ASP.NET Core日志记录不适用于生产环境

Question

Turns out the issue was not anyway related to NLog or ASP.NET Logging system. Logging was configured correctly but the build server was publishing a Debug build to the Production due to a configuration error.

I am trying to setup a third party logger in my ASP.NET Core 2.0 (SDK 2.1.401 ) project. So far I have tried Serilog and NLog . However I am having same issue for both. To summarise the issue,

• It works as intended when I run the app like dotnet run (ie. In Development environment)
• But it does not when I run the binary dotnet MyApplication.dll (ie. In Production environment).
• I do not have anything defined in "Logging" section for Development environment in my appsettings.Development.json file.

The issue described below is for NLog . I have tried SeriLog and hit the same issue.

Here is the relevant part from Program.cs

public static IWebHost BuildWebHost(string[] args) =>
    WebHost.CreateDefaultBuilder(args)
        .UseApplicationInsights()
        .UseStartup<Startup>()
        .ConfigureLogging((env, logging) =>
        {
            logging.ClearProviders();
            logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
        })
        .UseNLog()
        .Build();

Note I have cleared all providers and added NLog also the nlog.config file is defined:

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  autoReload="true"
  internalLogLevel="error"
  internalLogFile="./internal-nlog.txt">

  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
  </extensions>

  <targets>
    <target name="Console" 
      xsi:type="Console" 
      layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}" />
  </targets>

  <rules>
    <logger name="*" minlevel="Trace" writeTo="Console" />
  </rules>
</nlog>

When running in Development mode, I see the logs exactly as I expected

$ dotnet run
Using launch settings from .. /Properties/launchSettings.json...
2018-09-16 19:04:39.7585||DEBUG|My.WebApp.Program|init main |url: |action:
Hosting environment: Development
Content root path: /Users/ ...
Now listening on: http://localhost:61638
Application started. Press Ctrl+C to shut down.
2018-09-16 19:04:46.5405|1|INFO|Microsoft.AspNetCore.Hosting.Internal.WebHost|Request starting HTTP/1.1 GET http://localhost:61638/api/_doc   |url: http://localhost/api/_doc|action:
2018-09-16 19:04:46.7381|1|INFO|Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker|Executing action method My.WebApp.RestApi.Doc (My.WebApp) with arguments ((null)) - ModelState is Valid |url: http://localhost/api/_doc|action: Doc

However, when I run the app in Production envoronment, the console output looks as if I do not have NLog installed and I haven't cleared the default providers.

dotnet .\My.WebApp.dll
Hosting environment: Production
Content root path: C:\inetpub\wwwroot\myapp\wwwroot
Now listening on: http://localhost:5000
Application started. Press Ctrl+C to shut down.
info: Microsoft.AspNetCore.Hosting.Internal.WebHost[1]
      Request starting HTTP/1.1 GET http://localhost:5000/
info: Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[1]
      Executing action method My.WebApp.Controllers.HomeController.Index (My.WebApp) with arguments ((null)) - ModelState is Valid

Notice those lines begins with info: ? those are standard console logging format you get when you use the default logging setup defined in Microsoft.Extensions.Logging . But I definitely cleared Console provider by calling logging.ClearProviders(); in the Program.cs file.

Thanks for any help.

Answer 1

I was able to reproduce your problem and fix it. Please find my configuration here.

appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Trace",
      "Microsoft": "Information"
    }
  },
  "AllowedHosts": "*"
}

nlog.config

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      internalLogLevel="error"
      internalLogFile="./internal-nlog.txt">

  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
  </extensions>

  <targets>
    <target name="Console"
            xsi:type="Console"
            layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}" />
  </targets>

  <rules>
    <logger name="*" minlevel="Trace" writeTo="Console" />

    <!--Skip non-critical Microsoft logs and so log only own logs-->
    <logger name="Microsoft.*" maxLevel="Info" final="true" />
    <!-- BlackHole without writeTo -->
    <logger name="*" minlevel="Trace" writeTo="Console" />
  </rules>
</nlog>

Program.cs

public class Program
{
    public static void Main(string[] args)
    {
        var logger = NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();

        try
        {
            logger.Debug("init main");
            CreateWebHostBuilder(args).Build().Run();
        }
        catch (Exception ex)
        {
            //NLog: catch setup errors
            logger.Error(ex, "Stopped program because of exception");
            throw;
        }
        finally
        {
            // Ensure to flush and stop internal timers/threads before application-exit (Avoid segmentation fault on Linux)
            NLog.LogManager.Shutdown();
        }
    }

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .ConfigureLogging((env, logging) =>
            {
                logging.ClearProviders();
                logging.SetMinimumLevel(LogLevel.Trace);
            })
            .UseNLog();
}

added the following entry to .csproj file

<ItemGroup>
    <Content Update="nlog.config">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
</ItemGroup>

Reference:

1. https://github.com/NLog/NLog.Web/wiki/Getting-started-with-ASP.NET-Core-2