---
layout: wiki
title: TracCgi
updated: 2020-06-20 21:43
author: trac
default: true
toc: true
---

## Installing Trac as CGI

> ''Please note that using Trac via CGI is the slowest deployment method available. It is slower than [wiki:TracModWSGI mod_wsgi], [TracModPython mod_python], [TracFastCgi FastCGI] and even [trac:TracOnWindowsIisAjp IIS/AJP] on Windows.''

CGI script is the entrypoint that web-server calls when a web-request to an application is made. The \`trac.cgi\` script can be created using the \`trac-admin <env> deploy <dir>\` command which automatically substitutes the required paths, see [TracInstall](/notes/TracInstall/)#cgi-bin. Make sure the script is executable by your web server.

### Apache web-server configuration

In [Apache](https://httpd.apache.org/) there are two ways to run Trac as CGI:

1. Use a \`ScriptAlias\` directive that maps a URL to the \`trac.cgi\` script (recommended)
1. Copy the \`trac.cgi\` file into the directory for CGI executables used by your web server (commonly named \`cgi-bin\`). You can also create a symbolic link, but in that case make sure that the \`FollowSymLinks\` option is enabled for the \`cgi-bin\` directory.

To make Trac available at \`<http://yourhost.example.org/trac`> add \`ScriptAlias\` directive to Apache configuration file, changing \`trac.cgi\` path to match your installation:

```apache
ScriptAlias /trac /path/to/www/trac/cgi-bin/trac.cgi
```

> ''Note that this directive requires that the `mod_alias` module is enabled.''
If you're using Trac with a single project you need to set its location using the \`TRAC_ENV\` environment variable:

```apache
<Location "/trac">
  SetEnv TRAC_ENV "/path/to/projectenv"
</Location>
```

Or to use multiple projects you can specify their common parent directory using the \`TRAC_ENV_PARENT_DIR\` variable:

```apache
<Location "/trac">
  SetEnv TRAC_ENV_PARENT_DIR "/path/to/project/parent/dir"
</Location>
```

>  ''Note that the `SetEnv` directive requires that the `mod_env` module is enabled.''
An alternative to \`SetEnv\` is editing \`TRAC_ENV\` or \`TRAC_ENV_PARENT_DIR\` in \`trac.cgi\`:

```python
    os.environ['TRAC_ENV'] = "/path/to/projectenv"
```

```python
    os.environ['TRAC_ENV_PARENT_DIR'] = "/path/to/parent/dir"
```

If you are using the [Apache suEXEC](https://httpd.apache.org/docs/suexec.html) feature please see trac:ApacheSuexec.

On some systems, you *may* need to edit the shebang line in the \`trac.cgi\` file to point to your real Python installation path. On a Windows system you may need to configure Windows to know how to execute a \`.cgi\` file (Explorer -> Tools -> Folder Options -> File Types -> CGI).

#### Python Egg Cache

The egg-cache can be configured using an \`os.environ\` statement in \`trac.cgi\`, as shown above.
To do the same from the Apache configuration, use the \`SetEnv\` directive:

```apache
SetEnv PYTHON_EGG_CACHE /path/to/dir
```

Put this directive next to where you set the path to the [Trac environment](/notes/TracEnvironment/), i.e. in the same \`<Location>\` block.

```apache
 <Location /trac>
   SetEnv TRAC_ENV /path/to/projenv
   SetEnv PYTHON_EGG_CACHE /path/to/dir
 </Location>
```

#### Using WSGI

You can run a [WSGI handler](http://henry.precheur.org/python/how_to_serve_cgi) [under CGI](https://thejimmyg.github.io/pythonweb/projects/webmodules/doc/0.5.3/html_multipage/lib/example-webserver-web-wsgi-simple-cgi.html).  You can write your own application function, or use the deployed trac.wsgi's application.

### Mapping Static Resources

See [TracInstall](/notes/TracInstall/)#MappingStaticResources.

### Adding Authentication

See [TracInstall](/notes/TracInstall/)#ConfiguringAuthentication.

---

See also:  [TracInstall](/notes/TracInstall/), [TracModWSGI](/notes/TracModWSGI/), [TracFastCgi](/notes/TracFastCgi/), [TracModPython](/notes/TracModPython/)