Synnefo

import logging

from django.db import transaction

from django.conf import settings

from snf_django.lib.api import faults

from synnefo.db.models import Volume

from synnefo.volume import util

from synnefo.logic import server_attachments

log = logging.getLogger(__name__)

@transaction.commit_on_success

def create(user_id, size, server_id, name=None, description=None,

           source_volume_id=None, source_snapshot_id=None,

           source_image_id=None, metadata=None):

    # Currently we cannot create volumes without being attached to a server

    if server_id is None:

        raise faults.BadRequest("Volume must be attached to server")

    server = util.get_server(user_id, server_id, for_update=True,

                             exception=faults.BadRequest)

    # Assert that not more than one source are used

    sources = filter(lambda x: x is not None,

                     [source_volume_id, source_snapshot_id, source_image_id])

    if len(sources) > 1:

        raise faults.BadRequest("Volume can not have more than one source!")

    if source_volume_id is not None:

        source_type = "volume"

        source_uuid = source_volume_id

    elif source_snapshot_id is not None:

        source_type = "snapshot"

        source_uuid = source_snapshot_id

    elif source_image_id is not None:

        source_type = "image"

        source_uuid = source_image_id

    else:

        source_type = source_uuid = None

    volume = _create_volume(server, user_id, size, source_type, source_uuid,

                            name, description, index=None)

    if metadata is not None:

        for meta_key, meta_val in metadata.items():

            volume.metadata.create(key=meta_key, value=meta_val)

    server_attachments.attach_volume(server, volume)

    return volume

def _create_volume(server, user_id, size, source_type, source_uuid,

                   name=None, description=None, index=None,

                   delete_on_termination=True):

    # Only ext_ disk template supports cloning from another source. Otherwise

    # is must be the root volume so that 'snf-image' fill the volume

    disk_template = server.flavor.disk_template

    teplate, provider = util.get_disk_template_provider(disk_template)

    can_have_source = (index == 0 or

                       provider in settings.GANETI_CLONE_PROVIDERS)

    if not can_have_source and source_type != "blank":

        msg = ("Volumes of '%s' disk template cannot have a source" %

               disk_template)

        raise faults.BadRequest(msg)

    # TODO: Check Volume/Snapshot Status

    if source_type == "volume":

        source_volume = util.get_volume(user_id, source_uuid,

                                        for_update=True,

                                        exception=faults.BadRequest)

        if source_volume.status != "IN_USE":

            raise faults.BadRequest("Cannot clone volume while it is in '%s'"

                                    " status" % source_volume.status)

        # If no size is specified, use the size of the volume

        if size is None:

            size = source_volume.size

        elif size < source_volume.size:

            raise faults.BadRequest("Volume size cannot be smaller than the"

                                    " source volume")

        source = Volume.prefix_source(source_uuid, source_type="volume")

        origin = source_volume.backend_volume_uuid

    elif source_type == "snapshot":

        source_snapshot = util.get_snapshot(user_id, source_uuid,

                                            exception=faults.BadRequest)

        source = Volume.prefix_source(source_uuid,

                                      source_type="snapshot")

        if size is None:

            raise faults.BadRequest("Volume size is required")

        elif (size << 30) < int(source_snapshot["size"]):

            raise faults.BadRequest("Volume size '%s' is smaller than"

                                    " snapshot's size '%s'"

                                    % (size << 30, source_snapshot["size"]))

        origin = source_snapshot["checksum"]

    elif source_type == "image":

        source_image = util.get_image(user_id, source_uuid,

                                      exception=faults.BadRequest)

        if size is None:

            raise faults.BadRequest("Volume size is required")

        elif (size << 30) < int(source_image["size"]):

            raise faults.BadRequest("Volume size '%s' is smaller than"

                                    " image's size '%s'"

                                    % (size << 30, source_image["size"]))

        source = Volume.prefix_source(source_uuid, source_type="image")

        origin = source_image["checksum"]

    elif source_type == "blank":

        if size is None:

            raise faults.BadRequest("Volume size is required")

        source = origin = None

    else:

        raise faults.BadRequest("Unknwon source type")

    volume = Volume.objects.create(userid=user_id,

                                   size=size,

                                   disk_template=disk_template,

                                   name=name,

                                   machine=server,

                                   description=description,

                                   delete_on_termination=delete_on_termination,

                                   source=source,

                                   origin=origin,

                                   #volume_type=volume_type,

                                   status="CREATING")

    return volume

@transaction.commit_on_success

def delete(volume):

    """Delete a Volume"""

    # A volume is deleted by detaching it from the server that is attached.

    # Deleting a detached volume is not implemented.

    if volume.machine_id is not None:

        server_attachments.detach_volume(volume.machine, volume)

        log.info("Detach volume '%s' from server '%s', job: %s",

                 volume.id, volume.machine_id, volume.backendjobid)

    else:

        raise faults.BadRequest("Cannot delete a detached volume")

    return volume

@transaction.commit_on_success

def rename(volume, new_name):

    volume.name = new_name

    volume.save()

    return volume

@transaction.commit_on_success

def update_description(volume, new_description):

    volume.description = new_description

    volume.save()

    return volume