Werkzeug

一个简单的WSGI应用

"""
created by 贝壳 on 2022/5/4
"""
__autor__ = 'shelly'

import os
import redis
from werkzeug.urls import url_parse
from werkzeug.wrappers import Request, Response
from werkzeug.routing import Map, Rule
from werkzeug.exceptions import HTTPException, NotFound
from werkzeug.middleware.shared_data import SharedDataMiddleware
from werkzeug.utils import redirect
from jinja2 import Environment, FileSystemLoader


#一个简单的WSGI 应用
class Shortly(object):

   def __init__(self, config):
       self.redis = redis.Redis(
           config['redis_host'], config['redis_port'], decode_responses=True
       )

   def dispatch_request(self, request):
       return Response('Hello World!')

   def wsgi_app(self, environ, start_response):
       #start_response 是一个方法function WSGIRequestHandler.run_wsgi.<locals>.start_response
       request = Request(environ)
       response = self.dispatch_request(request)
       return response(environ, start_response)

   def __call__(self, environ, start_response):
       #每一个请求进来，都会进入，去到环境中的数据
       return self.wsgi_app(environ, start_response)


def create_app(redis_host='localhost', redis_port=6379, with_static=True):
   app = Shortly({
       'redis_host':       redis_host,
       'redis_port':       redis_port
   })
   #optionally with a piece of WSGI middleware that exports all the files on the static folder on the web
   if with_static:
       app.wsgi_app = SharedDataMiddleware(app.wsgi_app, {
           '/static':  os.path.join(os.path.dirname(__file__), 'static')
       })
   return app

if __name__ == '__main__':
   from werkzeug.serving import run_simple
   app = create_app()
   run_simple('127.0.0.1', 5000, app, use_debugger=True, use_reloader=True)

Shortly就是一个简单的WSGI Application，每一个请求都会调用Shortly app，然后调用其call函数，在call函数里面，取到环境所有的环境参数，然后去处理请求。
重要的环境参数有：
'werkzeug.request': <Request 'http://127.0.0.1:5000/favicon.ico' [GET]>
'HTTP_COOKIE': 'csrftoken=WVWbK0r6HIOuGD1ybGmodXUqGWDQTS1E26WlbvhnoHIe1UVc31K9bz402YwedkUC
sessionid=hjyq9l4jxu4uwe3w7nyrjgmcpdmh39qn;
'QUERY_STRING': '',