opentelemetry-go/example/dice/rolldice_go1.22.go

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

//go:build go1.22
// +build go1.22

package main

import (
	"fmt"
	"io"
	"math/rand"
	"net/http"
	"strconv"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
)

func rolldice(w http.ResponseWriter, r *http.Request) {
	ctx, span := tracer.Start(r.Context(), "roll")
	defer span.End()

	roll := 1 + rand.Intn(6)

	var msg string
	if player := r.PathValue("player"); player != "" {
		msg = fmt.Sprintf("%s is rolling the dice", player)
	} else {
		msg = "Anonymous player is rolling the dice"
	}
	logger.InfoContext(ctx, msg, "result", roll)

	rollValueAttr := attribute.Int("roll.value", roll)
	span.SetAttributes(rollValueAttr)
	rollCnt.Add(ctx, 1, metric.WithAttributes(rollValueAttr))

	resp := strconv.Itoa(roll) + "\n"
	if _, err := io.WriteString(w, resp); err != nil {
		logger.ErrorContext(ctx, "Write failed", "error", err)
	}
}