Azure app service diagnostic blob not logging nlog based application logs

Question

I want to log nlog generated application logs in app service diagnostic blob [i.e, Application Logging (Blob) ] but only default logs are printed not the nlog based custom logs but I can print Application Logging (Filesystem) when file target is added to nlog.config. The problem is only with blob.

nlog.config file:

<?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"  
      throwConfigExceptions="true"  
      internalLogLevel="info"  
      internalLogFile="d:\home\LogFiles\temp\internal-nlog-AspNetCore3.txt">  
  
    <!-- enable asp.net core layout renderers -->  
    <extensions>  
        <add assembly="NLog.Web.AspNetCore"/>  
    </extensions>  
  
    <!-- the targets to write to -->  
    <targets>  
        <target xsi:type="Trace" name="String" layout="${level}\: ${logger}[0]${newline} |trace| ${message}${exception:format=tostring}" />  
        <target xsi:type="Console" name="lifetimeConsole" layout="${level}\: ${logger}[0]${newline} |console| ${message}${exception:format=tostring}" />  
    </targets>  
  
    <rules>  
        <logger name="*" minlevel="Trace" writeTo="lifetimeConsole,String" final="true"/>  
    </rules>  
</nlog>  

program.cs file

namespace testapp  
{  
    public class Program  
    {  
        public static void Main(string[] args)  
        {  
            var logger = NLog.Web.NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();  
            try  
            {  
                logger.Debug("init main");  
                CreateHostBuilder(args).Build().Run();  
            }  
            catch (Exception exception)  
            {  
                logger.Error(exception, "Stopped program because of exception");  
                throw;  
            }  
            finally  
            {  
                NLog.LogManager.Shutdown();  
            }  
        }  
  
  
        public static IHostBuilder CreateHostBuilder(string[] args) =>  
        Host.CreateDefaultBuilder(args)  
        .ConfigureLogging(logging =>  
        {  
            logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);  
            logging.AddConsole();  
            logging.AddDebug();  
            logging.AddAzureWebAppDiagnostics();  
        })  
        .UseNLog()  
        .ConfigureWebHostDefaults(webBuilder =>  
        {  
            webBuilder.UseStartup<Startup>();  
        });  
    }  
}  

The Nlog based application logs are not logged in app service diagnostic blob, instead only default logging is printed.
Kindly help to resolve this issue.

Answer 1

Hi @Ram Shankar ,

Please have a look at https://github.com/JDetmar/NLog.Extensions.AzureStorage. You'll need to add the nuget package and configure NLog to use Azure Blob Storage by setting it as a target in the web.config file. The snippet below was taken from the README.md.

    <target type="AzureBlobStorage"  
            name="Azure"  
            layout="${longdate:universalTime=true} ${level:uppercase=true} - ${logger}: ${message} ${exception:format=tostring}"  
            connectionString="DefaultEndpointsProtocol=https;AccountName=##accountName##;AccountKey=##accountKey##;EndpointSuffix=core.windows.net"  
            container="${machinename}"  
            blobName="${logger}/${date:universalTime=true:format=yy-MM-dd}/${date:universalTime=true:format=HH}.log">  
                <metadata name="mymeta" layout="mymetavalue" />   <!-- Multiple allowed -->  
                <tag name="mytag" layout="mytagvalue" /> <!-- Multiple allowed -->  

By adding the additional target, NLog should send the logging information to your blob storage.

Regards,
Ryan