Source code for provy.core.utils

#!/usr/bin/python
# -*- coding: utf-8 -*-

'''
Core utilities.

Provides the :class:`AskFor` class, which is used to prompt for a password.
'''

from getpass import getpass
import os


def provyfile_path_from(args):
    if args:
        path = args[0]
        if not os.path.exists(path):
            raise IOError('provy file "%s" does not exist.' % path)
        if os.path.isabs(path):
            raise ValueError('provy file "%s" is absolute. Please provide a path that is relative to the current working directory.')
        return path
    elif os.path.exists('provyfile.py'):
        return 'provyfile.py'
    elif os.path.exists('provy_file.py'):
        return 'provy_file.py'
    raise IOError('No provyfile was found. Please specify an existant provyfile path, or create either a "provyfile.py" or "provy_file.py"')


def provyfile_module_from(path):
    (base, ext) = os.path.splitext(path)
    base = base.replace('/', '.')
    return base


def import_module(module_name):
    module = __import__(module_name)
    if '.' in module_name:
        return reduce(getattr, module_name.split('.')[1:], module)
    return module


class AskFor(object):
    '''
    Responsible for prompting for a password to the user.

    You may pass an instance of it, instead of a plain value, in the ``servers`` dictionary, so that you require the user to enter a value.
    '''
    def __init__(self, key, question):
        self.key = key
        self.question = question

    def get_value(self, server):
        value = getpass("[Server at %s] - %s: " % (server['address'], self.question))
        return value