CustomAppender.cs

namespace Bonfire.LogAppender
{
    using log4net.Appender;
    using log4net.spi;
    using SharpRaven;
    using SharpRaven.Data;

    public class CustomAppender : AppenderSkeleton
    {
        public string DSN { get; set; }

        protected override void Append(LoggingEvent loggingEvent)
        {
            if (string.IsNullOrEmpty(DSN)) return;

            var ravenClient = new RavenClient(DSN);
            ravenClient.Capture(new SentryEvent(loggingEvent.RenderedMessage));
        }
    }
}