switch-hosts

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

import os
import shutil
from optparse import OptionParser


config_path = '/etc/switch-host/'
default_backup_file = 'default-hosts'
default_hosts_path = '/etc/hosts'


def check_config_path():
    if not os.path.exists(config_path):
        os.mkdir(config_path)


def check_config_file(filename):
    file_path = config_path + filename
    if not os.path.exists(file_path):
        raise ValueError('Config file %s in not found in %s' %
            (filename, config_path))


def switch_hosts(filename):
    check_config_file(filename)
    file_path = config_path + filename
    shutil.copyfile(file_path, default_hosts_path)
    print 'Your hosts has beed switched to %s successfully!' % filename


def backup_hosts(target_file):
    file_path = config_path + target_file
    shutil.copyfile(default_hosts_path, file_path)
    print 'Your hosts has beed backuped to %s successfully!' % file_path


def list_hosts_config():
    print 'Available hosts configs:'
    for config in os.listdir(config_path):
        print config


def main(list_hosts, config_file, backup_file):
    check_config_path()

    if list_hosts:
        list_hosts_config()
        return

    if config_file:
        switch_hosts(config_file)
        return

    if backup_file:
        backup_hosts(backup_file)
        return


if __name__ == '__main__':

    parser = OptionParser()
    parser.add_option('-c', '--config', dest='config_file',
                      help='Specify your hosts config name')
    parser.add_option('-b', '--backup', dest='backup_file',
                      default=default_backup_file,
                      help='Backup your current hosts config to')
    parser.add_option('-l', '--list', dest='list_hosts',
                      action='store_true',
                      help='Specify your hosts config name')

    options, args = parser.parse_args()

    config_file = None

    if len(args) > 0:
        config_file = args[0]

    if options.config_file:
        config_file = options.config_file

    backup_file = options.backup_file
    list_hosts = options.list_hosts

    try:
        main(list_hosts, config_file, backup_file)
    except ValueError as e:
        print e.message