创建Cinder-API核心资源

同事整理了一份“如何创建Cinder-API核心资源”的步骤，请原谅我的拿来主义：

核心资源的python文件在 /cinder/api/v2/ 目录下面。Cinder-API的核心资源包括：volumes，types，snapshots，limits等。核心资源在Cinder-API启动时通过/etc/cinder/api-paste.ini文件中定义的APIRouter类进行加载。
新增核心资源：
1.创建核心资源的Controller类

# -*- coding:utf-8 -*-
from oslo_log import log as logging
import webob.exc
from cinder.api.openstack import wsgi
LOG = logging.getLogger(__name__)

class RuijieController(wsgi.Controller):
    def __init__(self, ext_mgr):
        self.ext_mgr = ext_mgr
        super(RuijieController, self).__init__()

    def index(self, req):
        """对应GET /v2/< tenant_id >/ruijies"""
        LOG.debug("GET Request : {0}".format(req))
        return webob.Response(status_int=202)

2.在对应的python文件中创建静态方法create_resource，该方法返回一个Controller实例。

def create_resource(ext_mgr):
return wsgi.Resource(RuijieController(ext_mgr))

3.创建新的Router类，该类型用来追加我们新添加的核心资源

# -*- coding:utf-8 -*-
from cinder.api.v2 import router
from cinder.api.v2 import ruijie_demo

class RuijieAPIRouter(router.APIRouter):
    """定义新的Router类型，该类型用来追加我们新添加的核心资源"""

    def _setup_routes(self, mapper, ext_mgr):
        super(RuijieAPIRouter,self)._setup_routes(mapper=mapper,ext_mgr=ext_mgr)
        self.resources['ruijies'] = ruijie_demo.create_resource(ext_mgr)
        mapper.resource("ruijie", "ruijies",
                        controller=self.resources['ruijies'],
                        collection={'detail': 'GET'},
                        member={'action': 'POST'}
                        )

4.修改配置文件/etc/cinder/api-paste.ini，用新定义的RuijieAPIRouter替换原有的cinder.api.v2.router.APIRouter

[app:apiv2]
#paste.app_factory = cinder.api.v2.router:APIRouter.factory
paste.app_factory = cinder.api.v2.ruijie_router:RuijieAPIRouter.factory