This article illustrates how to install and test Tornado a scalable, non-blocking web server and web application framework useful to write web application written in Python.

"Because it is non-blocking and uses epoll or kqueue, it can handle thousands of simultaneous standing connections, which means the framework is ideal for real-time web services".

• Tornado overview

Install Tornado on Aria, Terra or FOX boards

Download and save the file tornado-x.x.x.tar.gz on the CORE9G25 board microSD which contains the latest stable version of Tornado from the following link:

• www.tornadoweb.org/en/stable

Untar the archive file:

debarm:~# tar xvzf tornado-x.x.x.tar.gz
...

Move into the new directory and install Tornado by typing:

debarm:~# cd tornado-x.x.x                                                      
debarm:~/tornado-x.x.x# python setup.py install
...

Run your first web server

This is the basic example to build a simple web server which serves static html file.

import tornado.ioloop
import tornado.web

application = tornado.web.Application([
	(r"/(.*)", tornado.web.StaticFileHandler, {"path": ".","default_filename": "index.html"})
])

if __name__ == "__main__":
	application.listen(8080,"0.0.0.0")
	tornado.ioloop.IOLoop.instance().start()

I'm your default index page

• A binary favicon.ico file

Run it by typing:

debarm:~/playground/python/tornado# python basic.py

Open a browser on your PC and take a look to the Tornado web page using this URL:

• http://board_ip_address:8080

Let's try now to access the default web pages available on /var/www with our new small web server .

Stop basic.py by typing ctrl-c and change this line:

(r"/(.*)", tornado.web.StaticFileHandler, {"path": ".","default_filename": "index.html"})

in:

(r"/(.*)", tornado.web.StaticFileHandler, {"path": "/var/www","default_filename": "index.html"})

In this way we have changed the default path. Start again the web server and reload the web page on your browser.

Related links

• Tornado Web page
• Tornado documentation
• Facebook's Tornado repository on Github
• Wikipedia definition of Tornado
• Introduction to Tornado O'Reilly book sample code on GitHub
• Tornado Web Server Google Group
• Tool to generate favicon.ico file on line