Each App Service you will create in Azure will have some app settings to configure. These app settings are some configurable items that you would like to configure for the app without changing any piece of the code. The application settings of the App Service can be accessed by navigating to App Service and select the App Service you wish and click on Application settings.

The application settings are classified into the following categories:

• General settings: Here, you can specify the following:
  • Framework: Framework versions that the app is using, such as .NET, PHP, Java, and Python.
  • Platform: Specify the platform architecture that you want to run your web app on, whether it is 32 bit or 64 bit.
  • Web sockets: You can enable web sockets for your applications in case your web app is using socket.io or ASP.NET SignalR. In addition to that, web sockets allow for more flexible connectivity between web apps and modern browsers. Your web app would need to be built to leverage these capabilities.
  • Always On: This setting would load your web app all the time, because by default, web apps are unloaded after they have been idle for a while. It's recommended to enable this setting if you have continuous WebJobs running on the web app.
  • Managed pipeline version: This setting identifies the IIS application pool mode. It's recommended to use the integrated mode unless you have a legacy application that depends on IIS versions older than IIS 7; then you can select Classic.
  • HTTP version: Select the HTTP version that suits your needs.
  • ARR affinity: If you turn on this setting, it will ensure that the client is routed to the same VM when you have multiple VMs hosting your web app during the life of the session.
  • Auto swap: This setting can be configured for any deployment slot, other than the production one. In order to configure it for a deployment slot, you have to navigate to App Service then select Deployment slots and then select the deployment slot you want to configure this setting for. A new blade will be opened for the deployment slots with the same configurations in the blade of the original App Service, from there you can click on Application settings to be able to view the app settings of the slot and configure it accordingly. Therefore, if this setting is enabled, it will automatically swap this slot with the slot that you will specify in the next step whenever an update is pushed to that slot.
  • Auto swap slot: If the previous setting is enabled, you have to specify which slot you should swap.
  • FTP access: Specify the way in which FTP accesses the App Service, whether by enabling it for FTP and FTPS, or FTPS only, or just disable it if you do not want to use it:

• Debugging: In this category, you can specify the following:
  • Remote debugging: You can specify whether you want to enable or disable remote debugging for this App Service. If it is enabled, the remote debugger of Visual Studio can be connected directly to the web app.
  • Remote Visual Studio version: Specify the version of Visual Studio you have. Only the 2015 and 2017 versions are supported at the time of writing:

• Application settings: In this category, you can provide some settings that you want to force your web application to load on every startup in the form of name/value pairs. For example, if you want to configure the application to be monitored by Application Insights, you can set the application setting's name and value, as shown in the following screenshot:

• Connection strings: You can specify the connection strings between the application and the databases.
• Default documents: In this category, you can specify the documents that would be displayed at the home page of the web app.
• Handler mappings: In this category, you can add custom script processors so you can handle requests based on a specific file extension by specifying the following:
  • Extension: The extension of the file you want to be handled.
  • Script processor path: This is an absolute path to the script processor that will operate to process requests for files that corresponds to the pattern specified in the extension.
  • Optional arguments: This can be used to add another path to a script for the script processor. Therefore, any arguments you would like to specify when the script processor is enabled can be proceeded with.

• Virtual applications and directories: In this category, you can add virtual applications and directories, where you can specify the virtual directory and its physical path according to the root of the website.