Add an option to set DCP log file name suffix based on test name (#9088)

Author: karolz-ms

src/Aspire.Hosting/Dcp/DcpHost.cs

@@ -141,6 +141,10 @@ private void EnsureDcpHostRunning()
                 loggingSocket.Listen(LoggingSocketConnectionBacklog);
 
                 dcpProcessSpec.EnvironmentVariables.Add("DCP_LOG_SOCKET", _locations.DcpLogSocket);
+                if (!string.IsNullOrWhiteSpace(_dcpOptions.LogFileNameSuffix))
+                {
+                    dcpProcessSpec.EnvironmentVariables.Add("DCP_LOG_FILE_NAME_SUFFIX", _dcpOptions.LogFileNameSuffix);
+                }
 
                 _logProcessorTask = Task.Run(() => StartLoggingSocketAsync(loggingSocket));
             }

src/Aspire.Hosting/Dcp/DcpOptions.cs

@@ -88,6 +88,12 @@ internal sealed class DcpOptions
     /// before DcpExecutor.StopAsync() returns. Default is false (resources are cleaned up asynchronously).
     /// </summary>
     public bool WaitForResourceCleanup { get; set; }
+
+    /// <summary>
+    /// Gets or sets the suffix to use for DCP log file names (applicable when verbose DCP logging is enabled).
+    /// By default log file name suffix defaults to the current process ID.
+    /// </summary>
+    public string? LogFileNameSuffix { get; set; }
 }
 
 internal class ValidateDcpOptions : IValidateOptions<DcpOptions>
@@ -190,6 +196,7 @@ public void Configure(DcpOptions options)
         options.WaitForResourceCleanup = dcpPublisherConfiguration.GetValue(nameof(options.WaitForResourceCleanup), options.WaitForResourceCleanup);
         options.ServiceStartupWatchTimeout = configuration.GetValue(KnownConfigNames.ServiceStartupWatchTimeout, KnownConfigNames.Legacy.ServiceStartupWatchTimeout, options.ServiceStartupWatchTimeout);
         options.ContainerRuntimeInitializationTimeout = dcpPublisherConfiguration.GetValue(nameof(options.ContainerRuntimeInitializationTimeout), options.ContainerRuntimeInitializationTimeout);
+        options.LogFileNameSuffix = dcpPublisherConfiguration[nameof(options.LogFileNameSuffix)];
     }
 
     private static string? GetMetadataValue(IEnumerable<AssemblyMetadataAttribute>? assemblyMetadata, string key)

tests/testproject/TestProject.AppHost/TestProgram.cs

@@ -54,6 +54,7 @@ private TestProgram(
         builder.Configuration["DcpPublisher:ResourceNameSuffix"] = $"{Random.Shared.Next():x}";
         builder.Configuration["DcpPublisher:RandomizePorts"] = randomizePorts.ToString(CultureInfo.InvariantCulture);
         builder.Configuration["DcpPublisher:WaitForResourceCleanup"] = "true";
+        builder.Configuration["DcpPublisher:LogFileNameSuffix"] = testName;
 
         AppBuilder = builder;