Source code for score.geoip._init

# Copyright © 2015,2016 STRG.AT GmbH, Vienna, Austria
#
# This file is part of the The SCORE Framework.
#
# The SCORE Framework and all its parts are free software: you can redistribute
# them and/or modify them under the terms of the GNU Lesser General Public
# License version 3 as published by the Free Software Foundation which is in the
# file named COPYING.LESSER.txt.
#
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# PARTICULAR PURPOSE. For more details see the GNU Lesser General Public
# License.
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from score.init import parse_object, ConfiguredModule
import re
import dns.resolver


defaults = {
    'backend': 'score.geoip.backend.IpApi()'
}


def init(confdict, kvcache=None):
    """
    Initializes this module acoording to :ref:`our module initialization
    guidelines <module_initialization>` with the following configuration keys:

    :confkey:`backend` :confdefault:`score.geoip.backend.IpApi()`
        The backend object configuration that will be passed to
        :func:`score.init.parse_object`. Will use the `ip-api`_ backend by
        default, which is free for non-commercial projects.

        .. _ip-api: http://ip-api.com/
    """
    conf = defaults.copy()
    conf.update(confdict)
    backend = parse_object(conf, 'backend')
    cache_container = None
    if kvcache is not None:
        kvcache.register_generator('score.geoip', backend.__getitem__)
        cache_container = kvcache['score.geoip']
    return ConfiguredGeoipModule(backend, cache_container)


class ConfiguredGeoipModule(ConfiguredModule):
    """
    This module's :class:`configuration object
    <score.init.ConfiguredModule>`.
    """

    def __init__(self, backend, cache_container=None):
        super().__init__(__package__)
        self.backend = backend
        self.cache_container = cache_container

    def __getitem__(self, ip):
        if not re.match(r'^\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}$', ip):
            try:
                ip = str(dns.resolver.query(ip)[0])
            except dns.resolver.NXDOMAIN:
                raise ValueError('Invalid IP ' + ip)
        if self.cache_container is None:
            return self.backend[ip]
        return self.cache_container[ip]


class IPNotFound(Exception):
    """
    Thrown if IP lookup failed.
    """

    def __init__(self, ip, cause=None):
        self.ip = ip
        self.cause = cause