Adding an application to an Azure Application Service Environment (ASE) is a pretty straight-forward operation, but sometimes you will get: "No App Service Environments in this subscription" What does this mean? Why isn't the App Service Environment in the list?
App Service Environments are a premium feature of the Microsoft Cloud. It provides a fully isolated and dedicated environment for securely running Azure App Service apps at high scale, including Web Apps, Mobile Apps, and API Apps. App Service Environments scale differently than most apps in Azure. First, the ASE itself defines a set of worker pool instances:
The pool instance counts represent the number of physical resources available in each worker pool in your ASE. If you click on your ASE's main blade, then select Worker Pools. Then choose a worker pool. You can see the resources allocated in the pool:
Notice the "Workers Available" is 0. Because of this I'm unable to add any new applications or App Service Plans to the ASE. You first need to increase the scale of the pool to accommodate additional resources.
Here I've increased the Worker pool 1 Instance Count from 2 to 3. At the time of this writing, ASE scale operations take several hours to complete. You will see this notification while the scale operation is in progress.
Once completed. You now have an extra instance available in your worker pool to add an additional App Service Plan and Application.
You can see the App Service Environment is now available in the Location drop down, now that there is additional capacity in the Worker Pool for the App Service Plan.