WSGI+pastedeploy+webob

web server接收HTTP请求，封装环境变量，按照WSGI接口标准调用注册的WSGI Application，返回响应给客户端。

paste.deploy

openstack使用pastedeploy组件来完成WSGI服务器和应用的构建

• section：[type: name]
  • type = composite
    •  把URL请求分发给对应的app
  • type = app
    • app是具体的WSGI Application
  • type = filter-app
    • 过滤并转发给app
  • type = filter
    • 类似于filter-app，但没有next
  • type = pipeline
    • 由filter+...+filter+app组成

# config.ini 

[composite:main]
# use表明具体的分发方式
# egg:Paste#urlmap表示使用paste包中的urlmap模块
use = egg:Paste#urlmap     
# key=value表示使用urlmap进行分发的参数
/ = home
/wiki = wiki
/blog = blog
/cms = config:cms.ini

[app:home]
# use指定app
# python egg
use = egg:Paste#static

[app:app2]
# config.ini
use = config:myconfig.ini#app_name

[app:app3]
# 直接调用另外一个模块中的app
use = call:myproject:application

[app:app4]
# 另外一个section
use = myotherapp

[app:app5]
# myapp.modulename
paste.app_factory = myapp.modulename:app_factory

[filter-app:blog]
# use指定过滤条件
use = egg:Authentication#auth
# next表示过滤后的app
next = blogapp
roles = admin
htpasswd = /home/me/users.htpasswd

[pipeline:main]
pipeline = filter1 egg:FilterEgg#filter2 filter3 app

[filter:filter1]
...

• app_factory

def app_factory(loader, global_config, **local_conf)
    return wsgi_app

• 调用paste.deploy

from paste.deploy import loadapp
wsgi_app = loadapp('config:/path/to/config.ini')

webob

webob对WSGI请求与响应进行封装

• webob.Request

  • 对WSGI请求的environ参数进行封装

• webob.Response

  • 包含所有标准WSGI响应要素

• webob.exc

  • 封装HTTP错误代码

• webob.dec.wsgify

  • 封装WSGI参数和返回格式

 

• 标准WSGI格式

def application(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/html')])
    return '<h1>Hello</h1>'

• webob.dec.wsgify封装格式

@webob.dec.wsgify
def application(req):
    return webob.Response('OK')

# RequestClass过滤
@webob.dec.wsgify(RequestClass=MyRequest)

WSGI

• 标准WSGI格式

def application(environ, start_response):
    # HTTP请求：environ
    # HTTP响应：start_response(HTTP响应码，HTTP Header, 错误信息)
    start_response('200 OK', [('Content-Type', 'text/html')], exc_info=None)
    # 返回Body
    return '<h1>Hello</h1>'

WSGI+pastedeploy+webob

 

# tsroutes.ini

[composite:main]
use=egg:Paste#urlmap
/=show

[pipeline:show]
pipeline = root

[app:root]
paste.app_factory = tsroutes:Router.app_factory

 

# tsroutes.py

import logging
import os

import webob.dec
import webob.exc

from paste.deploy import loadapp
from wsgiref.simple_server import make_server

import routes.middleware


LOG = logging.getLogger(__name__)


class Controller(object):
    @webob.dec.wsgify
    def __call__(self, req):
        arg_dict = req.environ['wsgiorg.routing_args'][1]
        action = arg_dict.pop('action')

        return webob.Response('OK')

    def getMessage(self, context, user_id):
        return {'Message': 'TestMessage'}


class Router(object):
    def __init__(self):
        self._mapper = routes.Mapper()
        self._mapper.connect('/test/{user_id}',
                             controller=Controller(),
                             action='getMessage',
                             conditions={'method': ['GET']})
        self._router = routes.middleware.RoutesMiddleware(self._dispatch, self._mapper)


    @webob.dec.wsgify
    def __call__(self, req):
        return self._router

    @staticmethod
    @webob.dec.wsgify
    def _dispatch(req):
        match = req.environ['wsgiorg.routing_args'][1]

        if not match:
            return webob.exc.HTTPNotFound()

        app = match['controller']
        return app

    @classmethod
    def app_factory(cls, global_config, **local_config):
        return cls()


if __name__ == '__main__':
    configfile = 'tsroutes.ini'
    appname = "main"
    wsgi_app = loadapp("config:%s" % os.path.abspath(configfile), appname)
    httpd = make_server('localhost', 8282, wsgi_app)
    httpd.serve_forever()

测试：localhost:8282/test/1