azure - 无法查看 Azure 日志流中的日志

Question

在我的 Web Api 应用程序中，我有 Controller :

[Route("api/[controller]")]
public class ValuesController : Controller
{
    // GET api/values
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }

    // GET api/values/5
    [HttpGet("{id}")]
    public string Get(int id)
    {
        System.Diagnostics.Trace.TraceInformation("in get...");
        return "value";
    }
}

我希望在发布日志时能够在 Azure 上看到“in get...”日志。在 Azure 上，在应用服务日志中，我打开应用程序日志记录(文件系统)并将级别设置为信息。在日志流中，当我转到该方法的 url 时，我在日志中看到:

Connecting... 2020-02-09T06:07:38 Welcome, you are now connected to log-streaming service. The default timeout is 2 hours. Change the timeout with the App Setting SCM_LOGSTREAM_TIMEOUT (in seconds). 2020-02-09 06:08:07.158 +00:00 [Information] Microsoft.AspNetCore.Hosting.Internal.WebHost: Request starting HTTP/1.1 GET http://testapi20200208104448.azurewebsites.net/api/values/5 2020-02-09 06:08:07.159 +00:00 [Information] Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker: Executing action method TestApi.Controllers.ValuesController.Get (TestApi) with arguments (5) - ModelState is Valid 2020-02-09 06:08:07.160 +00:00 [Information] Microsoft.AspNetCore.Mvc.Internal.ObjectResultExecutor: Executing ObjectResult, writing value Microsoft.AspNetCore.Mvc.ControllerContext.

但我没有看到我的日志“在获取...”

Answer 1

这是一个known issue对于.NET core(但是对于.NET Framework，它可以很好地工作)。

作为 .NET core Web 应用程序的解决方法，我建议您可以使用 ILogger，它可以将消息写入应用程序日志。在Startup.cs -> Configure方法中，重写Configure方法，如下所示:

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
   //your other code

   //add the following 2 lines of code.
   loggerFactory.AddConsole();
   loggerFactory.AddDebug();

   app.UseStaticFiles();

   //your other code
}

然后在ValuesController中:

public class ValuesController : Controller
{
   private readonly ILogger _logger; 

   public ValuesController(ILoggerFactory loggerFactory)
   {
      _logger = loggerFactory.CreateLogger<ValuesController>();
   }

   // GET api/values
   [HttpGet]
   public IEnumerable<string> Get()
   {
      return new string[] { "value1", "value2" };
   }

   // GET api/values/5
   [HttpGet("{id}")]
   public string Get(int id)
   {
      //System.Diagnostics.Trace.TraceInformation("in get...");

      //use ILogger here.
      _logger.LogInformation("in get...");
      return "value";
   }
}