Create a web app in an App Service Environment v1


This article is about the App Service Environment v1. There is a newer version of the App Service Environment that is easier to use and runs on more powerful infrastructure. To learn more about the new version start with the Introduction to the App Service Environment.


This tutorial shows how to create web apps and App Service plans in an App Service Environment v1 (ASE).


If you want to learn how to create a web app but don't need to do it in an App Service Environment, see Create a .NET web app or one of the related tutorials for other languages and frameworks.


This tutorial assumes you have created an App Service Environment. If you haven't done that yet, see Create an App Service Environment.

Create a web app

  1. In the Azure Portal, click Create a resource > Web + Mobile > Web App.

    Screenshot that shows where to create a web app in the Azure portal.

  2. Select your subscription.

    If you have multiple subscriptions be aware that to create an app in your App Service Environment, you need to use the same subscription that you used when creating the environment.

  3. Select or create a resource group.

    Resource groups enable you to manage related Azure resources as a unit and are useful when establishing Azure role-based access control (Azure RBAC) rules for your apps. For more information, see Azure Resource Manager overview.

  4. Select or create an App Service plan.

    App Service plans are managed sets of web apps. Normally when you select pricing, the price charged is applied to the App Service plan rather than to the individual apps. In an ASE you pay for the compute instances allocated to the ASE rather than what you have listed with your ASP. To scale up the number of instances of a web app you scale up the instances of your App Service plan and it affects all of the web apps in that plan. Some features such as site slots or VNET Integration also have quantity restrictions within the plan. For more information, see Azure App Service plans overview

    You can identify the App Service plans in your ASE by looking at the location that is noted under the plan name.

    Screenshot that shows were to view the App Service plans in your ASE.

    If you want to use an App Service plan that already exists in your App Service Environment, select that plan. If you want to create a new App Service plan, see the following section of this tutorial, Create an App Service plan in an App Service Environment.

  5. Enter the name for your web app, and then click Create.

    If your ASE uses an External VIP the URL of an app in an ASE is: [sitename].[name of your App Service Environment] instead of [sitename]

    If your ASE uses an Internal VIP then the URL of an app in that ASE is: [sitename].[subdomain specified during ASE creation]
    After you select your ASP during ASE creation you will see the subdomain update below Name

Create an App Service plan

When you create an App Service plan in an App Service Environment, your worker choices are different as there are no shared workers in an ASE. The workers you have to use are the ones that have been allocated to the ASE by the admin. This means that to create a new plan, you need to have more workers allocated to your ASE worker pool than the total number of instances across all of your plans already in that worker pool. If you don't have enough workers in your ASE worker pool to create your plan, you need to work with your ASE admin to get them added.

Another difference with App Service plans hosted by an App Service Environment is the lack of pricing selection. When you have an App Service Environment you are paying for compute resources used by the system and do not have added charges for the plans in that environment. Normally when you create an App Service plan you select a pricing plan which determines your billing. An App Service Environment is essentially a private location where you can create content. You pay for the environment and not to host your content.

The following instructions show how to create an App Service plan while you are creating a web app as explained in the previous section of the tutorial.

  1. Click Create New in the plan selection UI and provide a name for your plan just as you normally would outside of an ASE.

  2. Select the ASE that you want to use from your location picker.

    Because an App Service Environment is essentially a private deployment location, it shows under Location.

    Screenshot that shows the location picker for selecting the ASE you want.

    After selection of an ASE in the location picker, the App Service plan creation UI updates. The location now shows the name of the ASE system and the region it is in, and the pricing plan picker is replaced with a worker pool picker.

    Screenshot that shows the ASE system details after selecting the ASE in the location picker.

Selecting a worker pool

Normally in Azure App Service and outside of an App Service Environment, there are 3 compute sizes that are available with the selection of a dedicated price plan. In a similar fashion, for an ASE you can define up to 3 pools of workers and specify the compute size that is used for that worker pool. What that means for tenants of the ASE is that instead of selecting a pricing plan with compute size for your App Service plan, you select what is called a worker pool.

The worker pool selection UI shows the compute size used for that worker pool below the name. The quantity available refers to how many compute instances are available for use in that pool. The total pool may actually have more instances than this number but this value refers to simply how many are not in use. If you need to adjust your App Service Environment to add more compute resources see Configuring your App Service Environment.

Screenshot that shows the Worker Pool pane where you can select worker pools for the ASE.

In this example you see only two worker pools available. That is because the ASE administrator only allocated hosts into those two worker pools. The third would show up when there are VMs allocated into it.

After web app creation

There are a few considerations for running web apps and managing App Service plans in an ASE that need to be taken into account.

As noted earlier, the owner of the ASE is responsible for the size of the system and as a result they are also responsible for ensuring that there is sufficient capacity to host the desired App Service plans. If there are no available workers, you will not be able to create your App Service plan. This is also true to scaling up your web app. If you need more instances then you would have to get your App Service Environment admin to add more workers.

After creating your web app and App Service plan it is a good idea to scale it up. In an ASE you always need to have at least 2 instances of your App Service plan to provide fault tolerance for your apps. Scaling an App Service plan in an ASE is the same as normal through the App Service plan UI. For more information about scaling, How to scale a web app in an App Service Environment