get message index of components for urllib2.

    Args:
        url(string):

    Returns:
        list: messages

def message_index(index_url):
    """get message index of components for urllib2.

    Args:
        url(string):

    Returns:
        list: messages
    """
    idx = csv.reader(urllib2.urlopen(index_url), delimiter=':')
    messages = []
    for line in idx:
        messages.append(line)
    return messages