CherryPy

Dispatching

is the art of locating the appropriate page handler for a given request

Usually, dispatching is based on the request’s URL, the query-string and, sometimes, the request’s method (GET, POST, etc.)

hook

A hook point is a point during the request/response processing “on_start_resource” - The earliest hook; the Request-Line and request headers have been processed and a dispatcher has set request.handler and request.config.

before_request_body

before_handler

before_finalize

on_end_resource

before_error_response

after_error_response

on_end_request

Plugins

Plugins, simply put, are entities that play with the bus, either by publishing or subscribing to channels, usually both at the same time.

create your own plugins

enable/disable a plugin

CherryPy

• Micro web frameworks, bottle, flask, web2py
• Minimal framework for creating APIs
• Very fast, netflix uses it to route traffic b/w datacentres, disney, splunk
• came in 2002, relatively old
• Class name is usually the route of application
• Bulitin HTTP server cherrypy.quickstart has handlers for uWSGI, development server, tornado application, tie into Django
• HTTP server mounts the class which has index method in it.
• cherrypy.tools are like Django middleware. Can manupulate response before or after you are done with it.
• tools to upload/download file
• Configs
  • Application level, mostly routing, specifying static folder location, manually changing header
  • what HTTP server do we use? which port?
• Make your won cherry tools using @cherrypy.tools.register('before_habdler')
  • 8 hooks provided by cherrypy to insert handler
• Route grafting can have multiple SPA running on same URL
• minimalistic server is 6 lines of code
• Support FCGI and lighthttpd server mode
• Multiple apps could be mounted at different routes
• Process monitoring with supervisord
• A HTTP/1.1-compliant, WSGI thread-pooled webserver.[4] Typically, CherryPy itself takes only 1–2 ms per page.
• CherryPy 3 has fastest WSGI server yet 12/23/06
• CherryPy uses a tree-based mapper which does not accommodate well with segments that have no physical reality as a Python object

Logging

most arcane standard library module

• Most ingolorious programmers start with print statements unless it hits them in face
• By default would show only the warning, why worry about things which are going good.
• logging module assumes a lot of things
• Handler to make HTTP POST calls of standard logging events

1. Everything info level and above, default is warning level and above.
2. Give us more infomration that we did not put in

Use cases

1. Send JSON / HTML response
2. Accept JSON input request

Footnotes