REPL example app with Honeycomb events

events.go

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"time"

	libhoney "github.com/honeycombio/libhoney-go"
)

func main() {
	br := bufio.NewReader(os.Stdin)

	libhoney.Init(libhoney.Config{
		WriteKey: "HoneycombWriteKey",
		Dataset:  "HoneycombDatasetName",
	})
	defer libhoney.Close()

	for {
		evt := libhoney.NewEvent()
		if err := readEvaluateProcess(evt, br); err != nil {
			if err == io.EOF {
				return
			}
			evt.AddField("error", err)
		}
		evt.Send()
	}
}

func readEvaluateProcess(evt *libhoney.Event, br *bufio.Reader) error {
	t1 := time.Now()
	
  fmt.Printf("> ")

	line, err := readLine(evt, br)
	if err != nil {
		evt.AddField("error", err)
		return err
	}

	out, err := processLine(evt, line)
	if err != nil {
		evt.AddField("error", err)
		return err
	}

	fmt.Printf("< %s\n\n", out)

	t2 := time.Now()
	duration := int64(t2.Sub(t1) / time.Millisecond)

	evt.AddField("duration_ms", duration)
	return nil
}

func readLine(evt *libhoney.Event, br *bufio.Reader) ([]byte, error) {
	line, _, err := br.ReadLine()
	evt.AddField("input", string(line))
	if err != nil {
		return nil, err
	}

	return line, nil
}

func processLine(evt *libhoney.Event, in []byte) (out string, err error) {
	outputBytes := bytes.ToUpper(in)
	output := string(outputBytes)
	evt.AddField("output", output)
	return output, nil
}