trove instance service 总结

def create(self, req, body, tenant_id):    # TODO(hub-cap): turn this into middleware    LOG.info(_LI("Creating a database instance for tenant ‘%s‘"),             tenant_id)    LOG.debug("req : ‘%s‘\n\n", strutils.mask_password(req))    LOG.debug("body : ‘%s‘\n\n", strutils.mask_password(body))    context = req.environ[wsgi.CONTEXT_KEY]    context.notification = notification.DBaaSInstanceCreate(context,                                                            request=req)    datastore_args = body[‘instance‘].get(‘datastore‘, {})    datastore, datastore_version = (        datastore_models.get_datastore_version(**datastore_args))    image_id = datastore_version.image_id    name = body[‘instance‘][‘name‘]    flavor_ref = body[‘instance‘][‘flavorRef‘]    flavor_id = utils.get_id_from_href(flavor_ref)

    configuration = self._configuration_parse(context, body)    databases = populate_validated_databases(        body[‘instance‘].get(‘databases‘, []))    database_names = [database.get(‘_name‘, ‘‘) for database in databases]    users = None    try:        users = populate_users(body[‘instance‘].get(‘users‘, []),                               database_names)    except ValueError as ve:        raise exception.BadRequest(msg=ve)

    if ‘volume‘ in body[‘instance‘]:        volume_info = body[‘instance‘][‘volume‘]        volume_size = int(volume_info[‘size‘])        volume_type = volume_info.get(‘type‘)    else:        volume_size = None        volume_type = None

    if ‘restorePoint‘ in body[‘instance‘]:        backupRef = body[‘instance‘][‘restorePoint‘][‘backupRef‘]        backup_id = utils.get_id_from_href(backupRef)    else:        backup_id = None

    availability_zone = body[‘instance‘].get(‘availability_zone‘)    nics = body[‘instance‘].get(‘nics‘)

    slave_of_id = body[‘instance‘].get(‘replica_of‘,                                       # also check for older name                                       body[‘instance‘].get(‘slave_of‘))    replica_count = body[‘instance‘].get(‘replica_count‘)    modules = body[‘instance‘].get(‘modules‘)    locality = body[‘instance‘].get(‘locality‘)    if locality:        locality_domain = [‘affinity‘, ‘anti-affinity‘]        locality_domain_msg = ("Invalid locality ‘%s‘. "                               "Must be one of [‘%s‘]" %                               (locality,                                "‘, ‘".join(locality_domain)))        if locality not in locality_domain:            raise exception.BadRequest(msg=locality_domain_msg)        if slave_of_id:            dupe_locality_msg = (                ‘Cannot specify locality when adding replicas to existing ‘                ‘master.‘)            raise exception.BadRequest(msg=dupe_locality_msg)

    instance = models.Instance.create(context, name, flavor_id,                                      image_id, databases, users,                                      datastore, datastore_version,                                      volume_size, backup_id,                                      availability_zone, nics,                                      configuration, slave_of_id,                                      replica_count=replica_count,                                      volume_type=volume_type,                                      modules=modules,                                      locality=locality)

    view = views.InstanceDetailView(instance, req=req)    return wsgi.Result(view.data(), 200)

基本就是四步走，首先是请求上下文，然后创建实例对象，然后操作，最后返回wsgi