PublishAsExisting on AzureAppServiceEnvironmentResource doesn't use existing

[rjpowers10]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Aspire.Hosting.Azure.AppService version 13.1.0-preview.1.25616.3

Calling the PublishAsExisting method on IResourceBuilder<AzureAppServiceEnvironmentResource> appears to have no effect on the generated bicep. I know it's in preview but the docs suggest it should work.

The same result happens whether I use AsExisting or PublishAsExisting.

Expected Behavior

The bicep is generated to use an existing app service plan.

Steps To Reproduce

Create the starter app

aspire new aspire-starter -n AspireApp -o AspireApp

Add App Service

aspire add azure-appservice

✔  The package Aspire.Hosting.Azure.AppService::13.1.0-preview.1.25616.3 was added successfully.

Replace the contents of AppHost.cs as follows.

var builder = DistributedApplication.CreateBuilder(args);

var existingAppServicePlanName = builder.AddParameter("ExistingAppServicePlanName", "existing-plan-name");
var existingAppServicePlanResourceGroup = builder.AddParameter("ExistingAppServicePlanResourceGroup", "existing-resource-group");

builder.AddAzureAppServiceEnvironment("env").PublishAsExisting(existingAppServicePlanName, existingAppServicePlanResourceGroup);

builder.Build().Run();

Publish

aspire publish

We can see in env.bicep that the existing keyword is missing.

resource env_asplan 'Microsoft.Web/serverfarms@2025-03-01' = {
  name: take('envasplan-${uniqueString(resourceGroup().id)}', 60)
  location: location
  properties: {
    perSiteScaling: true
    reserved: true
  }
  kind: 'Linux'
  sku: {
    name: 'P0V3'
    tier: 'Premium'
  }
}

In main.bicep my parameters ExistingAppServicePlanResourceGroup and ExistingAppServicePlanName appear but are unused.

targetScope = 'subscription'

param resourceGroupName string

param location string

param principalId string

param ExistingAppServicePlanResourceGroup string

param ExistingAppServicePlanName string

resource rg 'Microsoft.Resources/resourceGroups@2023-07-01' = {
  name: resourceGroupName
  location: location
}

module env_acr 'env-acr/env-acr.bicep' = {
  name: 'env-acr'
  scope: rg
  params: {
    location: location
  }
}

module env 'env/env.bicep' = {
  name: 'env'
  scope: rg
  params: {
    location: location
    env_acr_outputs_name: env_acr.outputs.name
    userPrincipalId: principalId
  }
}

Exceptions (if any)

No response

.NET Version info

.NET SDK:
Version: 10.0.102
Commit: 4452502459
Workload version: 10.0.100-manifests.6d969a7e
MSBuild version: 18.0.7+445250245

Runtime Environment:
OS Name: Windows
OS Version: 10.0.26200
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\10.0.102\

.NET workloads installed:
There are no installed workloads to display.
Configured to use workload sets when installing new manifests.
No workload sets are installed. Run "dotnet workload restore" to install a workload set.

Host:
Version: 10.0.2
Architecture: x64
Commit: 4452502459

.NET SDKs installed:
9.0.309 [C:\Program Files\dotnet\sdk]
10.0.102 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 10.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.23 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 10.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.23 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 10.0.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
Not set

global.json file:
Not found

Anything else?

Aspire version 13.1.0