Trac and mod_python

Trac 0.7.1 and later supports ​mod_python, which speeds up Trac's response times considerably and permits use of many Apache features not possible with tracd/mod_proxy.

Note: The mod_python support in 0.7.1 has a couple of bugs that have since been fixed in both the ​0.7 branch and ​trunk, and will be released with ​0.8.

Simple configuration

Here's a typical Trac CGI/Apache setup:

ScriptAlias /trac/myproject /path/to/python/share/trac/cgi-bin/trac.cgi
<Location /trac/myproject>
   SetEnv TRAC_ENV /var/svn/trac/myproject
</Location>

The equivalent mod_python setup is:

<Location /trac/myproject>
   SetHandler mod_python
   PythonHandler trac.ModPythonHandler
   PythonOption TracUriRoot "/trac/myproject"
   PythonOption TracEnv /var/svn/trac/myproject
</Location>

Note that the option TracUriRoot may or may not be necessary in your setup. Try without first, and if the URLs produced by Trac look wrong, add the TracUriRoot option.

Setting up multiple projects

The easy way

The Trac mod_python handler handler supports a configuration option similar to Subversion's SvnParentPath, called TracEnvParentDir:

<LocationMatch /trac>
  SetHandler mod_python
  PythonHandler trac.ModPythonHandler
  PythonOption TracUriRoot /trac
  PythonOption TracEnvParentDir "/var/www/projects"
</LocationMatch>

When you request the /trac URL, you will get a (currently very simple) listing of all subdirectories of the directory you set as TracEnvParentDir. Selecting any project in the list will bring you to the corresponding Trac instance. You should make sure that the configured directory only contains Trac environment directories that match the currently installed Trac version, because that is not checked prior the the generation of the project list.

Or the hard way

The Trac mod_python handler can be configured to serve multiple projects, as can be seen in the following simple example:

<LocationMatch /trac/[[:alnum:]]+>
  SetHandler mod_python
  PythonHandler trac.ModPythonHandler
</LocationMatch>
<Location /trac/exampleone>
  PythonOption TracUriRoot "/trac/exampleone"
  PythonOption TracEnv "/var/www/projects/exampleone"
</Location>
<Location /trac/exampletwo>
  PythonOption TracUriRoot "/trac/exampletwo"
  PythonOption TracEnv "/var/www/projects/exampletwo"
</Location>

This sets up two projects. The disadvantage of the approach used here is that you need one additional <Location> directive per Trac instance. You may be able to eliminate this using some mod_rewrite tricks.

Adding authentication

Adding authentication is straightforward in both cases. For example:

<LocationMatch /trac/[[:alnum:]]+/login>
  AuthType Basic
  AuthName "Trac"
  AuthUserFile /var/www/passwd
  Require valid-user
</LocationMatch>

Win32 Issues

If you run trac with mod_python on Windows, attachments will not work.

There is a (simple) workaround for this which is to apply the patch attached to ticket ​#554.

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See also TracGuide, TracInstall, TracMultipleProjects