Unhandled exception: Unsupported value type System.Boolean when referencing Azure Storage resource

[eerhardt]

• Is there an existing issue for this?

  • I have searched the existing issues

• Describe the bug
  A NotSupportedException is thrown when referencing Azure Storage resources in an Aspire distributed app scenario. The error indicates "Unsupported value type System.Boolean" from AzureResourcePreparer.

• Expected Behavior
  The application should run without throwing a NotSupportedException when referencing Azure Storage resources.

• Steps To Reproduce
  Use the following repro code:

  using Aspire.Hosting.Yarp;
  using Aspire.Hosting.Yarp.Transforms;
  using Yarp.ReverseProxy.Configuration;
  
  var builder = DistributedApplication.CreateBuilder(args);
  
  builder.AddAzureStorage("storage");
  
  var apiService = builder.AddProject<Projects.aspirenew_ApiService>("apiservice")
      .WithHttpHealthCheck("/health");
  
  builder.AddProject<Projects.aspirenew_Web>("webfrontend")
      .WithExternalHttpEndpoints()
      .WithHttpHealthCheck("/health")
      .WithReference(apiService)
      .WaitFor(apiService);
  
  builder.AddYarp("mobile-bff")
      .WithConfiguration(builder =>
      {
          builder.AddRoute("/catalog-api/api/catalog/items", apiService.GetEndpoint("http"))
              .WithMatchRouteQueryParameter([new () { Name = "api-version", Values = ["1.0", "1", "2.0"], Mode = QueryParameterMatchMode.Exact }])
              .WithTransformPathRemovePrefix("/catalog-api");
      });
  
  builder.Build().Run();

• Exceptions (if any)

  Unhandled exception. System.AggregateException: One or more errors occurred. (Unsupported value type System.Boolean)
   ---> System.NotSupportedException: Unsupported value type System.Boolean
     at Aspire.Hosting.Azure.AzureResourcePreparer.ProcessAzureReferences(HashSet`1 azureReferences, Object value) in /_/src/Aspire.Hosting.Azure/AzureResourcePreparer.cs:line 463
     at Aspire.Hosting.Azure.AzureResourcePreparer.GetAzureReferences(IResource resource, CancellationToken cancellationToken) in /_/src/Aspire.Hosting.Azure/AzureResourcePreparer.cs:line 377
     at Aspire.Hosting.Azure.AzureResourcePreparer.BuildRoleAssignmentAnnotations(DistributedApplicationModel appModel, List`1 azureResources, AzureProvisioningOptions options, CancellationToken cancellationToken) in 
  /_/src/Aspire.Hosting.Azure/AzureResourcePreparer.cs:line 142
     at Aspire.Hosting.Azure.AzureResourcePreparer.BeforeStartAsync(DistributedApplicationModel appModel, CancellationToken cancellationToken) in /_/src/Aspire.Hosting.Azure/AzureResourcePreparer.cs:line 39
     at Aspire.Hosting.DistributedApplication.ExecuteBeforeStartHooksAsync(CancellationToken cancellationToken) in /_/src/Aspire.Hosting/DistributedApplication.cs:line 475
     at Aspire.Hosting.DistributedApplication.RunAsync(CancellationToken cancellationToken) in /_/src/Aspire.Hosting/DistributedApplication.cs:line 425
     --- End of inner exception stack trace ---
     at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
     at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
     at System.Threading.Tasks.Task.Wait()
     at Aspire.Hosting.DistributedApplication.Run() in /_/src/Aspire.Hosting/DistributedApplication.cs:line 456
     at Program.<Main>$(String[] args) in D:\DotNetTest\aspirenew\aspirenew.AppHost\AppHost.cs:line 26
  

• .NET Version info

• Anything else?

  • ASP.NET Core version:
  • .NET Aspire version (e.g. package versions):
  • The IDE (VS / VS Code / Rider / Other) you're running on, and its version (and any extension versions):

  Please investigate why referencing Azure Storage in this scenario triggers an unsupported value type exception and how to resolve it.

[eerhardt]

The issue is these 2 lines of code:

aspire/src/Aspire.Hosting.Yarp/YarpEnvConfigGenerator.cs

Lines 37 to 40 in d9055e9

	if (IsSimple(obj))
	{
	environmentVariables.Add(prefix, obj);
	}

Which allows for bools to be directly added to env vars.

and

aspire/src/Aspire.Hosting.Azure/AzureResourcePreparer.cs

Lines 399 to 404 in d9055e9

	private static void ProcessAzureReferences(HashSet<IAzureResource> azureReferences, object value)
	{
	if (value is string or EndpointReference or ParameterResource or EndpointReferenceExpression or HostUrl)
	{
	return;
	}

Note this bug happens elsewhere too:

aspire/src/Aspire.Hosting.Azure.AppContainers/ContainerAppContext.cs

Lines 522 to 526 in d9055e9

	private (object, SecretType) ProcessValue(object value, SecretType secretType = SecretType.None, object? parent = null)
	{
	if (value is string s)
	{
	return (s, secretType);

aspire/src/Aspire.Hosting.Azure.AppService/AzureAppServiceWebsiteContext.cs

Lines 108 to 113 in d9055e9

	private (object, SecretType) ProcessValue(object value, SecretType secretType = SecretType.None, object? parent = null)
	{
	if (value is string s)
	{
	return (s, secretType);
	}

aspire/src/Aspire.Hosting.Kubernetes/KubernetesServiceResourceExtensions.cs

Lines 13 to 21 in d9055e9

	internal static async Task<object> ProcessValueAsync(this KubernetesResource resource, KubernetesEnvironmentContext context, DistributedApplicationExecutionContext executionContext, object value)
	{
	while (true)
	{
	if (value is string s)
	{
	return s;
	}