api.py 文件源码

def instance_for_format(image, mountdir, partition):
        """Get a Mount instance for the image type

        :param image: instance of nova.virt.image.model.Image
        :param mountdir: path to mount the image at
        :param partition: partition number to mount
        """
        LOG.debug("Instance for format image=%(image)s "
                  "mountdir=%(mountdir)s partition=%(partition)s",
                  {'image': image, 'mountdir': mountdir,
                   'partition': partition})

        if isinstance(image, imgmodel.LocalFileImage):
            if image.format == imgmodel.FORMAT_RAW:
                LOG.debug("Using LoopMount")
                return importutils.import_object(
                    "nova.virt.disk.mount.loop.LoopMount",
                    image, mountdir, partition)
            else:
                LOG.debug("Using NbdMount")
                return importutils.import_object(
                    "nova.virt.disk.mount.nbd.NbdMount",
                    image, mountdir, partition)
        elif isinstance(image, imgmodel.LocalBlockImage):
            LOG.debug("Using BlockMount")
            return importutils.import_object(
                    "nova.virt.disk.mount.block.BlockMount",
                    image, mountdir, partition)
        else:
            # TODO(berrange) We could mount RBDImage directly
            # using kernel RBD block dev support.
            #
            # This is left as an enhancement for future
            # motivated developers todo, since raising
            # an exception is on par with what this
            # code did historically
            raise exception.UnsupportedImageModel(
                image.__class__.__name__)