Fix dotnet watch.

playground/CosmosEndToEnd/CosmosEndToEnd.AppHost/Program.cs

@@ -15,6 +15,6 @@
 // to test end developer dashboard launch experience. Refer to Directory.Build.props
 // for the path to the dashboard binary (defaults to the Aspire.Dashboard bin output
 // in the artifacts dir).
-builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard);
+builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard).ExcludeFromManifest();
 
 builder.Build().Run();

playground/CosmosEndToEnd/CosmosEndToEnd.AppHost/Properties/launchSettings.json

@@ -10,8 +10,7 @@
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:16175",
-        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true" // Display dashboard resource in console for local development
-      }
+        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true"
     },
     "generate-manifest": {
       "commandName": "Project",

playground/SqlServerEndToEnd/SqlServerEndToEnd.AppHost/Program.cs

@@ -13,6 +13,6 @@
 // to test end developer dashboard launch experience. Refer to Directory.Build.props
 // for the path to the dashboard binary (defaults to the Aspire.Dashboard bin output
 // in the artifacts dir).
-//builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard);
+builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard).ExcludeFromManifest();
 
 builder.Build().Run();

playground/SqlServerEndToEnd/SqlServerEndToEnd.AppHost/Properties/launchSettings.json

@@ -10,7 +10,7 @@
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:16175",
-        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true" // Display dashboard resource in console for local development
+        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true"
       }
     },
     "generate-manifest": {

playground/dapr/AppHost/Program.cs

@@ -17,7 +17,7 @@
 // to test end developer dashboard launch experience. Refer to Directory.Build.props
 // for the path to the dashboard binary (defaults to the Aspire.Dashboard bin output
 // in the artifacts dir).
-builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard);
+builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard).ExcludeFromManifest();
 
 using var app = builder.Build();
 

playground/dapr/AppHost/Properties/launchSettings.json

@@ -9,7 +9,7 @@
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:16031",
-        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true" // Display dashboard resource in console for local development
+        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true"
       }
     },
     "generate-manifest": {

playground/eShopLite/AppHost/Program.cs

@@ -37,6 +37,6 @@
 // to test end developer dashboard launch experience. Refer to Directory.Build.props
 // for the path to the dashboard binary (defaults to the Aspire.Dashboard bin output
 // in the artifacts dir).
-builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard);
+builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard).ExcludeFromManifest();
 
 builder.Build().Run();

playground/eShopLite/AppHost/Properties/launchSettings.json

@@ -9,7 +9,7 @@
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:16031",
-        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true" // Display dashboard resource in console for local development
+        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true"
       }
     },
     "generate-manifest": {

playground/eShopLite/AppHost/appsettings.json

@@ -2,7 +2,8 @@
   "Logging": {
     "LogLevel": {
       "Default": "Information",
-      "Microsoft.AspNetCore": "Warning"
+      "Microsoft.AspNetCore": "Warning",
+      "Aspire.Hosting.Dcp": "Warning"
     }
   }
 }

playground/mongo/Mongo.AppHost/Properties/launchSettings.json

@@ -5,12 +5,12 @@
       "commandName": "Project",
       "dotnetRunMessages": true,
       "launchBrowser": true,
-      "applicationUrl": "http://localhost:15888",
+      "applicationUrl": "http://localhost:15888/",
       "environmentVariables": {
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:16175",
-        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true" // Display dashboard resource in console for local development
+        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true"
       }
     },
     "generate-manifest": {

playground/orleans/OrleansAppHost/Program.cs

@@ -23,7 +23,7 @@
 // to test end developer dashboard launch experience. Refer to Directory.Build.props
 // for the path to the dashboard binary (defaults to the Aspire.Dashboard bin output
 // in the artifacts dir).
-builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard);
+builder.AddProject<Projects.Aspire_Dashboard>(KnownResourceNames.AspireDashboard).ExcludeFromManifest();
 
 using var app = builder.Build();
 

playground/orleans/OrleansAppHost/Properties/launchSettings.json

@@ -9,7 +9,7 @@
         "ASPNETCORE_ENVIRONMENT": "Development",
         "DOTNET_ENVIRONMENT": "Development",
         "DOTNET_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:16031",
-        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true" // Display dashboard resource in console for local development
+        "DOTNET_ASPIRE_SHOW_DASHBOARD_RESOURCES": "true"
       }
     },
     "generate-manifest": {

src/Aspire.Hosting/Dcp/ApplicationExecutor.cs

@@ -1,12 +1,12 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Diagnostics.CodeAnalysis;
 using System.Net.Sockets;
 using Aspire.Hosting.ApplicationModel;
 using Aspire.Hosting.Dashboard;
 using Aspire.Hosting.Dcp.Model;
 using Aspire.Hosting.Lifecycle;
+using Aspire.Hosting.Utils;
 using k8s;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
@@ -138,12 +138,12 @@ private async Task ConfigureAspireDashboardResource(IResource dashboardResource,
         {
             if (Environment.GetEnvironmentVariable("ASPNETCORE_URLS") is not { } appHostApplicationUrl)
             {
-                throw new DistributedApplicationException("Dashboard inner loop hook failed to configure resource because ASPNETCORE_URLS environment variable was not set.");
+                throw new DistributedApplicationException("Failed to configure dashboard resource because ASPNETCORE_URLS environment variable was not set.");
             }
 
             if (Environment.GetEnvironmentVariable("DOTNET_DASHBOARD_OTLP_ENDPOINT_URL") is not { } otlpEndpointUrl)
             {
-                throw new DistributedApplicationException("Dashboard inner loop hook failed to configure resource because DOTNET_DASHBOARD_OTLP_ENDPOINT_URL environment variable was not set.");
+                throw new DistributedApplicationException("Failed to configure dashboard resource because DOTNET_DASHBOARD_OTLP_ENDPOINT_URL environment variable was not set.");
             }
 
             // Grab the resource service URL. We need to inject this into the resource.
@@ -254,7 +254,7 @@ private static TimeSpan DashboardAvailabilityTimeoutDuration
 
     private async Task CheckDashboardAvailabilityAsync(string delimitedUrlList, CancellationToken cancellationToken)
     {
-        if (TryGetUriFromDelimitedString(delimitedUrlList, ";", out var firstDashboardUrl))
+        if (StringUtils.TryGetUriFromDelimitedString(delimitedUrlList, ";", out var firstDashboardUrl))
         {
             await WaitForHttpSuccessOrThrow(firstDashboardUrl, DashboardAvailabilityTimeoutDuration, cancellationToken).ConfigureAwait(false);
         }
@@ -669,21 +669,6 @@ private async Task CreateExecutablesAsync(IEnumerable<AppResource> executableRes
         }
     }
 
-    private static bool TryGetUriFromDelimitedString(string input, string delimiter, [NotNullWhen(true)]out Uri? uri)
-    {
-        if (!string.IsNullOrEmpty(input)
-            && input.Split(delimiter) is { Length: > 0} splitInput
-            && Uri.TryCreate(splitInput[0], UriKind.Absolute, out uri))
-        {
-            return true;
-        }
-        else
-        {
-            uri = null;
-            return false;
-        }
-    }
-
     private static void ApplyLaunchProfile(AppResource executableResource, Dictionary<string, string> config, string launchProfileName, LaunchSettings launchSettings)
     {
         // Populate DOTNET_LAUNCH_PROFILE environment variable for consistency with "dotnet run" and "dotnet watch".

src/Aspire.Hosting/DistributedApplication.cs

@@ -5,9 +5,11 @@
 using Aspire.Hosting.ApplicationModel;
 using Aspire.Hosting.Lifecycle;
 using Aspire.Hosting.Publishing;
+using Aspire.Hosting.Utils;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
 namespace Aspire.Hosting;
@@ -46,6 +48,7 @@ public class DistributedApplication : IHost, IAsyncDisposable
 {
     private readonly IHost _host;
     private readonly string[] _args;
+    private readonly ILogger<DistributedApplication> _logger;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="DistributedApplication"/> class.
@@ -55,6 +58,7 @@ public class DistributedApplication : IHost, IAsyncDisposable
     public DistributedApplication(IHost host, string[] args)
     {
         _host = host;
+        _logger = host.Services.GetRequiredService<ILogger<DistributedApplication>>();
         _args = args;
     }
 
@@ -111,8 +115,38 @@ public ValueTask DisposeAsync()
     /// <inheritdoc cref="IHost.StartAsync" />
     public async Task StartAsync(CancellationToken cancellationToken = default)
     {
-        await ExecuteBeforeStartHooksAsync(cancellationToken).ConfigureAwait(false);
+        SuppressLogs();
+        WriteStartupMessages();
         await _host.StartAsync(cancellationToken).ConfigureAwait(false);
+        await ExecuteBeforeStartHooksAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private void WriteStartupMessages()
+    {
+        var options = _host.Services.GetRequiredService<IOptions<PublishingOptions>>();
+
+        if (options.Value?.Publisher == "manifest")
+        {
+            // If we are producing the manifest, don't write startup messages.
+            return;
+        }
+
+        if (Environment.GetEnvironmentVariable("ASPNETCORE_URLS") is { } dashboardUrls
+            && StringUtils.TryGetUriFromDelimitedString(dashboardUrls, ";", out var dashboardUrl))
+        {
+            // dotnet watch appears to blindly append a training slash to the URI which present
+            // on this message. This results in an address that looks like http://host:port// which
+            // is a 404 on the dashboard. This is a quick workaround.
+            var dotnetWatchSafeDashboardUrl = dashboardUrl.ToString().TrimEnd('/');
+            _logger.LogInformation("Now listening on: {DashboardUrl}", dotnetWatchSafeDashboardUrl);
+        }
+
+        if (Environment.GetEnvironmentVariable("DOTNET_DASHBOARD_OTLP_ENDPOINT_URL") is { } otlpEndpointUrl)
+        {
+            _logger.LogInformation("OTLP endpoint listening on: {OtlpEndpointUrl}", otlpEndpointUrl);
+        }
+
+        _logger.LogInformation("Application started. Press Ctrl+C to shut down.");
     }
 
     /// <inheritdoc cref="IHost.StopAsync" />
@@ -121,29 +155,34 @@ public async Task StopAsync(CancellationToken cancellationToken = default)
         await _host.StopAsync(cancellationToken).ConfigureAwait(false);
     }
 
-    private void SuppressLifetimeLogsDuringManifestPublishing()
+    private void SuppressLogs()
     {
         var config = (IConfigurationRoot)_host.Services.GetRequiredService<IConfiguration>();
-        var options = _host.Services.GetRequiredService<IOptions<PublishingOptions>>();
-
-        if (options.Value?.Publisher != "manifest")
-        {
-            // If we aren't doing manifest publishing we want the logs
-            // to be produced as normal.
-            return;
-        }
 
+        // Suppress excess logging from lifetime logger category. This blocks the "Now listening on"
+        // message. This is not a problem for VS usage, but it does confuse "dotnet watch" which looks
+        // at the stdout to figure out when it should launch the browser. Rather than relying on
+        // lifetime logger category for this special string we will emit it ourselves to make
+        // sure that it is correct.
         var hostingLifetimeLoggingLevelSection = config.GetSection("Logging:LogLevel:Microsoft.Hosting.Lifetime");
         hostingLifetimeLoggingLevelSection.Value = "Warning";
 
+        // Suppresses warning that we've overridden the default ASPNETCORE_URLS value. This is
+        // because the endpoints that we host in the AppHost is a randomly assinged resource
+        // endpoint that is used for the dashboard. The ASPNETCORE_URLS value is actually passed
+        // into the dashboard that is launched out of process.
+        var aspNetCoreServerKestrelLoggingLevelSection = config.GetSection("Logging:LogLevel:Microsoft.AspNetCore.Server.Kestrel");
+        aspNetCoreServerKestrelLoggingLevelSection.Value = "None";
+
         config.Reload();
     }
 
     /// <inheritdoc cref="HostingAbstractionsHostExtensions.RunAsync" />
     public async Task RunAsync(CancellationToken cancellationToken = default)
     {
-        SuppressLifetimeLogsDuringManifestPublishing();
+        SuppressLogs();
         await ExecuteBeforeStartHooksAsync(cancellationToken).ConfigureAwait(false);
+        WriteStartupMessages();
         await _host.RunAsync(cancellationToken).ConfigureAwait(false);
     }
 

src/Aspire.Hosting/Utils/StringUtils.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace Aspire.Hosting.Utils;
+
+internal static class StringUtils
+{
+    public static bool TryGetUriFromDelimitedString(string input, string delimiter, [NotNullWhen(true)] out Uri? uri)
+    {
+        if (!string.IsNullOrEmpty(input)
+            && input.Split(delimiter) is { Length: > 0 } splitInput
+            && Uri.TryCreate(splitInput[0], UriKind.Absolute, out uri))
+        {
+            return true;
+        }
+        else
+        {
+            uri = null;
+            return false;
+        }
+    }
+
+}