'Return data about the given volume attachment.'

@extensions.expected_errors(404)
def show(self, req, server_id, id):

    context = req.environ['nova.context']
    context.can((va_policies.POLICY_ROOT % 'show'))
    volume_id = id
    instance = common.get_instance(self.compute_api, context, server_id)
    bdms = objects.BlockDeviceMappingList.get_by_instance_uuid(context, instance.uuid)
    if (not bdms):
        msg = (_('Instance    %s    is    not    attached.') % server_id)
        raise exc.HTTPNotFound(explanation=msg)
    assigned_mountpoint = None
    for bdm in bdms:
        if (bdm.volume_id == volume_id):
            assigned_mountpoint = bdm.device_name
            break
    if (assigned_mountpoint is None):
        msg = (_('volume_id    not    found:    %s') % volume_id)
        raise exc.HTTPNotFound(explanation=msg)
    return {'volumeAttachment': _translate_attachment_detail_view(volume_id, instance.uuid, assigned_mountpoint)}
