Installing Kallithea on Microsoft Internet Information Services (IIS)

The following is documented using IIS 7/8 terminology. There should be nothing preventing you from applying this on IIS 6 well.


Installing Kallithea under IIS can enable Single Sign-On to the Kallithea web interface from web browsers that can authenticate to the web server. (As an alternative to IIS, SSO is also possible with for example Apache and mod_sspi.)

Mercurial and Git do however by default not support SSO on the client side and will still require some other kind of authentication. (An extension like hgssoauthentication_ might solve that.)


For the best security, it is strongly recommended to only host the site over a secure connection, e.g. using TLS.


Apart from the normal requirements for Kallithea, it is also necessary to get an ISAPI-WSGI bridge module, e.g. isapi-wsgi.


The following assumes that your Kallithea is at c:\inetpub\kallithea, and will be served from the root of its own website. The changes to serve it in its own virtual folder will be noted where appropriate.

Application pool

Make sure that there is a unique application pool for the Kallithea application with an identity that has read access to the Kallithea distribution.

The application pool does not need to be able to run any managed code. If you are using a 32-bit Python installation, then you must enable 32-bit program in the advanced settings for the application pool; otherwise Python will not be able to run on the website and neither will Kallithea.


The application pool can be the same as an existing application pool, as long as the Kallithea requirements are met by the existing pool.

ISAPI handler

The ISAPI handler can be generated using:

paster install-iis my.ini --virtualdir=/

This will generate a file in the current directory that contains the necessary components to finalize an installation into IIS. Once this file has been generated, it is necessary to run the following command due to the way that ISAPI-WSGI is made:

python2 install

This accomplishes two things: generating an ISAPI compliant DLL file, _dispatch.dll, and installing a script map handler into IIS for the --virtualdir specified above pointing to _dispatch.dll.

The ISAPI handler is registered to all file extensions, so it will automatically be the one handling all requests to the specified virtual directory. When the website starts the ISAPI handler, it will start a thread pool managed wrapper around the paster middleware WSGI handler that Kallithea runs within and each HTTP request to the site will be processed through this logic henceforth.

Authentication with Kallithea using IIS authentication modules

The recommended way to handle authentication with Kallithea using IIS is to let IIS handle all the authentication and just pass it to Kallithea.


As an alternative without SSO, you can also use LDAP authentication with Active Directory, see Setting up LDAP support.

To move responsibility into IIS from Kallithea, we need to configure Kallithea to let external systems handle authentication and then let Kallithea create the user automatically. To do this, access the administration’s authentication page and enable the kallithea.lib.auth_modules.auth_container plugin. Once it is added, enable it with the REMOTE_USER header and check Clean username. Finally, save the changes on this page.

Switch to the administration’s permissions page and disable anonymous access, otherwise Kallithea will not attempt to use the authenticated user name. By default, Kallithea will populate the list of users lazily as they log in. Either disable external auth account activation and ensure that you pre-populate the user database with an external tool, or set it to Automatic activation of external account. Finally, save the changes.

The last necessary step is to enable the relevant authentication in IIS, e.g. Windows authentication.


Typically, any issues in this setup will either be entirely in IIS or entirely in Kallithea (or Kallithea’s WSGI/paster middleware). Consequently, two different options for finding issues exist: IIS’ failed request tracking which is great at finding issues until they exist inside Kallithea, at which point the ISAPI-WSGI wrapper above uses win32traceutil, which is part of pywin32.

In order to dump output from WSGI using win32traceutil it is sufficient to type the following in a console window:

python2 -m win32traceutil

and any exceptions occurring in the WSGI layer and below (i.e. in the Kallithea application itself) that are uncaught, will be printed here complete with stack traces, making it a lot easier to identify issues.