Import processutils from oslo-incubator.

1 files changed, 498 insertions, 0 deletions

diff --git a/os_net_config/openstack/common/gettextutils.py b/os_net_config/openstack/common/gettextutils.py
new file mode 100644
index 0000000..8e0081f
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+++ b/os_net_config/openstack/common/gettextutils.py
@@ -0,0 +1,498 @@
+# Copyright 2012 Red Hat, Inc.
+# Copyright 2013 IBM Corp.
+# All Rights Reserved.
+#
+#    Licensed 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, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+gettext for openstack-common modules.
+
+Usual usage in an openstack.common module:
+
+    from os_net_config.openstack.common.gettextutils import _
+"""
+
+import copy
+import functools
+import gettext
+import locale
+from logging import handlers
+import os
+
+from babel import localedata
+import six
+
+_AVAILABLE_LANGUAGES = {}
+
+# FIXME(dhellmann): Remove this when moving to oslo.i18n.
+USE_LAZY = False
+
+
+class TranslatorFactory(object):
+    """Create translator functions
+    """
+
+    def __init__(self, domain, lazy=False, localedir=None):
+        """Establish a set of translation functions for the domain.
+
+        :param domain: Name of translation domain,
+                       specifying a message catalog.
+        :type domain: str
+        :param lazy: Delays translation until a message is emitted.
+                     Defaults to False.
+        :type lazy: Boolean
+        :param localedir: Directory with translation catalogs.
+        :type localedir: str
+        """
+        self.domain = domain
+        self.lazy = lazy
+        if localedir is None:
+            localedir = os.environ.get(domain.upper() + '_LOCALEDIR')
+        self.localedir = localedir
+
+    def _make_translation_func(self, domain=None):
+        """Return a new translation function ready for use.
+
+        Takes into account whether or not lazy translation is being
+        done.
+
+        The domain can be specified to override the default from the
+        factory, but the localedir from the factory is always used
+        because we assume the log-level translation catalogs are
+        installed in the same directory as the main application
+        catalog.
+
+        """
+        if domain is None:
+            domain = self.domain
+        if self.lazy:
+            return functools.partial(Message, domain=domain)
+        t = gettext.translation(
+            domain,
+            localedir=self.localedir,
+            fallback=True,
+        )
+        if six.PY3:
+            return t.gettext
+        return t.ugettext
+
+    @property
+    def primary(self):
+        "The default translation function."
+        return self._make_translation_func()
+
+    def _make_log_translation_func(self, level):
+        return self._make_translation_func(self.domain + '-log-' + level)
+
+    @property
+    def log_info(self):
+        "Translate info-level log messages."
+        return self._make_log_translation_func('info')
+
+    @property
+    def log_warning(self):
+        "Translate warning-level log messages."
+        return self._make_log_translation_func('warning')
+
+    @property
+    def log_error(self):
+        "Translate error-level log messages."
+        return self._make_log_translation_func('error')
+
+    @property
+    def log_critical(self):
+        "Translate critical-level log messages."
+        return self._make_log_translation_func('critical')
+
+
+# NOTE(dhellmann): When this module moves out of the incubator into
+# oslo.i18n, these global variables can be moved to an integration
+# module within each application.
+
+# Create the global translation functions.
+_translators = TranslatorFactory('os_net_config')
+
+# The primary translation function using the well-known name "_"
+_ = _translators.primary
+
+# Translators for log levels.
+#
+# The abbreviated names are meant to reflect the usual use of a short
+# name like '_'. The "L" is for "log" and the other letter comes from
+# the level.
+_LI = _translators.log_info
+_LW = _translators.log_warning
+_LE = _translators.log_error
+_LC = _translators.log_critical
+
+# NOTE(dhellmann): End of globals that will move to the application's
+# integration module.
+
+
+def enable_lazy():
+    """Convenience function for configuring _() to use lazy gettext
+
+    Call this at the start of execution to enable the gettextutils._
+    function to use lazy gettext functionality. This is useful if
+    your project is importing _ directly instead of using the
+    gettextutils.install() way of importing the _ function.
+    """
+    # FIXME(dhellmann): This function will be removed in oslo.i18n,
+    # because the TranslatorFactory makes it superfluous.
+    global _, _LI, _LW, _LE, _LC, USE_LAZY
+    tf = TranslatorFactory('os_net_config', lazy=True)
+    _ = tf.primary
+    _LI = tf.log_info
+    _LW = tf.log_warning
+    _LE = tf.log_error
+    _LC = tf.log_critical
+    USE_LAZY = True
+
+
+def install(domain, lazy=False):
+    """Install a _() function using the given translation domain.
+
+    Given a translation domain, install a _() function using gettext's
+    install() function.
+
+    The main difference from gettext.install() is that we allow
+    overriding the default localedir (e.g. /usr/share/locale) using
+    a translation-domain-specific environment variable (e.g.
+    NOVA_LOCALEDIR).
+
+    :param domain: the translation domain
+    :param lazy: indicates whether or not to install the lazy _() function.
+                 The lazy _() introduces a way to do deferred translation
+                 of messages by installing a _ that builds Message objects,
+                 instead of strings, which can then be lazily translated into
+                 any available locale.
+    """
+    if lazy:
+        from six import moves
+        tf = TranslatorFactory(domain, lazy=True)
+        moves.builtins.__dict__['_'] = tf.primary
+    else:
+        localedir = '%s_LOCALEDIR' % domain.upper()
+        if six.PY3:
+            gettext.install(domain,
+                            localedir=os.environ.get(localedir))
+        else:
+            gettext.install(domain,
+                            localedir=os.environ.get(localedir),
+                            unicode=True)
+
+
+class Message(six.text_type):
+    """A Message object is a unicode object that can be translated.
+
+    Translation of Message is done explicitly using the translate() method.
+    For all non-translation intents and purposes, a Message is simply unicode,
+    and can be treated as such.
+    """
+
+    def __new__(cls, msgid, msgtext=None, params=None,
+                domain='os_net_config', *args):
+        """Create a new Message object.
+
+        In order for translation to work gettext requires a message ID, this
+        msgid will be used as the base unicode text. It is also possible
+        for the msgid and the base unicode text to be different by passing
+        the msgtext parameter.
+        """
+        # If the base msgtext is not given, we use the default translation
+        # of the msgid (which is in English) just in case the system locale is
+        # not English, so that the base text will be in that locale by default.
+        if not msgtext:
+            msgtext = Message._translate_msgid(msgid, domain)
+        # We want to initialize the parent unicode with the actual object that
+        # would have been plain unicode if 'Message' was not enabled.
+        msg = super(Message, cls).__new__(cls, msgtext)
+        msg.msgid = msgid
+        msg.domain = domain
+        msg.params = params
+        return msg
+
+    def translate(self, desired_locale=None):
+        """Translate this message to the desired locale.
+
+        :param desired_locale: The desired locale to translate the message to,
+                               if no locale is provided the message will be
+                               translated to the system's default locale.
+
+        :returns: the translated message in unicode
+        """
+
+        translated_message = Message._translate_msgid(self.msgid,
+                                                      self.domain,
+                                                      desired_locale)
+        if self.params is None:
+            # No need for more translation
+            return translated_message
+
+        # This Message object may have been formatted with one or more
+        # Message objects as substitution arguments, given either as a single
+        # argument, part of a tuple, or as one or more values in a dictionary.
+        # When translating this Message we need to translate those Messages too
+        translated_params = _translate_args(self.params, desired_locale)
+
+        translated_message = translated_message % translated_params
+
+        return translated_message
+
+    @staticmethod
+    def _translate_msgid(msgid, domain, desired_locale=None):
+        if not desired_locale:
+            system_locale = locale.getdefaultlocale()
+            # If the system locale is not available to the runtime use English
+            if not system_locale[0]:
+                desired_locale = 'en_US'
+            else:
+                desired_locale = system_locale[0]
+
+        locale_dir = os.environ.get(domain.upper() + '_LOCALEDIR')
+        lang = gettext.translation(domain,
+                                   localedir=locale_dir,
+                                   languages=[desired_locale],
+                                   fallback=True)
+        if six.PY3:
+            translator = lang.gettext
+        else:
+            translator = lang.ugettext
+
+        translated_message = translator(msgid)
+        return translated_message
+
+    def __mod__(self, other):
+        # When we mod a Message we want the actual operation to be performed
+        # by the parent class (i.e. unicode()), the only thing  we do here is
+        # save the original msgid and the parameters in case of a translation
+        params = self._sanitize_mod_params(other)
+        unicode_mod = super(Message, self).__mod__(params)
+        modded = Message(self.msgid,
+                         msgtext=unicode_mod,
+                         params=params,
+                         domain=self.domain)
+        return modded
+
+    def _sanitize_mod_params(self, other):
+        """Sanitize the object being modded with this Message.
+
+        - Add support for modding 'None' so translation supports it
+        - Trim the modded object, which can be a large dictionary, to only
+        those keys that would actually be used in a translation
+        - Snapshot the object being modded, in case the message is
+        translated, it will be used as it was when the Message was created
+        """
+        if other is None:
+            params = (other,)
+        elif isinstance(other, dict):
+            # Merge the dictionaries
+            # Copy each item in case one does not support deep copy.
+            params = {}
+            if isinstance(self.params, dict):
+                for key, val in self.params.items():
+                    params[key] = self._copy_param(val)
+            for key, val in other.items():
+                params[key] = self._copy_param(val)
+        else:
+            params = self._copy_param(other)
+        return params
+
+    def _copy_param(self, param):
+        try:
+            return copy.deepcopy(param)
+        except Exception:
+            # Fallback to casting to unicode this will handle the
+            # python code-like objects that can't be deep-copied
+            return six.text_type(param)
+
+    def __add__(self, other):
+        msg = _('Message objects do not support addition.')
+        raise TypeError(msg)
+
+    def __radd__(self, other):
+        return self.__add__(other)
+
+    if six.PY2:
+        def __str__(self):
+            # NOTE(luisg): Logging in python 2.6 tries to str() log records,
+            # and it expects specifically a UnicodeError in order to proceed.
+            msg = _('Message objects do not support str() because they may '
+                    'contain non-ascii characters. '
+                    'Please use unicode() or translate() instead.')
+            raise UnicodeError(msg)
+
+
+def get_available_languages(domain):
+    """Lists the available languages for the given translation domain.
+
+    :param domain: the domain to get languages for
+    """
+    if domain in _AVAILABLE_LANGUAGES:
+        return copy.copy(_AVAILABLE_LANGUAGES[domain])
+
+    localedir = '%s_LOCALEDIR' % domain.upper()
+    find = lambda x: gettext.find(domain,
+                                  localedir=os.environ.get(localedir),
+                                  languages=[x])
+
+    # NOTE(mrodden): en_US should always be available (and first in case
+    # order matters) since our in-line message strings are en_US
+    language_list = ['en_US']
+    # NOTE(luisg): Babel <1.0 used a function called list(), which was
+    # renamed to locale_identifiers() in >=1.0, the requirements master list
+    # requires >=0.9.6, uncapped, so defensively work with both. We can remove
+    # this check when the master list updates to >=1.0, and update all projects
+    list_identifiers = (getattr(localedata, 'list', None) or
+                        getattr(localedata, 'locale_identifiers'))
+    locale_identifiers = list_identifiers()
+
+    for i in locale_identifiers:
+        if find(i) is not None:
+            language_list.append(i)
+
+    # NOTE(luisg): Babel>=1.0,<1.3 has a bug where some OpenStack supported
+    # locales (e.g. 'zh_CN', and 'zh_TW') aren't supported even though they
+    # are perfectly legitimate locales:
+    #     https://github.com/mitsuhiko/babel/issues/37
+    # In Babel 1.3 they fixed the bug and they support these locales, but
+    # they are still not explicitly "listed" by locale_identifiers().
+    # That is  why we add the locales here explicitly if necessary so that
+    # they are listed as supported.
+    aliases = {'zh': 'zh_CN',
+               'zh_Hant_HK': 'zh_HK',
+               'zh_Hant': 'zh_TW',
+               'fil': 'tl_PH'}
+    for (locale, alias) in six.iteritems(aliases):
+        if locale in language_list and alias not in language_list:
+            language_list.append(alias)
+
+    _AVAILABLE_LANGUAGES[domain] = language_list
+    return copy.copy(language_list)
+
+
+def translate(obj, desired_locale=None):
+    """Gets the translated unicode representation of the given object.
+
+    If the object is not translatable it is returned as-is.
+    If the locale is None the object is translated to the system locale.
+
+    :param obj: the object to translate
+    :param desired_locale: the locale to translate the message to, if None the
+                           default system locale will be used
+    :returns: the translated object in unicode, or the original object if
+              it could not be translated
+    """
+    message = obj
+    if not isinstance(message, Message):
+        # If the object to translate is not already translatable,
+        # let's first get its unicode representation
+        message = six.text_type(obj)
+    if isinstance(message, Message):
+        # Even after unicoding() we still need to check if we are
+        # running with translatable unicode before translating
+        return message.translate(desired_locale)
+    return obj
+
+
+def _translate_args(args, desired_locale=None):
+    """Translates all the translatable elements of the given arguments object.
+
+    This method is used for translating the translatable values in method
+    arguments which include values of tuples or dictionaries.
+    If the object is not a tuple or a dictionary the object itself is
+    translated if it is translatable.
+
+    If the locale is None the object is translated to the system locale.
+
+    :param args: the args to translate
+    :param desired_locale: the locale to translate the args to, if None the
+                           default system locale will be used
+    :returns: a new args object with the translated contents of the original
+    """
+    if isinstance(args, tuple):
+        return tuple(translate(v, desired_locale) for v in args)
+    if isinstance(args, dict):
+        translated_dict = {}
+        for (k, v) in six.iteritems(args):
+            translated_v = translate(v, desired_locale)
+            translated_dict[k] = translated_v
+        return translated_dict
+    return translate(args, desired_locale)
+
+
+class TranslationHandler(handlers.MemoryHandler):
+    """Handler that translates records before logging them.
+
+    The TranslationHandler takes a locale and a target logging.Handler object
+    to forward LogRecord objects to after translating them. This handler
+    depends on Message objects being logged, instead of regular strings.
+
+    The handler can be configured declaratively in the logging.conf as follows:
+
+        [handlers]
+        keys = translatedlog, translator
+
+        [handler_translatedlog]
+        class = handlers.WatchedFileHandler
+        args = ('/var/log/api-localized.log',)
+        formatter = context
+
+        [handler_translator]
+        class = openstack.common.log.TranslationHandler
+        target = translatedlog
+        args = ('zh_CN',)
+
+    If the specified locale is not available in the system, the handler will
+    log in the default locale.
+    """
+
+    def __init__(self, locale=None, target=None):
+        """Initialize a TranslationHandler
+
+        :param locale: locale to use for translating messages
+        :param target: logging.Handler object to forward
+                       LogRecord objects to after translation
+        """
+        # NOTE(luisg): In order to allow this handler to be a wrapper for
+        # other handlers, such as a FileHandler, and still be able to
+        # configure it using logging.conf, this handler has to extend
+        # MemoryHandler because only the MemoryHandlers' logging.conf
+        # parsing is implemented such that it accepts a target handler.
+        handlers.MemoryHandler.__init__(self, capacity=0, target=target)
+        self.locale = locale
+
+    def setFormatter(self, fmt):
+        self.target.setFormatter(fmt)
+
+    def emit(self, record):
+        # We save the message from the original record to restore it
+        # after translation, so other handlers are not affected by this
+        original_msg = record.msg
+        original_args = record.args
+
+        try:
+            self._translate_and_log_record(record)
+        finally:
+            record.msg = original_msg
+            record.args = original_args
+
+    def _translate_and_log_record(self, record):
+        record.msg = translate(record.msg, self.locale)
+
+        # In addition to translating the message, we also need to translate
+        # arguments that were passed to the log method that were not part
+        # of the main message e.g., log.info(_('Some message %s'), this_one))
+        record.args = _translate_args(record.args, self.locale)
+
+        self.target.emit(record)