= Running Trac on IIS 6 using Isapi-wsgi =

Contributed by:[[br]]
Seb Patane

I did this with:
 * Windows Server 2003 SP2
 * Python 2.7
 * IIS 6
 * Trac 0.12
It may work for other versions.

-------------------------------
Jeremy Mattke, Minneapolis, USA.
I was able to do this with:
 * Windows 8.1
 * Python 2.7
 * IIS 8.5
 * Trac 1.0
------------------------------

I also haven't tested standard authentication as I use the [http://trac-hacks.org/wiki/AccountManagerPlugin AccountManagerPlugin]. I also found this to be significantly faster than the TracOnWindowsIisAjp.

The only downside is that whenever a plugin is manually installed/code is changed a full `iisreset` needs to be done to reload the ISAPI dll. Restarting the IIS Site alone doesn't seem to be enough.

1. Download & install the latest [http://code.google.com/p/isapi-wsgi/ Isapi-wsgi] (I used 0.4.2 exe), depends on [http://sourceforge.net/projects/pywin32/files/pywin32 pywin32] (I used Build 216 exe)
1. Generate a `trac.wsgi` script using `trac-admin <env> deploy <dir>` (see TracInstall#cgi-bin)
1. copy `trac.wsgi` into a new file called `trac_wsgi.py` for Isapi-wsgi. Replace the dot with the underscore!
1. Append these extra bits so Isapi-wsgi can generate an ISAPI DLL:
{{{
#!C:\Python27\python.exe
import isapi_wsgi
# The entry points for the ISAPI extension.
def __ExtensionFactory__():
    # can also be isapi_wsgi.ISAPISimpleHandler
    return isapi_wsgi.ISAPIThreadPoolHandler(application)

if __name__=='__main__':
    # If run from the command-line, install ourselves.
    from isapi.install import *
    params = ISAPIParameters()
    # Setup the virtual directories - this is a list of directories our
    # extension uses - in this case only 1.
    # Each extension has a "script map" - this is the mapping of ISAPI
    # extensions.
    sm = [
        ScriptMapParams(Extension="*", Flags=0)
    ]
    # To serve from root, just set Name="/"
    vd = VirtualDirParameters(Name="/trac",
                              Description = "ISAPI-WSGI Trac",
                              ScriptMaps = sm,
                              ScriptMapUpdate = "replace"
                              )
    params.VirtualDirs = [vd]
    HandleCommandLine(params)
}}}
1. Ensure everything has the right Permissions for the IIS Site user.
 * READ/EXECUTE: imports from site-packages (including eggs), generated ISAPI dll, trac directory & subdirectories
 * WRITE/MODIFY: trac/conf/trac.ini, trac/log directory, trac/plugins directory, trac/attachments directory (?), trac/db directory (?), .htpasswd file (if using Account Manager)
1. Generate and Install the ISAPI dll using `python trac_wsgi.py install [--server=<IIS Web Site Name>]`. Don't forget to do an `iisreset` whenever the filter is reinstalled.
 * This will automatically create the Virtual Directory, install the ISAPI filter and allow it in Web Service Extensions
1. That's it, everything should work! NOTE: if you have a problem with trac.web.main being found you need to unzip your eggs in the python/lib/site-packages directory for Trac, Genshi and setuptools

If there are problems you can enable debugging by inserting the following at the top of `trac_wsgi.py`, reinstalling the ISAPI dll and running `python -m win32traceutil` (will also display TracLogging to `stderr`).
{{{
#!C:\Python27\python.exe
import sys

if hasattr(sys, "isapidllhandle"):
    import win32traceutil
}}}

TracModWSGI is probably a good starting point as well, even though it deals with Apache.

== Broken Authentication ==
I had a problem with the [http://trac-hacks.org/wiki/AccountManagerPlugin AccountManagerPlugin] always returning `Invalid Username or Password`. This is because the `REMOTE_USER` environment variable is set (I'm not sure why, since it seems to be empty).

In any event, putting `del environ['REMOTE_USER']` in `trac_wsgi.py` solved the problem.

== Appendix A - My working trac_wsgi.py (with useful extras) ==
{{{
#!C:\Python27\python.exe
# -*- coding: utf-8 -*-
#
# Copyright (C)2008-2009 Edgewall Software
# Copyright (C) 2008 Noah Kantrowitz <noah@coderanger.net>
# All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at http://trac.edgewall.org/wiki/TracLicense.
#
# This software consists of voluntary contributions made by many
# individuals. For the exact contribution history, see the revision
# history and logs, available at http://trac.edgewall.org/log/.
#
# Author: Noah Kantrowitz <noah@coderanger.net>
#
# IMPORTANT: when you make changes to this file you need to
#            update the ISAPI filter with the following commands -
#   C:\Inetpub\trac\cgi-bin> python trac_wsgi.py install --server=Trac
#   C:\Inetpub\trac\cgi-bin> iisreset
#
import os

"""
# Uncommenting this enables debug output
# you can see it by opening up a command prompt and executing
#	> python -m win32traceutil
import sys

if hasattr(sys, "isapidllhandle"):
    import win32traceutil
"""

def application(environ, start_request):
    if not 'trac.env_parent_dir' in environ:
        environ.setdefault('trac.env_path', 'C:\\Inetpub\\trac')
    if 'PYTHON_EGG_CACHE' in environ:                                           
        os.environ['PYTHON_EGG_CACHE'] = environ['PYTHON_EGG_CACHE']
    elif 'trac.env_path' in environ:
        os.environ['PYTHON_EGG_CACHE'] = \
            os.path.join(environ['trac.env_path'], '.egg-cache')
    elif 'trac.env_parent_dir' in environ:
        os.environ['PYTHON_EGG_CACHE'] = \
            os.path.join(environ['trac.env_parent_dir'], '.egg-cache')

    # Required for Account Manager logins to work
    del environ['REMOTE_USER']

    from trac.web.main import dispatch_request
    return dispatch_request(environ, start_request)

"""
# Uncommenting this enables middleware profiling at /__profile__
# Requires the repoze.profiler egg to be installed
from repoze.profile.profiler import AccumulatingProfileMiddleware
application = AccumulatingProfileMiddleware(application,
                                            log_filename='C:\\repoze.log',
                                            discard_first_request=True,
                                            flush_at_shutdown=True,
                                            path='/__profile__')
"""

import isapi_wsgi
# The entry points for the ISAPI extension.
def __ExtensionFactory__():
    return isapi_wsgi.ISAPIThreadPoolHandler(application)

if __name__=='__main__':
    # If run from the command-line, install ourselves.
    from isapi.install import *
    params = ISAPIParameters()
    # Setup the virtual directories - this is a list of directories our
    # extension uses - in this case only 1.
    # Each extension has a "script map" - this is the mapping of ISAPI
    # extensions.
    sm = [
        ScriptMapParams(Extension="*", Flags=0)
    ]
    # To serve from root, just set Name="/"
    vd = VirtualDirParameters(Name="/trac",
                              Description = "ISAPI-WSGI Trac",
                              ScriptMaps = sm,
                              ScriptMapUpdate = "replace"
                              )
    params.VirtualDirs = [vd]
    HandleCommandLine(params)
}}}