Nancy and New Relic

New Relic is a nice tool used to monitor applications and collect performance metrics running on pretty much any platform, including .NET. Wiring up Nancy with New Relic is a cinch! Be sure to install the appropriate packages first. In the following example, we identify each new Relic transaction as the HTTP Method and the Route. Otherwise all transactions show up as NancyHttpHandler - not very useful! We also log all exceptions via the error pipeline.

    using NewRelicAgent = NewRelic.Api.Agent.NewRelic; // protip: don't give class and namespace the same name. it's awkward.
    public class NewRelicStartup : IApplicationStartup
    {
        private readonly IRouteResolver routeResolver;

        public NewRelicStartup(IRouteResolver routeResolver)
        {
            this.routeResolver = routeResolver;
        }

        public void Initialize(IPipelines pipelines)
        {
            pipelines.BeforeRequest.AddItemToStartOfPipeline(
                context =>
                    {
                        var route = routeResolver.Resolve(context);
                        if (route == null || route.Item1 == null || route.Item1.Description == null) // probably not necessary but don't want the chance of losing visibility on anything
                        {
                            NewRelicAgent.SetTransactionName(
                                context.Request.Method, 
                                context.Request.Url.ToString());
                        }
                        else
                        {
                            NewRelicAgent.SetTransactionName(
                                route.Item1.Description.Method,
                                route.Item1.Description.Path);
                        }
                        return null;
                    });

            pipelines.OnError.AddItemToEndOfPipeline(
                (context, ex) =>
                    {
                        NewRelicAgent.NoticeError(
                            ex);
                        return null;
                    });
        }
    }