ASP.NET Core 2.0 using Serilog to log stacktrace when exception is thrown

Question

So I've recently started to build a asp.net core application and for the logging i'm using SeriLog. This was working fine until recently I found out that most of the time the stacktrace of an exception is not being transferred to my logs. I'm using the .WriteTo.RollingFile() method to write to a .txt file in my LoggerConfiguration in Startup.cs like so

public void ConfigureServices(IServiceCollection services)
{
    //add a bunch of services

    services.AddLogging(builder =>
    {
        builder.AddConsole();
        builder.AddDebug();

        var logger = new LoggerConfiguration()
            .MinimumLevel.Verbose()
            .MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
            .Enrich.WithExceptionDetails()
            .WriteTo.RollingFile(Configuration.GetValue<string>("LogFilePath") + "-{Date}.txt", LogEventLevel.Information,
                outputTemplate: "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level}] ({SourceContext}) {Message}{NewLine}{Exception}")
            .CreateLogger();

        builder.AddSerilog(logger);
    });

    services.AddMvc();
}

And in my loggerFactory I added the Serilog with this line of code

loggerFactory.AddSerilog();

My BuildWebHost method does not have the .UserSerilog() and looks like this:

public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();

This method gets called as the last step in my Main method in Program.cs Reading Serilog's documentation the {Exception} in the outputTemplate of the RollingFile should also log the stacktrace of the exception. However when for example I log an error like so (using the Microsoft.Extensions.Logging.ILogger)

_log.LogError("Exception thrown when trying to convert customer viewmodel to model or getting data from the database with id: " + id, ex);

This logs:

2017-12-12 10:59:46.871 +01:00 [Error] (ProjectName.Controllers.CustomersController) Exception thrown when trying to convert customer viewmodel to model or getting data from the database with id: 137dfdc1-6a96-4621-106c-08d538a26c5b

It does not have a stacktrace. But when for example I forget to inject a class into the constructor of a class through constructor injection from my .addServices it does log the stacktrace. For example:

2017-12-12 11:03:23.968 +01:00 [Error] (Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware) An unhandled exception has occurred while executing the request
System.InvalidOperationException: Unable to resolve service for type 'TypeName' while attempting to activate 'ProjectName.Controllers.CustomersController'.
   at Microsoft.Extensions.Internal.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired)
   at lambda_method(Closure , IServiceProvider , Object[] )

How do I get the stacktrace to show up in my logging .txt file?

score 34 · Accepted Answer · answered Dec 12 '17 at 11:24

LogError extension method has following overrides:

public static void LogError(this ILogger logger, Exception exception, string message, params object[] args);
public static void LogError(this ILogger logger, string message, params object[] args);

When you call

_log.LogError("Exception thrown when trying to convert customer viewmodel to model or getting data from the database with id: " + id, ex);

you actually use the second one and ex object is passed just as parameter for formatting. As far as your message does not have formatting items, passed exception is just ignored.

To fix the problem just switch arguments in your call, exception should be the first:

_log.LogError(ex, "Exception thrown when trying to convert customer viewmodel to model or getting data from the database with id: " + id);

ASP.NET Core 2.0 using Serilog to log stacktrace when exception is thrown

1 Answers1