.NET Core DI Logger on Console app not logging to Console

Question

I've got a .NET Core console app. Pretty simple. At this point the goal was just to get DI and Configuration integrated. However, the LogDebug isn't logging to the console.

What could I have possibly done wrong here?

class Program
{
    static void Main(string[] args)
    {
        var topic = Environment.GetEnvironmentVariable("RECEIVER_TOPIC");
        var entity = Environment.GetEnvironmentVariable("RECEIVER_ENTITY");

        //setup our DI
        var serviceProvider = new ServiceCollection()
            .AddLogging()
            .BuildServiceProvider();

        //configure console logging
        serviceProvider
            .GetService<ILoggerFactory>()
            .AddConsole(LogLevel.Debug);

        var logger = serviceProvider
            .GetService<ILoggerFactory>()
            .CreateLogger<Program>();
        logger.LogDebug($"Starting application. Topic: {topic}. Entity: {entity}.");

        if (Debugger.IsAttached)
        {
            Console.ReadLine();
        }
    }

    static IConfigurationRoot GetConfiguration()
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);

        return builder.Build();
    }
}

Update 1

I added the Microsoft.Extensions.Logging.Debug NuGet package, and modified the serviceProvider initialization to append the AddDebug like so:

serviceProvider
    .GetService<ILoggerFactory>()
    .AddConsole(LogLevel.Debug)
    .AddDebug();

But it's not even logging to the Debug window.

Answer 1

Got it working. I think the key was that I wasn't yet clear that concretes needed to be registered because I thought the extension was registering the concretes.

class Program
{
    static void Main(string[] args)
    {
        var topic = Environment.GetEnvironmentVariable("RECEIVER_TOPIC");
        var entity = Environment.GetEnvironmentVariable("RECEIVER_ENTITY");

        // Create service collection
        var serviceCollection = new ServiceCollection();
        ConfigureServices(serviceCollection);

        // Create service provider
        var serviceProvider = serviceCollection.BuildServiceProvider();

        var logger = serviceProvider
            .GetRequiredService<ILoggerFactory>()
            .CreateLogger<Program>();
        logger.LogDebug($"Starting application. Topic: {topic}. Entity: {entity}.");

        if (Debugger.IsAttached)
        {
            Console.ReadLine();
        }
    }

    static void ConfigureServices(IServiceCollection serviceCollection)
    {
        // Add logging
        serviceCollection.AddSingleton<ILoggerFactory, LoggerFactory>();
        serviceCollection.AddSingleton(typeof(ILogger<>), typeof(Logger<>));
        serviceCollection.AddLogging(loggingBuilder => loggingBuilder
            .AddConsole()
            .AddDebug()
            .SetMinimumLevel(LogLevel.Debug));

        // Build configuration
        var configuration = new ConfigurationBuilder()
            .SetBasePath(AppContext.BaseDirectory)
            .AddJsonFile("appsettings.json", false)
            .Build();

        // Add access to generic IConfigurationRoot
        serviceCollection.AddSingleton(configuration);
    }
}

Answer 2

I recently ran into the same exact problem, saw your answer, but did not understand why 'AddDebug()' was necessary. Removing it though stops the logger from logging to console. See Logging to Console with DI in C# if interested. My guess is that Console logger spins off a separate thread and tries to aggregate logs and flush on timer to not be as intrusive. The Debug logger logs immediately, but I only wanted one. Switching to having an App class with async Run() method solves all problems.