Shorten Functions storage prefix and use AppHost name SHA (#6301)

* Shorten Functions storage prefix and use AppHost name SHA

* Use name only when IsPublishMode == true

* Add tests and change Functions logic

* Update doc string

Author: captainsafia

src/Aspire.Hosting.Azure.Functions/AzureFunctionsProjectResourceExtensions.cs

@@ -14,7 +14,16 @@ namespace Aspire.Hosting;
 /// </summary>
 public static class AzureFunctionsProjectResourceExtensions
 {
-    internal const string DefaultAzureFunctionsHostStorageName = "defaultazfuncstorage";
+    /// <remarks>
+    /// The prefix used for configuring the name default Azure Storage account that is used
+    /// for Azure Functions bookkeeping. Locally, the name is generated using a combination of this
+    /// prefix, a hash of the AppHost project name. During publish mode, the name generated
+    /// is a combination of this prefix and  the name of the resource group associated with
+    /// the deployment. We want to keep the total number of characters in the name under
+    /// 24 characters to avoid truncation by Azure and allow
+    /// for unique enough identifiers.
+    /// </remarks>
+    internal const string DefaultAzureFunctionsHostStorageName = "funcstorage";
 
     /// <summary>
     /// Adds an Azure Functions project to the distributed application.
@@ -29,7 +38,7 @@ public static class AzureFunctionsProjectResourceExtensions
 
         // Add the default storage resource if it doesn't already exist.
         var storageResourceName = builder.CreateDefaultStorageName();
-        AzureStorageResource? storage = builder.Resources
+        var storage = builder.Resources
             .OfType<AzureStorageResource>()
             .FirstOrDefault(r => r.Name == storageResourceName);
 
@@ -198,6 +207,10 @@ public static IResourceBuilder<AzureFunctionsProjectResource> WithReference<TSou
 
     private static string CreateDefaultStorageName(this IDistributedApplicationBuilder builder)
     {
+        if (builder.ExecutionContext.IsPublishMode)
+        {
+            return DefaultAzureFunctionsHostStorageName;
+        }
         var applicationHash = builder.Configuration["AppHost:Sha256"]![..5].ToLowerInvariant();
         return $"{DefaultAzureFunctionsHostStorageName}{applicationHash}";
     }

src/Aspire.Hosting/DistributedApplicationBuilder.cs

@@ -151,17 +151,13 @@ public DistributedApplicationBuilder(DistributedApplicationOptions options)
         var appHostName = options.ProjectName ?? _innerBuilder.Environment.ApplicationName;
         AppHostPath = Path.Join(AppHostDirectory, appHostName);
 
-        var appHostShaBytes = SHA256.HashData(Encoding.UTF8.GetBytes(AppHostPath));
-        var appHostSha = Convert.ToHexString(appHostShaBytes);
-
         // Set configuration
         ConfigurePublishingOptions(options);
         _innerBuilder.Configuration.AddInMemoryCollection(new Dictionary<string, string?>
         {
             // Make the app host directory available to the application via configuration
             ["AppHost:Directory"] = AppHostDirectory,
             ["AppHost:Path"] = AppHostPath,
-            ["AppHost:Sha256"] = appHostSha,
         });
 
         _executionContextOptions = _innerBuilder.Configuration["Publishing:Publisher"] switch
@@ -172,13 +168,24 @@ public DistributedApplicationBuilder(DistributedApplicationOptions options)
 
         ExecutionContext = new DistributedApplicationExecutionContext(_executionContextOptions);
 
-        // 
         Eventing.Subscribe<BeforeResourceStartedEvent>(async (@event, ct) =>
         {
             var rns = @event.Services.GetRequiredService<ResourceNotificationService>();
             await rns.WaitForDependenciesAsync(@event.Resource, ct).ConfigureAwait(false);
         });
 
+        // Conditionally configure AppHostSha based on execution context. For local scenarios, we want to
+        // account for the path the AppHost is running from to disambiguate between different projects
+        // with the same name as seen in https://github.com/dotnet/aspire/issues/5413. For publish scenarios,
+        // we want to use a stable hash based only on the project name.
+        var appHostShaBytes = SHA256.HashData(Encoding.UTF8.GetBytes(AppHostPath));
+        var appHostNameShaBytes = SHA256.HashData(Encoding.UTF8.GetBytes(appHostName));
+        var appHostSha = ExecutionContext.IsPublishMode ? Convert.ToHexString(appHostNameShaBytes) : Convert.ToHexString(appHostShaBytes);
+        _innerBuilder.Configuration.AddInMemoryCollection(new Dictionary<string, string?>
+        {
+            ["AppHost:Sha256"] = appHostSha
+        });
+
         // Core things
         _innerBuilder.Services.AddSingleton(sp => new DistributedApplicationModel(Resources));
         _innerBuilder.Services.AddHostedService<DistributedApplicationLifecycle>();

tests/Aspire.Hosting.Azure.Tests/AzureFunctionsTests.cs

@@ -149,6 +149,17 @@ public async Task AddAzureFunctionsProject_WorksWithMultipleProjects()
         await host.StopAsync();
     }
 
+    [Fact]
+    public void AddAzureFunctionsProject_UsesCorrectNameUnderPublish()
+    {
+        using var builder = TestDistributedApplicationBuilder.Create(DistributedApplicationOperation.Publish);
+        builder.AddAzureFunctionsProject<TestProject>("funcapp");
+
+        var resource = Assert.Single(builder.Resources.OfType<AzureStorageResource>());
+
+        Assert.Equal(AzureFunctionsProjectResourceExtensions.DefaultAzureFunctionsHostStorageName, resource.Name);
+    }
+
     private sealed class TestProject : IProjectMetadata
     {
         public string ProjectPath => "some-path";

tests/Aspire.Hosting.Tests/Utils/VolumeNameGeneratorTests.cs

@@ -3,6 +3,7 @@
 
 using static Aspire.Hosting.Utils.VolumeNameGenerator;
 using Xunit;
+using Aspire.Hosting.Utils;
 
 namespace Aspire.Hosting.Tests.Utils;
 
@@ -47,4 +48,24 @@ private sealed class TestResource(string name) : IResource
 
         public ResourceAnnotationCollection Annotations { get; } = [];
     }
+
+    [Fact]
+    public void VolumeNameDiffersBetweenPublishAndRun()
+    {
+        var runBuilder = TestDistributedApplicationBuilder.Create();
+        var publishBuilder = TestDistributedApplicationBuilder.Create(DistributedApplicationOperation.Publish);
+
+        var runVolumePrefix = $"{Sanitize(runBuilder.Environment.ApplicationName).ToLowerInvariant()}-{runBuilder.Configuration["AppHost:Sha256"]!.ToLowerInvariant()[..10]}";
+        var publishVolumePrefix = $"{Sanitize(publishBuilder.Environment.ApplicationName).ToLowerInvariant()}-{publishBuilder.Configuration["AppHost:Sha256"]!.ToLowerInvariant()[..10]}";
+
+        var runResource = runBuilder.AddResource(new TestResource("myresource"));
+        var publishResource = publishBuilder.AddResource(new TestResource("myresource"));
+
+        var runVolumeName = CreateVolumeName(runResource, "data");
+        var publishVolumeName = CreateVolumeName(publishResource, "data");
+
+        Assert.Equal($"{runVolumePrefix}-{runResource.Resource.Name}-data", runVolumeName);
+        Assert.Equal($"{publishVolumePrefix}-{publishResource.Resource.Name}-data", publishVolumeName);
+        Assert.NotEqual(runVolumeName, publishVolumeName);
+    }
 }