#!/usr/bin/python
# Copyright (C) 2013-2015 Codethink Limited
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program.  If not, see <http://www.gnu.org/licenses/>.


'''A Morph deployment write extension for deploying to OpenStack.'''


import os
import subprocess
import tempfile
import urlparse

import writeexts


class OpenStackWriteExtension(writeexts.WriteExtension):

    '''See openstack.write.help for documentation'''

    def process_args(self, args):
        if len(args) != 2:
            raise writeexts.ExtensionError(
                'Wrong number of command line args')

        temp_root, location = args

        os_params = self.get_openstack_parameters()

        fd, raw_disk = tempfile.mkstemp()
        os.close(fd)
        self.create_local_system(temp_root, raw_disk)
        self.status(msg='Temporary disk image has been created at %s'
                    % raw_disk)

        self.set_extlinux_root_to_virtio(raw_disk)

        self.configure_openstack_image(raw_disk, location, os_params)

    def set_extlinux_root_to_virtio(self, raw_disk):
        '''Re-configures extlinux to use virtio disks'''
        self.status(msg='Updating extlinux.conf')
        with self.find_and_mount_rootfs(raw_disk) as mp:
            path = os.path.join(mp, 'extlinux.conf')

            with open(path) as f:
                extlinux_conf = f.read()

            extlinux_conf = extlinux_conf.replace('root=/dev/sda',
                                                  'root=/dev/vda')
            with open(path, "w") as f:
                f.write(extlinux_conf)

    def get_openstack_parameters(self):
        '''Get the environment variables needed.

        The environment variables are described in the class documentation.
        '''

        keys = ('OPENSTACK_USER', 'OPENSTACK_TENANT',
                'OPENSTACK_IMAGENAME', 'OPENSTACK_PASSWORD')
        return (os.environ[key] for key in keys)

    def configure_openstack_image(self, raw_disk, auth_url, os_params):
        '''Configure the image in OpenStack using glance-client'''
        self.status(msg='Configuring OpenStack image...')

        username, tenant_name, image_name, password = os_params
        cmdline = ['glance',
                   '--os-username', username,
                   '--os-tenant-name', tenant_name,
                   '--os-password', password,
                   '--os-auth-url', auth_url,
                   'image-create',
                   '--name=%s' % image_name,
                   '--disk-format=raw',
                   '--container-format', 'bare',
                   '--file', raw_disk]
        subprocess.check_call(cmdline)

        self.status(msg='Image configured.')

OpenStackWriteExtension().run()