= Trac and mod_python =
Trac supports [http://www.modpython.org/ mod_python], which speeds up Trac's response times considerably, especially compared to TracCgi, and permits use of many Apache features not possible with [wiki:TracStandalone tracd]/mod_proxy.
'''Attention: These instructions apply to Trac version [milestone:0.9]. If you're installing Trac 0.8.x, please see a [http://projects.edgewall.com/trac/wiki/TracModPython?version=38 previous version of this page.] If you're upgrading from 0.8.x to 0.9, please read the [wiki:TracUpgrade#From0.8.xto0.9 upgrade instructions].
'''
Be sure to grab mod_python 3.1.3 and later for ''SetHandler'' ''mod_python'' directive to work. Also, older versions may generate an internal error (see #1090)
What is the preferred MPM method, or does it matter (worker or prefork)
== Simple configuration ==
If you just installed mod_python, you may have to add a line to load the module in the Apache configuration:
{{{
LoadModule python_module modules/mod_python.so
}}}
A simple setup of Trac on mod_python looks like this:
{{{
SetHandler mod_python
PythonHandler trac.web.modpython_frontend
PythonOption TracEnv /var/trac/myproject
PythonOption TracUriRoot /projects/myproject
}}}
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 or if Trac does not seem to recognize the URLs correctly, add the `TracUriRoot` option.
Configuring authentication works the same as for [wiki:TracCgi#AddingAuthentication CGI]:
{{{
AuthType Basic
AuthName "myproject"
AuthUserFile /var/trac/myproject/.htaccess
Require valid-user
}}}
If the Trac installation isn't installed in your Python path, you'll have to tell Apache where to find the Trac mod_python handler using the `PythonPath` directive:
{{{
...
PythonPath "sys.path + ['/path/to/trac']"
...
}}}
== Setting up multiple projects ==
The Trac mod_python handler supports a configuration option similar to Subversion's `SvnParentPath`, called `TracEnvParentDir`:
{{{
SetHandler mod_python
PythonHandler trac.web.modpython_frontend
PythonOption TracEnvParentDir /var/trac
PythonOption TracUriRoot /projects
}}}
When you request the `/projects` URL, you will get a listing of all subdirectories of the directory you set as `TracEnvParentDir`. Selecting any project in the list will bring you to the corresponding Trac environment.
If you don't want to have the subdirectory listing as your projects home page you can use a
{{{
}}}
This will instruct Apache to use mod_python for all locations different from root while having the possibility of placing a custom home page for root in your !DocumentRoot folder.
You can also use the same authentication realm for all of the projects using a `` directive:
{{{
AuthType Basic
AuthName "Trac"
AuthUserFile /var/trac/.htaccess
Require valid-user
}}}
== Virtual Host Configuration ==
Below is the sample configuration required to set up your trac as a virtual server (i.e. when you access it at the URLs like
!http://trac.mycompany.com):
{{{
DocumentRoot /var/trac/myproject
ServerName trac.mycompany.com
SetHandler mod_python
PythonHandler trac.web.modpython_frontend
PythonOption TracEnv /var/trac/myproject
PythonOption TracUriRoot /
AuthType Basic
AuthName "MyCompany Trac Server"
AuthUserFile /var/trac/myproject/.htusers
Require valid-user
}}}
If your images and CSS are not applying properly add this within the !VirtualHost directives
{{{
Alias /trac /usr/share/trac/htdocs
SetHandler None
}}}
For a virtual host that supports multiple projects replace 'TracEnv' /var/trac/myproject with 'TracEnvParentDir' /var/trac/
== Troubleshooting ==
=== Form submission problems ===
If you're experiencing problems submitting some of the forms in Trac (a common problem is that you get redirected to the start page after submission), check whether your {{{DocumentRoot}}} contains a folder or file with the same path that you mapped the mod_python handler to. For some reason, mod_python gets confused when it is mapped to a location that also matches a static resource.
=== Using .htaccess ===
Although it may seem trivial to rewrite the above configuration as a directory in your document root with a `.htaccess` file, this does not work. Apache will append a "/" to any Trac URLs, which interferes with its correct operation.
It may be possible to work around this with mod_rewrite, but I failed to get this working. In all, it is more hassle than it is worth. Stick to the provided instructions. :)
=== Win32 Issues ===
Don't feel like compiling the source? Windows installers are available at the following URLs. Make sure you grab an installer which works with your version of Python:
[http://www.apache.org/dist/httpd/modpython/win/3.2.7/] or
[http://www.lehuen.com/nicolas/download/mod_python/]
If you run trac with mod_python < 3.2 on Windows,
uploading attachments will '''not''' work. This problem which is discussed in #554 is resolved in mod_python > 3.1.4 so please upgrade mod_python to fix this.
=== OS X issues ===
When using mod_python on OS X you will not be able to restart Apache using `apachectl restart`. This is apparently fixed in mod_python 3.2, but there's also a patch available for earlier versions [http://www.dscpl.com.au/projects/vampire/patches.html here].
=== SELinux issues ===
If Trac reports something like: ''Cannot get shared lock on db.lock''
The security context on the repository may need to be set:
{{{ chcon -R -h -t httpd_sys_content_t PATH_TO_REPOSITORY }}}
See also [[http://subversion.tigris.org/faq.html#reposperms]]
----
See also TracGuide, TracInstall, TracCgi, TracFastCgi, [wiki:TracMultipleProjectsSVNAccess]