ISAPI filter RRS feed

  • Question

  • I'm in the process of trying to migrate an IIS Application (Dokuwiki) to an Azure Web App but I'm having issues with an ISAPI filter we added. At the moment, in IIS, I specify the dll under ISAPI and CGI Restrictions and set this to allowed. From here, I open the web application and set it to allowed under the ISAPI Filters. After moving the application to Azure, the dll which handles redirection no longer works. Am I missing something obvious?

    Thanks in advice for any help


    Monday, July 13, 2015 2:44 PM


All replies

  • Hi,

     Web Apps can support the use of ISAPI Filters. You need to do the following:
    • deploy the DLLs with your web app
    • register the DLLs using Web.config

    I would suggest you to refer this link for more details:


    Azam Khan

    Monday, July 13, 2015 5:58 PM
  • Hi Azam,

    Thanks for the reply. I assume you are suggesting modifying DokuWiki to include the dll prior to adding it into Azure? I'm used to working with web.config files but application deployment from Visual Studio etc is not something I'm familiar with.

    Thanks for the pointers, hopefully I'll be able to get this working.



    Tuesday, July 14, 2015 7:01 AM
  • Hi Azam,

    I have added the dll to the site under a folder called filter and uploaded using the migration tool. I have then added the following to my web.config file: -

                name="Help URL rewriter"
                path="filter\DokuWikiRedirects.dll" />

    In the wwwroot I have created applicationHost.xdt and added: -

    <?xml version="1.0"?>
    <configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
        <sectionGroup name="system.webServer">
          <section name="isapiFilters" xdt:Transform="SetAttributes(overrideModeDefault)" overrideModeDefault="Allow" />

    When I try to load the site I now just get an error 500.

    Any thoughts on how I can troubleshoot this?



    Tuesday, July 14, 2015 3:48 PM
  • Hi,

    For 500 Errors, One good way is to turn diagnostics on and to look at the logs - both the application event logs and the failed request logs might help. Here is the link:

    Azam khan

    Wednesday, July 22, 2015 11:22 AM