Although Django is well packaged for Debian, I've recently come to the conculsion that the packages are really not what I want. The problem is that my server runs Debian stable, while my development laptop runs unstable, and Django revisions definitely fall into the "unstable" category. There really is no way to use a system Django 1.1 on one side, and a system Django 1.0 on the other.

After a bit of work, I think I've got something together that works, and I post it here in the hope it is useful for someone else. This info has been gleaned from similar references such as this and this.

This is aimed at running a server using Debian stable (5.0) for production and an unstable environment for development. You actually need both to get this running. This is based on a project called "project" that lives in /var/www

1. First step is to install python-virtualenv on both.
2. Create a virtualenv on both, using the --no-site-packages to make it a stand-alone environment. This is like a chroot for python.

   $ virtualenv --no-site-packages project
   New python executable in project/bin/python
   Installing setuptools............done.
   

3. The unstable environment has a file you'll need to copy into the stable environment - bin/activate_this.py. The stable version of python-virtualenv isn't recent enough to include this file, but you need it to essentially switch the system python into the chrooted environment. This will come in handy later when setting up the webserver.
4. There are probably better ways to keep the two environments in sync, but I simply take a manual approach of doing everything twice, once in each. So from now on, do the following in both environments.
5. Activate the environment

   /var/www$ cd project
   /var/www/project$ . bin/activate
   (project) /var/www/project$
   

6. Use easy_install to install pip

   (project) /var/www/project$ easy_install pip
   Searching for pip
   Reading http://pypi.python.org/simple/pip/
   Reading http://pip.openplans.org
   Best match: pip 0.4
   Downloading http://pypi.python.org/packages/source/p/pip/pip-0.4.tar.gz#md5=b45714d04f8fd38fe8e3d4c7600b91a2
   Processing pip-0.4.tar.gz
   Running pip-0.4/setup.py -q bdist_egg --dist-dir /tmp/easy_install-Wu9O-U/pip-0.4/egg-dist-tmp-xjSdxq
   warning: no previously-included files matching '*.txt' found under directory 'docs/_build'
   no previously-included directories found matching 'docs/_build/_sources'
   zip_safe flag not set; analyzing archive contents...
   pip: module references __file__
   Adding pip 0.4 to easy-install.pth file
   Installing pip script to /var/www/project/bin
   
   Installed /var/www/project/lib/python2.5/site-packages/pip-0.4-py2.5.egg
   Processing dependencies for pip
   Finished processing dependencies for pip
   

7. Install setuptools, also using easy_install (for some reason, pip can't install it). There is a trick here, you need to specify at least version 0.6c9 or there will be issues with the SVN version on Debian stable when you try to get Django in the next step.

   (project) /var/www/project$ easy_install setuptools==0.6c9
   Searching for setuptools==0.6c9
   Reading http://pypi.python.org/simple/setuptools/
   Best match: setuptools 0.6c9
   Downloading http://pypi.python.org/packages/2.5/s/setuptools/setuptools-0.6c9-py2.5.egg#md5=fe67c3e5a17b12c0e7c541b7ea43a8e6
   Processing setuptools-0.6c9-py2.5.egg
   Moving setuptools-0.6c9-py2.5.egg to /var/www/project/lib/python2.5/site-packages
   Removing setuptools 0.6c8 from easy-install.pth file
   Adding setuptools 0.6c9 to easy-install.pth file
   Installing easy_install script to /var/www/project/bin
   Installing easy_install-2.5 script to /var/www/project/bin
   
   Installed /var/www/project/lib/python2.5/site-packages/setuptools-0.6c9-py2.5.egg
   Processing dependencies for setuptools==0.6c9
   Finished processing dependencies for setuptools==0.6c9
   

8. Create a requirements.txt with the path to the Django SVN for pip to install, then and then install it.

   (project) /var/www/project$ cat requirements.txt
   -e svn+http://code.djangoproject.com/svn/django/tags/releases/1.0.3/#egg=Django
   (project) /var/www/project$ pip install -r requirements.txt
   Obtaining Django from svn+http://code.djangoproject.com/svn/django/tags/releases/1.0.3/#egg=Django (from -r requirements.txt (line 1))
     Checking out http://code.djangoproject.com/svn/django/tags/releases/1.0.3/ to ./src/django
   
   (project) /var/www/project$ pip install -r requirements.txt
   Obtaining Django from svn+http://code.djangoproject.com/svn/django/tags/releases/1.0.3/#egg=Django (from -r requirements.txt (line 1))
     Checking out http://code.djangoproject.com/svn/django/tags/releases/1.0.3/ to ./src/django
   ... so on ...
   

9. Almost there! You can keep installing more Python requirements with pip if you need, but we've got enough here to start.
10. Create a file in /var/www/project called project-python.py. This will be the Python interpreter the webserver uses, and basically exec's itself into the virtalenv. The file should contain the following:

    activate_this = "/var/www/project/bin/activate_this.py"
    execfile(activate_this, dict(__file__=activate_this))
    
    from django.core.handlers.modpython import handler
    

11. Now it's time to start the Django project. I like to create a new directory called project, which will be the parent directory kept in the SCM with all the code, media, templates, database (if using SQLite) etc. In this way to keep the two environments up-to-date I simply svn ci on one side, and svn co on the other.

    (project) /var/www/project$ mkdir project
    (project) /var/www/project/project$ mkdir db django media www
    (project) /var/www/project/project$ cd django/
    (project) /var/www/project/project/django$ django-admin startproject myproject
    

12. Last step now is to wire-up Apache to serve it all up. The magic is making sure you specify the correct PythonHandler that you made before to use the virtualenv, and include the right paths so you can find it and all the required Django settings.

    DocumentRoot /var/www/project
    
    <Location "/">
        SetHandler python-program
        PythonHandler project-python
        PythonPath "['/var/www/project/','/var/www/project/project/django/'] + sys.path"
        SetEnv DJANGO_SETTINGS_MODULE myproject.settings
        PythonDebug On
    </Location>
    
    Alias /media /var/www/project/project/media
    <Location "/media">
        SetHandler none
    </Location>
    <Directory "/var/www/project/project/media">
        AllowOverride none
        Order allow,deny
        Allow from all
        Options FollowSymLinks Indexes
    </Directory>
    

With all this, you should be up and running in a basic but stable environment. It's easy enough to update packages for security fixes, etc via pip after activating your virtualenv.

posted at: Fri, 11 Sep 2009 22:49 | in /linux/debian | permalink | add comment (6 others)