Serilog creates the log file but doesn't write into it

Question

So I've started using Serilog withing my ASP .NET Core 3.1 Web API as follows:

public static void Main(string[] args)
{
    CreateHostBuilder(args).Build().Run();
}

public static IHostBuilder CreateHostBuilder(string[] args) =>                
    Host.CreateDefaultBuilder(args).ConfigureWebHostDefaults(webBuilder =>
    {
        webBuilder.UseStartup<Startup>()
                  .UseSerilog((hostingContext, loggerConfiguration) =>
       loggerConfiguration.ReadFrom.Configuration(hostingContext.Configuration));
     });   

However, the log file gets created, but nothing gets written into it, no matter where I call something like Log.Debug("Write this"). I tried using different paths to avoid any writing credential issue of some sort, to no avail. Also, I can't see anything in the Output window of Visual Studio, despite setting a Console log too. Here's what I wrote in my appSettings.json:

"Serilog": {
"MinimumLevel": {
  "Default": "Debug"
},
"WriteTo": [      
  {
    "Name": "Console"
  },
  {
    "Name": "File",
    "Args": {
      "path": "log.txt",
      "rollingInterval": "Day",
      "retainedFileCountLimit": 7,
      "buffered": true
    }
  }
]
  },

Am I missing something?

Answer 1

Update: OP edited the question after my answer below and removed the part o the code that I'm pointing out.

---

In your example above, you are writing to Serilog at the very start of your App, way before Serilog has even been configured, so your messages are just being discarded...

In order to do what you want, you need to set up Serilog first.

Follow the EarlyInitializationSample in the Serilog.AspNetCore repo to see how it's done, which looks something like this:

using System;
using System.IO;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Serilog;

namespace EarlyInitializationSample
{
    public class Program
    {
        public static IConfiguration Configuration { get; } = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
            .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Production"}.json", optional: true)
            .AddEnvironmentVariables()
            .Build();

        public static int Main(string[] args)
        {
            Log.Logger = new LoggerConfiguration()
                .ReadFrom.Configuration(Configuration)
                .Enrich.FromLogContext()
                .WriteTo.Debug()
                .WriteTo.Console(
                    outputTemplate: "[{Timestamp:HH:mm:ss} {Level:u3}] {Message:lj} {Properties:j}{NewLine}{Exception}")
                .CreateLogger();

            try
            {
                Log.Information("Getting the motors running...");

                CreateHostBuilder(args).Build().Run();

                return 0;
            }
            catch (Exception ex)
            {
                Log.Fatal(ex, "Host terminated unexpectedly");
                return 1;
            }
            finally
            {
                Log.CloseAndFlush();
            }
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                })
                .UseSerilog();
    }
}

---

Debugging and Diagnostics

When Serilog is not behaving as you expect, this may be caused by an internal exception or configuration issue. Here are a couple of ways to sort things out.