I’ve been struggling trying to get Serilog to send telemetry over to the dotnet Aspire dashboard. Once the Aspire dashboard opens, the Structured logs tab is always empty.

If I comment out the Serilog configuration in Program.cs (thus using the default ILogger) then I start seeing structured logs on the dashboard.

There are currently two issues on the Aspire repo which didn’t seem to help me:

• Serilog for Dotnet Aspire
• duplicate service name when using OTLP logging

This is where our Serilog configuration stands at the moment:

// This extension is auto generated when adding Aspire. More on that below..
builder.AddServiceDefaults();

builder.Host.UseSerilog((hostContext, services, loggerConfiguration) => loggerConfiguration
    .ReadFrom.Configuration(builder.Configuration)
    .Enrich.FromLogContext()
    .Enrich.WithPropertiesMasking(builder.Configuration)
    .Enrich.WithProperty("ServiceName", DaprConstants.API_SERVICE_NAME)
    .Enrich.WithThreadId()
    .Enrich.WithCorrelationIdHeader("X-Correlation-ID")
    .WriteTo.ApplicationInsights
    (        
        new TelemetryConfiguration() { ConnectionString = builder.Configuration["APPLICATIONINSIGHTS_CONNECTION_STRING"] },
        TelemetryConverter.Traces
    )
    .WriteTo.OpenTelemetry(opts =>
    {
        opts.Endpoint = builder.Configuration["OTEL_EXPORTER_OTLP_ENDPOINT"]!;
        opts.ResourceAttributes.Add("service.name", builder.Configuration["OTEL_SERVICE_NAME"] ?? "Unknown");
    })
);

If you’re unfamiliar with some of those environment variables you can read more about it here: .NET Aspire telemetry

From the GitHub issues I linked to above I’ve also modified the Extensions within the ServiceDefaults project that gets auto generated when you add Aspire to your application. I should note that I also tried keeping all the configuration in the Extensions class the same as well.

public static class Extension
{
    public static IHostApplicationBuilder AddServiceDefaults(this IHostApplicationBuilder builder)
    {
        builder.ConfigureOpenTelemetry();

        /* Other configuration... */

        return builder;
    }

    public static IHostApplicationBuilder ConfigureOpenTelemetry(this IHostApplicationBuilder builder)
    {
        // Tried commenting this out.
        /*builder.Logging.AddOpenTelemetry(logging =>
        {
            logging.IncludeFormattedMessage = true;
            logging.IncludeScopes = true;
        });*/

        builder.Services.AddOpenTelemetry()
            .WithMetrics(metrics =>
            {
                metrics.AddAspNetCoreInstrumentation()
                    .AddHttpClientInstrumentation()
                    .AddRuntimeInstrumentation();
            })
            .WithTracing(tracing =>
            {
                if (builder.Environment.IsDevelopment())
                {
                    // We want to view all traces in development
                    tracing.SetSampler(new AlwaysOnSampler());
                }

                tracing.AddAspNetCoreInstrumentation()
                    .AddHttpClientInstrumentation();
            });

        builder.AddOpenTelemetryExporters();

        return builder;
    }

    private static IHostApplicationBuilder AddOpenTelemetryExporters(this IHostApplicationBuilder builder)
    {
        var useOtlpExporter = !string.IsNullOrWhiteSpace(builder.Configuration["OTEL_EXPORTER_OTLP_ENDPOINT"]);

        if (useOtlpExporter)
        {
            // In one of the GitHub issues David Fowler suggested commenting this line out.
            //builder.Services.Configure<OpenTelemetryLoggerOptions>(logging => logging.AddOtlpExporter());
            builder.Services.ConfigureOpenTelemetryMeterProvider(metrics => metrics.AddOtlpExporter());
            builder.Services.ConfigureOpenTelemetryTracerProvider(tracing => tracing.AddOtlpExporter());
        }

        if (!string.IsNullOrEmpty(builder.Configuration["APPLICATIONINSIGHTS_CONNECTION_STRING"]))
        {
            builder.Services.AddOpenTelemetry()
               .UseAzureMonitor();
        }

        return builder;
    }
}

I didn’t show the AppHost here as I didn’t think it mattered to the aforementioned issue.

Has anyone who is currently trying out Aspire with Serilog been able to get this to work correctly?

If so, any pointers?