Synnefo

import logging

from django.db import transaction

from synnefo.db.models import Volume

from snf_django.lib.api import faults

from synnefo.volume import util

from synnefo.logic import backend

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):

    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!")

    # Only ext_ disk template supports cloning from another source

    disk_template = server.flavor.disk_template

    if not disk_template.startswith("ext_") and sources:

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

               disk_template)

        raise faults.BadRequest(msg)

    origin = None

    source = None

    if source_volume_id is not None:

        source_volume = util.get_volume(user_id, source_volume_id,

                                        for_update=True,

                                        exception=faults.BadRequest)

        # Check that volume is ready to be snapshotted

        if source_volume.status != "AVAILABLE":

            msg = ("Cannot take a snapshot while snapshot is in '%s' state"

                   % source_volume.status)

            raise faults.BadRequest(msg)

        source = Volume.SOURCE_VOLUME_PREFIX + str(source_volume_id)

        origin = source_volume.backend_volume_uuid

    elif source_snapshot_id is not None:

        source_snapshot = util.get_snapshot(user_id, source_snapshot_id,

                                            exception=faults.BadRequest)

        # TODO: Check the state of the snapshot!!

        origin = source_snapshot["checksum"]

        source = Volume.SOURCE_SNAPSHOT_PREFIX + str(source_snapshot_id)

    elif source_image_id is not None:

        source_image = util.get_image(user_id, source_image_id,

                                      exception=faults.BadRequest)

        origin = source_image["checksum"]

        source = Volume.SOURCE_IMAGE_PREFIX + str(source_image_id)

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

                                   size=size,

                                   name=name,

                                   machine=server,

                                   description=description,

                                   source=source,

                                   origin=origin,

                                   #volume_type=volume_type,

                                   status="CREATING")

    if metadata is not None:

        for meta_key, meta_val in metadata.items():

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

    # Create the disk in the backend

    volume.backendjobid = backend.attach_volume(server, volume)

    volume.save()

    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.index == 0:

        raise faults.BadRequest("Cannot detach the root volume of a server")

    if volume.machine_id is not None:

        volume.backendjobid = backend.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