How to customize exception output using serilog

Question

I'm using Serilog as my logging framework (with Seq as my log sink). When logging exceptions I'm using something like:

log.Error(ex, "Operation Failed");

My application makes heavy use of async/await methods. When unhandled exceptions occur the stack traces are very hard to read. There is a nuget package that cleans up async stack traces (https://github.com/aelij/AsyncFriendlyStackTrace). This creates an extension method to give you access to a modified/clean stack trace:

ex.ToAsyncString()

I'd like to be able to use this library to intercept the stack trace before it is written to Seq and instead log the clean/modified stack trace.

Is there a way with Serilog/Seq to control the exact output of the error string that is sent to the log sink?

Answer 1

Perhaps enrichment might be helpful here. While not specifically discussed in that link, you can build custom enrichers:

public class ExceptionEnricher : ILogEventEnricher
{
    public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
    {
        if (logEvent.Exception != null)
        {
            // do something here

            propertyFactory.CreateProperty("ExtraExceptionDetail", extraDetail);
        }
    }
}

then...

var loggerConfig = new LoggerConfiguration()
    .MinimumLevel.Debug()
    .WriteTo.Seq(url)
    .Enrich.With<ExceptionEnricher>()
    .Enrich.FromLogContext();

I don't have any experience with the package you referenced, but this approach lets you intercept and modify/add/remove properties of the event before it's written to Seq.