Nov 3, 2009

How to set up cherokee and uWSGI

A couple of post ago I have "blogged" about cherokee which is a light weight web server, fast and extremely simple to configure thanks to its great admin interface.

The most common configuration to use cherokee with django is described here and to put is in a nutshell it was based on flup using SCGI or FASTCGI protocol.

However a couple of weeks ago a new contender pop up on my radar. It is called uWSGI and it might become in the near future very popular to power django application. You can find more information about it on on the pages below :
* example [2]
* Documentation [3]

From an architecture stand point it might provide us python web developer an interesting piece of software that could operate with virtually any webserver. There is already an apache module and cherokee handler. The documentation mentions that the core developers have started to develop an nginx adaptor.


Software prerequisites

cherokee 0.99.26
uWSGI (changeset: 85:61dcfd718023)

I have installed cherokee using the PPA on launchpad [1] and uWSGI directly from the mercurial repository.

hg clone http://projects.unbit.it/hg/uwsgi

Installation

Installation of both product is relatively straight forward and well documented. I will not detail it more here but rather point you to cherokee [4] and uWSGI website [5].
Here it is how you would compile uWSGI on Ubuntu 9.04

make -f Makefile.Linux.Py26

Note: The compilation will create a binairy called uwsgi26. It is important to add it into your PATH under the name of uwsgi. If you don't do this cherokee's wizard  will complain about not being able to find uWSGI server. I have created a symbolic link but you could also copy it into /usr/local/bin.

Configuration

The amazing admin interface of cherokee make it dead simple once you know what need to be done. In the latest version of cherokee a wizzard has been added to make the configuration even simpler.

First thing first you need to create 2 configurations file into your django project directory called respectively : django_wsgi.py and uwsgi.conf

------ django_wsgi.py ------------------

  import os import django.core.handlers.wsgi  
  os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings' 
  application = django.core.handlers.wsgi.WSGIHandler() 
 

------ uwsgi.conf --------------------

<uwsgi>

    <pythonpath>/home/yml/workdir/webdev/fabric_factory/20091023/fabric_factory/ve/lib/python2.6/site-packages/</pythonpath>

    <pythonpath>/home/yml/workdir/webdev/fabric_factory/20091023/fabric_factory/src/</pythonpath>

    <app mountpoint="/">

        <script>project.django_wsgi</script>

    </app>

</uwsgi>



Once this is done you can launch cherokee admin : 'cherokee-admin -u' and point your browser to this URL :
* http://127.0.0.1:9090/

Once in cherokee you can use the uWSGI wizard to create automatically your information sources and add a new rule. In order to do so you need to go into the virtual server section on the behavior tab [6]. Below the table there is an hyperlink called wizards. It will take you to a list of wizards, click on uWSGI.




Cherokee asks for the path to the uwsgi.conf file that we have created earlier. The last bit you might want to do is to add a rule to serve the admin media.





Troubleshooting

Here it is some basic technics to understand what is going on and solve your issues. Look at cherokee's log files :


sudo tail -f /var/log/cherokee/cherokee.error
and
sudo tail -f /var/log/cherokee/cherokee.access 

Look into the section called "information sources" in cherokee-admin. Explore the information sources created by the uWSGI wizard. Copy the text in the interpreter field, in my case it is :


/usr/local/bin/uwsgi -s /tmp/cherokee-source1.sock -C -x /[Path to my django project]/uwsgi.conf

Then you can paste it in a terminal this will give you a way to see what it is going on.

This new combination is still very young but it looks promising to me. I am sure that if we get enough people to hammer on it can quickly becomes popular.

[1] https://launchpad.net/~cherokee-webserver/+archive/ppa
[2] http://projects.unbit.it/uwsgi/wiki/Example
[3] http://projects.unbit.it/uwsgi/wiki/Doc
[4] http://www.cherokee-project.com/doc/basics_installation.html
[5] http://projects.unbit.it/uwsgi/wiki/Install
[6] http://127.0.0.1:9090/vserver/10
blog comments powered by Disqus