This repo contains a middleware that uses the FlightRecorder from x/exp/trace to record trace data from a running Go application.
To setup the middleware, you need to provide a directory where the trace data will be stored, a FlightRecorder instance and a function that will be called for each request to decide if the trace data should be recorded.
fr := trace.NewFlightRecorder()
fr.Start()
frmw, err := flightrecordermw.New("/tmp", fr, func(r *http.Request, stats flightrecordermw.Stats) bool {
return stats.Elapsed > 100*time.Millisecond
})
if err != nil {
return err
}To use the middleware, you need to wrap your handler with it.
mux.Handle("/hello", frmw.Middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello, World!"))
})))That's it!
The middleware also provides a handler that can be used to serve the trace data.
mux.Handle("/traces/", http.StripPrefix("/traces/", frmw))You will find a listing of all the available traces in the directory provided when creating the middleware.
You can find a complete example in the example directory.
This project is licensed under the Apache 2.0 License - see the LICENSE file for details