SelfLog not writing to Text File

See original GitHub issue

I’m trying to debug an issue where ‘some’ of our logs never appear in LogAnalytics using the Serilog.Sinks.AzureAnalytics (see issue here https://github.com/saleem-mirza/serilog-sinks-azure-analytics/issues/42).

.NET Core 2.1 api, using: Serilog.AspNetCore 2.1.1 Serilog.Sinks.AzureAnalytics 4.0.0

Based on your wiki under the Debug and Diagnose section I’m doing the following as the first statements in my startup.cs:

var file = File.CreateText("myFilePath"); Serilog.Debugging.SelfLog.Enable(TextWriter.Synchronized(file)); Serilog.Debugging.SelfLog.Enable(msg => Debug.WriteLine(msg)); Serilog.Debugging.SelfLog.Enable(Console.Error); The other debug outputs work fine and I can see the batch logs, but the logging to the file is empty. The file does indeed get created, it’s just empty.

I’ve seen other issues on here stating to use Log.CloseAndFlush(); but I can’t do this as this is a continuously running api.

Am I missing something vital?

Issue Analytics

State:
Created 5 years ago
Comments:5 (2 by maintainers)

Top GitHub Comments

7reactions

tsimbalarcommented, Jan 17, 2019

Hi,

Every time you call SelfLog.Enable(...) , you replace previous Selflog error handler …

Which means that :

var file = File.CreateText("myFilePath"); Serilog.Debugging.SelfLog.Enable(TextWriter.Synchronized(file));
// right now SelfLog should write to file ...
Serilog.Debugging.SelfLog.Enable(msg => Debug.WriteLine(msg)); 
// right now selfLog should write to Debug, but no longer to file
Serilog.Debugging.SelfLog.Enable(Console.Error);
// right now selflog should write to Console.Error, but no longer to Debug or File ...

If you want the SelfLog to write to multiple outputs, you need to do it all in a single SelfLog.Enable() call like :

var writer = TextWriter.Synchronized(file);
SelfLog.Enable(msg => {
  Debug.WriteLine(msg);
  Console.Error(msg);
  writer.WriteLine(msg);
  writer.Flush();
});

I hope this helps !

(you may also want to try/catch around the writing to file just in case …

0reactions

filmicocommented, Jul 11, 2021

Another Sample that append the Serilog Internal Errors to a file

Serilog.Debugging.SelfLog.Enable(message => {

  // 	C# StreamWriter Example
  // https://www.c-sharpcorner.com/article/csharp-streamwriter-example/

  var filePath = Server.MapPath("~/Logs/SerilogInternalErrors.log");

  using (var sw = new StreamWriter(filePath, append: true, Encoding.UTF8))
  {
      sw.WriteLine(message);
  }

  Log.CloseAndFlush();

});