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Signal Sciences Azure site extension

The Azure site extension for Signal Sciences adds Signal Sciences' next-gen Web Application Firewall (WAF) to any IIS web application hosted on Azure App Service.

The Signal Sciences Azure site extension downloads and installs the Signal Sciences agent and IIS module. The extension also registers the IIS module to the IIS web server in Azure App Service by generating the XML transformation file, applicationHost.xdt. XML transformations are currently the only way to edit the IIS configuration file, applicationHost.config.

The Signal Sciences IIS module and agent are configured by using environment variables. Environment variables are set in the web app configuration in the Azure Portal.

Module and agent binaries are extracted into a directory in the App Service environment with the name derived from the downloaded zip file. Agent and module binaries may not be deleted if the the site is running.

Signal Sciences Agent Access Keys Configuration

Before adding the Signal Sciences site extension, you must first set the Signal Sciences Agent Access Key and Secret Key by setting environment variables in the application settings on https://portal.azure.com/

  1. In the Azure Portal, go to App Service and select web app

  2. Set environment variables

    Click on Configuration > Application settings > New application setting and set the following variables as two name/value pairs.

    Note: Key id and secret can be found in Signal Sciences console Agents > click on View Agent Keys.

    ``` Name: SIGSCI_ACCESSKEYID Value:

    Name: SIGSCI_SECRETACCESSKEY Value: ```

    Click on Save after adding the application settings

  3. Restart the web app

    Click on Overview in the side bar, click on Stop and Start button.

Install the Signal Sciences Site Extension

  1. In the Azure Portal, go to App Service and select web app

  2. First stop the web app

    Click on Overview in the side bar, click on Stop button.

  3. Add site extension

    Click on Extensions in the sidebar > Add > Choose Extension > Signal Sciences WAF > OK

  4. Start the web app

    Click on Overview in the side bar, click on Start button.

Note: The site extension will take a few minutes to download and install. During this time, the web application may be unavailable or display a 502 error until the site extension is installed.

Uninstall the Site Extension

  1. In the Azure Portal, go to App Service and select web app

  2. First stop the web app

    Click on Overview in the side bar, click on Stop button.

  3. Delete site extension

    Click on Extensions in the sidebar, Click on Signal Sciences WAF, Click on Delete.

Upgrading the Signal Sciences Agent and Module

There are two methods for upgrading the Signal Sciences agent and module that are downloaded when the site extension is first installed:

  1. Uninstall and reinstall the site extension. When the extension is reinstalled, the latest version of the Signal Sciences agent and IIS module will be downloaded and installed.

  2. Open the Azure CLI and run the install.cmd script in the site extension directory. This method could also be used in a powershell script for automating the upgrade of multiple agents.

    1. Open the windows cmd shell by clicking on Console in the sidebar
    2. Run the install script > cd D:\home\SiteExtensions\SignalSciences.Azure.Site.Extension > install.cmd

Troubleshooting

  • If changing the Application Platform between 32-bit and 64-bit, follow the upgrading instructions to uninstall and reinstall the Signal Sciences agent and module.

  • All private site extensions can be disabled by setting

WEBSITE_PRIVATE_EXTENSIONS to 0 in Application settings

Note: Stop/start the web app after saving the setting to reflect the changes.

  • Windows event log can be viewed at https://.scm.azurewebsites.net/DebugConsole/?shell=powershell

Click on LogFiles > eventlog.xml