Windows Server 2008 Server Core : Managing IIS - Working with the ApplicationHost.CONFIG File

Figure 1. The ApplicationHost.CONFIG file normally contains native code settings.

Even though the file appears quite complex, you can break the ApplicationHost.CONFIG file into five major areas. Once you know which area to view for a particular kind of data, working with the file becomes considerably easier. The following list describes each of the major areas.

configSections

The configSections element defines the sections within the configuration file. You'll never need to change anything in this element because IIS depends on a specific configuration to accomplish tasks and you'll use other means to configure custom applications.

configProtectedData

The configProtectedData element contains the security provider information for the system. You normally won't need to change this information unless you obtain a third-party provider (there aren't any available for IIS 7 at the time of this writing). If you do obtain a third-party provider, it's likely that the provider's installation program will make all of the appropriate entries for you. In sum, you probably won't need to change the settings in this element.

system.applicationHost

The system.applicationHost element is a configured section—one that doesn't necessarily have to appear by default, but you'll normally see it. This element contains a number of interesting configuration options that include the application pools, custom metadata, listener adapters, log file settings, and some Web site settings. A number of these settings are impossible to set using the graphical utilities. For example, you can't set the log file settings using the graphical interface, but you can set them quite easily using the settings in this file. The Web site settings include the Web site bindings, failed request logging, and application location information.

system.webServer

The system.webServer element is a configured section—one that doesn't necessarily have to appear by default, but you'll normally see it. Many of these entries look like they came directly from the graphical interface. For example, you'll find the CGI settings here, as well as the default Web page and directory browsing settings for the Web server as a whole. Some settings aren't available from the graphical interface. For example, you can set up ODBC logging using elements contained within this element. One of the performance options you'll want to check is caching. You can enable or disable caching for the Web server as a whole or for the kernel.

location

Every time you create a new location in IIS, IIS creates a new location element to hold it. The location element contains a path attribute as a minimum that describes the location. For example, you'll find an entry for the Default Web Site in the list. Every application, virtual directory, or folder with special settings appears in the list. A common child element is system.webServer. This element may contain any number of child elements or no child elements at all. The elements you see depend on the special settings for the location. When working with an application, it's common to see elements for setting the security, default directory, and handlers.

1. Working with the Administration.CONFIG File

The \Windows\System32\inetsrv\config\Administration.CONFIG file contains administrative settings for the server. For example, you'll configure the actual list of administrators here and define the list of administrator providers you want to use, as shown in Figure 2. As with the ApplicationHost.CONFIG file, the Administration.CONFIG file contains a number of required entries that you probably won't change, including the configSections element.

Figure 2. The Administration.CONFIG file contains administrative settings.

The main item of interest is the moduleProviders element. It contains a list of modules that IIS uses to perform useful work. You can't access these providers from the graphical interface—they affect IIS at a relatively low level. IIS sorts them by server and ASP.NET modules. As with the security profiles, the modules you use must appear in the GAC. You can add new modules by registering the module in the GAC using the GACUtil utility and then adding the appropriate entry to the moduleProviders element.

Simply adding an add element to the moduleProviders element won't make the provider accessible to the server. You must link the provider to a particular location, which is where the locationelement comes into play in this file. When you open the location element, you'll find that it contains a modules element that has a list of modules for that location. You simply refer to the name of the element you created in the moduleProviders element. When you remove an element from this list, the server no longer uses the module provider for that particular location, but it remains configured for use later. The default IIS setup only includes one location, the Web server itself.