libcloud/__init__.py

# Licensed to the Apache Software Foundation (ASF) under one or more
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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
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#
#     http://www.apache.org/licenses/LICENSE-2.0
#
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"""
libcloud provides a unified interface to the cloud computing resources.

@var __version__: Current version of libcloud
"""

__all__ = ['__version__', 'enable_debug']
__version__ = '0.13.2'

import os
import atexit

try:
    import paramiko
    have_paramiko = True
except ImportError:
    have_paramiko = False


def enable_debug(fo):
    """
    Enable library wide debugging to a file-like object.

    @param fo: Where to append debugging information
    @type fo: File like object, only write operations are used.
    """
    from libcloud.common.base import (Connection,
                                      LoggingHTTPConnection,
                                      LoggingHTTPSConnection,
                                      REQUESTS_LOG)
    LoggingHTTPSConnection.log = fo
    LoggingHTTPConnection.log = fo
    Connection.conn_classes = (LoggingHTTPConnection,
                               LoggingHTTPSConnection)

    # Register a handler which prints some request statistics upon exit
    enable_requests_stats = os.getenv('LIBCLOUD_REQUESTS_STATS')

    if enable_requests_stats:
        from libcloud.utils.debug import print_request_statistics

        LoggingHTTPSConnection.enable_requests_stats = True
        LoggingHTTPConnection.enable_requests_stats = True
        atexit.register(print_request_statistics, fo=fo,
                        requests_log=REQUESTS_LOG)


def _init_once():
    """
    Utility function that is ran once on Library import.

    This checks for the LIBCLOUD_DEBUG enviroment variable, which if it exists
    is where we will log debug information about the provider transports.
    """
    path = os.getenv('LIBCLOUD_DEBUG')
    if path:
        fo = open(path, 'a')
        enable_debug(fo)

        if have_paramiko:
            paramiko.common.logging.basicConfig(level=paramiko.common.DEBUG)

_init_once()