Default LogLevel from appsettings doesn't do anything

[rwb196884]

Description

Example program:

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace ConsoleAppLogSpam
{
    internal class Program
    {
        static void Main(string[] args)
        {
            System.Console.WriteLine("-- ConsoleAppLogSpam --");

            using (IHost host = Host.CreateDefaultBuilder(args)
                .ConfigureLogging((HostBuilderContext context, ILoggingBuilder cfg) =>
                {
                    cfg.ClearProviders();
                    cfg.AddConfiguration(context.Configuration.GetSection("Logging"));
                    cfg.AddDebug();
                }).
                ConfigureServices((HostBuilderContext context, IServiceCollection services) =>
                {
                    services.AddSingleton<Job>();
                })
                .Build()
                )
            {
                using (IServiceScope scope = host.Services.CreateScope())
                {
                    Job j = scope.ServiceProvider.GetRequiredService<Job>();
                    j.Do();

                    System.Console.WriteLine("That's all folks. Press <enter> to quit.");
                    System.Console.ReadLine();
                }
            }
            System.Console.WriteLine("Done.");
        }
    }

    class Job
    {
        private readonly ILogger<Job> _Logger;

        public Job(ILogger<Job> logger)
        {
            _Logger = logger;
        }

        public void Do()
        {
            _Logger.LogTrace("LogTrace");
            _Logger.LogDebug("LogDebug");
            _Logger.LogInformation("LogInformation");
            _Logger.LogWarning("LogWarning");
            _Logger.LogError("LogError");
            _Logger.LogCritical("LogCritical");
        }
    }
}

With appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning",
      "ConsoleAppLogSpam": "Warning"
    }
  }
}

Output is

ConsoleAppLogSpam.Job: Information: LogInformation
ConsoleAppLogSpam.Job: Warning: LogWarning
ConsoleAppLogSpam.Job: Error: LogError
ConsoleAppLogSpam.Job: Critical: LogCritical

The appsettings.json has no effect.

Reproduction Steps

As above.

Expected behavior

That logging output should change according to the settings.

Actual behavior

Logging output is always at Information level.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

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[svick]

Your code works as expected for me, the output is just:

ConsoleAppLogSpam.Job: Warning: LogWarning
ConsoleAppLogSpam.Job: Error: LogError
ConsoleAppLogSpam.Job: Critical: LogCritical

This could be happening because the appsettings.json is not being copied to the build output directory. In a console app, you need something like the following in your csproj:

<ItemGroup>
  <None Update="appsettings.json">
    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </None>
</ItemGroup>

(Note that this happens automatically in web apps.)

If you think the appsettings.json is being copied correctly, can you share your csproj?

[dotnet-policy-service]

This issue has been marked needs-author-action and may be missing some important information.

[tarekgh]

@rwb196884 Add a quick check before Build() and check the output:

Console.WriteLine(File.Exists(Path.Combine(Directory.GetCurrentDirectory(), "appsettings.json")));
Console.WriteLine(context.Configuration.GetSection("Logging:LogLevel:Default").Value); // expect "Warning"