Expose publish lifecycle events to polyglot AppHosts

.github/workflows/polyglot-validation/Dockerfile.golang

@@ -10,16 +10,14 @@
 #
 # Note: Expects self-extracting binary and NuGet artifacts to be pre-downloaded to /workspace/artifacts/
 #
-FROM mcr.microsoft.com/devcontainers/go:1.26-trixie
+FROM golang:1.26-trixie
 
-# Ensure Yarn APT repository signing key is available (base image includes Yarn repo)
-RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | gpg --dearmor | sudo tee /etc/apt/keyrings/yarn-archive-keyring.gpg > /dev/null
-
-# Install system dependencies (wget, docker CLI, jq for JSON manipulation)
+# Install system dependencies (wget, Docker CLI, jq for JSON manipulation, ICU for the Aspire CLI)
 RUN apt-get update && apt-get install -y \
     wget \
     docker.io \
     jq \
+    libicu76 \
     && rm -rf /var/lib/apt/lists/*
 
 # Pre-configure Aspire CLI path

src/Aspire.Hosting/Ats/BuilderExports.cs

@@ -3,6 +3,7 @@
 
 using Aspire.Hosting.ApplicationModel;
 using Aspire.Hosting.Eventing;
+using Aspire.Hosting.Publishing;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Hosting;
 
@@ -30,6 +31,8 @@ namespace Aspire.Hosting.Ats;
 /// <list type="bullet">
 ///   <item><description><c>subscribeBeforeStart</c> - Called before the application starts</description></item>
 ///   <item><description><c>subscribeAfterResourcesCreated</c> - Called after resources are created</description></item>
+///   <item><description><c>subscribeBeforePublish</c> - Called before the application is published</description></item>
+///   <item><description><c>subscribeAfterPublish</c> - Called after the application is published</description></item>
 /// </list>
 /// </para>
 /// </remarks>
@@ -209,6 +212,54 @@ public static DistributedApplicationEventSubscription SubscribeBeforeStart(
         });
     }
 
+    /// <summary>
+    /// Subscribes to the BeforePublish event, which fires before the application is published.
+    /// </summary>
+    /// <remarks>
+    /// This event provides access to the service provider and distributed application model,
+    /// allowing you to perform final configuration or validation before publish pipeline steps run.
+    /// </remarks>
+    /// <param name="builder">The builder handle.</param>
+    /// <param name="callback">A callback that receives the exported event when the event fires.</param>
+    /// <returns>A subscription handle that can be used to unsubscribe.</returns>
+    [AspireExport(Description = "Subscribes to the BeforePublish event")]
+    public static DistributedApplicationEventSubscription SubscribeBeforePublish(
+        this IDistributedApplicationBuilder builder,
+        Func<BeforePublishEvent, Task> callback)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+        ArgumentNullException.ThrowIfNull(callback);
+
+        return builder.Eventing.Subscribe<BeforePublishEvent>(async (@event, ct) =>
+        {
+            await callback(@event).ConfigureAwait(false);
+        });
+    }
+
+    /// <summary>
+    /// Subscribes to the AfterPublish event, which fires after the application is published.
+    /// </summary>
+    /// <remarks>
+    /// This event provides access to the service provider and distributed application model,
+    /// allowing you to inspect the model after publish pipeline steps complete.
+    /// </remarks>
+    /// <param name="builder">The builder handle.</param>
+    /// <param name="callback">A callback that receives the exported event when the event fires.</param>
+    /// <returns>A subscription handle that can be used to unsubscribe.</returns>
+    [AspireExport(Description = "Subscribes to the AfterPublish event")]
+    public static DistributedApplicationEventSubscription SubscribeAfterPublish(
+        this IDistributedApplicationBuilder builder,
+        Func<AfterPublishEvent, Task> callback)
+    {
+        ArgumentNullException.ThrowIfNull(builder);
+        ArgumentNullException.ThrowIfNull(callback);
+
+        return builder.Eventing.Subscribe<AfterPublishEvent>(async (@event, ct) =>
+        {
+            await callback(@event).ConfigureAwait(false);
+        });
+    }
+
     /// <summary>
     /// Subscribes to the AfterResourcesCreated event, which fires after all resources are created.
     /// </summary>

src/Aspire.Hosting/Ats/ServiceCollectionExports.cs

@@ -4,6 +4,7 @@
 using Aspire.Hosting.ApplicationModel;
 using Aspire.Hosting.Eventing;
 using Aspire.Hosting.Lifecycle;
+using Aspire.Hosting.Publishing;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Aspire.Hosting.Ats;
@@ -76,6 +77,36 @@ public static DistributedApplicationEventSubscription OnBeforeStart(this Eventin
         return context.Eventing.Subscribe<BeforeStartEvent>((@event, _) => callback(@event));
     }
 
+    /// <summary>
+    /// Subscribes to the BeforePublish event from an eventing subscriber registration context.
+    /// </summary>
+    /// <param name="context">The eventing subscriber registration context.</param>
+    /// <param name="callback">The callback to invoke when the event fires.</param>
+    /// <returns>The event subscription.</returns>
+    [AspireExport("eventingSubscriberOnBeforePublish", MethodName = "onBeforePublish", Description = "Subscribes an eventing subscriber to the BeforePublish event")]
+    public static DistributedApplicationEventSubscription OnBeforePublish(this EventingSubscriberRegistrationContext context, Func<BeforePublishEvent, Task> callback)
+    {
+        ArgumentNullException.ThrowIfNull(context);
+        ArgumentNullException.ThrowIfNull(callback);
+
+        return context.Eventing.Subscribe<BeforePublishEvent>((@event, _) => callback(@event));
+    }
+
+    /// <summary>
+    /// Subscribes to the AfterPublish event from an eventing subscriber registration context.
+    /// </summary>
+    /// <param name="context">The eventing subscriber registration context.</param>
+    /// <param name="callback">The callback to invoke when the event fires.</param>
+    /// <returns>The event subscription.</returns>
+    [AspireExport("eventingSubscriberOnAfterPublish", MethodName = "onAfterPublish", Description = "Subscribes an eventing subscriber to the AfterPublish event")]
+    public static DistributedApplicationEventSubscription OnAfterPublish(this EventingSubscriberRegistrationContext context, Func<AfterPublishEvent, Task> callback)
+    {
+        ArgumentNullException.ThrowIfNull(context);
+        ArgumentNullException.ThrowIfNull(callback);
+
+        return context.Eventing.Subscribe<AfterPublishEvent>((@event, _) => callback(@event));
+    }
+
     /// <summary>
     /// Subscribes to the AfterResourcesCreated event from an eventing subscriber registration context.
     /// </summary>

src/Aspire.Hosting/Publishing/AfterPublishEvent.cs

@@ -11,6 +11,7 @@ namespace Aspire.Hosting.Publishing;
 /// </summary>
 /// <param name="services">The <see cref="IServiceProvider"/> for the app host.</param>
 /// <param name="model">The <see cref="DistributedApplicationModel"/>.</param>
+[AspireExport(ExposeProperties = true)]
 public sealed class AfterPublishEvent(IServiceProvider services, DistributedApplicationModel model) : IDistributedApplicationEvent
 {
     /// <summary>
@@ -22,4 +23,4 @@ public sealed class AfterPublishEvent(IServiceProvider services, DistributedAppl
     /// The <see cref="DistributedApplicationModel"/> instance.
     /// </summary>
     public DistributedApplicationModel Model { get; } = model;
-}
+}

src/Aspire.Hosting/Publishing/BeforePublishEvent.cs

@@ -11,6 +11,7 @@ namespace Aspire.Hosting.Publishing;
 /// </summary>
 /// <param name="services">The <see cref="IServiceProvider"/> for the app host.</param>
 /// <param name="model">The <see cref="DistributedApplicationModel"/>.</param>
+[AspireExport(ExposeProperties = true)]
 public sealed class BeforePublishEvent(IServiceProvider services, DistributedApplicationModel model) : IDistributedApplicationEvent
 {
     /// <summary>
@@ -22,4 +23,4 @@ public sealed class BeforePublishEvent(IServiceProvider services, DistributedApp
     /// The <see cref="DistributedApplicationModel"/> instance.
     /// </summary>
     public DistributedApplicationModel Model { get; } = model;
-}
+}

src/Aspire.Hosting/api/Aspire.Hosting.Capabilities.txt

@@ -59,6 +59,8 @@ Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStepContext [ExposeProperties]
 Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStepFactoryContext [ExposeProperties]
 Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineSummary [ExposeMethods]
 Aspire.Hosting/Aspire.Hosting.ProjectResourceOptions [ExposeProperties]
+Aspire.Hosting/Aspire.Hosting.Publishing.AfterPublishEvent [ExposeProperties]
+Aspire.Hosting/Aspire.Hosting.Publishing.BeforePublishEvent [ExposeProperties]
 Microsoft.Extensions.Configuration.Abstractions/Microsoft.Extensions.Configuration.IConfiguration [interface]
 Microsoft.Extensions.Configuration.Abstractions/Microsoft.Extensions.Configuration.IConfigurationSection [interface, ExposeProperties]
 Microsoft.Extensions.Hosting.Abstractions/Microsoft.Extensions.Hosting.IHostEnvironment [interface, ExposeProperties]
@@ -232,6 +234,10 @@ Aspire.Hosting.Pipelines/PipelineStepFactoryContext.setPipelineContext(context:
 Aspire.Hosting.Pipelines/PipelineStepFactoryContext.setResource(context: Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStepFactoryContext, value: Aspire.Hosting/Aspire.Hosting.ApplicationModel.IResource) -> Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStepFactoryContext
 Aspire.Hosting.Pipelines/PipelineSummary.add(context: Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineSummary, key: string, value: string) -> void
 Aspire.Hosting.Pipelines/requiredBy(context: Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStep, stepName: string) -> void
+Aspire.Hosting.Publishing/AfterPublishEvent.model(context: Aspire.Hosting/Aspire.Hosting.Publishing.AfterPublishEvent) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.DistributedApplicationModel
+Aspire.Hosting.Publishing/AfterPublishEvent.services(context: Aspire.Hosting/Aspire.Hosting.Publishing.AfterPublishEvent) -> System.ComponentModel/System.IServiceProvider
+Aspire.Hosting.Publishing/BeforePublishEvent.model(context: Aspire.Hosting/Aspire.Hosting.Publishing.BeforePublishEvent) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.DistributedApplicationModel
+Aspire.Hosting.Publishing/BeforePublishEvent.services(context: Aspire.Hosting/Aspire.Hosting.Publishing.BeforePublishEvent) -> System.ComponentModel/System.IServiceProvider
 Aspire.Hosting/addConnectionString(name: string, environmentVariableName?: string) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.IResourceWithConnectionString
 Aspire.Hosting/addConnectionStringBuilder(name: string, connectionStringBuilder: callback) -> Aspire.Hosting/Aspire.Hosting.ConnectionStringResource
 Aspire.Hosting/addConnectionStringExpression(name: string, connectionStringExpression: Aspire.Hosting/Aspire.Hosting.ApplicationModel.ReferenceExpression) -> Aspire.Hosting/Aspire.Hosting.ConnectionStringResource
@@ -350,7 +356,9 @@ Aspire.Hosting/publishResourceUpdate(resource: Aspire.Hosting/Aspire.Hosting.App
 Aspire.Hosting/publishWithContainerFiles(source: Aspire.Hosting/Aspire.Hosting.IResourceWithContainerFiles, destinationPath: string) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.IContainerFilesDestinationResource
 Aspire.Hosting/run(context: Aspire.Hosting/Aspire.Hosting.DistributedApplication, cancellationToken?: cancellationToken) -> void
 Aspire.Hosting/saveStateJson(json: string, cancellationToken?: cancellationToken) -> void
+Aspire.Hosting/subscribeAfterPublish(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/subscribeAfterResourcesCreated(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
+Aspire.Hosting/subscribeBeforePublish(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/subscribeBeforeStart(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/tryGetResourceState(resourceName: string) -> Aspire.Hosting/Aspire.Hosting.Ats.ResourceEventDto
 Aspire.Hosting/updateTask(statusText: string, cancellationToken?: cancellationToken) -> void

src/Aspire.Hosting/api/Aspire.Hosting.ats.txt

@@ -79,6 +79,8 @@ Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStepContext [ExposeProperties]
 Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStepFactoryContext [ExposeProperties]
 Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineSummary [ExposeMethods]
 Aspire.Hosting/Aspire.Hosting.ProjectResourceOptions [ExposeProperties]
+Aspire.Hosting/Aspire.Hosting.Publishing.AfterPublishEvent [ExposeProperties]
+Aspire.Hosting/Aspire.Hosting.Publishing.BeforePublishEvent [ExposeProperties]
 Microsoft.Extensions.Configuration.Abstractions/Microsoft.Extensions.Configuration.IConfiguration [interface]
 Microsoft.Extensions.Configuration.Abstractions/Microsoft.Extensions.Configuration.IConfigurationSection [interface, ExposeProperties]
 Microsoft.Extensions.Hosting.Abstractions/Microsoft.Extensions.Hosting.IHostEnvironment [interface, ExposeProperties]
@@ -400,6 +402,10 @@ Aspire.Hosting.Pipelines/PipelineSummary.add(context: Aspire.Hosting/Aspire.Host
 Aspire.Hosting.Pipelines/requiredBy(context: Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStep, stepName: string) -> void
 Aspire.Hosting.Pipelines/steps(context: Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineEditor) -> Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStep[]
 Aspire.Hosting.Pipelines/stepsByTag(context: Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineEditor, tag: string) -> Aspire.Hosting/Aspire.Hosting.Pipelines.PipelineStep[]
+Aspire.Hosting.Publishing/AfterPublishEvent.model(context: Aspire.Hosting/Aspire.Hosting.Publishing.AfterPublishEvent) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.DistributedApplicationModel
+Aspire.Hosting.Publishing/AfterPublishEvent.services(context: Aspire.Hosting/Aspire.Hosting.Publishing.AfterPublishEvent) -> System.ComponentModel/System.IServiceProvider
+Aspire.Hosting.Publishing/BeforePublishEvent.model(context: Aspire.Hosting/Aspire.Hosting.Publishing.BeforePublishEvent) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.DistributedApplicationModel
+Aspire.Hosting.Publishing/BeforePublishEvent.services(context: Aspire.Hosting/Aspire.Hosting.Publishing.BeforePublishEvent) -> System.ComponentModel/System.IServiceProvider
 Aspire.Hosting/addConnectionString(name: string, environmentVariableNameOrExpression?: string|Aspire.Hosting/Aspire.Hosting.ApplicationModel.ReferenceExpression) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.IResourceWithConnectionString
 Aspire.Hosting/addContainer(name: string, image: string|Aspire.Hosting/Aspire.Hosting.Ats.AddContainerOptions) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.ContainerResource
 Aspire.Hosting/addContainerRegistry(name: string, endpoint: string|Aspire.Hosting/Aspire.Hosting.ApplicationModel.ParameterResource, repository?: string|Aspire.Hosting/Aspire.Hosting.ApplicationModel.ParameterResource) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.ContainerRegistryResource
@@ -462,7 +468,9 @@ Aspire.Hosting/dockerfileStageRun(command: string) -> Aspire.Hosting/Aspire.Host
 Aspire.Hosting/emptyLine() -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.Docker.DockerfileStage
 Aspire.Hosting/entrypoint(command: string[]) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.Docker.DockerfileStage
 Aspire.Hosting/env(name: string, value: string) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.Docker.DockerfileStage
+Aspire.Hosting/eventingSubscriberOnAfterPublish(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/eventingSubscriberOnAfterResourcesCreated(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
+Aspire.Hosting/eventingSubscriberOnBeforePublish(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/eventingSubscriberOnBeforeStart(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/excludeFromManifest() -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.IResource
 Aspire.Hosting/excludeFromMcp() -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.IResource
@@ -544,7 +552,9 @@ Aspire.Hosting/publishWithContainerFilesFromResource(source: Aspire.Hosting/Aspi
 Aspire.Hosting/run(context: Aspire.Hosting/Aspire.Hosting.DistributedApplication, cancellationToken?: cancellationToken) -> void
 Aspire.Hosting/runWithMounts(command: string, mounts: string[]) -> Aspire.Hosting/Aspire.Hosting.ApplicationModel.Docker.DockerfileStage
 Aspire.Hosting/saveStateJson(json: string, cancellationToken?: cancellationToken) -> void
+Aspire.Hosting/subscribeAfterPublish(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/subscribeAfterResourcesCreated(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
+Aspire.Hosting/subscribeBeforePublish(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/subscribeBeforeStart(callback: callback) -> Aspire.Hosting/Aspire.Hosting.Eventing.DistributedApplicationEventSubscription
 Aspire.Hosting/tryAddEventingSubscriber(subscribe: callback) -> void
 Aspire.Hosting/tryGetResourceState(resourceName: string) -> Aspire.Hosting/Aspire.Hosting.Ats.ResourceEventDto