Serilog无法使用asp.net core 2.2 API中的配置

Question

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

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
           .UseSerilog((ctx, config) => { config.ReadFrom.Configuration(ctx.Configuration); })
           .UseStartup<Startup>();
}


public class Startup
{
    public IContainer Container { get; private set; }
    public Startup(IConfiguration configuration)
    {
        Log.Warning("test");
        Configuration = configuration;
    }

}

appsettings.json

{
    "Serilog": {
    "MinimumLevel": {
      "Default": "Information",
      "Override": {
        "Default": "Information",
        "Microsoft": "Information",
        "System": "Information"
      }
    },
    "WriteTo": [

      {
        "Name": "RollingFile",
        "Args": {
          "pathFormat": "C:\\test.txt",
          "outputTemplate": "{Timestamp:yyyy-MM-dd HH:mm:ss.ffff}|{TenantName}|{RequestId}|{SourceContext}|{Level:u3}|{Message:lj}{NewLine}{Exception}",
          "restrictedToMinimumLevel": "Information"
        }
      }
    ]
  },

  "AllowedHosts": "*"
}

I have all the packages installed

• Serilog,
• Serilog.AspCore,
• Serilog.Settings.Configuration,
• Serilog.Sink.File

Answer 1

Your config is for RollingFile but your package list says Serilog.Sinks.File . These are different. You need to add the Serilog.Sinks.RollingFile package and it should start working.

If you want to use the File sink (which, as @Kirk mentioned in the comments, is the recommended option now) then you need to change the settings to

"WriteTo": [
    {
        "Name": "File",
        "Args": {
            "path": "C:\\test.txt",
            "outputTemplate": "{Timestamp:yyyy-MM-dd HH:mm:ss.ffff}|{TenantName}|{RequestId}|{SourceContext}|{Level:u3}|{Message:lj}{NewLine}{Exception}",
            "restrictedToMinimumLevel": "Information"
        }
    }

NOTE

The pathFormat should be path for the File sink

See the Serilog File Sink Documentation

Answer 2

It seems the problem was writing directly to c: and not using File in config which seems not to work, but writing to a different directory works.

Here is the final solution for anyone coming across this

Program.cs

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

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
              WebHost.CreateDefaultBuilder(args)
                  .UseStartup<Startup>()
                  .UseSerilog();
}

Startup.cs

public Startup(IConfiguration configuration)
{
        var logConfiguration = new LoggerConfiguration()
            .ReadFrom.Configuration(configuration);

        Log.Logger = logConfiguration.CreateLogger();
        Configuration = configuration;

}

appsettings.json

"Serilog": {
"WriteTo": [
  {
    "Name": "File",
    "Args": {
      "path": "C:\\temp\\log.txt",
      "rollingInterval": "Day"
    }
  }
]

}

Answer 3

This is not an answer but an observation. I had observed a definite problem here. I have got three settingss files.

1. appsettings.json,
2. appsettings.Development.json,
3. appsettings.VivekDev.json

I have selected the profile from launchSettings.json such that the environment is VivekDev as follows.

"ASPNETCORE_ENVIRONMENT": "VivekDev"

Now when i have the following setting in appsettings.VivekDev.json without having any Serilog setting in appsettings.json , then things are working fine.

  "Serilog": {
    "WriteTo": [
      {
        "Name": "File",
        "Args": {
          "path": "log.txt",
          "rollingInterval": "Day"
        }
      }
    ]
  },

But when I have

"Serilog": {
  "WriteTo": [ "Debug" ]
},

in appsettings.json , this is somehow overriding the setting in appsettings.VivekDev.json . As per my understanding this is incorrect and the setting inside of appsettings.VivekDev.json should override appsettings.json .

And this is happening only in case of File sink. If I use other sink such as console then things are working as expected. That is the serilog setting inside of appsettings.VivekDev.json is correctly overriding the serilog setting of appsettings.json .

Something is definitely buggy here.

So of the now, I have removed the serilog settings in the appsettings.json and kept the serilog write to file setting in appsettings.VivekDev.json .