django-virtualenv-apache-mod_wsgi

15y, 298d ago [edited]

Django virtualenv Apache2 mod_wsgi

By the end of this article you will know how to deploy a Django web application using a python virtualenv, using an Apache2 webserver with mod_wsgi.

You should bookmark this page.

Why use wsgi and virtualenv?

I also host pylons applications using mod_wsgi and apache2 and mod_python is incompatible.

mod_wsgi is fast.

I don't want my public site-packages library conflicting with other applications.

Install virtualenv

Install Setup tools:

$ sudo apt-get install python-setuptools memcached
Install virtualenv:

$ sudo easy_install virtualenv

Create a virtualenv

Move to the directory where you want to create the virtualenv:

$ cd /www/lostquery.com
Create python environment:

$ virtualenv --no-site-packages virtpy

Install Django

Activate the virtualenv:

$ source virtpy/bin/activate
The shell should have changed to (virtpy) $ . Run this command to install django to the virtualenv:

# I know this version works... $ easy_install django==1.3.1
Install any dependencies you will need to the virtualenv:

$ easy_install MySQL-python markdown html5lib modwsgideploy python-openid South python-memcached

Install and configure the Django web application

Get the sourcecode:

$ svn co http://svn.osqa.net/svnroot/osqa/trunk
Configure the application:

$ cd trunk

$ cp settings_local.py.dist settings_local.py

$ vi settings_local.py
You must tell the Django's application what database to use. Also configure memcached:

# database settings DATABASE_NAME = 'databasename' # Or path to database file if using sqlite3. DATABASE_USER = 'username' # Not used with sqlite3. DATABASE_PASSWORD = 'p@ssw0rd' # Not used with sqlite3. DATABASE_ENGINE = 'mysql' #mysql, etc DATABASE_HOST = 'localhost' DATABASE_PORT = ''

# memcached settings (osqa is slow as dirt without this) CACHE_BACKEND = 'memcached://127.0.0.1:11211/'
Give apache access to a few directories, /trunk/log and /trunk/forum/upfiles:

$ chmod 777 log $ chmod 777 forum/upfiles
Create the database (example syntax to create a mySQL database).

Let the django application build the tables in the new database:

$ python manage.py syncdb --all $ python manage.py migrate forum --fake

Configure Apache2 VirtualHost

Turn on mod_rewrite:

$ a2enmod rewrite
Create a sites-available vhost apache2 file:

$ sudo vi /etc/apache2/sites-available/007-lostquery
Setup the host file:

Configure mod_wsgi

Create the egg-cache directory:

$ mkdir /www/lostquery.com/mod_wsgi

$ mkdir /www/lostquery.com/mod_wsgi/egg-cache
Create the wsgi dispatch file:

$ vi /www/lostquery.com/mod_wsgi/dispatch.wsgi
Setup the wsgi dispatch file:

Enable the Virtual Host and reload Apache2

Reset apache2 so that it reads in the new config files:

$ a2ensite lostquery

$ sudo service apache2 reload

Django virtualenv Apache2 mod_wsgi
===============================================
 
 By the end of this article you will know how to deploy a Django web application using a python virtualenv, using an Apache2 webserver with mod_wsgi.

You should bookmark this page.

**Why use wsgi and virtualenv?**

* I also host pylons applications using mod_wsgi and apache2 and mod_python is incompatible.
 * mod_wsgi is fast.
 * I don't want my public site-packages library conflicting with other applications.

.. contents::

Install virtualenv
------------------

#. Install Setup tools:
 
   .. code-block :: bash

$ sudo apt-get install python-setuptools memcached

#. Install virtualenv:

.. code-block :: bash

$ sudo easy_install virtualenv

Create a virtualenv
---------------------
#. Move to the directory where you want to create the virtualenv:

.. code-block :: bash

$ cd /www/lostquery.com

#. Create python environment:

.. code-block :: bash

$ virtualenv --no-site-packages virtpy

Install Django
----------------

#. Activate the virtualenv:
     
   .. code-block :: bash

$ source virtpy/bin/activate

#. The shell should have changed to *(virtpy) $* .  Run this command to install django to the virtualenv:

.. code-block :: bash

# I know this version works... 
    $ easy_install django==1.3.1

#. Install any dependencies you will need to the virtualenv:

.. code-block :: bash

$ easy_install MySQL-python markdown html5lib modwsgideploy python-openid South python-memcached

Install and configure the Django web application
----------------------------------------------------

#. Get the sourcecode:

.. code-block :: bash

$ svn co http://svn.osqa.net/svnroot/osqa/trunk

#. Configure the application:
    
   .. code-block :: bash

$ cd trunk

$ cp settings_local.py.dist settings_local.py

$ vi settings_local.py

#. You must tell the Django's application what database to use.  Also configure memcached:
   
   .. code-block :: python
 
    # database settings
    DATABASE_NAME     =  'databasename' # Or path to database file if using sqlite3.
    DATABASE_USER     =  'username'     # Not used with sqlite3.
    DATABASE_PASSWORD =  'p@ssw0rd'     # Not used with sqlite3.
    DATABASE_ENGINE   =  'mysql'        #mysql, etc
    DATABASE_HOST     =  'localhost'
    DATABASE_PORT     =  ''

# memcached settings (osqa is slow as dirt without this)
    CACHE_BACKEND = 'memcached://127.0.0.1:11211/'

#. Give apache access to a few directories, /trunk/log and /trunk/forum/upfiles:

.. code-block :: bash
    
    $ chmod 777 log
    $ chmod 777 forum/upfiles

#. Create the database `(example syntax to create a mySQL database) <http://www.foxhop.net/mySQL#create-database>`_.

Let the django application build the tables in the new database:

.. code-block :: bash

$ python manage.py syncdb --all
    $ python manage.py migrate forum --fake

Configure Apache2 VirtualHost
--------------------------------

#. Turn on mod_rewrite:

.. code-block :: bash

$ a2enmod rewrite

#. Create a sites-available vhost apache2 file:

.. code-block :: bash

$ sudo vi /etc/apache2/sites-available/007-lostquery

#. Setup the host file:

.. code-block :: apache
    :linenos:

#lostquery.com

#Djangos embeded mod_wsgi
     <VirtualHost *:80>
          ServerName lostquery.com
          ServerAlias www.lostquery.com
          ServerAdmin admin@admin.com

# ReWrite URL to WWW
          RewriteEngine On
          RewriteCond %{HTTP_HOST} ^www.lostquery.com
          RewriteRule (.*) http://lostquery.com$1 [R=301,L]

# Log Files
          ErrorLog /var/log/apache2/error-lostquery.log
          CustomLog /var/log/apache2/access-lostquery.log combined

# Prevent django from serving static files
          DocumentRoot /www/lostquery.com/trunk/forum
          Alias /m/ /www/lostquery.com/trunk/forum/skins/
          Alias /upfiles/ /www/lostquery.com/trunk/forum/upfiles/
          <Directory /www/lostquery.com/trunk/forum/skins>
              Order allow,deny
              Allow from all
          </Directory>

# Setup mod_wsgi
          WSGIDaemonProcess lostquery display-name=lostquery user=www-data processes=2 threads=15
          WSGIScriptAlias / /www/lostquery.com/mod_wsgi/dispatch.wsgi

</VirtualHost>

Configure mod_wsgi
--------------------------------

#. Create the egg-cache directory:

.. code-block :: bash

$ mkdir /www/lostquery.com/mod_wsgi

$ mkdir /www/lostquery.com/mod_wsgi/egg-cache

#. Create the wsgi dispatch file:

.. code-block :: bash
  
    $ vi /www/lostquery.com/mod_wsgi/dispatch.wsgi

#. Setup the wsgi dispatch file:

.. code-block :: python
    :linenos:

import os
    import sys 
    sys.stdout = sys.stderr
    # Add the virtual Python environment site-packages directory to the path
    import site
    site.addsitedir('/www/lostquery.com/virtpy/lib/python2.6/site-packages')

# Avoid ``[Errno 13] Permission denied: '/var/www/.python-eggs'`` messages  
    import os
    os.environ['PYTHON_EGG_CACHE'] = '/www/lostquery.com/mod_wsgi/egg-cache'

#If your project is not on your PYTHONPATH by default you can add the following
    sys.path.append('/www/lostquery.com/trunk')
    os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'

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

Enable the Virtual Host and reload Apache2
------------------------------------------------

#. Reset apache2 so that it reads in the new config files:

.. code-block :: bash

$ a2ensite lostquery

$ sudo service apache2 reload

Comments

fritzvd 14y, 196d ago

Hi,

Thanks this is great and exhaustive. Helped me host my django. One question though, I usually do this: Create sites and put them in: sites-available. Reload apache2 for a graceful restart. Call them/switch on:

a2ensite lostquery

/etc/init.d/apache2 reload

Is there any special reason why you don't do this?

Fritz

remark

foxhop 14y, 195d ago

@fritzvd

I have recently started using the a2ensite method that you described.

Thanks for your input. I have adjusted the tutorial. Feel free to adjust anything you feel need work!

Foxhop

remark