?(--.+?)(?:\s|,|$)')
find_rst_ref = re.compile(r':\w+:`(.+?)`')
find_sformat = re.compile(r'%(\w)')


class Error(Exception):
    status = EX_FAILURE

    def __init__(self, reason, status=None):
        self.reason = reason
        self.status = status if status is not None else self.status
        super(Error, self).__init__(reason, status)

    def __str__(self):
        return self.reason
    __unicode__ = __str__


class UsageError(Error):
    status = EX_USAGE


class Extensions(object):

    def __init__(self, namespace, register):
        self.names = []
        self.namespace = namespace
        self.register = register

    def add(self, cls, name):
        heappush(self.names, name)
        self.register(cls, name=name)

    def load(self):
        try:
            from pkg_resources import iter_entry_points
        except ImportError:  # pragma: no cover
            return

        for ep in iter_entry_points(self.namespace):
            sym = ':'.join([ep.module_name, ep.attrs[0]])
            try:
                cls = symbol_by_name(sym)
            except (ImportError, SyntaxError) as exc:
                warnings.warn(
                    'Cannot load extension {0!r}: {1!r}'.format(sym, exc))
            else:
                self.add(cls, ep.name)
        return self.names


class HelpFormatter(IndentedHelpFormatter):

    def format_epilog(self, epilog):
        if epilog:
            return '\n{0}\n\n'.format(epilog)
        return ''

    def format_description(self, description):
        return text.ensure_2lines(text.fill_paragraphs(
            text.dedent(description), self.width))


class Command(object):
    """Base class for command-line applications.

    :keyword app: The current app.
    :keyword get_app: Callable returning the current app if no app provided.

    """
    Error = Error
    UsageError = UsageError
    Parser = OptionParser

    #: Arg list used in help.
    args = ''

    #: Application version.
    version = celery.VERSION_BANNER

    #: If false the parser will raise an exception if positional
    #: args are provided.
    supports_args = True

    #: List of options (without preload options).
    option_list = ()

    # module Rst documentation to parse help from (if any)
    doc = None

    # Some programs (multi) does not want to load the app specified
    # (Issue #1008).
    respects_app_option = True

    #: List of options to parse before parsing other options.
    preload_options = (
        Option('-A', '--app', default=None),
        Option('-b', '--broker', default=None),
        Option('--loader', default=None),
        Option('--config', default=None),
        Option('--workdir', default=None, dest='working_directory'),
        Option('--no-color', '-C', action='store_true', default=None),
        Option('--quiet', '-q', action='store_true'),
    )

    #: Enable if the application should support config from the cmdline.
    enable_config_from_cmdline = False

    #: Default configuration namespace.
    namespace = 'celery'

    #: Text to print at end of --help
    epilog = None

    #: Text to print in --help before option list.
    description = ''

    #: Set to true if this command doesn't have subcommands
    leaf = True

    # used by :meth:`say_remote_command_reply`.
    show_body = True
    # used by :meth:`say_chat`.
    show_reply = True

    prog_name = 'celery'

    def __init__(self, app=None, get_app=None, no_color=False,
                 stdout=None, stderr=None, quiet=False, on_error=None,
                 on_usage_error=None):
        self.app = app
        self.get_app = get_app or self._get_default_app
        self.stdout = stdout or sys.stdout
        self.stderr = stderr or sys.stderr
        self.no_color = no_color
        self.colored = term.colored(enabled=not self.no_color)
        self.quiet = quiet
        if not self.description:
            self.description = self.__doc__
        if on_error:
            self.on_error = on_error
        if on_usage_error:
            self.on_usage_error = on_usage_error

    def run(self, *args, **options):
        """This is the body of the command called by :meth:`handle_argv`."""
        raise NotImplementedError('subclass responsibility')

    def on_error(self, exc):
        self.error(self.colored.red('Error: {0}'.format(exc)))

    def on_usage_error(self, exc):
        self.handle_error(exc)

    def on_concurrency_setup(self):
        pass

    def __call__(self, *args, **kwargs):
        self.verify_args(args)
        try:
            ret = self.run(*args, **kwargs)
            return ret if ret is not None else EX_OK
        except self.UsageError as exc:
            self.on_usage_error(exc)
            return exc.status
        except self.Error as exc:
            self.on_error(exc)
            return exc.status

    def verify_args(self, given, _index=0):
        S = getargspec(self.run)
        _index = 1 if S.args and S.args[0] == 'self' else _index
        required = S.args[_index:-len(S.defaults) if S.defaults else None]
        missing = required[len(given):]
        if missing:
            raise self.UsageError('Missing required {0}: {1}'.format(
                text.pluralize(len(missing), 'argument'),
                ', '.join(missing)
            ))

    def execute_from_commandline(self, argv=None):
        """Execute application from command-line.

        :keyword argv: The list of command-line arguments.
                       Defaults to ``sys.argv``.

        """
        if argv is None:
            argv = list(sys.argv)
        # Should we load any special concurrency environment?
        self.maybe_patch_concurrency(argv)
        self.on_concurrency_setup()

        # Dump version and exit if '--version' arg set.
        self.early_version(argv)
        argv = self.setup_app_from_commandline(argv)
        self.prog_name = os.path.basename(argv[0])
        return self.handle_argv(self.prog_name, argv[1:])

    def run_from_argv(self, prog_name, argv=None, command=None):
        return self.handle_argv(prog_name,
                                sys.argv if argv is None else argv, command)

    def maybe_patch_concurrency(self, argv=None):
        argv = argv or sys.argv
        pool_option = self.with_pool_option(argv)
        if pool_option:
            maybe_patch_concurrency(argv, *pool_option)
            short_opts, long_opts = pool_option

    def usage(self, command):
        return '%prog {0} [options] {self.args}'.format(command, self=self)

    def get_options(self):
        """Get supported command-line options."""
        return self.option_list

    def expanduser(self, value):
        if isinstance(value, string_t):
            return os.path.expanduser(value)
        return value

    def handle_argv(self, prog_name, argv, command=None):
        """Parses command-line arguments from ``argv`` and dispatches
        to :meth:`run`.

        :param prog_name: The program name (``argv[0]``).
        :param argv: Command arguments.

        Exits with an error message if :attr:`supports_args` is disabled
        and ``argv`` contains positional arguments.

        """
        options, args = self.prepare_args(
            *self.parse_options(prog_name, argv, command))
        return self(*args, **options)

    def prepare_args(self, options, args):
        if options:
            options = dict((k, self.expanduser(v))
                           for k, v in items(vars(options))
                           if not k.startswith('_'))
        args = [self.expanduser(arg) for arg in args]
        self.check_args(args)
        return options, args

    def check_args(self, args):
        if not self.supports_args and args:
            self.die(ARGV_DISABLED.format(', '.join(args)), EX_USAGE)

    def error(self, s):
        self.out(s, fh=self.stderr)

    def out(self, s, fh=None):
        print(s, file=fh or self.stdout)

    def die(self, msg, status=EX_FAILURE):
        self.error(msg)
        sys.exit(status)

    def early_version(self, argv):
        if '--version' in argv:
            print(self.version, file=self.stdout)
            sys.exit(0)

    def parse_options(self, prog_name, arguments, command=None):
        """Parse the available options."""
        # Don't want to load configuration to just print the version,
        # so we handle --version manually here.
        self.parser = self.create_parser(prog_name, command)
        return self.parser.parse_args(arguments)

    def create_parser(self, prog_name, command=None):
        return self.prepare_parser(self.Parser(
            prog=prog_name,
            usage=self.usage(command),
            version=self.version,
            epilog=self.epilog,
            formatter=HelpFormatter(),
            description=self.description,
            option_list=(self.preload_options + self.get_options()),
        ))

    def prepare_parser(self, parser):
        docs = [self.parse_doc(doc) for doc in (self.doc, __doc__) if doc]
        for doc in docs:
            for long_opt, help in items(doc):
                option = parser.get_option(long_opt)
                if option is not None:
                    option.help = ' '.join(help).format(default=option.default)
        return parser

    def setup_app_from_commandline(self, argv):
        preload_options = self.parse_preload_options(argv)
        quiet = preload_options.get('quiet')
        if quiet is not None:
            self.quiet = quiet
        self.colored.enabled = \
            not preload_options.get('no_color', self.no_color)
        workdir = preload_options.get('working_directory')
        if workdir:
            os.chdir(workdir)
        app = (preload_options.get('app') or
               os.environ.get('CELERY_APP') or
               self.app)
        preload_loader = preload_options.get('loader')
        if preload_loader:
            # Default app takes loader from this env (Issue #1066).
            os.environ['CELERY_LOADER'] = preload_loader
        loader = (preload_loader,
                  os.environ.get('CELERY_LOADER') or
                  'default')
        broker = preload_options.get('broker', None)
        if broker:
            os.environ['CELERY_BROKER_URL'] = broker
        config = preload_options.get('config')
        if config:
            os.environ['CELERY_CONFIG_MODULE'] = config
        if self.respects_app_option:
            if app and self.respects_app_option:
                self.app = self.find_app(app)
            elif self.app is None:
                self.app = self.get_app(loader=loader)
            if self.enable_config_from_cmdline:
                argv = self.process_cmdline_config(argv)
        else:
            self.app = celery.Celery()
        return argv

    def find_app(self, app):
        try:
            sym = self.symbol_by_name(app)
        except AttributeError:
            # last part was not an attribute, but a module
            sym = import_from_cwd(app)
        if isinstance(sym, ModuleType):
            try:
                return sym.celery
            except AttributeError:
                if getattr(sym, '__path__', None):
                    try:
                        return self.find_app('{0}.celery:'.format(
                                             app.replace(':', '')))
                    except ImportError:
                        pass
                from celery.app.base import Celery
                for suspect in values(vars(sym)):
                    if isinstance(suspect, Celery):
                        return suspect
                raise
        return sym

    def symbol_by_name(self, name):
        return symbol_by_name(name, imp=import_from_cwd)
    get_cls_by_name = symbol_by_name  # XXX compat

    def process_cmdline_config(self, argv):
        try:
            cargs_start = argv.index('--')
        except ValueError:
            return argv
        argv, cargs = argv[:cargs_start], argv[cargs_start + 1:]
        self.app.config_from_cmdline(cargs, namespace=self.namespace)
        return argv

    def parse_preload_options(self, args):
        acc = {}
        opts = {}
        for opt in self.preload_options:
            for t in (opt._long_opts, opt._short_opts):
                opts.update(dict(zip(t, [opt] * len(t))))
        index = 0
        length = len(args)
        while index < length:
            arg = args[index]
            if arg.startswith('--'):
                if '=' in arg:
                    key, value = arg.split('=', 1)
                    opt = opts.get(key)
                    if opt:
                        acc[opt.dest] = value
                else:
                    opt = opts.get(arg)
                    if opt and opt.action == 'store_true':
                        acc[opt.dest] = True
            elif arg.startswith('-'):
                opt = opts.get(arg)
                if opt:
                    if opt.takes_value():
                        acc[opt.dest] = args[index + 1]
                        index += 1
                    elif opt.action == 'store_true':
                        acc[opt.dest] = True
            index += 1
        return acc

    def parse_doc(self, doc):
        options, in_option = defaultdict(list), None
        for line in doc.splitlines():
            if line.startswith('.. cmdoption::'):
                m = find_long_opt.match(line)
                if m:
                    in_option = m.groups()[0].strip()
                assert in_option, 'missing long opt'
            elif in_option and line.startswith(' ' * 4):
                options[in_option].append(
                    find_rst_ref.sub(r'\1', line.strip()).replace('`', ''))
        return options

    def with_pool_option(self, argv):
        """Returns tuple of ``(short_opts, long_opts)`` if the command
        supports a pool argument, and used to monkey patch eventlet/gevent
        environments as early as possible.

        E.g::
              has_pool_option = (['-P'], ['--pool'])
        """
        pass

    def simple_format(self, s, match=find_sformat, expand=r'\1', **keys):
        if s:
            host = socket.gethostname()
            name, _, domain = host.partition('.')
            keys = dict({'%': '%', 'h': host, 'n': name, 'd': domain}, **keys)
            return match.sub(lambda m: keys[m.expand(expand)], s)
        return s

    def _get_default_app(self, *args, **kwargs):
        from celery._state import get_current_app
        return get_current_app()  # omit proxy

    def pretty_list(self, n):
        c = self.colored
        if not n:
            return '- empty -'
        return '\n'.join(
            str(c.reset(c.white('*'), ' {0}'.format(item))) for item in n
        )

    def pretty_dict_ok_error(self, n):
        c = self.colored
        try:
            return (c.green('OK'),
                    text.indent(self.pretty(n['ok'])[1], 4))
        except KeyError:
            pass
        return (c.red('ERROR'),
                text.indent(self.pretty(n['error'])[1], 4))

    def say_remote_command_reply(self, replies):
        c = self.colored
        node = next(iter(replies))  # <-- take first.
        reply = replies[node]
        status, preply = self.pretty(reply)
        self.say_chat('->', c.cyan(node, ': ') + status,
                      text.indent(preply, 4) if self.show_reply else '')

    def pretty(self, n):
        OK = str(self.colored.green('OK'))
        if isinstance(n, list):
            return OK, self.pretty_list(n)
        if isinstance(n, dict):
            if 'ok' in n or 'error' in n:
                return self.pretty_dict_ok_error(n)
            else:
                return OK, json.dumps(n, sort_keys=True, indent=4)
        if isinstance(n, string_t):
            return OK, string(n)
        return OK, pformat(n)

    def say_chat(self, direction, title, body=''):
        c = self.colored
        if direction == '<-' and self.quiet:
            return
        dirstr = not self.quiet and c.bold(c.white(direction), ' ') or ''
        self.out(c.reset(dirstr, title))
        if body and self.show_body:
            self.out(body)


def daemon_options(default_pidfile=None, default_logfile=None):
    return (
        Option('-f', '--logfile', default=default_logfile),
        Option('--pidfile', default=default_pidfile),
        Option('--uid', default=None),
        Option('--gid', default=None),
        Option('--umask', default=0, type='int'),
    )