Apache Config – Using Variables to Reduce Duplication

apache-2.2

Is it possible to use variables in Apache config files?

For example, when I'm setting up a site with Django+WSGI, the config file might look like:

<Directory /path/to/foo/>
    Order allow,deny
    Allow from all
</Directory>
Alias /foo/static /path/to/foo/static
WSGIScriptAlias /foo /path/to/foo/run_wsgi

And I'd like to turn the '/path/to/foo' into a variable so it only needs to be defined in one place. Something like:

Variable FOO /path/to/foo
…

Thanks!

Best Answer

You could use mod_macro, which has been included in Apache httpd since version 2.4

Before that it had to be installed separately, see mod_macro. For example on Debian: apt-get install libapache2-mod-macro; a2enmod macro.

Example configuration

/etc/apache2/conf.d/vhost.macro

<Macro VHost $host $port>
  <VirtualHost $host:$port>

    ServerName $host
    DocumentRoot /var/vhosts/$host

    <Directory /var/vhosts/$host>
      # do something here...
    </Directory>
  </VirtualHost>
</Macro>

/etc/apache2/sites-available/vhost.mysite.com

Use VHost vhost.mysite.com 80

Related Solutions

Django/WSGI and PHP on Apache – How to Share Root Directory

Use method described in:

http://code.google.com/p/modwsgi/wiki/ConfigurationGuidelines#The_Apache_Alias_Directive

Thus have DocumentRoot setup as normal for static files and php files etc. Then add:

AddHandler wsgi-script .wsgi

to Directory block for DocumentRoot, or globally for server.

You will though need to have:

Options ExecCGI

enabled for DocumentRoot now if you don't already.

Then also add:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ /site.wsgi/$1 [QSA,PT,L]

where site.wsgi is in DocumentRoot and is the WSGI script file which maps to your Django application.

In Django WSGI script file change it to use:

import django.core.handlers.wsgi

_application = django.core.handlers.wsgi.WSGIHandler()

import posixpath

def application(environ, start_response):
    # Wrapper to set SCRIPT_NAME to actual mount point.
    environ['SCRIPT_NAME'] = posixpath.dirname(environ['SCRIPT_NAME'])
    if environ['SCRIPT_NAME'] == '/':
        environ['SCRIPT_NAME'] = ''
    return _application(environ, start_response)

That should be it.

Any request that maps to an actual file based resource under DocumentRoot, be it static file or php file, including as setup by DirectoryIndex, eg., index.php, will be handled normally. Any other URL which would otherwise result in 404, will instead be routed into the Django application.

The /johnfreep and /pages/john would have to have corresponding URL as if mounted at root, in the urls.py file.

If Django doesn't know what to do with a URL, then Django will return 404.

Read the wiki document for more information.

Reusing Apache Environment variables while using SetEnv

Environment variables only work with the following Apache modules:

They cannot be called with SetEnv because that is a directive of the mod_env module.

More information: http://httpd.apache.org/docs/2.2/env.html#using

Best Answer

Example configuration

Related Solutions

Django/WSGI and PHP on Apache – How to Share Root Directory

Reusing Apache Environment variables while using SetEnv

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