Logging message from Otlp target is not picked up by LogRecord processor

[jundayin]

In our application we have several processors in place to process the LogRecord (mainly enrich them).

I'm doing the experiment and see how does it the target pacakge work with NLog, I do notice that our LogRecord processor in the application (not the one in OTEL collector) does not pick up the LogRecord and enrich them. Is this by design? Or a missing feature?

A sample repro
Program.cs

public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder
                        .UseStartup<Startup>()
                        .ConfigureLogging(logging =>
                        {
                            logging.ClearProviders();
                            logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
                        })
                        .UseNLog();
                });

Startup.cs

services
    .AddOpenTelemetry()
    .WithLogging(builder =>
    {
        builder.AddProcessor<LogRecordTraceContextEnrichProcessor>();
        builder.AddProcessor<LogRecordExceptionParsingProcessor>();
       })

appSettings.json

  "NLog": {
    "autoReload": false,
    "throwConfigExceptions": true,
    "internalLogLevel": "Info",
    "extensions": [
      {
        "assembly": "NLog.Web.AspNetCore"
      },
      {
        "assembly": "NLog.Targets.OpenTelemetryProtocol"
      }
    ],
    "targets": {
      "consoleTarget": {
        "type": "ColoredConsole"
      },
      "otlp": {
        "type": "OtlpTarget",
        "resolveOptionsFromName": "Logging",
        "scheduledDelayMilliseconds": 1000
      }
    },
    "rules": [
      {
        "logger": "*",
        "minLevel": "Fatal",
        "writeTo": "consoleTarget"
      },
      {
        "logger": "*",
        "minLevel": "Info",
        "writeTo": "otlp"
      }
    ]
  }

[juliuskoval]

Hi, this is a missing feature. I'll try to think about how this could be implemented.

[snakefoot]

Created #31 with the ability to use resolve shared OpenTelemetry LoggerProvider from the HostBuilder. Instead of building own dedicated LoggerProvider.

[juliuskoval]

Like I said in the pull request, if you resolve an existing LoggerProvider and set IncludeFormattedMessage to true, the body won't be populated with the formatted message because of a bug in the OpenTelemetry libraries. A solution would be to add this to your LoggerProvider. Another solution would be to rename the attribute with the message format which currently isn't possible but I'll add the ability.

Edit: Nevermind, this is going to be a bit more complicated than I thought.

[juliuskoval]

@jundayin I released a new version of the package which should contain the resolveLoggerProvider property which is explained in the Readme. Like I said above, if you want to include the formatted message, either add the processor linked above to your setup or change the MessageTemplateAttribute property.