Net Core 2 Serilog inject from Console App to Webhost

Question

I would like to know how to manage and best way to bring Serilog instance from a console app to a StartUp class that configures a webhost.

Scenario:

I ve got a Main class from a console app where I configure a logger (serilog). Namespace 1

 static void Main(string[] args)
    {
        DateTime Date = new DateTime.Now;
           Log.Logger = = new LoggerConfiguration()
         .MinimumLevel.Debug()
         .MinimumLevel.Override("Microsoft", LogEventLevel.Information)
         .Enrich.FromLogContext()
         .WriteTo.Console()
         .WriteTo.File($"Log-Startup-{Date}.txt", rollingInterval: 
RollingInterval.Day, outputTemplate: "{Timestamp:yyyy-MM-dd HH:mm:ss.fff 
zzz}")
         .CreateLogger();

[...]

`StaticLauncherClass.Launch(args, config, Log.Logger)`;

Notice after this I'm just doing a call to static class method and I pass the Logger.

Static class is supposed to configure a Webhost as typical webhost app in net core 2. Launch Method does something like. Namespace2

      public static IConfiguration Config { get; private set; }


public static void Launch(string[] args, IConfigurationSection config, 
ILogger logger)
        {
            Log.Logger = logger;
            Config = config;
            CreateWebHostBuilder(args).Build().Run();
        }


      public static IWebHostBuilder CreateWebHostBuilder(string[] args)
        {
            Log.Information("Starting web host");
  Serilog.ILogger _logger = Log.Logger;
            try
            {
                return CreateWebhostBuilder(args)
                        // Use Serilog
                        // Evitar inicio de hospedaje
                        .UseSerilog()
                        .UseSetting(WebHostDefaults.PreventHostingStartupKey, 
"true")
                    .ConfigureServices(svc =>
{
    svc.AddSingleton(_logger);
})
                        .UseStartup<Startup>();
            }
[...]
}

In same class, finally CreateWebhostBuilder(args) configure webhost

 var builder = new WebHostBuilder()
           .UseKestrel()
            .UseContentRoot(Directory.GetCurrentDirectory())
            .ConfigureAppConfiguration((hostingContext, config) =>
            {
                var env = hostingContext.HostingEnvironment;

                if (env.IsDevelopment())
                {
                    var appAssembly = Assembly.Load(new 
AssemblyName(env.ApplicationName));
                    if (appAssembly != null)
                    {
                        config.AddUserSecrets(appAssembly, optional: true);
                    }
                }

                if (args != null)
                {
                    config.AddCommandLine(args);
                }
                config.SetBasePath(Directory.GetCurrentDirectory());
                // Add settings to bootstrap EF config.
            })

            .UseIISIntegration()
            .UseDefaultServiceProvider((context, options) =>
            {
                options.ValidateScopes = 
context.HostingEnvironment.IsDevelopment();
            });


    return builder;

And then my question si how with this scenario I can use my Logger in Startup used class. My intention is to globalize logger the best and easier way posible. What solutions you purpose?

 internal class Startup {
???
???
 public Startup(IConfiguration config, IHostingEnvironment environment)
    {       
        ???
    }

   public void ConfigureServices(IServiceCollection services)
    {
        Console.WriteLine("Startup");
        Log.Information("Startup: Configure services");
    }
}

Startup class is writing Console.WriteLine content but does not write Log.Information content. Edit: Actual status, bring service to Startup but does not apply configuration provided to log in file. I think it acts just by default.

Answer 1

You can register your logger in ConfigureServices method:

var builder = new WebHostBuilder()
            .UseKestrel()

            ...

            .UseIISIntegration()
            .ConfigureServices(servicesCollection =>
            {
                servicesCollection.AddSingleton<Serilog.ILogger>(logger);              
            })
            .UseDefaultServiceProvider((context, options) =>
            {
                options.ValidateScopes = 
context.HostingEnvironment.IsDevelopment();
            });