Last (?) post about MediaTemple (dv) and Django

This is a refinement of a previous post on the topic of Django integration into a MediaTemple (dv) account. Following a talk with MT and reading some knowledgebase info, here is the quick route to Django configuration happiness - now more better.

This is how we do it:

Add to base config aka /etc/httpd/conf/httpd.conf the following in the appropriate section:

LoadModule wsgi_module modules/mod_wsgi.so

And in the appropriate section, add this too:

NameVirtualHost *:80

#Add a VirtualHost Section for each Name-based virtual server

<VirtualHost>
ServerAdmin email@email.com
ServerName www.URL.com
ServerAlias URL.com *.URL.com

DocumentRoot /var/www/vhosts/URL/httpdocs

<Directory /var/www/vhosts/URL/httpdocs>
Order allow,deny
Allow from all
</Directory>

</VirtualHost>

then save the file and exit the editor.

In the directory of path '/var/www/vhosts/(DOMAIN NAME)/conf' there is a file called 'httpd.include.' It holds unique config info for each virtual domain. It is rebuilt automatically from time to time based on Plesk. Instead of editing that file, make a new one called 'vhost.conf' (if it doesn't already exist) and add the following info to this file:

WSGIDaemonProcess URL.com processes=1 threads=1 display-name=%{GROUP}
WSGIProcessGroup URL.com
WSGIScriptAlias /myapp /home/username/django/scripts/URL.com.wsgi

<Directory /home/username/django/scripts>
Order allow,deny
Allow from all
</Directory>

ErrorLog /var/log/URL.com-error_log
CustomLog /var/log/URL.com-access_log common

Notes on the above, in brief

1. LoadModule is in httpd.conf
2. NameVirtualHost declaration is in httpd.conf
3. virtualhosts make use of /virtualhostname/conf/vhost.conf
4. WSGIScriptAlias declarations are in respective vhost.conf, not in httpd.conf*

* This is because WSGIScriptAlias in httpd.conf didn't work

Once that is configured as you like, simply restart the server in this manner:

/usr/local/psa/admin/sbin/websrvmng --reconfigure-vhost --vhost-name=mt-example.com 

service httpd graceful

Now test your django. With any luck, you will see a screen confirming a correct installation.

Eclipse Galileo Drops!

Version 3.5 of the Eclipse Integrated Development Environment application has officially been released.

What is Eclipse? A free open-source software development platform you can install on mac, win or linux.

What does it run? Eclipse was originally written to support Java, but now it has language packs for over a dozen languages.

What is Galileo? For several years now the Eclipse Foundation, an organization of open source Eclipse developers, have released a new iterative version of Eclipse late June of each year. Galileo, code name for the latest Eclipse version, officially dropped a couple of days ago. It's version 3.5 of the venerable platform.

What do you use Eclipse for? Currently, I code Actionscript in Eclipse using the Flex SDK plug in. It streamlines all the complexities of developing RIAs, and it also incorporates Subversion, an open-source version control app.

What's next? Now that Galileo is officially released, is it worth upgrading to? Turns out, lots of applications are not ready to support it yet. I've found several blogs documenting attempted upgrades in Linux, Windows and OSX that ended in grief, and not just regarding the Flex Builder plug-in. Be sure to research compatibility before getting too deep into a new version of Eclipse.

Python Image Library (PIL) on MediaTemple (dv)

When you're on MediaTemple (dv) with root access, first get the TAR from here. As of this post, the latest version is 1.1.6.

wget http://effbot.org/downloads/Imaging-1.1.6.tar.gz

Untar in the usual way.

tar zxvf Imaging-1.1.6.tar.gz

Then, go into the created folder and install the package using:

python setup.py install

If all goes well your ssh will echo many installation processes, following which you will have an amazingly easy time working with images via http.

Subversion on MediaTemple (dv)

Just completing some upgrades to my service to incorporate subversion. I don't know how I got by without it for so long. My first exposure to version control software was Visual SourceSafe back in the dark ages, and since then I've either used that or similar routines involving backups and multiple versions in similarly-named folders. Subversion is a lean, command-line, open-source version of the same. Here's what I did.

In the case of MediaTemple, Subversion is already installed. All you have to do to get started is invoke a new instance on the command line.

svnadmin create /name/of/project/folder

Then build a project to import into svn, such as

tmp/project/trunk
tmp/project/branches
tmp/project/tags

Jump into the trunk and add some files to it

file1
file2
file3

When you import the project, subversion vacuums it all up.

svn import /tmp/project file:///name/of/project/folder -m "initial import"

Note the -m, ensures you won't get an error for not setting the default text editor for subversion. In case you would like to set it, just use the command:

export SVN_EDITOR=vi

Now you can checkout files using the checkout command

svn checkout file:///name/of/project/folder/trunk project

And you can post your revisions using commit

svn commit

Notice the difference in directory structure between creating, importing and checking out. Creating and importing require only the folder, but checking out requires the additional trunk folder and project name specified.

Here are some additional resources of note for subversion installations, with an emphasis on MediaTemple (dv) installations.

Ayman Hourieh Subversion Tutorial - quick and to the point.

Tony Spencer's Tutorial - includes basic WebDAV integration, also quick and to the point.

Python and Django in MediaTemple (dv) server

Getting Django to run on a dv server is not as easy as their preconfigured - and cheaper - grid containers. While the shared grid containers are ready to go out of the box, the dv has some server admin changes to get through before you see that welcome

"Hello World".

Specifically, the httpd.conf needs additional lines of code to connect the web root to the Django application. To add a little spin to it, there's also the config file generated by Plesk. That needs some edits as well.

The order of statements in the zz010_psa_httpd.conf file can be a particular obstacle. Seems you have to have the WSGIScriptAlias declarations high up in the page or they aren't acted on properly as the procedure continues. Changing LogLevels to info gives the most detailed view from your logfiles but may not ultimately identify the problems.

In any case, here are the steps in a nutshell:

(added to zz010_psa_httpd.conf - plesk)

Include /var/www/vhosts/urlone.com/conf/httpd.include
Include /var/www/vhosts/urltwo.com/conf/httpd.include
WSGIScriptAlias /myapp /var/www/vhosts/urlone.com/wsgi-scripts/myapp.wsgi
WSGIScriptAlias /django/test01 /var/www/vhosts/urltwo.com/wsgi-scripts/myapp.wsgi

(added both httpd.includes to file structure)

Seems simple enough once it works. I hope this gets you out of a pinch.

Serving Django on Apache

As an update on the previous post, looking into current Django docs, the Apache production server method of using mod_python to serve Django has been superseded by mod_wsgi. I had partially implemented the former method, so now I'm bringing it up to the latest spec.

According to google.code on Python WSGI, Apache 1.3, 2.0 or 2.2 are compatible. Apache on a MediaTemple dv account shows

httpd -v

Server version: Apache/2.2.3
Server built: Nov 12 2008 10:41:27

Python needs to be 2.3 through 2.5 and the vers on (mt) shows

Python 2.4.3 (#1, May 24 2008, 13:47:28)

So far, so what. Now to install wsgi...

wget http://modwsgi.googlecode.com/files/mod_wsgi-2.5.tar.gz
tar xvfz mod_wsgi-2.5.tar.gz
configure
make
make install

finally edit

httpd.conf

located in

/etc/httpd/conf.

Adding the lines:

LoadModule wsgi_module modules/mod_wsgi.so

and


<virtualhost *>
ServerAdmin jasonthewolf@gmail.com
ServerName www.unplugtheinternet.com
DocumentRoot /var/www/vhosts/unplugtheinternet.com
WSGIScriptAlias / /django/test01/apache/django.wsgi
</virtualhost>

In the above, WSGIScriptAlias deserves some explanation:
Description : WSGI maps a URL to a filesystem location and designates the target as a WSGI script.
Syntax : WSGIScriptAlias URL-path file-path|directory-path
Context : server config, virtual host
Module : mod_wsgi.c

A request for http://www.example.com/wsgi-scripts/name in this case would cause the server to run the WSGI application defined in /web/wsgi-scripts/name. This configuration is essentially equivalent to:

and restart apache with

apachectl restart

All reports are good from Apache so far. Now that the installation of wsgi is complete, back to Django implementation.

I once again edited httpd.conf, this time adding
WSGIScriptAlias / /path/to/mysite/apache/django.wsgi

which for my site and requirements was effectively:

WSGIScriptAlias /django/test01 /var/www/vhosts/unplugtheinternet.com/apache/django.wsgi

This is the folder I have chosen for my python tests. If they work out, I'll move them to the root of some url or another. Following the convention established in the example, I created directory apache and the used vi to create the textfile django.wsgi as:

import os
import sys

os.environ['DJANGO_SETTINGS_MODULE'] = 'mysite.settings'

import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()

Python and Django wrapup

Almost a wrapup.

Got django installed in /usr/lib/python2.4/site-packages/

Got django deployed in /var/www/vhosts/unplugtheinternet.com/django/test01/ with subfolder cms autogenerated

Got MySQLdb module added to python so django can use a MySQL database, and django has been successfully configured to build the schemas for the modules it deploys.

Created a vhost.conf to take care of webserver requests that python should handle (courtesy of Nick Sergeant's blog entry).

Still it isn't working properly. But since I'm leaving for a camping trip in ~1 hour, it's time to switch it off and go join my friends at Assateague Island.

Arrividerci pals.

MediaTemple, Python and Django

Just installing Django on my Mediatemple dv account.

First, log in to SSH as root user. Then use subversion, provided by mediatemple in

WebControl > Root Access & Developer Tools > Install Developer Tools,

which must at some point be enabled to be accessible. Following this,

Subversion grabs the latest version to /var/trunk/django.

In the case of dv accounts, python packages are located in /usr/lib/python2.4/site-packages

Create a symbolic link between these two locations using

ln -s /var/trunk/django /usr/lib/python2.4/site-packages

then add another symbolic link to bring the underlying python script to the root of the django trunk:

ln -s /var/trunk/django/bin/django-admin.py /usr/local/bin

Basically, what is happening here is:

Django Source /var/trunk : Subversion project root

\ --> accessible to /usr/lib : Libraries for programming and packages
\ --> accessible to /usr/local : Local hierarchy

More on this. Now:

import django

and


django.version

voila!

Next, you must add the MySQLdb interface for python if you are planning to use mySQL as your cms database. Here's a good reference for once you have the tarball in your directory. However, I'd rather wget it directly from the sourceforge site. Here is the command to use from root SSH:

wget http://downloads.sourceforge.net/mysql-python/MySQL-python-1.2.2.tar.gz

Works fine. Now install the module and it should run without an error.