py-i2phosts/pyi2phosts/lib/utils.py

import sys
import logging
import configobj
import validate
import hashlib
import base64

from logging import handlers

def get_logger(filename=None, log_level='debug'):
    """ Prepare logger instance for our scripts """

    # workaround for django
    if hasattr(logging, "web_logger"):
        return logging.web_logger

    LEVELS = {
        'debug': logging.DEBUG,
        'info': logging.INFO,
        'warning': logging.WARNING,
        'error': logging.ERROR,
        'critical': logging.CRITICAL
    }
    level = LEVELS.get(log_level, logging.NOTSET)
    format = '%(asctime)s %(module)s:%(lineno)d[%(process)d] %(levelname)s: %(message)s'
    formatter = logging.Formatter(format)
    logger = logging.getLogger(__name__)
    logger.setLevel(level)
    if filename:
        handler = logging.handlers.WatchedFileHandler(filename)
    else:
        handler = logging.StreamHandler()
    handler.setFormatter(formatter)
    logger.addHandler(handler)

    # workaround for django
    logging.web_logger = logger

    return logger


def validate_config(config):
    """ Validate configobj config """
    validator = validate.Validator()
    results = config.validate(validator)
    if results != True:
        for (section_list, key, _) in configobj.flatten_errors(config, results):
            if key is not None:
                sys.stderr.write('The "%s" key in the section "%s" failed validation' %
                        (key, ', '.join(section_list)))
            else:
                sys.stderr.write('The following section was missing:%s ' %
                    ', '.join(section_list))
        sys.exit(1)


def get_b32(dest):
    """ Calculate base32 hash from base64 """
    try:
        raw_key = base64.b64decode(dest.encode('utf-8'), '-~')
    except TypeError:
        return 'corrupted_base64_hash'
    else:
        hash = hashlib.sha256(raw_key)
        b32 = base64.b32encode(hash.digest()).lower().replace('=', '')+'.b32.i2p'
        return b32