How to format ExceptionDetail from a structure to a string?

Question

I'm using Serilog with various enrichers (including WithExceptionDetails. Logging to the console or file works as expected.

I added the Serilog.Sinks.Http and I am writing the log server which will insert the logs into a database table. All this is nearly set up and is also working.

However, various system, 3rd party and custom exceptions might be logged. All the exception properties are written in an ExceptionDetail section in the JSON. I will obviously not be adding all possible properties to the table.

If I use a custom formatter, how can I flatten the ExceptionDetail object into a single string and then write that string to the db?

Answer 1

You could just implement a custom json formatter and output logEvent.Exception as string

public class CustomJsonFormatter : ITextFormatter
{
    public void Format(LogEvent logEvent, TextWriter output)
    {
        var logObject = new
        {
            Timestamp = logEvent.Timestamp.ToString("yyyy-MM-ddTHH:mm:ss.fffZ"), // ISO 8601 format
            Level = logEvent.Level.ToString(),
            Message = logEvent.MessageTemplate.Render(logEvent.Properties),
            Properties = logEvent.Properties,  // Serialize all properties
            Exception = logEvent.Exception?.ToString() // Exception as string if present
        };

        // Serialize to JSON
        var json = JsonSerializer.Serialize(logObject, new JsonSerializerOptions { WriteIndented = true });
        output.WriteLine(json);
    }
}

Then use the formatter

       Log.Logger = new LoggerConfiguration()
            .WriteTo.Console(new CustomJsonFormatter()) 
            .WriteTo.File(new CustomJsonFormatter(), "logs/logfile.json") 
            .CreateLogger();