問題背景

最近在研究openstack 服務的源代碼，由於項目代碼較多對其又不熟悉，剛開始就不知道從哪裏開始入手分析。經過分析發現，在正式分析源碼之前需要對python的wsgi、paste、routes和webob這幾個模塊有所了解才可以繼續深入。在此，就我對paste的學習理解首先分享出來，其余模塊接下來會娓娓道來。

研究對象

• Devstack 安裝的OpenStack Pike版本的Cinder項目

研究過程

1、打開cinder項目下的paste.ini文件，如下所示：

#############
# OpenStack #
#############

[composite:osapi_volume]
use = call:cinder.api:root_app_factory
/: apiversions
/v1: openstack_volume_api_v1
/v2: openstack_volume_api_v2
/v3: openstack_volume_api_v3

[composite:openstack_volume_api_v1]
use = call:cinder.api.middleware.auth:pipeline_factory
noauth = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler noauth apiv1
keystone = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler authtoken keystonecontext apiv1
keystone_nolimit = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler authtoken keystonecontext apiv1

[composite:openstack_volume_api_v2]
use = call:cinder.api.middleware.auth:pipeline_factory
noauth = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler noauth apiv2
keystone = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler authtoken keystonecontext apiv2
keystone_nolimit = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler authtoken keystonecontext apiv2

[composite:openstack_volume_api_v3]
use = call:cinder.api.middleware.auth:pipeline_factory
noauth = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler noauth apiv3
keystone = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler authtoken keystonecontext apiv3
keystone_nolimit = cors http_proxy_to_wsgi request_id faultwrap sizelimit osprofiler authtoken keystonecontext apiv3

[filter:request_id]
paste.filter_factory = oslo_middleware.request_id:RequestId.factory

[filter:http_proxy_to_wsgi]
paste.filter_factory = oslo_middleware.http_proxy_to_wsgi:HTTPProxyToWSGI.factory

[filter:cors]
paste.filter_factory = oslo_middleware.cors:filter_factory
oslo_config_project = cinder

[filter:faultwrap]
paste.filter_factory = cinder.api.middleware.fault:FaultWrapper.factory

[filter:osprofiler]
paste.filter_factory = osprofiler.web:WsgiMiddleware.factory

[filter:noauth]
paste.filter_factory = cinder.api.middleware.auth:NoAuthMiddleware.factory

[filter:sizelimit]
paste.filter_factory = oslo_middleware.sizelimit:RequestBodySizeLimiter.factory

[app:apiv1]
paste.app_factory = cinder.api.v1.router:APIRouter.factory

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

[app:apiv3]
paste.app_factory = cinder.api.v3.router:APIRouter.factory

[pipeline:apiversions]
pipeline = cors http_proxy_to_wsgi faultwrap osvolumeversionapp

[app:osvolumeversionapp]
paste.app_factory = cinder.api.versions:Versions.factory

##########
# Shared #
##########

[filter:keystonecontext]
paste.filter_factory = cinder.api.middleware.auth:CinderKeystoneContext.factory

[filter:authtoken]
paste.filter_factory = keystonemiddleware.auth_token:filter_factory
 

OpenStack Paste.ini詳解